In Vitro Crude Protein Digestibility of Tenebrio Molitor and Hermetia Illucens Insect Meals and its Correlation with Chemical Composition Traits

Microbiota modulation by the inclusion of Tenebrio molitor larvae as alternative to fermented soy protein concentrate in growing pigs diet

Tenebrio molitor meal represents a promising protein source for animal nutrition due to its low environmental impact and high nutritional value. To date, there is limited data in the literature regarding the effects of Tenebrio molitor meal on the modulation of gut microbiota in growing animals, with most results focusing on poultry rather than pigs. The aim of this study was to evaluate the effects of replacing fermented soy protein concentrate with Tenebrio molitor meal on gut microbiota and feed digestibility in growing pigs. A total of 14 growing pigs (80 ± 2 days old) were randomly allotted to two groups: the control group (CON) was fed a commercial diet containing 4% fermented soy protein concentrate (48% crude protein), and the treatment group (TM) was fed a basal diet containing 5% of T. molitor larvae meal formulated to be isonitrogenous and isoenergetic. The study lasted 28 days. Animals were weekly weighted and feed refuse was routinely measured. Fecal, blood samples, and rectal swabs were collected for analysis. No differences were observed in growth and diet digestibility for the protein and lipid components throughout the trial. No differences in the serum concentrations of albumin, globulin, urea, and interleukin-6 were registered in both groups, suggesting an unaltered health status. The TM group showed a significant difference in the beta diversity index considering the total duration of the trial (treatment effect evaluated with PERMANOVA, R2 0.0771, p value = 0.0099) showing an increased abundance of Elusimicrobium spp. and a decrease in Asteroplasma spp. in TM compared to the CON group (p < 0.05). Obtained findings indicate that 5% T. molitor meal can be included as a partial replacement for soy in growing pig formula without impairing pig growth and gut microbiota composition.

Recombinant expression and characterization of the endochitinase Chit36-TA from Trichoderma asperellum in Komagataella phaffii for chitin degradation of black soldier fly exuviae

The natural polymer chitin is an abundant source for valuable N-acetylchitooligosaccharides and N-acetylglucosamine applicable in several industries. The endochitinase Chit36-TA from Trichoderma asperellum was recombinantly expressed in Komagataella phaffii for the enzymatic degradation of chitin from unused insect exuviae into N-acetylchitooligosaccharides. Chit36-TA was purified by Ni-NTA affinity chromatography and subsequently biochemically characterized. After deglycosylation, the endochitinase had a molecular weight of 36 kDa. The optimum pH for Chit36-TA was 4.5. The temperature maximum of Chit36-TA was determined to be 50 °C, while it maintained > 93% activity up to 60 °C. The chitinase was thermostable up to 45 °C and exhibited ~ 50% activity after a 15 min incubation at 57 °C. Chit36-TA had a maximum specific enzyme activity of 50 nkat/mg with a Km value of 289 µM with 4-methylumbelliferyl-N,N',N″-triacetyl-β-chitotrioside as substrate. Most tested cations, organic solvents and reagents were well-tolerated by the endochitinase, except for SDS (1 mM), Cu2+ (10 mM) and Mn2+ (10 mM), which had stronger inhibitory effects with residual activities of 3, 41 and 28%, respectively. With a degree of hydrolysis of 32% applying colloidal shrimp chitin (1% (w/v)) and 12% on insect larvae (1% (w/v)) after 24 h, the endochitinase was found to be suitable for the conversion of colloidal chitin as well as chitin from black soldier fly larvae into water-soluble N-acetylchitooligosaccharides. To prove scalability, a bioreactor process was developed in which a 55-fold higher enzyme activity of 49 µkat/l and a tenfold higher protein expression of 1258 mg/l were achieved.

Nutritional Value of the Larvae of the Black Soldier Fly (Hermetia illucens) and the House Fly (Musca domestica) as a Food Alternative for Farm Animals-A Systematic Review

Dietary alternatives using insect-based products as an alternative for farm animal nutrition have been the object of study due to the high nutritional value of these feeds and the costs related to both their production and consequently their commercialization. Thus, the use of flies, especially larvae, has a high content of proteins and lipids (fat), as well as minerals and essential nutrients for development and growth, directly impacting the production of these animals, whether meat or milk. Therefore, the objective of this study was to compile data from the literature on the nutritional value of adults and larvae of Black soldier (Hermetia illucens) and housefly (Musca domestica) as a dietary alternative for animal feed. The Prisma checklist was used. After reviewing the data found in the literature, following the systematic review, it was noted that studies emerge that larvae of black soldier flies and domestic flies of the order Diptera obtain essential sources in the nutrition of ruminants, in addition to obtaining rapid digestibility, thus adhering to reproduction with high nutritional content, due to incident levels of protein, lipids, and minerals in M. domestica and Lucilia sericata, making it a target for inclusion in the diet of farm animals. In addition, it is concluded that both species are studied for their sustainable potential as well as for offering greater economic and nutritional viability when compared to ingredients present in production animal feed.

Comparison of Cricket Protein Powder and Whey Protein Digestibility

With the global population projected to reach nine billion by 2050, the search for alternative protein sources has become critical. This study evaluated the digestibility of cricket protein powder compared with that of whey protein powder. Cricket protein powder had a slightly lower protein content but higher fat content than whey protein powder. Although both contained all essential amino acids, their quantities varied. The most abundant essential amino acid was leucine in both samples. The essential amino acid index (EAAI) for cricket protein powder reached 79% when utilising crude protein for calculation. When using the amino acid sum calculation method, it increased by nearly 13%. The EAAI for whey protein was then 94% when calculated based on crude protein, with a slight increase observed when using the amino acid sum calculation method. Cricket protein exhibited a gradual increase in digestibility during intestinal digestion, reaching nearly 80%, whereas whey protein digestibility surpassed 97%. Despite the lower digestibility of cricket protein compared with whey protein, it remains sufficiently high for consideration as a valuable protein source. This study highlights the potential of cricket proteins and underscores the importance of assessing their protein content and digestibility in evaluating their nutritional value.

Oven-drying and decontamination effects on crude protein concentration and in vitro crude protein digestibility of yellow mealworm (Tenebrio molitor) (Coleoptera: Tenebrionidae)

The study aims to assess the impact of oven-drying and decontamination on crude protein concentration and in vitro crude protein digestibility of yellow mealworms. Two kilograms of 12-wk-old mealworm larvae were subjected to freezing prior to the drying process. Approximately 1.5 kg of mealworm larvae were divided into 3 groups and exposed to oven-drying at temperatures of 50 °C for 36 h, 60 °C, and 70 °C for 24 h each. At intervals of 2 h, sets of 3 replicates were withdrawn to record water loss. Consistent weight stabilization was observed at 36 h for 50 °C (T50), 18 h for 60 °C (T60), and 14 h for 70 °C (T70). The remaining 0.5 kg of mealworm larvae was divided and dried under treatments T50, T60, and T70. Each treatment was then split into 2 portions, with one portion subjected to 90 °C for 15 min (denoted as T50-90, T60-90, T70-90) to eliminate microbial contamination. The 6 treatments were then used to determine concentrations of dry matter, crude ash, crude protein, pre-caecal protein digestibility, and dry matter residues after neutral detergent fiber, acid detergent fiber, and acid detergent lignin treatments. No interaction was observed between drying and decontamination treatments (P > 0.17). Pre-caecal crude protein digestibility increased with decreasing temperature (T50: 58% crude protein; T60: 51% crude protein; T70: 50% crude protein). Therefore, lower temperatures for longer times preserve crude protein digestibility. These findings are crucial for understanding how drying temperature and time impact protein bioavailability.

The Effects of Slaughter Methods and Drying Temperatures on the Protein Hydrolysis of Black Soldier Fly Larvae Meal

In recent years, the potential of insects as a sustainable protein alternative to feed the growing world population has been explored. Differences in the ways insects are processed can affect their proximate composition and digestibility. This work studied the effects of the combination of different types of slaughter methods and drying temperatures on the proximate composition, organic matter digestibility (OMd), hydrolysis degree (DH/NH2 and DH/100 g DM), total hydrolysis (TH), and hygienic and sanitary characteristics of BSFL (black soldier fly larvae) meal. Four types of slaughter methods were used including freezing (F), blanching + freezing (B), Melacide® + freezing (M), and liquid nitrogen slaughter (N). Each of these was used with three drying temperatures (50, 70, and 90 °C). A negative correlation between the acid detergent fiber (ADF) and protein digestibility parameters was obtained. The most suitable drying temperature was 70 °C, as it produced higher values of protein digestibility (DH and TH), resulting in hygienic and sanitary conditions suitable for food use. Slaughtering with liquid nitrogen and blanching was more conducive to achieving high protein digestibility results than traditional freezing or the use of Melacide®.

