Extraction, characterization, and use of edible insect oil - A review.

Population growth is driving the search for new food sources, including entomophagy, i.e., a diet based on edible insects. Insect powder are rich in essential fatty acids, minerals, vitamins, and bioactive compounds such as antioxidant phenolics. The technologies for extracting oil from insects must be efficient to guarantee high yields. This oil due to its favorable nutritional profile, and lower cost, can be a viable alternative to vegetable and fish oils. Although common in some cultures, the consumption of insects faces resistance in others due to its association with dirt. Efforts are being made to scientifically demonstrate the safety and nutritional benefits of insects as well as their sustainability as a food source. This first review of insect oils focuses on presenting their different characteristics and encouraging the production and use of these products in the food, pharmaceutical, or cosmetics industries.

Characterization of mixed-component oleogels: Beeswax and glycerol monostearate interactions towards Tenebrio Molitor larvae oil.

Edible insects are attracting attention as an alternative food due to their excellent production efficiency, lower carbon consumption, and containing high protein. Tenebrio Molitor larvae (TM), one of the approved edible insects worldwide, contain more than 30 % fat content consisting of 70 % unsaturated fatty acids, and particularly high phospholipids. Most of the research has focused on the utilization of proteins, and there are few studies using oils from TM. Therefore, in this study, to expand the utilization of TM oil in food applications, the oleogel was prepared with TM oil fortified by the incorporation of beeswax (BSW) and glycerol monostearate (GMS), and their structure, rheological and thermal properties were evaluated. The interaction between BSW and GMS contributed to the strength of the oleogel structure. The addition of GMS or the increase of the gelator concentrations resulted in increasing the melting point, which is consistent with the observed increase in viscoelasticity. As the temperature increased, the solid fat content decreased. The result of FT-IR suggests that TM oil is physically solidified without changing chemical composition through oleogelation. This study suggests a new processing direction for edible insects by confirming the rheological, thermal, and physicochemical characteristics of TM oil-based oleogel.

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.

Ultrasound-Assisted Alcoholic Extraction of Lesser Mealworm Larvae Oil: Process Optimization, Physicochemical Characteristics, and Energy Consumption.

The ultrasound-assisted extraction (UAE) of oil from lesser mealworm (Alphitobius diaperinus L.) larvae powders (LMLPs) using ethanol/isopropanol as the superior solvent was optimized. The evaluation of time (9.89−35.11 min), solvent-to-LMLPs (2.39−27.61 v/w), and temperature (16.36−83.64 °C) showed that the highest extraction efficiency (EE, 88.08%) and in vitro antioxidant activity (IVAA) of reducing power (0.651), and DPPH free-radical scavenging capacity (70.79%) were achieved at 22.5 v/w solvent-to-LMLPs and 70 °C for 22.64 min. Optimal ultrasound conditions significantly improved the EE than n-hexane extraction (60.09%) by reducing the electric energy consumption by ~18.5 times from 0.637 to 0.035 kWh/g. The oil diffusivity in ethanol-isopropanol during the UAE (0.97 × 10−9 m2/s) was much better than that of n-hexane (5.07 × 10−11 m2/s). The microstructural images confirmed the high efficiency of ethanol-isopropanol in the presence of ultrasounds to remove oil flakes from the internal and external surfaces of LMLPs. The improved IVAA was significantly associated with the total phenolic (4.306 mg GAE/g, r = 0.991) and carotenoid (0.778 mg/g, r = 0.937) contents (p < 0.01). Although there was no significant difference in the fatty acid profile between the two extracted oils, ethanol-isopropanol under sonication acceptably improved oxidative stability with lower peroxides, conjugated dienes and trienes, and free fatty acids.

Feeding silkworm (Bombyx mori L.) oil to growing rabbits improves the fatty acid composition of meat, liver and perirenal fat.

Silkworm oil was used in a rabbit diet to evaluate its benefit on the fatty acid (FA) profile of different carcass portions. Two experimental diets were prepared: a control diet (commercial diet with 13 g/kg sunflower oil) and a silkworm oil diet (SWO) (commercial diet with 13 g/kg silkworm oil). Rabbits received the experimental diets the last three weeks before slaughter, which occurred at 10 weeks of age. At slaughter, hind leg meat, liver, and perirenal fat were sampled for FA profile analysis. The SWO diet significantly increased the n-3 FA of all three sampling sites and halved the n-6/n-3 ratio of hind leg meat and perirenal fat. Furthermore, the liver of SWO rabbits was also richer in C22:6 n-3 compared to that of control rabbits. In conclusion, this study demonstrated that the total dietary replacement of sunflower oil with silkworm oil in fattening rabbits positively changed the FA profile of the considered carcass tissues.

