Effect of different killing methods on physicochemical traits, nutritional characteristics, in vitro human digestibility and oxidative stability during storage of the house cricket (Acheta domesticus L.)

Assessment of Changes in the Fat Profile of House Cricket Flour during 12 Months of Storage in Various Conditions

Considering Acheta domecticus flour's growing importance and utilization as an ingredient in many food products, research on its storage is essential. The objective of this study was to determine the chemical and nutritional fat profile of house cricket (Acheta domesticus) flour during storage for 12 months under different storage temperatures (-18 °C, +4 °C, and +20 °C in two variants, with and without access to light). Insect flour was studied using Fourier-transform infrared spectroscopy (FTIR). The fatty acids content was determined, and dietary indicators were calculated. The acid value, peroxide value, and anisidine value were also determined, and differential scanning calorimetry was performed. The results obtained from spectroscopic analysis of Acheta domesticus flour were consistent with the biochemical data. During the 12-month period of flour storage, the storage temperature significantly influenced the percentage composition of identified groups of fatty acids and the values of all presented ratios and dietary indices. During storage at refrigerated temperatures (-18 °C and +4 °C), no changes were observed in the fatty acid content and dietary indices, indicating that refrigerated temperatures provide oxidative stability to flour during 12 months of storage. Samples stored at 20 °C had higher acid values (AV), peroxide values (PV), and anisidine values (p-AV) compared to samples stored at lower temperatures (4 °C and -18 °C). Simultaneously, an increase in SFA and MUFA, as well as a decrease in PUFA and UFA, was noted in samples stored at room temperature. Storing cricket flour at lower temperatures when the storage period will be more than 12 months is essential to restrict the occurrence of fat oxidation. Elevated temperatures and exposure to light have a notable effect in hastening oxidation mechanisms, reducing thermal resilience, and inducing more pronounced alterations in the quality of fats.

Comparative analysis of nutritional quality and color properties of flours derived from Locusta migratoria at different developmental stages

This study was conducted to determine the variation in the chemical composition of flours derived from Locusta migratoria at two distinct developmental stages: the fourth instar and adult stages. Adult locust flour exhibited approximately two times higher fat content, similar protein content, ash content, CHNS elemental composition, and 45.7% lower total phenolic content compared to fourth instar locust flour. The flour from the adult locust was lighter, more red, and yellow than the fourth instar locust flour. Nineteen fatty acids were detected in both flours, with oleic acid, palmitic acid, and linoleic acid being the major ones. The ΣPUFA/ΣSFA of fourth instar and adult locusts was 0.82 and 0.78, respectively. The ratio of ω-6/ω-3 fatty acids was 2.1 for the fourth instar locust flour and 1.7 for the adult locust flour. Apart from gamma-aminobutyric acid (GABA), similar amino acids were found in both the flours. However, significant differences were detected in the levels of some of these amino acids between the fourth instar and adult locust flours. Of particular interest, adult locust flour showcased a GABA content of 25.4 mg/100 g dry weight, making it a valuable alternative protein source in developing innovative and nutritious food products.

Recent advances in edible insect processing technologies

Alternative foods have emerged as one of the hot research topics aiming at alleviating food shortage. Insects are one of the alternative foods due to their rich nutrients. Processing is a critical step to develop insect foods, while there is a lack of comprehensive reviews to summarize the main studies. This review aims to demonstrate different processing methods in terms of their impact on insect nutrition and their potential risks. Heat treatments such as boiling and blanching show a negative effect on insect nutrition, but essential to assure food safety. Insects treated by high-pressure hydrostatic technology (HPP) and cold atmospheric pressure plasma (CAPP) can achieve a similar sterilization effect but retain the nutritional and sensory properties. Drying is a practical processing method for industrial insect production, where oven drying serves as a cost-effective method yielding products comparable in quality to freeze-dried ones. In terms of extraction technology, supercritical carbon dioxide and ultrasound-assisted technology can improve the extraction efficiency of proteins and lipids from insects, enhance the production of composite insect-fortified foods, and thus facilitate the development of the insect food industry. To address the widespread negative perceptions and low acceptance towards insect foods among consumers, the primary development direction of the insect food industry may involve creating composite fortified foods and extracting insect-based food components.

