The Set of Serine Peptidases of the Tenebrio molitor Beetle: Transcriptomic Analysis on Different Developmental Stages.

Serine peptidases (SPs) of the chymotrypsin S1A subfamily are an extensive group of enzymes found in all animal organisms, including insects. Here, we provide analysis of SPs in the yellow mealworm Tenebrio molitor transcriptomes and genomes datasets and profile their expression patterns at various stages of ontogeny. A total of 269 SPs were identified, including 137 with conserved catalytic triad residues, while 125 others lacking conservation were proposed as non-active serine peptidase homologs (SPHs). Seven deduced sequences exhibit a complex domain organization with two or three peptidase units (domains), predicted both as active or non-active. The largest group of 84 SPs and 102 SPHs had no regulatory domains in the propeptide, and the majority of them were expressed only in the feeding life stages, larvae and adults, presumably playing an important role in digestion. The remaining 53 SPs and 23 SPHs had different regulatory domains, showed constitutive or upregulated expression at eggs or/and pupae stages, participating in regulation of various physiological processes. The majority of polypeptidases were mainly expressed at the pupal and adult stages. The data obtained expand our knowledge on SPs/SPHs and provide the basis for further studies of the functions of proteins from the S1A subfamily in T. molitor.

Molecular-Weight-Dependent Degradation of Plastics: Deciphering Host-Microbiome Synergy Biodegradation of High-Purity Polypropylene Microplastics by Mealworms.

The biodegradation of polypropylene (PP), a highly persistent nonhydrolyzable polymer, by Tenebrio molitor has been confirmed using commercial PP microplastics (MPs) (Mn 26.59 and Mw 187.12 kDa). This confirmation was based on the reduction of the PP mass, change in molecular weight (MW), and a positive Δδ13C in the residual PP. A MW-dependent biodegradation mechanism was investigated using five high-purity PP MPs, classified into low (0.83 and 6.20 kDa), medium (50.40 and 108.0 kDa), and high (575.0 kDa) MW categories to access the impact of MW on the depolymerization pattern and associated gene expression of gut bacteria and the larval host. The larvae can depolymerize/biodegrade PP polymers with high MW although the consumption rate and weight losses increased, and survival rates declined with increasing PP MW. This pattern is similar to observations with polystyrene (PS) and polyethylene (PE), i.e., both Mn and Mw decreased after being fed low MW PP, while Mn and/or Mw increased after high MW PP was fed. The gut microbiota exhibited specific bacteria associations, such as Kluyvera sp. and Pediococcus sp. for high MW PP degradation, Acinetobacter sp. for medium MW PP, and Bacillus sp. alongside three other bacteria for low MW PP metabolism. In the host transcriptome, digestive enzymes and plastic degradation-related bacterial enzymes were up-regulated after feeding on PP depending on different MWs. The T. molitor host exhibited both defensive function and degradation capability during the biodegradation of plastics, with high MW PP showing a relatively negative impact on the larvae.

Long-lasting insecticidal activity in plants driven by chlorogenic acid-loaded metal-organic frameworks.

Metal-organic frameworks (MOFs) possess a variety of interesting features related to their composition and structure that make them excellent candidates to be used in agriculture. However, few studies have reported their use as delivery agents of agrochemicals. In this work, the natural polyphenol chlorogenic acid (CGA) was entrapped via simple impregnation in the titanium aminoterephthalate MOF, MIL-125-NH2. A combination of experimental and computational techniques was used to understand and quantify the encapsulated CGA in MIL-125-NH2. Subsequently, CGA delivery studies were carried out in water at different pHs, showing a fast release of CGA during the first 2 h (17.3 ± 0.3% at pH = 6.5). In vivo studies were also performed against larvae of mealworm (Tenebrio molitor), evidencing the long-lasting insecticidal activity of CGA@MIL-125-NH2. This report demonstrates the potential of MOFs in the efficient release of agrochemicals, and paves the way to their study against in vivo models.

Pathogenicity of Metarhizium rileyi (Hypocreales: Clavicipitaceae) against Tenebrio molitor (Coleoptera: Tenebrionidae).

Tenebrio molitor L., also known as the mealworm, is a polyphagous insect pest that infests various stored grains worldwide. Both the adult and larval stages can cause significant damage to stored grains. The present study focused on isolating entomopathogenic fungi from an infected larval cadaver under environmental conditions. Fungal pathogenicity was tested on T. molitor larvae and pupae for 12 days. Entomopathogenic fungi were identified using biotechnological methods based on their morphology and the sequence of their nuclear ribosomal internal transcribed spacer (ITS). The results of the insecticidal activity indicate that the virulence of fungi varies between the larval and pupal stages. In comparison to the larval stage, the pupal stage is highly susceptible to Metarhizium rileyi, exhibiting 100% mortality rates after 12 days (lethal concentration 50 [LC50] = 7.8 × 106 and lethal concentration 90 (LC90) = 2.1 × 1013 conidia/mL), whereas larvae showed 92% mortality rates at 12 days posttreatment (LC50 = 1.0 × 106 and LC90 = 3.0 × 109 conidia/mL). The enzymatic analyses revealed a significant increase in the levels of the insect enzymes superoxide dismutase (4.76-10.5 mg-1) and glutathione S-transferase (0.46-6.53 mg-1) 3 days after exposure to M. rileyi conidia (1.5 × 105 conidia/mL) compared to the control group. The findings clearly show that M. rileyi is an environmentally friendly and effective microbial agent for controlling the larvae and pupae of T. molitor.

