Efficacy of silkworm (Bombyx mori L.) chrysalis oil as a lipid source in adult Wistar rats

Comparison of lipid profiles of male and female silkworm (Bombyx mori) pupae through high-resolution mass spectrometry-based lipidomics and chemometrics

Silkworm (Bombyx mori) pupae lipid profiles were analyzed using high-resolution mass spectrometry-based lipidomics. A total of 241 lipid molecular species were annotated with high confidence in male and female silkworm pupae. Triacylglycerol (TG), phosphoethanolamine (PE) and phosphocholine (PC) were the main lipid subclasses of silkworm pupae, accounting for 63, 41 and 38 lipid molecular species, respectively. No unique lipid molecular species were identified, but there were differences in the abundance of lipid molecular species between male and female silkworm pupae. Therefore, the differences in the lipid abundance of male and female silkworm pupae were analyzed by chemometrics. As a result, 8 lipid molecular species were screened for differential lipids. Hierarchical clustering analysis (HCA) showed that male and female silkworm pupae samples formed two distinct branches, indicating that these differential lipids could potentially be used as biomarkers to distinguish between male and female silkworm pupae.

Potential uses of silkworm pupae (Bombyx mori L.) in food, feed, and other industries: a systematic review

The increasing pressures imposed on ecosystems by the growing needs of the human population are stimulus for research into innovative and unconventional sources of raw materials for different industries. This systematic review was carried out to investigate the available literature on the possible industrial uses of silkworm (Bombyx mori L.) pupae, a residue of silk production. The review was conducted using an adapted version of PRISMA. After a screening process, 105 articles were obtained and subjected to a detailed quantitative and qualitative analysis. It was found that in the last decade there has been a significant increase in the number of papers devoted to the study of the potential use of silkworm pupae in different applications, with a significantly higher number in the last three years of the scope of this review, indicating a growing interest in the subject. From the analysis of the information collected, promising uses in human and animal food, such as fish, mammalian, poultry, swine and companion animals, as well as potential uses for the pharmaceutical industry, were identified. The evaluated research identified compounds with antioxidant activity and important contents of unsaturated fatty acids, which are related to beneficial effects on cardiovascular health, diabetes control, reduction of the risk of developing certain types of cancer and inflammatory activity, among other benefits. One of the most relevant findings is that many studies report a significant concentration of α-linolenic acid in silkworm pupae oil, which is attributed with anticancer, anti-inflammatory, antioxidant, anti-obesity and neuroprotective properties, among others.

Comprehensive quality control of silkworm chrysalis using chemical fingerprints combined with antioxidant activity and acetylcholine content

In recent years, some insects have become foods due to their high nutritional value. In order to solve the problem of the lack of quality control methods for insect foods, this study proposes a comprehensive control model using silkworm chrysalis (SC) as an example. Firstly, five-wavelength mean fusion fingerprints (FWMFF) and UV quantum fingerprints of 21 batches of SC were established. And the 21 batches of SC were classified into different grades from different perspectives by using the comprehensive linear quantified fingerprint method (CLQFM) as a quality evaluation method for qualitative and quantitative analysis. Secondly, this paper fully considered the issue of the reliability of fingerprint evaluation, which guaranteed the accuracy of the evaluation results. On this basis, the antioxidant capacity of the samples was used in vitro 1,1-Diphenyl-2-picrylhydrazylradical (DPPH) scavenging assay using IC50. The relationship between fingerprints and antioxidant activity was also discussed. Finally, the content of endogenous neurotransmitter (ACh) in SC determined by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in the range of 0.25-2.11μg/g. Overall, the present study proposes a comprehensive quality control strategy for functional foods based on the quality assessment of SC.

Fatty acid profile, minor bioactive constituents and physicochemical properties of insect-based oils: A comprehensive review

Insect-based food or ingredients have received tremendous attention worldwide because of their potential to ensure food and nutrition security, mitigating the reliance on land-dependent agricultural products. Indeed, insect-farming has low environmental impacts with reduced land, water and energy input. More importantly, insects are rich in high quality proteins and fats. They are also excellent sources of minerals, vitamins and bioactive compounds. Insect-based lipids are intriguing because they may contain high levels of unsaturated fatty acids particularly linoleic and α-linolenic acids. Besides, the insect-based lipids also show a considerable amount of bioactive components such as tocols, sterols and carotenoids. However, their fatty acid compositions and the nutritional values may vary depending on species, feed composition, developmental stage, geographical locations, and extraction techniques. Therefore, the present article aims to provide a comprehensive review on the fatty acid composition, the minor bioactive constituents and the physicochemical properties of fats and oils derived from insects of different orders (Coleoptera, Lepidoptera, Hymenoptera, Orthoptera, Hemiptera and Diptera). The various parameters affecting the nutritional compositions of the insect-based lipids will also be highlighted. These information will definitely provide a detailed insight on the potential applications of these fats in various food systems based on their unique properties.