Edible insects as a source of biopeptides and their role in immunonutrition

Many edible insect species are attracting the attention of the food industry and consumers in Western societies due to their high content and quality of protein, and consequently, the potential to be used as a more environmentally friendly dietary source could be beneficial for humans. On the other hand, prevention of inflammatory diseases using nutritional interventions is currently being proposed as a sustainable and cost-effective strategy to improve people's health. In this regard, finding bioactive compounds such as peptides with anti-inflammatory properties from sustainable sources (e.g., edible insects) is one area of particular interest, which might have a relevant role in immunonutrition. This review aims to summarize the recent literature on the discovery of immunomodulatory peptides through in vitro studies from edible insects, as well as to describe cell-based assays aiming to prove their bioactivity. On top of that, in vivo studies (i.e., animal and human), although scarce, have been mentioned in relation to the topic. In addition, the challenges and future perspectives related to edible-insect peptides and their role in immunonutrition are discussed. The amount of literature aiming to demonstrate the potential immunomodulatory activity of edible-insect peptides is scarce but promising. Different approaches have been employed, especially cell assays and animal studies employing insect meal as supplementation in the diet. Insects such as Tenebrio molitor or Gryllodes sigillatus are some of the most studied and have demonstrated to contain bioactive peptides. Further investigations, mostly with humans, are needed in order to clearly state that peptides from edible insects may contribute to the modulation of the immune system.

Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.)

Although edible rhinoceros beetle (Oryctes sp.) larvae are popularly consumed in many countries worldwide, they are prepared using different methods such as boiling, roasting, toasting, and deep-frying, whose effect on nutritional value and microbial safety is scarcely known. Here we investigated the effect of these methods on the nutritional value and microbial safety of Oryctes sp. larvae. Our hypothesis was that cooking the grubs using the four methods had no effect on their nutritional content and microbial loads and diversity. The grubs were analyzed for proximate composition, and fatty and amino acid profiles using standard chemical procedures; and microbial safety using standard culturing procedures. Deep-frying reduced protein and carbohydrate content, but elevated fat content. Boiling lowered ash content, but increased fibre and carbohydrate composition. Roasting and toasting increased protein and ash contents, respectively. Forty fatty acids were detected in the larvae, of which levels of only five were not significantly affected by cooking method, while the levels of the others were differentially affected by the different cooking methods. Amino acid profiles and levels were largely comparable across treatments, but lysine and arginine were higher in all cooked grubs than raw form. All the cooking methods eliminated Enterobacteriaceae, Shigella sp. and Campylobacter sp. from the grubs. Except boiling, all methods reduced total viable count to safe levels. Salmonella sp. were only eliminated by toasting and roasting; while boiling promoted growth of yeast and moulds. Staphylococcus aureus levels exceeded safety limits in all the cooking methods. These findings offer guidance on the type of method to use in preparing the grubs for desired nutritional and safety outcomes.

Combined Dietary Supplementation of Tenebrio molitor Larvae and Chitosan in Growing Pigs: A Pilot Study

Nowadays, the global animal industry faces considerable challenges in securing sufficient feed resources. Responding to consumer demands for reduced use of antibiotics in animal nutrition, better animal welfare status, and reduced impact on the environment, there is an increased urgency to develop innovative functional feeds with a reduced environmental footprint and the ability to improve meat quality and safety. In an effort to explore innovative feed ingredients for growing pig diets, the combined dietary supplementation of Tenebrio molitor larvae and chitosan was investigated. An experimental trial was performed with 48 weaned pigs (34 days of life; mixed sex) that were randomly assigned to four treatment groups (with six males and six females each): Group A (control), Group B (supplemented with T. molitor larvae at 10%), Group C (supplemented with chitosan at 0.05%), and Group D (supplemented with both ingredients at 10% and 0.05%, respectively). On the 42nd day of the experimental trial, samples of blood, feces, and carcass parts were taken for analysis. The results indicated that the insect larvae meal significantly improved (p < 0.05) overall performance, increased (p < 0.05) blood red blood cell content, increased meat phenolic content (p < 0.05), improved meat oxidative stability (p < 0.05), and affected meat fatty acid profile (p < 0.05). On the other hand, chitosan had no significant effect on overall performance (p > 0.05), but it significantly increased blood lymphocyte content (p < 0.05), affected the fecal microbiota (p < 0.05), improved meat oxidative stability (p < 0.05), increased meat phenolic content (p < 0.05), and affected meat fatty acid composition (p < 0.05) and (p < 0.05) meat color. Finally, the combined use of both T. molitor and chitosan significantly affected some important zootechnical parameters (p < 0.05), fecal microbial populations (p < 0.05), meat color (p < 0.05), and fatty acid profile (p < 0.05). Further investigation into the potential interaction between insect larvae meals and chitosan in pig diets is advised.

Effects of Partial Replacement of Soybean with Local Alternative Sources on Growth, Blood Parameters, Welfare, and Economic Indicators of Local and Commercial Broilers

The effects of the partial replacement of soybean with alternative local agri-industry by-products and black soldier fly (BSF) larvae meal on broiler growth performance, blood biochemistry, welfare, and, subsequently, economic performance of these diets were evaluated. A total of 524 day-old chicks from a local and a commercial strain were fed one of the three diets from the day of hatch to the slaughter age. The diets were the following: a soybean-based control diet, a diet in which soybean was partially replaced (SPR) with agri-industrial by-products, or a diet with BSF larvae meal added to the SPR (SPR + BSF). There was no effect of the diets on the slaughter weight, total feed consumption, and feed conversion of the chickens. The SPR + BSF diet reduced the blood glucose, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, protein, triglycerides, and cholesterol levels in the local chickens and the gamma-glutamyl transferase, protein, and creatinine levels in the commercial broilers. The negative effect of the SPR diet on plumage cleanliness in the commercial broilers was alleviated by the SPR + BSF diet, whereas 100% of the local birds presented either slight or moderate soiling. The results showed that, due to the high cost of the BSF larvae meal, the SPR + BSF diet was not economically feasible. In a further study, the price trends of BSF larvae will be examined from the standpoint of economic profitability conditions.

Effect of a Probiotic Beverage Enriched with Cricket Proteins on the Gut Microbiota: Composition of Gut and Correlation with Nutritional Parameters

The health and balance of the gut microbiota are known to be linked to diet composition and source, with fermented products and dietary proteins potentially providing an exceptional advantage for the gut. The purpose of this study was to evaluate the effect of protein hydrolysis, using a probiotic beverage enriched with either cricket protein (CP) or cricket protein hydrolysates (CP.Hs), on the composition of the gut microbiota of rats. Taxonomic characterization of the gut microbiota in fecal samples was carried out after a 14-day nutritional study to identify modifications induced by a CP- and CP.H-enriched fermented probiotic product. The results showed no significant differences (p > 0.05) in the diversity and richness of the gut microbiota among the groups fed with casein (positive control), CP-enriched, and fermented CP.H-enriched probiotic beverages; however, the overall composition of the microbiota was altered, with significant modifications in the relative abundance of several bacterial families and genera. In addition, fermented CP.H-enriched probiotic beverages could be related to the decrease in the number of potential pathogens such as Enterococcaceae. The association of gut microbiota with the nutritional parameters was determined and the results showed that digestibility and the protein efficiency ratio (PER) were highly associated with the abundance of several taxa.

Dietary full-fat or defatted black soldier fly larvae can replace protein sources with no detrimental effect on growth performance or intestinal health of nursery pigs

This work aimed to determine the effects of dietary full-fat or defatted black soldier fly larvae (BSFL) to replace protein sources on growth performance, blood parameters, intestinal morphology, and intestinal microbiota in nursery pigs and to investigate the effects of dietary defatted BSFL at up to 30% at the expense of protein sources on growth performance in nursery pigs. In Exp. 1, a total of 36 barrows with an initial body weight of 7.0 kg (SD = 0.8) were allotted to three dietary treatments in a randomized complete block design with four replicate pens per treatment and three barrows per pen. A corn-soybean meal (SBM)-whey-based control diet was prepared with soy protein concentrate and fish meal as additional protein supplements. Two additional diets were prepared to include 20% full-fat BSFL or 20% defatted BSFL to replace soy protein concentrate and fish meal to maintain the same energy and nutrient concentrations in all diets. In the 28-d feeding trial, pigs fed the diet containing defatted BSFL tended to consume more feeds (P < 0.10) than other groups during days 14 to 28 and the overall period. On day 28, the serum blood urea nitrogen in pigs fed the control diet was less (P < 0.05) than that fed the full-fat or defatted BSFL, but fecal score and jejunal morphology did not differ among the treatment groups. Relative abundance of Mycoplasma in the ileal digesta was less (P < 0.05) in the pigs fed the diet containing full-fat or defatted BSFL compared with the control group. In Exp. 2, a total of 192 pigs with an initial body weight of 7.8 (SD = 1.2 kg) were randomly allotted to one of four dietary treatments in a randomized complete block design with six replicate pens per treatment and four barrows and four gilts per pen. A control diet was mainly based on corn, SBM, fermented SBM, fish meal, and spray-dried plasma protein (SDPP). Three additional diets were prepared to contain 10%, 20%, and 30% defatted BSFL to replace SBM, fermented SBM, fish meal, and SDPP to maintain for the same energy and nutrient concentrations. Average daily gain, average daily feed intake, gain:feed, and fecal score were not affected by increasing dietary defatted BSFL. Overall, dietary BSFL did not compromise growth performance or intestinal health in nursery pigs. BSFL can be used in nursery pig diets to replace other protein sources without negative effects.

