Influence of substitution of sunflower oil by different oils on the growth, survival rate and fatty acid composition of Jamaican field cricket ( Gryllus assimilis )

Evaluation of rapeseed cake as a protein substitute in the feed of edible crickets: A case study using Gryllus assimilis

This paper aimed to investigate the optimization of Gryllus assimilis farming production by examining the effects of replacing soybean meal with rapeseed cake (25-100%) and supplementing it with rapeseed oil. The results reveal no adverse effects of soybean meal replacement on the feed conversion ratio and weight of the harvested crickets. However, incorporating larger quantities of rapeseed cake into the diet increased crude protein and decreased fat content. Moreover, the composition of fatty acids varied significantly, with increased levels of oleic acid and decreased levels of palmitic acid, while a high rapeseed cake content led to a decrease in the atherogenic and thrombogenic index values. The amino acid composition remained unaffected. In conclusion, the study demonstrates that rapeseed cake can serve as a viable substitute for soybean meal in the diet of Gryllus assimilis.

Balancing the Growth Performance and Nutritional Value of Edible Farm-Raised Sago Palm Weevil (Rhynchophorus ferregineus) Larvae by Feeding Various Plant Supplemented-Sago Palm Trunk Diets

Herein, the effect of supplementing ground sago palm trunk (GSPT) with varying concentrations of plant-based ingredients (PIs), including rice bran (RB), soybean meal (SM), and perilla seed (PS), on the nutritional profile of sago palm weevil larvae (SPWL) was investigated. Increased PS intake induced an increase in α-linolenic acid level and a reduction in the n-6/n-3 ratio in SPWL (p < 0.05). The presence of fatty acids in SPWL was determined predominantly by the fatty acid profile in the feed. The activities of Δ5 + Δ6 desaturases and thioesterase were not different among SPWL fed different diets (p < 0.05); however, PI intake resulted in low suppression of fads2 gene expression. RB, SM, and PS at the appropriate concentrations of 17.5%, 8.8%, and 7.0% in GSPT (F3 diet), respectively, boosted both protein quantity and quality of SPWL, as indicated by higher levels of essential amino acids, particularly lysine, than the FAO protein reference. Therefore, incorporating PIs into a regular diet is a viable method for enhancing the nutritional value and sustainability of farm-raised SPWL as a potential alternative source of high-quality lipid and protein.

A Novel Strategy for the Production of Edible Insects: Effect of Dietary Perilla Seed Supplementation on Nutritional Composition, Growth Performance, Lipid Metabolism, and Δ6 Desaturase Gene Expression of Sago Palm Weevil (Rhynchophorus ferrugineus) Larvae

The nutritional value, growth performance, and lipid metabolism of sago palm weevil larvae (Rhynchophorus ferrugineus, SPWL) raised on plant-based diets (soybean, rice bran, and ground sago palm trunk (GSPT)), supplemented with various concentrations (0, 3, 7, 15, and 20%) of perilla seed (PS) were compared with traditional diets i.e., regular GSPT (control) and GSPT supplemented with pig feed. All supplemented diets rendered SPWL with higher lipid and protein contents (p < 0.05). Supplementing with 7−20% PS enhanced α-linoleic acid content in SPWL, resulting in a decrease in the n-6:n-3 ratio to a desirable level. Dietary PS supplementation increased Δ9 (18), total Δ9 and Δ5 + Δ6 desaturase indexes, fatty acid (FA) unsaturation, and the polyunsaturated FA:saturated FA ratio in SPWL, while lowering atherogenicity index, thrombogenicity index, and Δ6 desaturase (fads2) gene expression. Boosting with 7% PS improved the majority of growth parameters and enhanced essential amino acid and mineral contents (p < 0.05).