Differences in ingestion and biodegradation of the melamine formaldehyde plastic by yellow mealworms Tenebrio molitor and superworms Zophobas atratus, and the prediction of functional gut microbes.

Plastics biodegradation by insect larvae is considered as a new strategy for plastic wastes treatment. To uncover the biodegradation of a more complex chemical polymer of melamine formaldehyde (MF) by insect larvae, two worm species of yellow mealworm Tenebrio molitor and superworm Zophobas atratus were fed on MF foam as sole diet for 45 days with sole bran diet as control. Although the MF foam consumption by yellow mealworms of 0.38 mg/d/g-larvae was almost 40% higher than that by superworms of 0.28 mg/d/g-larvae, a similar decrease of survival rates in both species were obtained at about 58%, indicating the adverse effects on their growth. Depolymerization and biodegradation of MF foam occurred in both larval guts, but was more extensive in yellow mealworms. MF foam sole diet influenced gut bacterial and fungal microbiomes of both larvae species, which were assessed by Illumina MiSeq on day 45. Compared to the bran-fed group, both gut bacterial and fungal communities significantly changed in MF-fed groups, but differed in the two larvae species. The results demonstrated a strong association between the distinctive gut microbiome and MF foam degradation, such as unclassified Enterobacteriaceae, Hyphopichia and Issatchenkia. However, sole MF foam diet negatively influenced worms, like lower survival rates and gut abnormalities. In summary, MF foam could be degraded by both yellow mealworms and superworms, albeit with adverse effects. Gut microbes were strongly associated to MF foam degradation, especially the gut fungi.

Ingestion and biodegradation of disposable surgical masks by yellow mealworms Tenebrio molitor larvae: Differences in mask layers and effects on the larval gut microbiome.

During the COVID-19 pandemic, the usage and production of face masks considerably increased, resulting in large quantities of mask waste accumulating in the natural environment. To investigate whether masks of polypropylene (PP) material could be ingested and degraded by insect worms like PP foam plastic, yellow mealworms were provided with different layers of disposable surgical masks as sole diets for 30 d. Although mask layers, especially the middle layer of melt-blown filter, could be ingested by yellow mealworms, sole mask layer diets had adverse effects on the larval survival and growth. Analyses of Fourier transform infrared spectroscopy, differential scanning calorimeter and thermogravimetric, and gel permeation chromatography demonstrated the changes of functional groups, thermostability and molecular weights in frass compared to original masks, indicating the partial oxidation and degradation of masks. And the depolymerization of the middle layer of masks by yellow mealworms was different from that of other layers. The larval gut bacterial and fungal microbiomes were assessed by Illumina MiSeq, indicating that both of them shifted upon sole layer mask diets. Changes in relative abundances of dominant bacterial and fungal genera demonstrated the strong association between gut microbiome and mask degradation. For instance, unclassified Enterobacteriaceae was closely associated with outer layers degradation. Lactococcus and unclassified Ascomycota were responsible for middle layers degradation, while Lactococcus and Morganella for inner layers degradation. In conclusion, disposable surgical masks of PP material could be ingested and biodegraded by yellow mealworms. The diversities of gut bacterial and fungal microbiomes were associated with the differences in rigid crystalline structures of the layer masks.

From waste to food and bioinsecticides: An innovative system integrating Tenebrio molitor bioconversion and pyrolysis bio-oil production.

To achieve a waste-free clean production, the present study aimed to valorize an underused agroindustrial byproduct (rice bran) by mealworms bioconversion and produce bio-oil from pyrolysis of insect excreta (frass) as bioinsecticide. To reach the first goal, the suitability of rice bran (RB) versus standard diet, wheat bran (WB), was examined by determining feed conversion, growth performance, and nutritional profile of T. molitor larvae. RB diet was an appropriate feed substrate for breeding mealworms, as evidenced by their high survival rates, optimal feed conversion parameters, and its capability to support the growth and life cycle of this insect. Besides, RB did not affect soluble larval protein content but modified crude fat content and fatty acid profile. In order to address the second aim, egested frass from RB and WB were subjected to pyrolysis to obtain bio-oils. The main compound was acetic acid (≈37%) followed by 1,6-anhydro-ß-d-glucopyranose (from 16 to 25%), as measured by GC-MS analysis. Nitrogen-containing chemicals accounted for ≈10%. Frass bio-oils could represent a novel source of bioinsecticides due to their bioeffectiveness in insect pests of economic importance (Plodia interpunctella and Tribolium castaneum) and medical interest (Culex pipiens pipiens). For P. interpunctella adults, frass bio-oils produced insecticidal activity by fumigant and contact exposure whereas for T. castaneum adults, just fumigant. By a miniaturized model that simulates semireal storage conditions, it was seen that, on T. castaneum, frass RB bio-oil generated higher repellent effect than frass WB. Finally, bio-oils proved to have larvicidal activity against Cx. p. pipiens.