Evaluation of In Vitro Protein Hydrolysis in Seven Insects Approved by the EU for Use as a Protein Alternative in Aquaculture

Rapid population growth is leading to an increase in the demand for high-quality protein such as fish, which has led to a large increase in aquaculture. However, fish feed is dependent on fishmeal. It is necessary to explore more sustainable protein alternatives that can meet the needs of fish. Insects, due to their high protein content and good amino acid profiles, could be a successful alternative to fishmeal and soybean meal traditionally used in sectors such as aquaculture. In this work, seven species of insects (Hermetia illucens, Tenebrio molitor, Acheta domestica, Alphitobius diaperinus, Gryllodes sigillatus, Gryllus assimilis, and Musca domestica) approved by the European Union (UE) for use as feed for farmed animals (aquaculture, poultry, and pigs) were studied. Their proximate composition, hydrolysis of organic matter (OMd), hydrolysis of crude protein (CPd), degree of hydrolysis (DH/NH2 and DH/100 g DM), and total hydrolysis (TH) were analyzed. The results showed that Tenebrio molitor had digestibility similar to that of fishmeal, while Acheta domestica and Hermetia illucens provided similar digestibility to that of soybean meal. The acid detergent fiber (ADF) data were negatively correlated with all protein digestibility variables. The differences in the degree of hydrolysis (DH) results and the similarity in total hydrolysis (TH) results could indicate the slowing effects of ADF on protein digestibility. Further in vivo studies are needed.

A Systematic Review and Metanalysis on the Use of Hermetia illucens and Tenebrio molitor in Diets for Poultry

Insect meal as a protein source has been considered a sustainable way to feed animals. H. illucens and T. molitor larvae meal are considered high-protein sources for poultry, also presenting considerable amounts of fatty acids, vitamins, and minerals. However, other potential components in insect meal and insect oil have been more extensively studied in recent years. Chitin, lauric acid, and antimicrobial peptides can present antimicrobial and prebiotic functions, indicating that low levels of their inclusion in insect meal can beneficially affect broilers' health and immune responses. This systematic review was developed to study the impact of insect products on the health parameters of broilers, and a metanalysis was conducted to evaluate the effects on performance. A database was obtained based on a selection of manuscripts from January 2016 to January 2023, following the mentioned parameters. Both H. illucens and T. molitor meal or oil products had positive effects on poultry health status, especially on the ileal and cecal microbiota population, immune responses, and antimicrobial properties. The average daily gain was greater in broilers fed T. molitor meal compared to H. illucens meal (p = 0.002). The results suggest that low levels of insect meal are suitable for broilers, without resulting in negative effects on body weight gain and the feed conversion ratio, while the insect oil can totally replace soybean oil without negative impacts.

Nutritional Value of Banded Cricket and Mealworm Larvae

Insect farming is more ecological than traditional animal farming, as it requires less water and contributes to lower greenhouse gas emissions. In our study, banded cricket (BC) and mealworm larvae (ML) were analyzed. The proximate composition was determined according to Association of Official Analytical Chemists. The mineral content was determined by colorimetry and mass spectrometry. Fatty acid methyl esters (FAMEs) were obtained from the samples and separated using a gas chromatography apparatus, coupled with a mass spectrometer. Our research confirmed that insects are a rich source of protein, with ML containing significantly more protein than BC (74.41 and 65.66 g/100 g dry matter (DM), respectively). In terms of the content of macrominerals, ML was significantly richer than BC, especially in terms of magnesium content (8.75 g/100 g DM). In terms of the content of saturated fatty acids, BC contained almost twice as much as ML (40.05 and 24.74% of the sum of fatty acids, respectively). EPA and DHA were only detected in the fat of BC. The presented results prove that both ML and BC can be good sources of protein both in human and companion animal diets. The component that is predominantly high in insects is fat, with a favorable fatty acid profile, especially in terms of polyunsaturated fatty acids. This study contributes new knowledge on the nutritional value of edible insects. In this research, we included three different nitrogen conversion factors for crude protein content. Our results partially confirm previous studies by other authors, although they provide new information on the content of fatty acids.

Bioactive Peptides Derived from Edible Insects: Effects on Human Health and Possible Applications in Dentistry

Novel foods, including edible insects, are emerging because of their nutritional characteristics and low environmental impacts and could represent a valid alternative source of food in a more sustainable way. Edible insects have been shown to have beneficial effects on human health. Insect-derived bioactive peptides exert antihypertensive, antioxidant, anti-inflammatory, and antimicrobial properties and have protective effects against common metabolic conditions. In this review, the roles of edible insects in human health are reported, and the possible applications of these peptides in clinical practice are discussed. A special mention is given to the role of antimicrobial peptides and their potential applications in controlling infections in orthodontic procedures. In this context, insects' antimicrobial peptides might represent a potential tool to face the onset of infective endocarditis, with a low chance to develop resistances, and could be manipulated and optimized to replace common antibiotics used in clinical practice so far. Although some safety concerns must be taken into consideration, and the isolation and production of insect-derived proteins are far from easy, edible insects represent an interesting source of peptides, with beneficial effects that may be, in the future, integrated into clinical and orthodontic practice.

Sustainable Aquafeed Formulations Containing Insect Larval Meal and Grape Marc for the New Zealand Farmed Abalone

The aquaculture industry has been criticised for the excessive use of fish meal (FM) in feeds due to the utilisation of wild fish in the formulation and the exacerbation of overfishing marine resources. Land-based abalone aquaculture mainly uses commercial feeds (CFs) to promote faster growth, which include FM as a primary protein component. Alternative ingredients, such as insect meal (IM) and grape marc (GM) are potential candidates for FM replacement due to their suitable nutritional profile and sustainable production. This paper reports on a novel nutritional approach for the New Zealand farmed abalone, which replaces FM with IM by 10% and includes a waste by-product (GM) by 30% as a potential prebiotic source. The study was performed in two stages: (a) physico-chemical determination of diets delivered in an alginate matrix (experimental diets) and their stability in seawater compared to CF and (b) evaluation of growth and feed intake for the New Zealand black-foot abalone. There were significant differences between experimental diets and CF in terms of sinking rate, particle weight, and microscopic observations. Water stability of the experimental diets was increased by 50% in 24 and 48 hr compared to CF, producing less solid waste, and potentially reducing cleaning efforts in the farm. The inclusion of IM and GM did not compromise overall animal growth or their feed conversion ratio, however, further evaluation need to be explored in the future research. The findings revealed that the developed encapsulated feeds are a more stable food delivery method for Haliotis iris compared to the CF. Furthermore, both IM and GM can be included in feed formulations as a more sustainable strategy without compromising weight and shell gains in the abalone farming.

Endogenous chitinase might lead to differences in growth performance and intestinal health of piglets fed different levels of black soldier fly larva meal

This study aimed to investigate the effects of different levels of black soldier fly (BSF) replacing soybean meal (SBM) in diets on the performance and health condition of piglets. A total of 180 weaned piglets were allocated into 5 treatments: BSF0 (corn-soybean meal basal diet), BSF25 (BSF replacing 25% SBM), BSF50 (BSF replacing 50% SBM), BSF75 (BSF replacing 75% SBM) and BSF100 (BSF replacing 100% SBM). During the whole period, in comparison with BSF0, average daily gain (ADG) and average daily feed intake increased in the BSF25 and BSF50 groups, whereas ADG decreased in the BSF75 and BSF100 groups (P < 0.05). The result of quadratic fitting curve showed that piglets exhibited the highest ADG when BSF replaced around 20% SBM. Compared with BSF0, organic matter and dry matter digestibility improved in the BSF25 group, whereas ether extract digestibility decreased in the BSF100 group (P < 0.05). In comparison with BSF0, piglets from the BSF25 group showed a higher duodenal ratio of villus height to crypt depth, increased jejunal sucrase activity, serum neuropeptide Y and ghrelin levels, elevated ileal immunoglobulin (Ig) A, IgG and IgM contents and a lower leptin level, and piglets from the BSF100 group exhibited an increased relative weight of kidney (P < 0.05). However, no significant differences were observed in the expression level of tight junction proteins and chitin-degrading enzyme. Additionally, compared with BSF0, the abundance of short chain fatty acid producing bacteria such as Ruminococcaceae, Faecalibacterium and Butyricicoccus increased, and potential pathogenic bacteria decreased in piglets from the BSF25 group, whereas piglets from the BSF100 group had a greater abundance of harmful bacteria. In conclusion, BSF replacing 25% SBM in diets could improve digestive parameters, immune function and intestinal microbiota, and thus improved growth performance of piglets. However, BSF replacing 100% SBM showed an adverse effect on piglet performance, and the reason might be related to the limited amount of chitin-degrading enzyme.