The Characteristic of Insect Oil for a Potential Component of Oleogel and Its Application as a Solid Fat Replacer in Cookies.

The larvae of Tenebrio molitor, an edible insect, have recently attracted attention in the food industry as a protein supplement or future food material. However, despite more than 30% of the total weight being fat content, few studies have been conducted on the fat (oil) derived from Tenebrio molitor larvae (TM oil) and its food utilization. In this study, TM oil was extracted and its fatty acid composition and antioxidant activity were investigated. Then, the oleogels were prepared with TM oil and oleogelators (candelilla wax, carnauba wax, and beeswax) and their rheological and thermal properties were evaluated to elucidate their utilization as a solid fat replacer in cookies. In the results, TM oil contained 73.6% unsaturated fatty acids and showed a lower antioxidant activity than olive oil. Although the highest hardness was shown in oleogel with candelilla wax, the highest viscoelasticity above 50 °C was observed for oleogel with carnauba wax. The highest melting point was observed in carnauba oleogel. Lower peroxide values were observed in the oleogel samples than for TM oil, indicating that oleogelation of structuring oil improved the oxidative stability of TM oil. In addition, the shortening replacement with carnauba wax oleogel showed a desirable cookie quality in terms of spreadability and texture properties.

Modulation of Atlantic salmon (Salmo salar) gut microbiota composition and predicted metabolic capacity by feeding diets with processed black soldier fly (Hermetia illucens) larvae meals and fractions.

BACKGROUND: Black soldier fly (Hermetia illucens) is a promising insect species to use as a novel ingredient in fish feeds. Black soldier fly larvae consists of three major fractions, namely protein, lipid, and exoskeleton. These fractions contain bioactive compounds that can modulate the gut microbiota in fish such as antimicrobial peptides, lauric acid, and chitin. However, it is not certain how, or which fractions of black solider fly would affect gut microbiota in fish. In the present study, black soldier fly larvae were processed into three different meals (full-fat, defatted and de-chitinized) and two fractions (oil and exoskeleton), and included in diets for Atlantic salmon (Salmo salar). Atlantic salmon pre-smolts were fed with these diets in comparison with a commercial-like control diet for eight weeks to investigate the effects of insect meals and fractions on the composition and predicted metabolic capacity of gut microbiota. The gut microbiota was profiled by 16S rRNA gene sequencing, and the predicted metabolic capacities of gut microbiota were determined using genome-scale metabolic models. RESULTS: The inclusion of insect meals and fractions decreased abundance of Proteobacteria and increased abundance of Firmicutes in salmon gut. The diets that contained insect chitin, i.e., insect meals or exoskeleton diets, increased abundance of chitinolytic bacteria including lactic acid bacteria and Actinomyces in salmon gut, with fish fed full-fat meal diet showing the highest abundances. The diets that contained insect lipids, i.e., insect meals and oil diets enriched Bacillaceae in fish gut. The fish fed diets containing full-fat insect meal had a unique gut microbiota composition dominated by beneficial lactic acid bacteria and Actinomyces, and showed a predicted increase in mucin degradation compared to the other diets. CONCLUSIONS: The present results showed that the dietary inclusion of insect meals and fractions can differently modulate the composition and predicted metabolic capacity of gut microbiota in Atlantic salmon pre-smolts. The use of full-fat black soldier fly larvae meal in diets for salmon is more favorable for beneficial modulation of gut microbiota than larvae processed by separation of lipid or exoskeleton fractions.

Insect (black soldier fly larvae) oil as a potential substitute for fish or soy oil in the fish meal-based diet of juvenile rainbow trout (Oncorhynchus mykiss).