Impact of Heating Temperature and Fatty Acid Type on the Formation of Lipid Oxidation Products During Thermal Processing

Thermal treatment of lipids rich in fatty acids contributes to the formation of lipid oxidation products (LOPs), which have potentially harmful effects on human health. This study included soybean oil (SO), palm oil (PO), olive oil (OO), and lard oil (LO) as the research objects, with an aim to investigate the impact of heating temperature and fatty acid type on the generation of LOPs (α-dicarbonyl compounds, malondialdehyde (MDA), α,β-unsaturated aldehydes, and 16 volatile aldehydes). Results showed that LOPs increased significantly (p &lt; 0.05) with the increase in temperature (100 ~ 200°C). Furthermore, the amount of 2,3-butanedione (159.53 μg/g), MDA (3.15 μg/g), 4-hydroxy-hexenal (3.03 μg/g), 2-butenal (292.18%), 2-pentenal (102.26%), hexanal (898.72%), and 2,4-heptadienal (E, E) (2182.05%) were more at 200°C in SO rich in polyunsaturated fatty acids (PUFAs) than other oils. Results from heat map analysis indicated that the 2, 4-heptadienal, and glyoxal related to the myristic acid of oil. Moreover, the MDA was in close association with PUFAs. Based on the effect of temperature and fatty acid type on the generation of LOPs, this study could serve as a control method to reduce harmful LOPs.

Improved long-chain omega-3 polyunsaturated fatty acids in sago palm weevil (Rhynchophorus ferrugineus) larvae by dietary fish oil supplementation

The nutritional values of sago palm weevil larvae (SPWL) reared on mixed plant-based diets (ground sago palm trunk (GS), cornmeal, rice bran, soybean, and perilla seed), containing different levels of dietary fish oil (FO) were compared to those reared on commercial pig feed (PF) and GS. Increased FO content resulted in an increase in ω-3 fatty acids (FA) in SPWL (p < 0.05), especially α-linolenic acid and eicosapentaenoic acid. When fed FO-fortified diets instead of PF, the health-promoting indices of the SPWL lipid improved significantly (e.g., decreased ω-6/ω-3 ratio, thrombogenicity index, and hypercholesterolemic FA with increased PUFA content). The lipid, protein, and mineral contents of SPWL were increased while growth performance was maintained on a 1.5% FO-fortified diet. Higher FO levels (3-5%) had a negative impact on the nutritional values and growth performance of the SPWL. Thus, there was a reasonable chance of developing a high-nutrient alternative insect for human consumption.

Dietary enrichment of edible insects with omega 3 fatty acids

Edible insects are advocated as sustainable and healthy food and feed. However, commercially produced insects are often low in n-3 fatty acids and have suboptimal n-6/n-3 ratios. A certain amount and proportion of these FAs is required to optimize human health. Flaxseed oil consists primarily (57%) out of alpha-linolenic acid. An experiment was conducted to quantify the effect of flaxseed oil provision on fatty acid composition and to determine the quantity needed to attain a beneficial n-6/n-3 ratio. Three species were used in the experiment: house crickets (Acheta domesticus [L.]), lesser mealworms (Alphitobius diaperinus [Pfanzer]) and black soldier flies (Hermetia illucens [L.]). These were provided with either a control diet or a diet enriched with 1%, 2%, or 4% flaxseed oil during their larval/nymphal stage. Fatty acid profiles of diets and insects were determined via GC-MS. The three species had distinct fatty acid profiles on all four diets, but responded similarly to flaxseed oil addition. For each percent added to the diet, the alpha-linolenic acid content of the insects increased by 2.3%-2.7%. Four percent addition increased the n-3 fatty acid content 10-20 fold in the three species and thereby strongly decreased n-6/n-3 ratios from 18-36 to 0.8-2.4. A ratio below 5 is considered optimal for human health and was achieved by 2% flaxseed oil inclusion for house crickets and lesser mealworms, and at 1% inclusion for black soldier flies. Adding a source of n-3 fatty acids to insect diets can thus improve the nutritional quality of insects.