Nutrient digestibility in black soldier fly larva was greater than in adults for pigs and could be estimated using fiber

The objectives of the present study were to determine the nutrient digestibility of fish meal, defatted black soldier fly larvae (BSFL), and adult flies and to develop equations for estimating in vitro nutrient digestibility of BSFL for pigs. in vitro digestion procedures were employed to mimic the digestion and absorption of nutrients in the pig intestine. Correlation coefficients between chemical composition and in vitro nutrient digestibility of BSFL were calculated. In Exp. 1, in vitro ileal digestibility (IVID) of dry matter (DM) and crude protein (CP) and in vitro total tract digestibility (IVTTD) of DM and organic matter in defatted BSFL meal were less (p < 0.05) than those in fish meal but were greater (p < 0.05) than those in adult flies. In Exp. 2, CP concentrations in BSFL were negatively correlated with ether extract (r = -0.91) concentration but positively correlated with acid detergent fiber (ADF; r = 0.98) and chitin (r = 0.95) concentrations. ADF and chitin concentrations in BSFL were negatively correlated with IVID of DM (r = -0.98 and -0.88) and IVTTD of DM (r = -1.00 and -0.94) and organic matter (r = -0.99 and -0.98). Prediction equations for in vitro nutrient digestibility of BSFL were developed: IVID of CP (%) = -0.95 × ADF (% DM) + 95 (r2 = 0.75 and p = 0.058) and IVTTD of DM (%) = -2.09 × ADF + 113 (r2 = 0.99 and p < 0.001). The present in vitro experiments suggest that defatted BSFL meal was less digestible than fish meal but was more digestible than adult flies, and nutrient digestibility of BSFL can be predicted using ADF as an independent variable.

Fish and Black Soldier Fly Meals as Partial Replacements for Soybean Meal Can Affect Sustainability of Productive Performance, Blood Constituents, Gut Microbiota, and Nutrient Excretion of Broiler Chickens

One hundred and twenty, one-day-old male broiler chicks were used to investigate the effects of supplementation with different dietary protein sources on their performance and immune systems. Chicks were randomly divided into four equal experimental groups (six replicates, each of five chicks). The first group served as a control and was fed a standard corn-soybean meal diet. The second, third, and fourth groups were fed diets in which the soybean meal (SBM) was partly replaced by fish meal (FM), black soldier fly larvae (BSFL), and black soldier fly prepupae (BSFP), respectively. Throughout 1-14 and 15-42 days of age, FM, BSFL, and BSFP were added at 3 and 5%, respectively. The feed conversion ratio (FCR) of the FM group was the best among the tested groups. Feeding BSFP decreased final body weight (BW), BW gain, feed intake, and impaired the FCR compared to the other treatments for the entire experimental period. The BSFP group had significantly lower cecal Salmonella counts compared to the control group and lower total bacterial counts compared to the other groups except for BSFL. BSFL can be fed to broiler chickens at 3% during the starter period and 5% during the grower-finisher periods without negative influences on growth performance, red blood cell characteristics, blood lipid profiles, and nutrient excretion, while BSFP can improve the chickens' gut ecosystem.

Insects as an alternative protein source for poultry nutrition: a review

This review summarizes the most relevant scientific literature related to the use of insects as alternative protein sources in poultry diets. The black soldier fly, the housefly, the beetle, mealworms, silkworms, earthworms, crickets, and grasshoppers are in the spotlight because they have been identified as an important future source of sustainable animal proteins for poultry feeding. Insect meals meet poultry requirements in terms of nutritional value, essential amino acid composition, nutrient digestibility, and feed acceptance. Furthermore, they are enriched with antimicrobial peptides and bioactive molecules that can improve global health. Results from poultry studies suggest equivalent or enhanced growth performances and quality of end-products as compared to fish meal and soybean meal. To outline this body of knowledge, this article states established threads of research about the nutrient profiles and the digestibility of insect meals, their subsequent effects on the growth and laying performances of poultry as well as the quality of meat, carcass, and eggs. To fully exploit insect-derived products, the effects of insect bioactive molecules (antimicrobial peptides, fatty acids, and polysaccharides) were addressed. Furthermore, as edible insects are likely to take a meaningful position in the feed and food chain, the safety of their derived products needs to be ensured. Some insights into the current knowledge on the prevalence of pathogens and contaminants in edible insects were highlighted. Finally, the effect of insect farming and processing treatment on the nutritive value of insect larvae was discussed. Our overview reveals that using insects can potentially solve problems related to reliance on other food sources, without altering the growth performances and the quality of meat and eggs.

Amino acid digestibility of insect meals and effects on key bacterial groups in excreta of caecectomised laying hens

The chemical composition and amino acids (AA) digestibility were determined in insect meals from mealworms, crickets, black soldier fly (BSF) larvae and BSF prepupae, and soybean meal. Six caecectomised laying hens were individually housed in metabolism cages and fed either a basal diet or one of five assay diets. Diets and hens were arranged in a 6 × 6 Latin square design with 6 subsequent periods. In each period, the laying hens were fed their respective diet for 9 d, and excreta samples were quantitatively collected twice daily from day 5 to 8. On day 9, a sterile plastic bag was attached to the cloaca of each hen to collect excreta for microbiota analysis. The AA digestibility of the insect meals and soybean meal were calculated using a linear regression approach. Crude protein (CP) concentrations in crickets and mealworms were higher than the value in soybean meal, BSF prepupae and BSF larvae. Ether extract concentrations were high in the insect meals and low in the soybean meal. The digestibility of most essential AA in soybean meal was higher (p < 0.05) than in crickets and BSF prepupae and not different from AA digestibility in mealworms and BSF larvae (except for arginine and histidine). The gene copy number of Escherichia coli in excreta from hens fed with BSF prepupae was lower (p < 0.05) than those fed with BSF larvae, whereas the gene copy number of Bacillus spp. and Clostridium spp. in excreta from hens fed with crickets was lower (p < 0.05) than those fed with BSF larvae. In conclusion, the chemical composition and AA digestibility varied among insect meals based on insect species and life stage. The high level of AA digestibility of insect meals supports the assessment that insect meals are a suitable feed component for laying hens, but differences in AA digestibility should be considered in diet formulation.

Effects of partial or complete replacement of soybean meal with commercial black soldier fly larvae (Hermetia illucens) meal on growth performance, cecal short chain fatty acids, and excreta metabolome of broiler chickens

Black soldier fly larvae meal (BSFLM) is receiving great attention as a rich source of protein and antimicrobials for poultry. Therefore, we evaluated the effects of partially or completely replacing soybean meal (SBM) with commercial BSFLM on growth performance, tibia traits, cecal short chain fatty acid (SCFA) concentrations, and excreta metabolomes in broiler chickens (Gallus gallus domesticus). A total of 480 day-old male Ross × Ross 708 chicks were assigned to 6 diets (8 replicates/diet): a basal corn-SBM diet with in-feed bacitracin methylene disalicylate (BMD), a corn-SBM diet without BMD (0% BSFLM), and four diets in which the SBM was substituted with 12.5, 25, 50, and 100% BSFLM. Body weight (BW), feed intake (FI) and cumulative feed conversion ratio (cFCR) were monitored on days 14, 28, and 35. Cecal SCFA levels were determined on days 14, 28, and 35. Tibia traits and excreta metabolomes were determined on day (d) 35. On d14, birds fed 12.5 and 25% BSFLM had a similar BW, FI, and cFCR as birds fed BMD (P > 0.05). On d 35, birds fed 12.5% BSFLM had a similar BW, FI and cFCR as birds fed BMD or 0% BSFLM (P > 0.05). For each phase, birds fed 100% BSFLM had a lower BW, FI and higher cFCR than birds fed BMD or 0% BSFLM (P < 0.05). On d 35, BW decreased linearly, quadratically, and cubically with increasing levels of BSFLM (P < 0.01). Overall (d 0-35), BSFLM linearly, quadratically, and cubically decreased FI and quadratically and cubically increased cFCR (P < 0.01). Quadratic responses were observed for tibia fresh weight (P = 0.049) and ash content (P = 0.022). BSFLM did not impact cecal SCFAs levels. The excreta metabolome of birds fed 100% BSFLM clustered independently from all other groups and exhibited greater levels of putatively identified methionine, lysine, valine, glutamine, histidine and lower levels of arginine as compared to all diets. Taken together, substitution of SBM with ≤25% of BSFLM in the starter phase may be used as an alternative to BMD.

Physiological Response of Grower African Catfish to Dietary Black Soldier Fly and Mealworm Meal

A six-week experiment was carried out to test the effects of total (100%) and partial (50%) replacement of fish meal in the diet of African catfish growers with black soldier fly (B) meal, yellow mealworm (M) meal, and a 1:1 combination of both (BM) on the production and health of fish. A total of 420 fish with an average initial body weight of 200 ± 0.5 g were randomly distributed in triplicate to seven diet groups (C, B50, B100, M50, M100, BM50, and BM100, respectively). The growth performance and feed utilization of fish fed with partial or total replacement levels of FM with B were not significantly affected (p > 0.05) during the 6 weeks of feeding. In contrast, significant differences were observed between the groups fed with a diet where FM was totally replaced with M meal and the control in terms of final body weight, specific growth rate, feed conversion ratio, protein efficiency ratio, and protein productive value. Among the blood plasma biochemistry parameters, total cholesterol exhibited a significant difference (p = 0.007) between the M treatments and the control diet. The fatty acid profile of the liver was changed with respect to the long-chain polyunsaturated fatty acid content in all experimental groups. Parallel with this, the upregulation of elovl5 and fas genes in liver was found in all experimental groups compared to the control. Overall, this study shows that fish meal cannot be substituted with yellow mealworm meal in the practical diet of African catfish without compromising the growth, health and feed utilization parameters.

