•Crude protein content of insects was similar to conventional meat products.•The amount of EAA of insects was higher than daily protein requirement of an adult.•The supernatant, pellet, fat and ...residue fractions were obtained after an aqueous extraction.•Protein bands were found <95kDa for supernatant fractions and <200kDa for pellet fractions.•Most supernatant fractions did not foam, but could form gels depending on protein concentration and the pH.
Tenebrio molitor, Zophobas morio, Alphitobius diaperinus, Acheta domesticus and Blaptica dubia were evaluated for their potential as a future protein source. Crude protein content ranged from 19% to 22% (Dumas analysis). Essential amino acid levels in all insect species were comparable with soybean proteins, but lower than for casein. After aqueous extraction, next to a fat fraction, a supernatant, pellet, and residue were obtained, containing 17–23%, 33–39%, 31–47% of total protein, respectively. At 3% (w/v), supernatant fractions did not form stable foams and gels at pH 3, 5, 7, and 10, except for gelation for A. domesticus at pH 7. At 30% w/v, gels at pH 7 and pH 10 were formed, but not at pH 3 and pH 5. In conclusion, the insect species studied have potential to be used in foods due to: (1) absolute protein levels; (2) protein quality; (3) ability to form gels.
Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on dried yellow mealworm (Tenebrio molitor larva) ...as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term yellow mealworm refers to the larval form of the insect species Tenebrio molitor. The NF is the thermally dried yellow mealworm, either as whole dried insect or in the form of powder. The main components of the NF are protein, fat and fibre (chitin). The Panel notes that the levels of contaminants in the NF depend on the occurrence levels of these substances in the insect feed. The Panel notes that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf life. The NF has a high protein content, although the true protein levels in the NF are overestimated when using the nitrogen‐to‐protein conversion factor of 6.25, due to the presence of non‐protein nitrogen from chitin. The applicant proposed to use the NF as whole, dried insect in the form of snacks, and as a food ingredient in a number of food products. The target population proposed by the applicant is the general population. The Panel notes that considering the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous. The submitted toxicity studies from the literature did not raise safety concerns. The Panel considers that the consumption of the NF may induce primary sensitisation and allergic reactions to yellow mealworm proteins and may cause allergic reactions in subjects with allergy to crustaceans and dust mites. Additionally, allergens from the feed may end up in the NF. The Panel concludes that the NF is safe under the proposed uses and use levels.
In view of demanding alternative protein sources to replace the conventional ones, egg-yolk free mayonnaise-type emulsions were made from protein preparations extracted from Tenebrio molitor larvae ...by applying alkaline extraction (ASP), alkaline extraction followed by isoelectric precipitation (AIP) and salt-assisted treatment followed by dialysis (SSP). Their droplet size, microstructure and rheological properties were compared with egg-yolk mayonnaise (CEY). All emulsions exhibited similar droplet size distribution, with the CEY-mayonnaise having a broader range. SSP showed the smallest mean droplet size acting as a more effective emulsifier. Steady-state flow properties and dynamic oscillatory experiments within the linear viscoelastic region of mayonnaise-type emulsions were performed. The higher value of G′ compared to the value of G″ indicated the elastic character of all samples. Both moduli were no-highly frequency dependent, which was in line with their solid-like nature. The thixotropic behaviour of the emulsions was evaluated by three-interval thixotropy tests revealing higher recovery rate in the case of CEY and ASP. Temperature sweeps were also performed and revealed that AIP and SSP showed less temperature dependence, indicating their lower sensitivity to temperature variations. Overall, the results of this study suggest that the protein preparations extracted from Tenebrio molitor larvae have the potential for producing egg yolk-free mayonnaise-type emulsions.
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•T. molitor protein emulsions exhibited uniform droplet size and microstructure.•Shear-thinning behaviour was exhibited by all protein preparations.•T. molitor proteins have the potential to replace eggs in mayonnaise-type products.
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•PVC ingested in Tenebrio molitor larvae was broadly depolymerized within 12–15 h.•Biodegradation of PVC was confirmed by polymer modification.•PVC was partially mineralized with ...about 3% to chloride.•Depolymerization was inhibited by gentamicin thus gut microbe dependent.•Gut microbiome shifted significantly after feeding PVC.