Hermetia illucens fat affects the gastrointestinal tract selected microbial populations, their activity, and the immune status of broiler chickens

The present study investigated the effect of Hermetia illucens larvae (BSFL) fat, derived using supercritical CO2 extraction and added to broiler chickens’ diets as a partial (50%) or total replacement for commonly used soybean oil, on the gastrointestinal tract (GIT) microbial population, its activity, and selected physiological and immune traits. A total of 576 one-dayold female Ross 308 chicks were randomly assigned to 3 dietary treatments with 16 replicates each. The following treatments were applied: SO – 100% soybean oil, BSFL50 – a mixture of BSFL and soybean oils in a 50:50 ratio, and BSFL100 – 100% BSFL fat. Digesta samples from the crop, jejunum and ceca were collected for further analyses, i.e., pH measurements, fluorescent in situ hybridization, and short-chain fatty acid (SCFA) concentrations. Additionally, the selected plasma biochemical parameters and immunological traits were assessed. In general, the implementation of BSFL fat in broilers’ diets resulted in increased proliferation of potentially pathogenic bacterial populations in the crop, such as Enterobacteriaceae, Bacteroides – Prevotella cluster, and Clostridium perfringens. Furthermore, BSFL100 enhanced microbial activity via total SCFA production and lowered the pH in this segment. However, no detrimental effects were observed in terms of other GIT segments, i.e., the jejunal and cecal microecosystems. The strongest impact on reduction of select components of the microbial population in the cecum was observed with the BSFL50 treatment for potentially pathogenic bacteria such as Enterobacteriaceae, Bacteroides – Prevotella cluster, while commensal populations were also limited, i.e., Bacillus spp., C. leptum subgroup, and C. coccoides – Eubacterium rectale cluster. Additionally, BSFL100 reduced the cholesterol concentration in the blood, while both experimental treatments decreased the ALT level. In conclusion, due to the insufficient release of lauric acid from the BSFL fat in the crop, an adverse shift in the microbiota can be noted. However, a positive suppressive effect on the select components of the cecal microbiota, as well as improvement of liver health suggests implying the BSFL fat in broiler nutrition.

An alternative solution for α-linolenic acid supplements: in vitro digestive properties of silkworm pupae oil in a pH-stat system

α-Linolenic acid (ALA) is recognised to have a regulatory effect on cardiovascular diseases. Due to the low bioavailability of linseed oil (LINO), which is the most common ALA supplement, it is necessary to find a replacement for ALA supplements that is more easily accepted by the human body. The content of ALA in silkworm pupae oil (SPO) is 32.60 ± 0.67%, and SPO can be substituted as a dietary lipid to meet the demand of the human body. In the present study, a pH-stat system was used to investigate the release degree of free fatty acids (FFAs) from SPO and construct a first-order kinetic model. Digestion experiments in vitro with different lipids showed that the maximum release FFA levels were SPO > SO (soybean oil) > LO (lard oil) > MSO (mulberry seed oil) > LINO, and the first-order kinetic apparent rate constants were LINO > SPO > LO > SO > MSO. Triacylglycerol (TAG) and fatty acid composition are the decisive factors in determining the level of lipid digestion. Therefore, the maximum level of FFAs released from SPO (84.34 ± 1.37%) was much higher than that of LINO (49.78 ± 0.52%) when the hydrolysis rates were 0.2114 s^-1 and 0.2249 s^-1, respectively. In addition, the smaller emulsion droplet size (609.24 ± 43.46 nm) and weaker surface charge (-17.93 ± 0.42 mV) also resulted in higher levels of SPO under in vitro digestion conditions. Meanwhile, due to low melting and crystallisation temperature, SPO is quickly absorbed by the human body. Overall, SPO can be used as a new alternative for ALA supplements based on its superior digestive properties.