Microencapsulated polyphenol extracts from Georgia-grown pomegranate peels delay lipid oxidation in salad dressing during accelerated and ambient storage conditions

Lipid oxidation is a major cause of quality deterioration in salad dressings. This study evaluated the effect of incorporating microencapsulated polyphenol extracts via spray drying from pomegranate peels (MPP) to delay lipid oxidation in Italian-style salad dressings (ISD) during accelerated (55°C) and ambient (25°C) storage conditions. ISDs, prepared at high (5000 rpm) and low (250 rpm) shear rates conditions, were formulated with unencapsulated polyphenol extracts from pomegranate peels (PPP), MPP, and/or grape seed extract (GSE). Lipid oxidation in ISDs was evaluated by measuring peroxide value (PV), iodine value (IV), and TBARS, stored in accelerated and ambient conditions for 21 days and 8 weeks, respectively. Tannis in extracts were measured via HPLC-DAD and the total hydrolyzable tannin content of PPP and MPP was 283.09 and 427.74 (mg/g extract), respectively. Condensed tannins were not detected in PPP and MPP but were found in GSE (348.53 mg/g extract). Salad dressings prepared at high shear rates had significantly (p < .05) higher emulsion stability than those homogenized at low shear rates. Mixing conditions did not affect the lipid oxidative stability of IDSs. Salad dressing stored under accelerated storage had higher lipid oxidation (higher PV, lower IV, and higher TBARS) after 21 days than IDSs stored under ambient conditions for 8 weeks. ISDs prepared with MPPP showed significantly (p < .05) lower lipid oxidation than the other ISDs at the end of the shelf life studies. Results from the accelerated storage suggested that incorporating MPP could have extended the shelf life of IDSs by 20% compared to using unencapsulated polyphenol extracts. The study demonstrated that MPP delays lipid oxidation in ISDs during storage more effectively than unencapsulated extracts. MPP may serve as a natural and effective functional food ingredient for controlling lipid oxidation in high-lipid and acidified foods.

The Interaction of Slaughtering, Drying, and Defatting Methods Differently Affects Oxidative Quality of the Fat from Black Soldier Fly (Hermetia illucens) Larvae

The interrelation effect of slaughtering, drying, and defatting methods of BSFL on the oxidative quality of the derived fat was studied. Blanching and freezing were compared as slaughtering methods, followed by oven or freeze-drying for drying and mechanical pressing or SFE for defatting. The oxidative state and stability of the extracted fat and defatted meals were monitored immediately after their production, using peroxide value (PV) and Rancimat test, and over 24 weeks of storage. Slaughtering and drying methods had an independent effect on PV, with freezing and freeze-drying being the best methods. Mechanical pressing and SFE were comparable and superior to conventional hexane defatting. Interactions were observed between slaughtering and defatting, drying and defatting, and between all three factors. Generally, freeze-drying combined with any of the slaughtering and defatting methods resulted in the lowest PVs, with mechanical pressing being preferred. Freeze-drying plus mechanical pressing also produced the most stable fats during storage according to the evolution of PV, while the combination of blanching and SFE produced the least stable. A significant correlation was found between the PV at 24 weeks and the antioxidant activity of the fats. Contrary to storage assays, in accelerated Rancimat assays, freeze-dried samples were the least stable, which was partially attributed to the significant correlation with the acid values of the samples. Defatted meals followed a similar pattern to the extracted fat, except for worse oxidation for SFE defatting. Therefore, the different processing methods of slaughtering, drying, and defatting of BSFL differently affect lipid oxidation, with interactions between such successive steps.

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.