Tenebrio molitor larvae (Coleoptera: Tenebrionidae) are capable of depolymerizing and biodegrading polystyrene and polyethylene. We tested for biodegradation of Polyvinyl Chloride (PVC) in T. molitor larvae using rigid PVC microplastic powders (MPs) (70–150 μm) with weight-, number-, and size-average molecular weights (Mw, Mn and Mz) of 143,800, 82,200 and 244,900 Da, respectively, as sole diet at 25 °C. The ingestion rate was 36.62 ± 6.79 mg MPs 100 larvae-1 d-1 during a 16-day period. The egested frass contained about 34.6% of residual PVC polymer, and chlorinated organic carbons. Gel permeation chromatography (GPC) analysis indicated a decrease in the Mw, Mn and Mz by 33.4%, 32.8%, and 36.4%, respectively, demonstrating broad depolymerization. Biodegradation and oxidation of the PVC MPs was supported by the formation of OC and OC functional groups using frontier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR), and by significant changes in the thermal characteristics using thermo-gravimetric analysis (TGA). Chloride released was counted as about 2.9% of the PVC ingested, indicating limited mineralization of the PVC MPs. T. molitor larvae survived with PVC as sole diet at up to 80% over 5 weeks but did not complete their life cycle with a low survival rate of 39% in three months. With PVC plus co-diet wheat bran (1:5, w/w), they completed growth and pupation as same as bran only in 91 days. Suppression of gut microbes with the antibiotic gentamicin severely inhibited PVC depolymerization, indicating that the PVC depolymerization/biodegradation was gut microbe-dependent. Significant population shifts and clustering in the gut microbiome and unique OTUs were observed after PVC MPs consumption. The results indicated that T. molitor larvae are capable of performing broad depolymerization/biodegradation but limited mineralization of PVC MPs.
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••Biochar was produced from Tenebrio molitor frass and modified by KOH.•• TMFBC-750A possessed high SBET of 1858.80m2g−1 with enhanced absorptivity.••The prevailing mechanisms of NEOs ...on BC were revealed.••TMFBC-750A realized efficient adsorption of NEOs in water.
Neonicotinoid pesticides (NEOs) are the most widely used insecticides in the world and pose a serious threat to ecological systems. Thus, the development of an efficient and sustainable technique for their removal is urgently needed. In this study, a novel biochar was prepared by pyrolysis of Tenebrio molitor frass and activated with KOH at 650 (TMFBC-650A), 750 (TMFBC-750A) and 850 °C (TMFBC-850A). Among them, TMFBC-750A showed the best adsorption performance, and the adsorption capacities for thiacloprid (THI), nitenpyram (NIT) and dinotefuran (DIN) were 155.08 mg·g−1, 195.86 mg·g−1, 325.81 mg·g−1, respectively. The isotherms for the adsorption of NIT and THI fit the Langmuir model quite well, while DIN fits the Freundlich model. Moreover, the adsorption of THI, NIT and DIN was well fitted by the pseudofirst-order kinetic model. The physicochemical characterization analysis demonstrated that the adsorption process of NEOs by TMFBC might be mainly controlled by micropore filling, π-π electron donor–acceptor interactions and functional group interactions (H-bonding, covalent bonding and hydrophobic interactions). Additionally, the thermodynamic parameters suggested that NEO adsorption in this work was a spontaneous, endothermic and randomly increasing process. TMFBC also exhibited a high selective adsorption capacity regardless of solution pH and inorganic ion strength concentrations. The regenerated TMFBC (via synergistic ultrasound/ethanol) could sustainably and efficiently absorb NEOs in reuse cycles, suggesting that TMFBC has excellent reusability and stability. These results indicated that TMFBC can be a potential and sustainable adsorbent for neonicotinoid pesticide removal.