Effects of Drying Methods and Blanching on Nutrient Utilization in Black Soldier Fly Larva Meals Based on In Vitro Assays for Pigs

The objective was to determine the effects of drying and blanching methods on the nutrient utilization of black soldier fly larva (BSFL; Hermetia illucens) meal by pigs using in vitro assays. Two-step and three-step in vitro assays were employed to simulate the gastrointestinal tract of pigs. Four BSFL meals were prepared using the following pretreatment methods: (1) microwave drying at 80 °C for 32 min, (2) hot-air drying at 60 °C for 17 h, (3) blanching for 5 min in boiling water and hot-air drying at 60 °C for 17 h, and (4) 2% citric acid solution blanching for 5 min in boiling solution and hot-air drying at 60 °C for 17 h. After the drying process, each BSFL was defatted and ground to obtain BSFL meals. The nitrogen (N) concentration in the test ingredients ranged from 8.5 to 9.4%, and the ether extract ranged from 6.9 to 11.5% on an as-is basis. The amino acid (AA) concentration in the BSFL meals ranged from 2.80 to 3.24% for Lys and 0.71 to 0.89% for Met on an as-is basis. Hot-air-dried BSFL meal had a greater in vitro ileal disappearance (IVID) of N compared with microwave-dried BSFL meal (p < 0.05). However, blanched BSFL meals in water or 2% citric acid solution before hot-air drying had a lower (p < 0.05) IVID of N compared with microwave-dried or hot-air-dried BSFL meal. Blanched BSFL meals in water or 2% citric acid solution before hot-air drying showed a lower (p < 0.05) in vitro total tract disappearance of dry matter and organic matter compared with microwave-dried or hot-air-dried BSFL meal. Microwave-dried BSFL meal had a lower (p < 0.05) IVID of indispensable AA, except for His, Lys, Met, and Phe, compared with hot-air-dried BSFL meals. However, blanched BSFL meals in water or 2% citric acid solution before hot-air drying showed a lower (p < 0.05) IVID of indispensable AA compared with microwave-dried or hot-air-dried BSFL meal. In conclusion, hot-air-dried BSFL meal presented greater nutrient utilization compared with microwave-dried BSFL meal for pigs. However, blanching in water or citric acid solution negatively affected the nutrient digestibility of BSFL meal based on in vitro assays.

Effects of Partial Replacement of Soybean Meal with Defatted Hermetia illucens Meal in the Diet of Laying Hens on Performance, Dietary Egg Quality, and Serum Biochemical and Redox Indices

This study was carried out on 96 caged Bovans Brown laying hens at an initial age of 25 weeks, which were randomly assigned to four experimental groups of 12 replicates (cages) of two hens per cage. The control group hens received a diet containing 20% soybean meal (SBM), without Hermetia illucens larvae meal (HIM) content. The hens in the experimental groups received a diet containing defatted HIM at levels of 5, 10, and 15% (HIM 5%, HIM 10%, and HIM 15%, respectively), at the expense of a proportionally decreasing content of SBM. During the 12-week experiment, the laying performance, biochemical and redox blood indices, and liver condition were examined. The cholesterol level, fatty acid profile, and malondialdehyde content in egg yolks were also evaluated to determine the dietary quality of the eggs. The inclusion of HIM at any level in the diet did not affect the laying performance parameters (p > 0.05). Increased serum Ca and uric acid contents were observed. There was no effect on the redox indices in plasma. The number of hepatocytes was decreased in the HIM-fed groups. The level of cholesterol in yolks was reduced, and the fatty acid profile showed significant changes. Despite the high lauric acid content in the H. illucens meal, it was present in trace amounts in yolks. In the HIM-fed groups, the levels of saturated fatty acids increased significantly, whereas those of unsaturated fatty acids decreased in the yolks in the same groups.

Standardized ileal digestibility of amino acids in extruded full-fat soybean fed to non-gestating, gestating, and lactating sows

This study was conducted to determine and compare the apparent ileal digestibility and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in extruded full-fat soybean (EFSB) fed to nongestating, midgestating, late-gestating, and lactating sows. Six EFSB samples were collected from different sources. Fourteen nongestating sows (Landrace × Yorkshire; parity 3 to 5) were fitted with a T-cannula at the distal ileum. After recovery, sows were assigned to a replicated 7 × 3 incomplete Latin square design. The diets included a nitrogen-free (NF) diet and six experimental diets (EFSB 1 to 6). Eight midgestating sows (Landrace × Yorkshire; parity 3; day 48 of gestation), eight late-gestating sows (Landrace × Yorkshire; parity 3; day 90 of gestation), and eight lactating sows (Landrace × Yorkshire; parity 3; day 6 of lactation) were all assigned to four dietary treatments in a repeated 4 × 3 incomplete Latin square design. The diets included a NF diet and three experimental diets (EFSB 4 to 6). Results showed that there were significant differences in the AID and SID of CP and other AA in nongestating sows (P < 0.05), the AID and SID values of EFSB 1 to 3 were higher than those of EFSB 4 to 6, and the value of EFSB 5 was the lowest. For midgestating sows, there were differences in the AID of methionine (EFSB 5 had a lower value than EFSB 4 and 6) (P < 0.01). For late-gestating sows, only the AID of methionine (EFSB 5 had a lower value than EFSB 4 and 6), tryptophan (EFSB 5 had a higher value than EFSB 4 and 6), and proline (EFSB 5 had a higher value than EFSB 4) was different (P < 0.05), and the SID of methionine (EFSB 4 had a higher value than EFSB 5) and tryptophan (EFSB 5 had a higher value than EFSB 4 and 6) was different (P < 0.05). The SID of histidine and valine was greater in lactation than in nongestation (P = 0.045 and P = 0.02, respectively). The SID of isoleucine was greater in lactation than in nongestation and gestation (P < 0.01). The SID of methionine in nongestation was lower than in gestation and lactation (P < 0.01). The SID of cysteine was the lowest in midgestation (P = 0.045), and the SID of proline was greater in midgestation than in lactation and nongestation (P < 0.01). In conclusion, the AA ileal digestibility of six EFSB samples from different sources was different, and the ileal digestibility of CP and most AA was not affected by the physiological stage of sows.

Complete replacement of soybean meal with black soldier fly larvae meal in feeding program for broiler chickens from placement through to 49 days of age reduced growth performance and altered organs morphology

Black soldier fly larvae meal (BSFLM) is characterized with good nutritional and functional attributes. However, there is limited data on inclusion of BSFLM in broiler chicken rations from placement through to market weight. Therefore, we examined growth and organ responses of partial to complete replacement of soybean meal (SBM) with BSFLM in a practical feeding program. A total of 1,152 d-old male Ross × Ross 708 chicks were allocated to 48 pens and assigned one of six diets (n = 8). The diets were: a basal corn-SBM diet (0%BSFLM), 4 diets in which SBM in 0%BSFLM was replaced with BSFLM at 12.5, 25, 50, and 100% and a final diet (0 + AGP) in which 0%BSFLM was treated with coccidiostat (70 mg Narasin/kg) and antibiotic (55 mg Bacitracin Methylene Disalicylate/kg). For energy fortification, soy oil was used for 0%BSFLM diets and black soldier fly oil in the other diets. Body weight, feed intake (FI), BW gain (BWG), and mortality-corrected feed conversion ratio (FCR) were reported. Organ weights were recorded on d 24 and 49. On d 10, birds fed diets 12.5, 25, and 0 + AGP had higher BWG than birds fed diets 0, 50, and 100 (P < 0.01), and birds fed diet 100 had lower BWG than birds fed diets 0 or 50 (P < 0.01). Birds fed diets 50 and 100 had lower BWG than birds fed all other diets on d 24 and 49 (P < 0.05). Overall (d 0-49), BSFLM linearly (P < 0.01) decreased BW, BWG, and FI and increased FCR and mortality. The overall BWG of 50 and 100% BSFLM birds was 92 and 81% of birds fed 0%BSFLM, repectively and coresponding overall FI was 96 and 90%. An increase in gizzard, small intestine, pancreas, and liver relative weights were observed with increasing BSFLM inclusion (P < 0.01). The data indicated that lower levels of BSFLM could provide some growth-promoting effects commensurate to antibiotics in the starter phase. However, replacing SBM with greater amounts (≥50) of BSFLM reduced growth and increased organ size.