Alternative sources of fish oil (FO) are one of the major problems in aquaculture; therefore, the goal of the present study was to examine insect (black soldier fly larvae) oil (BSLO) as a potential replacer of fish/soy oil in juvenile rainbow trout (initial average weight of 32 ± 0.15 g) feed. Four diets were formulated wherein FO (control diet) was completely replaced with either soybean oil (SO) or BSLO, and an additional BSLO-based diet supplemented with 1.5% bile acid (BSLO + BA) were fed to the fish for 10 weeks. Growth performance of the BSLO fed group was similar (P > 0.05) to that of the FO and SO fed groups, however, the fish fed BSLO + BA diet registered the lowest growth (P < 0.05). Oil sources did not (P > 0.05) affect the major nutrient content of whole-body, however, the fatty acid composition of the muscle and liver was influenced (P < 0.05), with the highest 14:0, 16:0, and total saturated fatty acid detected in BSLO or BSLO + BA fed trout compared to the others (P < 0.001). No significant differences were observed in eicosapentaenoic acid + docosahexaenoic acid (EPA + DHA) or total n-3 polyunsaturated fatty acid (PUFA) content in muscle among the groups, whereas, the highest EPA:DHA and n-3:n-6 ratios were detected in the FO group. Gene expression for fatty acid binding protein (fabp), fatty acid synthase (fas), and Δ5 desaturase in the liver was lower in FO (P < 0.05), while BSLO + BA registered the highest Δ6 expression (P = 0.006). Supplementation of BA in the BSLO diet increased superoxide dismutase (SOD) and catalase (CAT) activities compared to the other groups (P < 0.05). In conclusion, BSLO could serve as a substitute for FO and SO in rainbow trout diet without negatively impacting growth performance, whole-body composition and nutrient retention, and modulate the expression of fatty acid metabolism-related genes in rainbow trout.

Lipidome of cricket species used as food.

The variation in lipidome of house cricket, banded cricket, Jamaican field cricket and two-spotted cricket was studied using high-throughput screening techniques for fingerprinting (MALDI TOF MS, GC-MS and LC MS-MS) and well-stablished chromatographic techniques for quantification (HPLC-ELSD, GC- FID). Although the four cricket species were reared in identical conditions, two-spotted & banded crickets had a lipid content 1.5 fold higher than house cricket. The lipids were high in UFA (>63%) and unsaturated TAG (>98%) making them liquid at room temperature, thus an oil. Cholesterol and several phytosterols were profiled finding high cholesterol concentration which is a point of concern. Eight phospholipid types (211 species) were identified with no major differences among cricket species. Using high-throughput screening techniques we demonstrate the complexity of cricket lipidome. Information on the lipidome of these crickets with high commercial value is important to estimate its nutritional value and their potential food applications.

Development and Characterization of Nano-emulsions Based on Oil Extracted from Black Soldier Fly Larvae.

Insect-based biorefinery is seen as a potential alternative approach to manufacturing foods, feeds, and fuel because of the increasing demand for renewable and sustainable products. Insect oil and protein are the two major components that can be quantitatively obtained from insect farming. However, very few attempts have been conducted to utilize insect oil for the production of value-added products. In this study, the oil extracted from the black soldier fly (Hermetia illucens) larvae (BSFL) was used as a novel feedstock for preparing nano-emulsions. The nano-emulsions were prepared with BSFL oil, hydrogenated lecithin (HL), and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) in water using pre-homogenization followed by ultrasonication. The morphology and the particle size of nano-emulsions were affected by ratios of HL to TPGS. Moreover, the nano-emulsions showed a nearly Newtonian liquid behavior and the presence of TPGS was able to improve the storage stability of HL nano-emulsions. The addition of TPGS could eliminate the phase transition region of HL nano-emulsions but did not provide a significant change for the molecular mobility in the HL nano-emulsions. In summary, the BSFL oil could be used as a renewable feedstock for formulating nano-emulsions from the aspect of high value-added applications and physicochemical characteristics of the nano-emulsions could be adjusted by the mixed surfactant ratio, surfactant to oil ratio, and oil content. Graphical Abstract The physicochemical characteristics and optimization of nano-emulsions based on black soldier fly larvae oil were investigated.

Insect Oil as An Alternative to Palm Oil and Poultry Fat in Broiler Chicken Nutrition.

This study was conducted to evaluate the effects of Tenebrio molitor (TM) oil as a total replacement for palm oil and poultry fat in broiler chicken diets on growth performance, nutrient digestibility, pancreatic enzyme activity, selected blood parameters and the lipid fatty acid compositions of liver and breast muscle tissues. A total of 72 seven-day-old female Ross 308 broiler chickens were used. The birds were randomly distributed into three groups with 12 replicates each, using two birds per replicate for 30 days in metabolic cages. The basal diet was supplemented with 5% palm oil, poultry fat or TM oil. There was no effect (p > 0.05) caused by the dietary oil replacement on the birds' performance and apparent nutrient digestibility. Liver size (p = 0.033), the concentration of hepatic triglycerides (p = 0.049) and total cholesterol (p = 0.048) were reduced by TM oil supplementation. Furthermore, TM oil supplementation increased n-3 and n-6 fatty acids (p = 0.006; p < 0.001, respectively) in breast muscle tissue. In conclusion, the use of TM oil in broiler chickens' diets did not show any adverse effects on performance, nutrient digestibility and blood biochemical parameters. Moreover, TM oil supplementation improved the fatty acid profiles of liver and breast muscle tissues.