Insect Fat in Animal Nutrition – A Review

The aim of this review is to discuss the usage of insect fats as an energy source in animal nutrition. Insects are a rich carrier of proteins, fat, and minerals. They are successfully introduced in animal diets (poultry, swine, rabbits, fish, and pets) as a source of many nutrients, including energy and essential fatty acids (FAs). The insects’ fat content and quality are highly affected by the type of substrate provided to the insects during the rearing period. The majority of the studies have shown that insect fats may be used as promising substitutes for conventional energy resources in animal nutrition without adverse effects on growth performance and feed utilization. They can positively affect meat quality by increasing the level of long-chain polyunsaturated FAs but may also positively influence animals by regulating the gut microbiota and stimulating the immune system. In conclusion, insect fat supplementation showed promising results in terms of their application in animal nutrition. However, compared to insect protein application, very few studies have been performed on insect fats. Therefore, because of the fat quality and content of insects, there is a need to extend experimentation regarding their implementation in animals’ diets as a replacement for conventional dietary energy resources.

Improvement in serum lipids and liver morphology after supplementation of the diet with fish oil is more evident under regular feeding conditions than under high-fat or mixed diets in rats

BACKGROUND

Dietary n- 3 polyunsaturated fatty acids (PUFAs) have a role in preventing cardiovascular and hepatic diseases. However, their effects might differ significantly depending on individual dietary patterns. The aim of the present study was to evaluate the effects of dietary supplementation with ω-3 fatty acids (FA), administered in different schedules, on hepatic and aortic histological structure, lipid profile, and body weight (BW) in male Wistar rats under standard (SD), high-fat diet (HFD) and mixed feeding conditions.

METHODS

PUFA treatment consisted of the administration of 50 mg/kg fish oil (FO) daily by oral gavage. HFD was obtained by adding a suspension of 4% cholesterol, thiouracil and cholic acid to the animals' drinking water. The rats were maintained on the diets for 6 weeks, and different schedules of PUFA administration were used. At 14, 28, and 42 days, the morphology of liver and aortic samples and the levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), and triglycerides (TG) were assessed.

RESULTS

The HFD groups exhibited significant hyperlipidemia and aortic inflammation, with progression to atherogenesis after 6 weeks. Administration of PUFAs slightly attenuated the aortic changes in these groups and reduced the liver's tendency to steatosis. FO-induced metabolic improvement was more evident in SD than in HFD rats. For instance, after the first 2 weeks, SD animals that received PUFAs had significantly increased HDL levels vs. controls (62.375 ± 4.10 vs. 52.625 ± 8.38 mg/dL, P < 0.05), but HFD rats did not, and decreased TG levels were observed exclusively in the SD rats (57.6 ± 4.09 vs. 66 ± 4.69 mg/dL, P < 0.05). After 6 weeks of n- 3 PUFA administration, LDL was significantly lower in the SD rats than in controls (13.67 ± 4.13 vs. 30.83 ± 2.86 mg/dL, P < 0.001), but the decrease in the HFD rats, although significant (49.17 ± 5.85 mg/dL vs. 57.17 ± 4.96 g/dL, P < 0.05), was not as marked. In the mixed-diet groups, administration of 50 mg/kg/day FO for 14 days under SD conditions following 4 weeks of HFD slightly decreased TG (86.625 ± 11.67 vs. 73 ± 4.52 mg/dL, P < 0.05) and increased HDL (45.875 ± 5.28 vs. 56 ± 3.16 mg/dL). However, in these animals, n-3 PUFA administration had no effect on LDL or TC. Administration of half of the above dose failed to improve any biochemical parameters. FO protected against excessive weight gain mainly under SD conditions.

CONCLUSIONS

The results show that FO confers more protection against cardiovascular risk factors (increased LDL and TG, decreased HDL) and liver lipid accumulation when given to rats consuming regular diets than when given to rats consuming a high-fat diet. This argues that priority should be given to consumption of a healthy diet rather than to the use of supplements. The effectiveness of n-3 PUFAs might be reduced in the case of hyperlipidic intake or after consumption of a high-fat diet.

Replacement of soybean oil by Hermetia illucens fat in turkey nutrition: effect on performance, digestibility, microbial community, immune and physiological status and final product quality

1. The aim of the present study was to investigate the effect of partial (50%) or total replacement of soybean oil (SO) by black soldier fly larvae (BSFL) fat on the growth performance, coefficients of apparent nutrient digestibility, selected internal organ weights and length, pancreatic enzyme activity and gastrointestinal tract (GIT) microecology modulation, as well as microbiota activity, physiological and immunological responses in young turkey poults. 2. A total of 216, seven day old female turkeys (B.U.T 6) were randomly distributed to three dietary treatments using six replicate pens per group with 12 birds per pen. The following design of the trial was applied: SO 100% soybean oil; BSFL50 a 50/50 combination of SO and BSFL fat; or 100% BSFL fat (total replacement of SO). 3. The use of BSFL fat did not affect the growth performance, nutrient digestibility, GIT morphology, or quality of the breast and thigh muscles. However, reduced trypsin activity was noticed in the BSFL100 group, but this had no effect on digestibility. Total replacement of SO reduced proliferation of potentially pathogenic bacteria, i.e., Enterobacteriaceae spp., as well as decreasing levels of IL-6, while partial substitution lowered the TNF-α concentration. 4. The replacement of commonly used SO by BSFL fat can be successfully applied in young turkey poult nutrition. BSFL fat may be considered an antimicrobial agent and support immune responses.