Low inclusion levels of Tenebrio molitor larvae meal in laying Japanese quail (Coturnix japonica, Gould, 1837) diet improve the intestinal morphometry, enzymatic activity and caecal short chain fatty acids profile

One hundred twenty, 12 weeks old laying Japanese quails (JQ) were equally divided into 4 groups (6 replicates of 5 birds/group). The control group (CON) fed a corn-soybean diet; TML1.4, TML2.8, and TML5.6 groups fed a diet where a Tenebrio molitor larvae meal (TML) was included at 1.4, 2.8, and 5.6%, respectively. The trial lasted 54 days. The villi height (VH) and the crypt depth (CD) linearly decreased from the control to the TML5.6 group (P < 0.01) in the duodenum, while an opposite trend was observed for the Ab+ mucous cells count (P < 0.01). The highest VH/CD ratio was found in the TML1.4 group (P < 0.01). In the jejunum a lower VH was observed in the TML1.4 compared to the CON group; the Ab+ mucous cells increased (P < 0.01) according to the increase of the TM inclusion in the diet, while the highest VH/CD ratio (P < 0.01) was recorded in the TML2.8 group. In the duodenum only the L-ANP has been affected by TML (P < 0.001), with a quadratic and linear effect. The L-ANP is affected by the dietary treatment in the jejunum (P < 0.05), where showed a quadratic effect with the highest value in TML2.8. The % of butyric acid is maximized (P < 0.05) with the TML1.4 diet and that of the isobutyrate and valeric acids increased (P < 0.01) from TML1.4 to TML5.6. The use of TML at 1.4% in laying quail diets can be considered as a way to improve the intestinal health of the birds.

Available for millions of years but discovered through the last decade: Insects as a source of nutrients and energy in animal diets

The aim of this review is to present and discuss the most recent literature about the processing of insect biomass and its impact on nutritive value, further implementation of meals and fats derived from invertebrates to livestock (poultry and swine), aquaculture (salmonids), and companion animal diets and their impact on growth performance, metabolic response, and gastrointestinal microbiota shifts. Additionally, the most important barriers to obtaining unified products in terms of their nutritive value are considered, i.e., to define insects' nutrient requirements, including various technological groups and further biomass processing (slaughtering, drying, and storage). Due to the current limitation in the insect production process consisting of the lack of infrastructure, there is stress on the relatively small amount of insect products added to the animal diets as a functional feed additive. Currently, only in the case of pet nutrition may insects be considered a full replacement for commonly used environmentally harmful and allergenic products. Simultaneously, the least information has been published on this topic. Thus, more scientific data are needed, particularly when the pet food branch and insect-based diets are rapidly growing.

Assessing amino acid solubility of black soldier fly larvae meal in Atlantic salmon (Salmo salar) in vivo and in vitro

In vitro and in vivo methods were used to evaluate amino acids solubility of black soldier fly (BSF) larvae meal and two experimental diets (reference and test diets) for Atlantic salmon. The current study used in vitro method such as pH stat to compare and standardise the salmon extracted enzyme (SE), and commercial enzyme (CE) based on their hydrolytic capacity on a purified protein substrate. Further, an in vitro amino acid solubility of feed ingredients and diets were measured using the standardised enzyme volume from SE and CE. Results showed that SE and CE exhibit similar protein hydrolytic capacity upon standardisation on purified substrates. However, when using the two-stage hydrolysis (acidic and alkaline steps), significantly higher amino acid solubility was observed with CE except for glycine, and proline which were equally solubilised by both SE, and CE. No significant difference was observed between reference and test diet using the SE except for tyrosine, valine, leucine, and phenylalanine, which were significantly higher solubilised in reference diet than test diet. Whereas higher solubility of valine, isoleucine, aspartic acid, and glutamic acid was observed in test diet using CE than SE. Similarly, the solubility of valine, isoleucine, and glutamic acid were higher in BSF larvae meal when CE was used. The in vivo true protein digestibility of BSF larvae meal was 99%, and 81% for the test diet containing BSF larvae meal. The results demonstrated a positive correlation (r = 0.91; p < 0.01) between salmon and commercial enzymes but overall, no significant correlation was observed for amino acid solubility between in vivo and in vitro. However, there was a strong positive correlation for protein solubility using SE (r = 0.98) than CE (r = 0.74) with the in vivo true protein digestibility. The efficiency of SE, and CE can be compared, and standardised based on DH%, and hence correlates better with the in vivo protein digestibility but not with amino acid solubilities.

Formulation of Protein-Rich Chocolate Chip Cookies Using Cricket (Acheta domesticus) Powder

In the Western world, the successful introduction of insect consumption may need awareness of insect ingredient benefits, and consumers' anticipation of insect-based foods with sensory quality is crucial. The objective of this study was to develop protein-rich nutritional chocolate chip cookies (CCC) from cricket powder (CP) and analyze their physicochemical, liking, emotions, purchase intent, and sensory properties. The CP additions levels were 0%, 5%, 7.5%, and 10%. Chemical composition, physicochemical, and functional properties were analyzed using individual and mixed CP and wheat flour (WF). The proximate composition of CP mainly consisted of ash (3.9%), fat (13.4%), and protein (60.7%). In vitro protein digestibility of CP was 85.7%, whereas the essential amino acid score was 0.82. The CP inclusion significantly impacted the WF functional and rheological properties in all given incorporation levels in flour blends and doughs. The incorporation of CP produced darker and softer CCC, resulting from the effect of the CP protein. Adding 5% of CP did not impact the sensory attributes. Purchase intent and liking improved by using 5% of CP after panelists had revealed the beneficial information regarding CP. Concerning emotion terms, "happy" and "satisfied" significantly decreased while the negative emotion term "disgusted" increased among the highest CP substitute levels (7.5% and 10%) after beneficial information. Overall liking, flavor linking, education, consumption intent, gender, age, and positive emotion term "happy" were significantly assertive predictors affecting purchase intent.

Apparent Digestibility Coefficients of Black Soldier Fly (Hermetia illucens), Yellow Mealworm (Tenebrio molitor), and Blue Bottle Fly (Calliphora vicina) Insects for Juvenile African Catfish Hybrids (Clarias gariepinus × Heterobranchus longifilis)

A digestibility trial was conducted with African catfish hybrid juveniles in order to determine the apparent digestibility coefficients (ADCs) of different nutrients. The experimental diets contained defatted black soldier fly (BSL), yellow mealworm (MW), or fully fat blue bottle fly (BBF) meals, in a 70 : 30 ratio between the control diet and the tested insect meals. The indirect method for the digestibility study was performed using 0.1% yttrium oxide as an inert marker. Fish juveniles of 217.4 ± 9.5 g initial weight were distributed in 1 m³ tanks (75 fish/tank) of a recirculating aquaculture system (RAS), in triplicates, and fed until satiation for 18 days. The average final weight of the fish was 346 ± 35.8 g. The ADCs of the dry matter, protein, lipid, chitin, ash, phosphorus, amino acids, fatty acids, and gross energy for the test ingredients and diets were calculated. A six-month storage test was carried out to evaluate the shelf life of the experimental diets, while the peroxidation and microbiological status of the diets were also assessed. The ADC values of the test diets differed significantly (p < 0.001) compared to those of the control for most of the nutrients. Altogether, the BSL diet was significantly more digestible for protein, fat, ash, and phosphorus than the control diet but less digestible for essential amino acids. Significant differences were found between the ADCs of the different insect meals evaluated (p < 0.001) for practically all nutritional fractions analyzed. The African catfish hybrids were able to digest BSL and BBF more efficiently than MW, and the calculated ADC values agreed with those of other fish species. The lower ADCs of the tested MW meal correlated (p < 0.05) with the markedly higher acid detergent fiber (ADF) levels present in the MW meal and MW diet. Microbiological evaluation of the feeds revealed that mesophilic aerobic bacteria in the BSL feed were 2-3 orders of magnitude more abundant than those in the other diets and their numbers significantly increased during storage. Overall, BSL and BBF proved to be potential feed ingredients for African catfish juveniles and the shelf life of the produced diets with 30% inclusion of insect meal retained the required quality during a six-month period of storage.