3D printing technology was employed to obtain snacks with a designed cylindrical geometry from wheat flour dough enriched by ground larvae of Yellow mealworms (Tenebrio molitor) as novel source of ...proteins. The main microstructural features, overall quality, and nutritional attributes were studied as a function of formulation, time and temperature of baking. The addition of ground insects up to 20 g/100 g (d.b.) resulted in softer dough. This caused an overflow in dough deposition producing the increase in diameter, height and weight of snacks. Baking conditions did not alter the overall aspect of the snacks, but modification of the main dimensional and microstructure attributes were observed due to the better water evaporation. The optimization of baking conditions found that 22 min and 200 °C allowed obtaining a maximum desirability of 0.693. Baked in these conditions, the printed snacks enriched with 10 and 20% of ground insects significantly increased the total essential amino acid, from 32.5 (0% insects) to 38.2 and 41.3 g/100 g protein, respectively. The protein digestibility corrected amino acid score increased from 41.6 to 65.2 from 0 to 20% insect enrichment, with lysine and methionine + cysteine being the respective limiting amino acid. Our results evidenced the rational promotion of insects based on nutritional arguments and validated the use of 3D printing as technology to manufacture innovative printed snacks without adverse impact on technological quality.
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•3D printed edible objects based on flour dough enriched with insects were obtained.•Different levels of Yellow mealworms were used as innovative protein source.•Insects modified dough printability due to its changes in rheological properties.•Both protein content and amino-acid profile significantly improved.
Polylactic acid (PLA) is biodegraded rapidly under composting or thermophilic temperature but slowly under natural conditions with substantial microplastics generated. In this study, we examined the ...feasibility of PLA biodegradation and developed a novel approach for PLA waste management using yellow mealworms (Tenebrio molitor larvae) to achieve biodegradation and resource recovery simultaneously. Results confirmed PLA biodegradation in mealworms as sole PLA and PLA-bran mixtures (10%, 20%, 30% and 50% PLA, wt/wt). Feeding PLA-bran mixtures supported the larval development with higher survival rates and lower cannibal rates than feeding PLA only at ambient temperature. The PLA conversion efficiency was 90.9% with 100% PLA diet and was around 81.5–86.9% with PLA-bran mixtures. A peak insect biomass yield was achieved at a PLA ratio of 20%. PLA biodegradation was verified via detection of chemical and thermal modifications. Gut microbial community analysis indicated that intestinal communities shifted with PLA biodegradation, resulting in clusters with OTUs unique to the PLA diet. Based on these findings, we propose a circular approach for PLA waste management via resource recovery of used PLA as the feedstock for insect biomass production, management of mealworm excrement waste as fertilizer, and utilization of agricultural products for PLA production.
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•Mealworms digested polylactic acid (PLA) to support their life activities.•Biodegradation of PLA in mealworms was confirmed via FTIR and TGA.•A peak biomass yield was achieved at 20% PLA with a co-diet bran (wt/wt).•The removal efficiency of PLA ingested was more than 81.5% in mealworms.•The gut microbiome significantly shifted due to PLA biodegradation.
A fundamental strategy evolved by organisms in cold habitats, obliged to cope with ice and freeze injuries, is ice-binding proteins (IBP). These proteins directly interact with ice surfaces and serve ...to depress the freezing point of the body fluids, to inhibit ice recrystallization, or to promote ice nucleation. The delicate control over ice growth make these proteins applicable in any field that requires control over ice growth, namely, in cryopreservation of cells, tissues and organs, in cryosurgery and in agriculture, in the frozen food industry and in complex material engineering. A variety of IBPs have been studied in the past decade, differing in sequences, structures, and specific activities. Most IBPs are grossly classified to moderate and hyperactive according to their thermal hysteresis activity, which is the gap between the equilibrium melting point and the freezing point of an ice crystal grown in IBP solution. We have studied the ability of IBPs to shape ice crystals in distinguishable forms characteristic of the particular protein type. IBPs with moderate thermal hysteresis activities induce elongated bipyramidal crystals – often with well-defined facets – while hyperactive IBPs produce more varied crystal shapes, such as the “lemon-like” crystals typically observed with Tenebrio molitor IBP. These unique morphologies are frequently considered to be growth shapes. We conducted a systematic study of ice shaping in solutions containing a wide range of IBPs. We found that although ice crystals in solutions of moderate IBPs do indeed grow into their faceted shapes, in the presence of most hyperactive IBPs, ice melts into its final shape. These melting shapes result from the affinity of the hyperactive IBPs for the basal planes of ice. A 3D simulation of a melting process using a velocity profile that reflects melting perpendicular to the basal plane confirmed our findings. Our results show a clear difference in the ice shaping mechanisms of moderate and hyperactive IBPs. This study implies that basal plane affinity may be predicted by simple observation of an ice crystal. Understanding the differences between the interactions of the various IBPs and ice is important for the future utilization of these proteins in industry and medicine.