From Waste to Sustainable Feed Material: The Effect of Hermetia Illucens Oil on the Growth Performance, Nutrient Digestibility, and Gastrointestinal Tract Morphometry of Broiler Chickens

In the present study, the complete cycle of the preconsumer waste transition by black soldier fly larvae (BSFL) into sustainable raw material (dietary fat) for broiler chickens was examined. In two individual experiments, the effects of selected rearing medium made from various preconsumer wastes on the nutritive value and performance of BSFL were tested (1st trial). In the second experiment, partial (25, 50, or 75%) or total replacement of soybean oil fed to broiler chickens by BSFL fat obtained via supercritical CO2 extraction from larvae from the 1st experiment was conducted. In the performance trial on birds, nutrient digestibility, selected gastrointestinal tract (GIT) segments, internal organ traits, and welfare status were also measured. In the first trial, 1-day-old BSFL were allotted to 5 treatments (8 replicates each). The following substrates were tested, i.e., wheat bran, carrots, cabbage, potatoes, and a mixture of the previously mentioned organic food wastes (equal ratio of each). In the second experiment, a total of 960 day-old female Ross 308 chicks were randomly assigned to 5 dietary treatments (16 replicates and 12 birds per replicate). The following groups were applied: SO – 100% soybean oil, HI25 – a mixture containing 25% BSFL fat and 75% SO, HI50 – addition of BSFL and SO in a 50:50 ratio, HI75 – a mixture containing 75% BSFL fat and 25% SO, and HI100 – 100% BSFL fat. The results of the present study showed high variability in the chemical composition of insects among groups (410 vs. 550 g kg−1 CP; 60 vs. 170 g kg−1 EE), as well as a significant influence of rearing substrate composition on BSFL performance, i.e., the average mass of 100 randomly chosen larvae (P<0.001), waste reduction rate (P<0.001), and conversion rate (P=0.008). Moreover, the partial or total replacement of SO by BSFL fat did not affect (P>0.05) the growth performance, coefficients of apparent ileal digestibility of nutrients, selected organ weights and length, or the welfare status of the broilers. In conclusion, it is possible to obtain an environmentally friendly, sustainable energy source from BSFL biomass and implement it in broiler diets without a negative effect on the birds’ production.

Protective effect of silkworm pupa oil on hydrochloric acid/ethanol-induced gastric ulcers

BACKGROUND

Silkworm pupae are a traditional Chinese food, rich in various saturated and unsaturated fatty acids. Unsaturated fatty acids have a certain protective effect against oxidative damage. The present study used an animal model to determine the protective effect of silkworm pupa oil on hydrochloric acid / ethanol-induced gastric ulcer.

RESULTS

Silkworm pupa oil is rich in unsaturated fatty acids, including palmitoleic acid 63.4 g kg^-1 , oleic acid 249.1 g kg^-1 , linoleic acid 47.0 g kg^-1 , and linolenic acid 337.8 g kg^-1 , whereas its unsaturated fatty acid content is 700 g kg^-1 . Compared to a gastric ulcer control group, high and low doses of pupa oil reduced gastric ulcer area and gastric secretion, whereas gastric pH increased. It also increased serum antioxidant superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) levels, somatostatin (SST), and vasoactive intestinal peptide (VIP) levels, and reduced serum interleukin-6 (IL-6), interleukin-12 (IL-12), tumor necrosis factor (TNF-α), and interferon-γ (IFN-γ), motilin (MTL), and gastrin (GT) levels. RT-qPCR and western blot analyses indicated that silkworm pupa oil significantly increased CAT, GSH-Px, epidermal growth factor (EGF), Epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), Cu/Zn-SOD, Mn-SOD, and NF-kappa-B inhibitor-α (IκB-α) expression and lowered nuclear factor-kappa B (NF-κB), B-cell lymphoma-2 (Bcl-2), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) expression.

CONCLUSION

Silkworm pupa oil treatment reduced oxidative damage and inflammation in mice, and high-dose silkworm pupa oil was superior to low-dose silkworm pupa oil, following ranitidine. © 2018 Society of Chemical Industry.