Black soldier fly full-fat meal in Atlantic salmon nutrition – Part A: Effects on growth performance, feed utilization, selected nutriphysiological traits and production sustainability in fries

Black soldier fly larva meal (BSFM) application as an innovative feed material has been developed in aquaculture nutrition. However, recent scientific literature is still lacking in the case of insect meal effects on different stages of salmonid fish, and the vast majority of research is focused on farmed Atlantic salmon. Therefore, the holistic approach was undertaken in the cycle of two studies carried out: on fries and pre-smolts. This study aimed to evaluate the effect of fish meal (FM) replacement by full-fat BSFM in Atlantic salmon fry diets on the growth performance, feed utilization, crude protein and crude fat digestibility, somatic indices, histomorphology of intestines, and environmental sustainability. Additionally, pellet quality was assessed. Two experiments were performed on 360 Atlantic salmon fries – each of which lasted 60 days. For the first experiment, 240 individuals were distributed to four experimental groups: six replicates (tanks) per group and 10 fish per tank. For the second experiment, 120 individuals were distributed to four experimental groups: three replicates (tanks) per group and 10 fish per tank were used. The following groups were applied: CON – without the addition of full-fat BSFM and with 39% FM; BSFM5 – with 5% addition of full-fat BSFM and 36.1% FM; BSFM10 – with 10% full-fat BSFM and 33.3% FM; BSFM15 – with 15% addition of full-fat BSFM and 30.3% FM. The present study showed satisfactory results of BSFM inclusion at the levels of 5% and 10% as a replacement for fish meal in feeds for Atlantic salmon fries. No negative effects on growth performance, feed utilization, protein and fat digestibility, or intestinal structure were recorded. Simultaneously, insect meal inclusion in Atlantic salmon diets significantly improved the environmental sustainability of the feed. In the case of BSFM15, decreases in body weight gain, protein lipid efficiency ratio, and lipid efficiency ratio, as well as increases in feed conversion ratio, were observed. Therefore, the use of shares higher than 10% of BSFM in Atlantic salmon fries may not be recommended.

Carob (Ceratonia siliqua) as Functional Feed Is Beneficial in Yellow Mealworm (Tenebrio molitor) Rearing: Evidence from Growth, Antioxidant Status and Cellular Responses

In terms of sustainability and circular economy, agricultural by-products may be efficiently reused in insects’ rearing for high-quality protein sources in human diet and animal feeds. The present study aimed to explore whether the utilization of carob pods as feeding substrate may beneficially affect Tenebrio molitor’s growth, nutritional value, antioxidant status and cellular responses. Increasing levels of milled whole carob pods (0, 25, 50, 75, 100%) were used as alternative wheat bran (control) substrates for yellow mealworm rearing, while growth performance, proximate composition, total phenolic content, antioxidant enzyme activity and the expression of stress- and apoptotic-related proteins were evaluated in larvae. The results showed that carob pods’ content up to 75% did not significantly differentiate larvae weight, development time and total dry matter. Larvae total phenolic content and antioxidant activity exhibited a significant increase at 75% content. Although the antioxidant enzymes’ activity decreased at both 25 and 50% levels, higher carob content levels (75 and 100%) resulted in no significant changes compared to the control. Carob pods led to decreased apoptotic indicators and the low expression of most stress-related proteins compared to the control. The present findings demonstrate that carob pods and their antioxidant properties exert beneficial effects on T. molitor’s rearing and nutritional status, although 100% carob content may impact adversely the larvae due to the high amounts of carob tannins.

Growth performance and intestinal morphometric features of broiler chickens fed on dietary inclusion of yellow mealworm (Tenebrio molitor) larvae powder

BACKGROUND

Climate change and the lack of conventional feed ingredients have made edible insects a highly nutritious alternative to feed production. The use of insects as food may help solve socio-economic and environmental problems around the world and be in line with the United Nations Sustainable Development Goals.

OBJECTIVE

In this study, the growth performance and intestinal morphology of broiler chickens were evaluated under the influence of adding different levels of Tenebrio molitor larvae meal (TM meal) to their diets.

METHODS

One hundred and eighty one-day-old broiler chickens were divided into three treatments and five replications (12 chickens/pen). The experimental diets included a control diet and treatments containing 2.5% and 5% TM meal, which were fed to birds in the starter (0-10 days) and grower (11-25 days) stages, and during the final period (26-42 days), all birds were fed a regular finisher diet.

RESULTS

The results showed that the diet containing TM meal had no remarkable effect on the mortality rate and feed intake of broilers (p > 0.05). In the starter period, the addition of 2.5% TM meal to broilers' diet increased body weight gain than the control group (p ≤ 0.05). Also, the use of 2.5% TM meal in the starter period showed a significant effect on reducing the feed conversion ratio, compared to the birds fed by the control diet (p ≤ 0.05). Besides, the height of the villus, the depth of the crypt and their ratio were not altered among the different treatments (p > 0.05).

CONCLUSIONS

Overall, it can be concluded that TM meal could improve growth performance in the starter period and had no negative effects on broilers' performance and intestinal morphology in all the periods of the experiment.

Nutritional composition and sensory Properties of wheat muffins enriched with Gonimbrasia zambesina, walker caterpillar flour

Sub-Saharan Africa still bears the greatest forms of malnutrition. Attention is shifting to the use of edible insects in forms which are acceptable to people irrespective of their social status and level of civilization in efforts to alleviate protein malnutrition. Gonimbrasia zambesina (Lepidoptera: Saturniidae) caterpillars emerge seasonally in the coastal part of Kenya and despite their rich nutritional profile, their consumption is low. This study was thus undertaken to evaluate the effect of substituting wheat flour with G. zambesina caterpillar flour at 0%, 5%, 10%, 15% and 20% substitution levels on the nutritional composition and sensory properties of wheat muffins. Substituting wheat flour with G. zambesina caterpillar flour resulted in significantly high protein, fat and fibre contents of enriched wheat muffins. There was also an increasing trend in the ash, minerals and tocopherol content. Invitro protein digestibility significantly decreased from 10 to 20% substitution levels. There was a significant difference (p < 0.05) in the carbohydrate contents of enriched wheat muffins. The sensory scores for colour, texture, aroma and the overall acceptability of wheat muffins decreased with increasing substitution levels. At 10% substitution level, wheat muffins had significantly higher nutritional content than control wheat muffins (0%) and were comparable to muffins enriched with 5% G. zambesina caterpillar flour in terms of overall acceptability. Thus, enriching wheat muffins with G. zambesina caterpillar flour at 10% substitution level has the potential to contribute to improved protein nutrition since they have a higher protein content than the control wheat muffin and are 88.8% digestible (in vitro).

In Vitro Crude Protein Digestibility of Insects: A Review

The high protein content of insects has been widely studied. They can be a good food alternative, and therefore it is important to study the effect of digestion on their protein. This review examines the different in vitro protein digestibility methodologies used in the study of different edible insects in articles published up to 2021. The most important variables to be taken into account in in vitro hydrolysis are the following: phases (oral, gastric and intestinal), enzymes, incubation time and temperature, method of quantification of protein hydrolysis and sample preprocessing. Insects have high digestibility data, which can increase or decrease depending on the processing of the insect prior to digestion, so it is important to investigate which processing methods improve digestibility. The most commonly used methods are gut extraction, different methods of slaughtering (freezing or blanching), obtaining protein isolates, defatting, thermal processing (drying or cooking) and extrusion. Some limitations have been encountered in discussing the results due to the diversity of methodologies used for digestion and digestibility calculation. In addition, articles evaluating the effect of insect processing are very limited. It is concluded that there is a need for the standardisation of in vitro hydrolysis protocols and their quantification to facilitate comparisons in future research.

A Narrative Review of Alternative Protein Sources: Highlights on Meat, Fish, Egg and Dairy Analogues

The research and development of alternatives to meat (including fish) and dairy products for human consumption have been increasing in recent years. In the context of these alternatives, there is a diversity of products such as tofu, tempeh, seitan, pulses, algae, seeds, nuts and insects. Apart from these, some products require new technical processes such as needed by milk drink alternatives, mycoprotein and meat, cheese and fish analogues. The aim of these analogues is to mimic the physical and organoleptic properties of animal origin products through fibrous composition and mix of ingredients from vegetable sources using adequate technology, which allow providing similar texture and flavor. Using a narrative approach to review literature, the objectives of this paper are to systematize the arguments supporting the adoption of meat, eggs and dairy alternatives, to identify the diversity of alternatives to these products on the market, including the related technological processes, and to project the challenges that the food industry may face soon. From a total of 302 scientific papers identified in databases, 186 papers were considered. More research papers on products associated with alternatives to milk were found. Nevertheless, there are products that need more research as analogues to meat and dairy products. A general scheme that brings together the main reasons, resources and challenges that the food industry faces in this promising area of alternatives to meat and dairy products is presented.

The Effect of Substrate on the Nutrient Content and Fatty Acid Composition of Edible Insects

Simple Summary

The search of new sustainably produced protein sources for food and feed is vigorously under investigation. One promising possibility is to increase the use of edible insects as a part of our diet. The nutrient content of edible insects, in particular, a high content of good quality protein and unsaturated fatty acids with essential fatty acids, is an important health aspect when screening the most potential insect species for human consumption. Based on this review, the substrate affects the nutrient content of insects. Moreover, our correlation calculations demonstrated that the fatty acid content of the substrate influences the nutritional value of insects. In general, high content of unsaturated fatty acids in the substrate increased the amount of unsaturated fatty acids in insects. For example, the content of essential fatty acids, linoleic and alpha linolenic acids, can be raised by feeding insects with modified substrate. Thus, edible insects can be a healthy protein source to ease the increased demand for high quality food.