Source of funding: M.B.D was supported by The Lady Davis Fellowship thrust and The Valazzi-Pikovsky Fellowship Fund. The research was funded by the National Science Foundation (NSF), the Israel Science Foundation (ISF), the European Research Council (ERC).
Conflict of interest: None declared.
maya.bar1@mail.huji.ac.il
The global interest in edible insects as sustainable protein sources raises concerns about the bioaccumulation of contaminants, including polycyclic aromatic hydrocarbons (PAHs), to problematic ...levels. Understanding the accumulation dynamics of PAHs in edible insects is highly relevant due to the widespread sources and toxicological profiles; however, the bioaccumulative potential of PAHs in edible insects is unexplored. This study examined the uptake and elimination dynamics of benzo(a)pyrene (B(a)P), a representative and carcinogenic PAH, in yellow mealworm larvae (YMW, Tenebrio molitor). Larvae were exposed to feeding substrate with varying B(a)P concentrations (0.03, 0.3, and 3 mg kg−1), and uptake (21 days in B(a)P-contaminated substrate) and elimination (21 days in B(a)P-free substrate) kinetics were subsequently assessed. The results showed that YMW can eliminate B(a)P, revealing dose-dependent B(a)P bioaccumulation in these insects. Larvae fed on a substrate with 0.03 mg kg−1 accumulated B(a)P over 21 days, presenting values of 0.049 (Standard deviation - 0.011) mg kg−1 and a kinetic-based (BAFkinetic) of 1.93 g substrate g organism−1, exceeding the EU regulatory limits for food. However, with a B(a)P half-life (DT50) of 4.19 days in the larvae, an EU legislation safety criterion was met after a 13-day depuration period in clean substrate. Larvae exposed to substrates with 0.3 and 3 mg kg−1 showed B(a)P accumulation, with BAFkinetic values of 3.27 and 2.09 g substrate g organism−1, respectively, not meeting the current legal standards for food consumption at the end of the exposure to B(a)P. Although the B(a)P half-life values after 35 days were 4.30 and 10.22 days (DT50s), the larvae retained B(a)P levels exceeding permitted food safety limits. These findings highlight a significant oversight in regulating PAHs in animal feed and the need for comprehensive safety evaluations of PAH hazards in edible insects for improved PAH feeding guidelines.
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•Toxicokinetics of Benzo(a)pyrene was studied in edible insect larvae.•Dose-dependent accumulation in yellow mealworms was observed.•Introducing a depuration phase to the practice of insect rearing as solution.•The study results support the improvement of using insects as feed and food.
Edible insects have been used as an alternative protein source for food and animal feed, and the market size for edible insects has increased. Tenebrio molitor larvae, also known as mealworm and ...yellow mealworm, are considered a good protein source with nutritional value, digestibility, flavor, and a functional ability. Additionally, they are easy to breed and feed for having a stable protein content, regardless of their diets. Therefore, T. molitor larvae have been produced industrially as feed for pets, zoo animals, and even for production animals. To maintain the nutrient composition and safety of T. molitor larvae, slaughtering (heating or freezing) and post- slaughtering (drying and grinding) procedures should be improved for animal feed. T. molitor larvae are also processed with defatting or hydrolysis before grinding. They have a high quality and quantity of protein and amino acid profile, so are considered a highly sustainable protein source for replacing soybean meal or fishmeal. T. molitor has a chitin in its cuticle, which is an indigestible fiber with positive effects on the immune system. In studies of poultry, the supplementation of T. molitor larvae improved the growth performance of broiler chickens, without having negative effects on carcass traits, whereas some studies have reported that there were no significant differences in the growth performance and carcass yield of broiler chickens. In studies of swine, the supplementation of T. molitor larvae improved the growth performance and protein utilization of weaning pigs. Furthermore, 10% of T. molitor larvae showed greater amino acid digestibility than conventional animal proteins in growing pigs. However, there are some challenges regarding the biosafety, consumer's acceptance, and price for the use of T. moiltor larvae in animal feed. Consequently, T. molitor larvae could be used as an alternative or sustainable protein source in monogastric animal feed with a consideration of the nutritional values, biosafety, consumer's acceptance, and market price of T. molitor larvae products.
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