Green Technology for Pork Loin Wet Curing-Unconventional Use of Cow and Soy Milk Treated with Non-Thermal Atmospheric Plasma

This study was conducted to evaluate the possibility of using plasma-activated cow and soy milk powders as a substitute for sodium nitrite for wet curing of pork meat (m. longissimus thoracis et lumborum). Pork loin slices were cured for 4 d at refrigerate conditions in four brines: water + salt (NC group), water + salt + sodium nitrite (PC group), water + salt + plasma-activated cow milk powder (B1 group), and water + salt + plasma-activated soy milk powder (B2 group). Importantly, brines from groups PC, B1, and B2 were characterized by the same concentration of NO2− ions (200 ppm). Results show that samples from B1 and B2 groups had significantly (p < 0.05) higher values of redness, nitrosylhemochrome content, and lower values of thiobarbituric acid reactive substances (TBARS) compared to samples from the NC group. At the same time, the groups cured with alternative curing agents were characterized by lower residual nitrite content with regard to groups cured with NaNO2. No significant differences (p ≥ 0.05) were found in pH and shear force values among the treatments. Finally, the aroma profile of the samples from groups B1 and B2 was similar to the aroma profile of the samples from the PC group (the aroma differed by a maximum of 1.73% in the case of brine containing plasma-activated cow milk powder) but differed significantly from the NC group (the aroma differed in 97.21%). Due to the higher nitrite depletion in the final product, while maintaining the quality parameters similar to traditionally cured pork loins, both alternative curing agents can be recommended, with a predominance of plasma-treated soy milk.

Consumption of cricket (Acheta domesticus) flour decreases insulin resistance and fat accumulation in rats fed with high-fat and -fructose diet

The consumption of cricket (Acheta domesticus, AD) has recently increased due to its high nutritional and bioactive compound contents. However, limited studies have explored the beneficial effects of AD consumption. Therefore, we aimed to evaluate the protective effect of a diet supplemented with AD flour on obesity control and its complications in an in vivo model. The chemical profiling of the AD showed an important protein content, chitin, and polyunsaturated fatty acids contents. For the in vivo study, a high-fructose and saturated fat diet (HFFD) was supplemented with AD (4% and 8%). The 8% AD supplementation reduced body weight gain (19%) and serum triglycerides (37%) in HFFD-fed rats. These benefits were related to a greater lipid excretion in feces (97%) and the partial inhibition of pancreatic lipase in vitro by the aqueous extract and the hydrolyzed proteins obtained from AD. Additionally, the 8% AD supplementation improved insulin resistance measured by the HOMA index (61%). Thus, 8% AD supplementation to HFFD-fed rats was effective in preventing obesity, dyslipidemia, and insulin resistance. PRACTICAL APPLICATIONS: Obesity is a risk factor for developing insulin resistance and dyslipidemia. Therefore, there is an increasing interest in consuming foods rich in bioactive compounds as therapeutic alternatives for managing the development of obesity and its complications. Edible insects, such as crickets, are attractive for treating obesity due to their content of protein, fiber, and polyunsaturated fatty acids. Studies have explored the effect of glycosaminoglycan (GAG)-enriched extracts from the cricket Gryllus bimaculatus against obesity. However, GAG content in crickets is low, and crickets are commonly consumed whole instead of extracts. The cricket Acheta domesticus (AD) is among the most rearing cricket species as it is easy to farm and has a better flavor. However, limited studies have explored the beneficial effects of AD consumption. This study demonstrates that AD prevents obesity and ameliorates dyslipidemia and insulin resistance. Therefore, AD is a valuable entomotherapeutic strategy to reduce the comorbidities associated with diet-induced obesity.

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.

Transgenerational effects of grandparental and parental diets combine with early-life learning to shape adaptive foraging phenotypes in Amblyseius swirskii

Transgenerational effects abound in animals. While a great deal of research has been dedicated to the effects of maternal stressors such as diet deficiency, social deprivation or predation risk on offspring phenotypes, we have a poor understanding of the adaptive value of transgenerational effects spanning across multiple generations under benign conditions and the relative weight of multigenerational effects. Here we show that grandparental and parental diet experiences combine with personal early-life learning to form adaptive foraging phenotypes in adult plant-inhabiting predatory mites Amblyseius swirskii. Our findings provide insights into transgenerational plasticity caused by persistent versus varying conditions in multiple ancestral generations and show that transgenerational effects may be adaptive in non-matching ancestor and offspring environments.