Abstract

Demand for new food sources and production methods is increasing due to overall population growth, as well as the aim towards more sustainable use of natural resources and circular economy. Edible insects already used in many parts of the world have recently attracted interest as a new protein source in Europe, and novel food acceptance procedures are ongoing in the European Union for several insect species. In this paper, the effects of substate on the nutritional value, especially the fatty acid composition, of edible insects were reviewed and correlation calculations performed. The nutritional value of edible insects is an important health aspect, in particular, a high content of good-quality protein and unsaturated fatty acids with essential fatty acids, and an optimal fatty acid n6/n3 ratio. On the basis of our findings, the nutrient content of insects can be modified by using a feed substrate carefully designed for each individual insect species. In addition, our correlation calculations demonstrated that the contents of linoleic and alpha linolenic acids in insects reflected the contents of these acids in the substrate. In conclusion, optimizing the composition and structure of the substrate and rearing conditions and duration for each insect species might also aid standardization of the nutritional composition of edible insects.

Isolation of Chitinolytic Bacteria from European Sea Bass Gut Microbiota Fed Diets with Distinct Insect Meals

Insect meal (IM), recently authorized for use in aquafeeds, positions itself as a promising commodity for aquafeed inclusion. However, insects are also rich in chitin, a structural polysaccharide present in the exoskeleton, which is not digested by fish, resulting in lower fish performance. Through the application of a dietary pressure, this study aimed to modulate European sea bass gut microbiota towards the enrichment of chitinolytic bacteria to allow the isolation of novel probiotics capable of improving the use of IM-containing diets, overcoming chitin drawbacks. Five isoproteic (44%) and isolipidic (18%) diets were used: a fish meal (FM)-based diet (diet CTR), a chitin-supplemented diet (diet CHIT5), and three diets with either 25% of Hermetia illucens and Tenebrio molitor larvae meals (HM25 and TM25, respectively) or H. illucens exuviae meal (diet HEM25) as partial FM substitutes. After an 8-week feeding trial, the results showed a clear modulatory effect towards spore-forming bacteria by HM25 and HEM25 diets, with the latter being responsible for the majority of the chitinolytic fish isolates (FIs) obtained. Sequential evaluation of the FI hemolytic activity, antibiotic resistance, total chitinolytic activity, sporulation, and survival in gastrointestinal-like conditions identified FI645 and FI658 as the most promising chitinolytic probiotics for in vivo application.

Changes in the Chemical Composition of Edible Grasshoppers (Sphenarium purpurascens) Fed Exclusively with Soy Sprouts or Maize Leaves

Simple Summary

One of the most used insects in Mexico is the grasshopper, which is mostly consumed as a snack and collected in open fields where maize or alfalfa is grown. In this study, diet control of grasshoppers has helped to raise some important components such as protein, unsaturated fatty acids, and fiber content. Therefore, diet control could help to obtain insects with a preferred chemical and nutrient composition, making them a more nutritious alternative for human intake. Additionally, this strategy could improve the techno-functional properties of edible insects and their incorporation as ingredients in daily food.

Abstract

In recent times, insects have gained attention because of their nutritional characteristics as well as the environmental advantages of their production. In this research, the effect of the diet of grasshoppers (Sphenarium purpurascens) under controlled conditions on their chemical and nutritional content was studied. The insects were divided into two groups: maize leaf-fed grasshoppers (MFG) and soy sprout-fed grasshoppers (SFG). To evaluate the changes in composition, chemical analysis (protein, fiber, fat, ashes, and chitin) was carried out in triplicate according to AOAC procedures, and a Student’s t-test was used to determine any significant differences. The results showed a higher content of crude protein, in vitro protein digestibility percentage, and sum of non-essential amino acids (NEAAs) in the MFG samples compared with the SFG samples. The total dietary fiber, insoluble dietary fiber, soluble dietary fiber, sum of the EAA, non-essential amino acid percentage (EAA%), and biological value percentage (BV%) were higher in the SFG than the MFG, while in the amino acid profile and chitin content, no significant differences were obtained, although an increase in oleic acid in the SFG was observed. In FTIR, a β-sheet appeared in the SFG, which could be related to the low in vitro protein digestibility. The use of a soy sprout diet caused changes in the chemical composition and nutritional content of grasshoppers. This represents an opportunity to improve their nutritional value for commercial interests.

Potential Utilization of Insect Meal as Livestock Feed

Globally, the utilization of alternative protein sources in livestock feed has been extensively deliberated and established to be the best novel approach. Extensive research indicated that insects provide good opportunities as a sustainable, high quality, and low-cost component of animal feed. The use of insects in animal diet sounds to be the prospective opportunity leading to sustainability of animal feeds and meet the intensifying worldwide plea for livestock products. The value of these protein sources has, however, increased due to limited production, competition between humans and animals. The use of insects for feeding farmed animals represents a promising alternative because of the nutritional properties of insects and the possible environmental benefits, given the sustainability of this type of farming. Yet little has been documented about the nutrient composition of various insect meals, the impact of insect meal in the animal feed industry, safety, and attitude and willingness of farmers to accept insect-based animal feed and food. Therefore, this chapter seeks to document the potential utilization of insect meal as livestock feed.

Comparison of Nutritional Profiles of Super Worm (Zophobas morio) and Yellow Mealworm (Tenebrio molitor) as Alternative Feeds Used in Animal Husbandry: Is Super Worm Superior?

Edible insects are acknowledged as a valuable nutritional source and promising alternative to traditional feed ingredients, while the optimization of rearing conditions is required for their wider utilization in the animal feed industry. The main goal of this study was to compare and optimize the rearing conditions of the two species' larvae and identify the most favorable nutritive composition of the full-fat larval meal. For that purpose, Tenebrio molitor (TM) and Zophobas morio (ZM) were reared on three different substrates and harvested after three time periods. An artificial neural network (ANN) with multi-objective optimization (MOO) was used to investigate the influence between the observed parameters as well as to optimize and determine rearing conditions. The optimization of the larval rearing conditions showed that the best nutritive composition of full-fat larval meal was obtained for ZM larvae reared on a mixture of cabbage, carrot and flaxseed and harvested after 104 days. The best nutritive composition contained 39.52% protein, 32% crude fat, 44.01% essential amino acids, 65.21 mg/100 g Ca and 651.15 mg/100 g P with a favorable ratio of 1.5 of n6/n3 fatty acids. Additionally, the incorporation of flaxseed in the larval diet resulted in an increase in C18:3n3 content in all samples.

How to Develop Strategies to Use Insects as Animal Feed: Digestibility, Functionality, Safety, and Regulation

Various insects have emerged as novel feed resources due to their economical, eco-friendly, and nutritive characteristics. Fish, poultry, and pigs are livestock that can feed on insects. The digestibility of insect-containing meals were presented by the species, life stage, nutritional component, and processing methods. Several studies have shown a reduced apparent digestibility coefficient (ADC) when insects were supplied as a replacement for commercial meals related to chitin. Although the expression of chitinase mRNA was present in several livestock, indigestible components in insects, such as chitin or fiber, could be a reason for the reduced ADC. However, various components can positively affect livestock health. Although the bio-functional properties of these components have been verified in vitro, they show positive health-promoting effects owing to their functional expression when directly applied to animal diets. Changes in the intestinal microbiota of animals, enhancement of immunity, and enhancement of antibacterial activity were confirmed as positive effects that can be obtained through insect diets. However, there are some issues with the safety of insects as feed. To increase the utility of insects as feed, microbial hazards, chemical hazards, and allergens should be regulated. The European Union, North America, East Asia, Australia, and Nigeria have established regulations regarding insect feed, which could enhance the utility of insects as novel feed resources for the future.

Edible Insect Farming in the Context of the EU Regulations and Marketing—An Overview

Simple Summary

Insects have been identified as an alternative in the development of food systems and as a response to the growing demand for protein in the world. Edible insects have been recognized as an important innovation in the food sector. In the past, insects have been consumed in many cultures, and they are presently being introduced to Europe as a novel food and livestock. This article comprehensively reviews the use of edible insects in relation to their breeding, production technology, legal and socio-economic aspects. The role of food safety and legislation in implementing insects as food and feed is discussed. Moreover, the article introduces the breeding of edible insects as a developing and future-oriented business sector. In conclusion, the consumption of insects by humans and animals can significantly contribute to better diversification and security of the global food chain. The low acceptance of insect-based foods, in particular in Western societies, is an important problem that has been identified in this article. Consumer acceptance of insects as a rich source of nutrients is required for the further development of the sector. Consumer education and appropriate marketing strategies are required to promote the growth of the edible insect industry.

Abstract

Insects are increasingly being considered as an attractive source of protein that can cater to the growing demand for food around the world and promote the development of sustainable food systems. Commercial insect farms have been established in various countries, mainly in Asia, but in Europe, edible insects have not yet emerged as a viable alternative to traditional plant- and animal-based sources of protein. In this paper, we present an interdisciplinary overview of the technological aspects of edible insect farming in the context of the EU regulations and marketing. Based on a review of the literature, we have concluded that edible insect farming can be a viable business sector that significantly contributes to the overall sustainability of food systems if the appropriate regulations are introduced and food safety standards are guaranteed. However, the success of the edible insect industry also requires consumer acceptance of entomophagy, which is rather low in Western societies. Therefore, targeted marketing strategies are indispensable to support the implementation of edible insect programs.