Microbiological Profile and Bioactive Properties of Insect Powders Used in Food and Feed Formulations

Microbiological, nutritional and bioactive properties of edible powders obtained from Acheta domesticus (house cricket) and Tenebrio molitor (mealworm) were investigated. Except for the enterobacteria, viable bacteria were at a higher concentration in mealworm flour. The diversity evaluation carried out using MiSeq Illumina that mainly identified Citrobacter and Enterobacteriaceae in mealworm powder and members of the Porphyromonadaceae family in house cricket powder. Enterococci were identified and characterized for their safety characteristics in terms of the absence of antibiotic resistance and virulence. Both powders represent a good source of proteins and lipids. The fatty acid profile of mealworm powder was characterized by the predominance of the monounsaturated fatty acids and house cricket powder by saturated fatty acids. The enzymatic hydrolysis produced the best results in terms of percentage of degree of hydrolysis with the enzyme Alcalase, and these data were confirmed by SDS-PAGE electrophoresis. Furthermore, the results showed that the protein hydrolysate of these powders produces a significant antioxidant power.

Review of Black Soldier Fly (Hermetia illucens) as Animal Feed and Human Food

Food futurists accept that sustainability-minded humanity will increasingly incorporate insects as alternative protein. The most studied and easily reared species are not necessarily the most sustainable, acceptable, or delicious. Here, we review the literature on the black soldier fly, Hermetia illucens, which is capable of efficiently converting a wide variety of organic materials, from food waste to manure, into insect biomass. They can be grown and harvested without dedicated facilities and are not pestiferous. Their larvae are 42% crude protein and 29% fat, although they are higher in saturated fats than most insects. They do not concentrate pesticides or mycotoxins. They are already grown and recommended for use as animal feed, but with regional legal restrictions on how this is done. For commercial use in human foods, larvae could potentially be milled and converted into a textured protein with a strong flavor. Their biggest advantage over other insects is their ability to convert waste into food, generating value and closing nutrient loops as they reduce pollution and costs. This general advantage is also their greatest disadvantage, for the social stigmas and legal prohibitions against eating organisms that eat waste are added to extant taboos facing insect consumption.

Lowering Chitin Content of Cricket (<I>Gryllus assimilis</I>) Through Exoskeleton Removal and Chemical Extraction and its Utilization as a Ruminant Feed <I>in vitro</I>

BACKGROUND AND OBJECTIVE

Cricket contains high crude protein level but it also contains considerable amount of chitin that may impede nutrient digestion and decrease production performance of animal. This experiment aimed to decrease chitin content of cricket (C) through exoskeleton removal (CER) or by chemical extraction (CCE).

MATERIALS AND METHODS

Nutritional evaluation of cricket was performed in two experiments. In experiment 1, three forms of cricket were prepared, i.e., C, CER and CCE. These were subjected to chemical composition determination and in vitro rumen fermentation incubation as individual substrates. In experiment 2, C and CER were included in concentrate rations at different proportions to substitute soybean meal (SBM), i.e., R1 (concentrate containing 30% SBM), R2 (50% SBM was substituted by C), R3 (100% SBM was replaced by C) and R4 (100% SBM was replaced by CER). The concentrates were then evaluated in vitro for their rumen fermentation and digestibility characteristics. Data were analyzed with analysis of variance and Duncan's test.

RESULTS

Cricket was high in crude protein(CP), ether extract (EE) and chitin contents. Removal of exoskeleton decreased CP and chitin contents of cricket. Chemical extraction of cricket increased its CP and completely removed its chitin. Main fatty acids observed in cricket were linoleic acid, palmitic acid, oleic acid and stearic acid and the composition was unaltered due to exoskeleton removal or chemical extraction. Cricket was relatively highly digestible and exoskeleton removal and chemical extraction did not further improve in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) of cricket. The R1 and R2 revealed similar IVDMD and IVOMD, but R3 and R4 resulted in lower values for both parameters than those of R1 and R2 (p<0.05).

CONCLUSION

Exoskeleton removal or chemical extraction effectively reduced chitin content of cricket and the insect may be used to substitute SBM up to 50% in concentrate for ruminant.