Potentiality Assessment of the Acetylcholinesterase-Inhibitory Activity of Olive Oil with an Additive Edible Insect Powder.

Edible insects (Alphitobius diaperinus Panzer, Gryllus campestris, Tenebrio molitor, Chorthippus biguttulus) are rich in nutrients that potentially inhibit acetylcholinesterase (AChE), but also improve cognition. The aim of this study was to evaluate four varied species of freeze-dried edible insects (purchased from a store); their nutrient composition, including fat, total phenolic compounds, vitamins, and antioxidant properties; and the potential inhibitory effect of AChE. An additional goal was to obtain olive oil with the addition of edible insects. Such oil was characterized by high oxidizing properties and showed high affinity to AChE. The results showed that mealworms and grasshoppers had the highest content of fats (PUFA/SFA) and phenolic compounds. These insects also showed a high content of vitamins, which correlated with the highest affinity for AChE. Therefore, they were added as a functional additive to olive oil. Olive oil with the addition of edible insects showed a higher affinity for AChE and enriched the olive oil with vitamin C and B vitamins.

Mammalian neurotoxins, Blarina paralytic peptides, cause hyperpolarization of human T-type Ca channel hCav3.2 activation.

Among the rare venomous mammals, the short-tailed shrew Blarina brevicauda has been suggested to produce potent neurotoxins in its saliva to effectively capture prey. Several kallikrein-like lethal proteases have been identified, but the active substances of B. brevicauda remained unclear. Here, we report Blarina paralytic peptides (BPPs) 1 and 2 isolated from its submaxillary glands. Synthetic BPP2 showed mealworm paralysis and a hyperpolarization shift (-11 mV) of a human T-type Ca2+ channel (hCav3.2) activation. The amino acid sequences of BPPs were similar to those of synenkephalins, which are precursors of brain opioid peptide hormones that are highly conserved among mammals. However, BPPs rather resembled centipede neurotoxic peptides SLPTXs in terms of disulfide bond connectivity and stereostructure. Our results suggested that the neurotoxin BPPs were the result of convergent evolution as homologs of nontoxic endogenous peptides that are widely conserved in mammals. This finding is of great interest from the viewpoint of the chemical evolution of vertebrate venoms.

Analysis of the effect of Tenebrio Molitor rennet on the flavor formation of Cheddar cheese during ripening based on gas chromatography-ion mobility spectrometry (GC-IMS).

This study aimed to evaluate the potential application of Tenebrio Molitor rennet (TMR) in Cheddar cheese production, and to use gas chromatography-ion mobility spectrometry (GC-IMS) to monitor flavor compounds and fingerprints of cheese during ripening. The results indicated that Cheddar cheese prepared from TMR (TF) has fat content significantly lower than that of commercial rennet (CF) (p < 0.05). However, the results of the sensory evaluation showed that there were no statistically significant differences between the two kinds of cheese (p > 0.05). Both cheeses were rich in free amino acids and free fatty acids. Compared to the CF cheese, gamma-aminobutyric acid and Ornithine contents of the TF cheese reached 187 and 749 mg/kg, respectively, during 120 days of ripening. Moreover, GC-IMS provided information on the characteristics of 40 flavor substances (monomers and dimers) in the TF cheese during ripening. Only 30 flavor substances were identified in the CF cheese. The fingerprint of the two kinds of cheese during ripening can be established by GC-IMS and principal component analysis based on the identified flavor compounds. Therefore, TMR has potential application in Cheddar cheese production. GC-IMS might be applied for the quick, accurate and comprehensive monitoring of cheese flavor during ripening.

IKKß regulates antimicrobial innate immune responses in the yellow mealworm, Tenebrio molitor.

Toll and IMD pathways regulate antimicrobial innate immune responses in insect model systems. The transcriptional activation of antimicrobial peptides (AMPs) confers humoral immunity in the host against invaded pathogens. The IKK kinase complex (IKKα, IKKß, and the regulatory subunit IKKγ/NEMO) centrally regulates the NF-κB response to various stimuli. It triggers an appropriate antimicrobial immune response in the host. In this study, a TmIKKß (or TmIrd5) homolog was screened from the RNA-seq database of the coleopteran beetle, Tenebrio molitor. A single exon characterizes the TmIKKß gene, and the open reading frame (ORF) comprises of 2112 bp that putatively encodes a polypeptide of 703 amino acid residues. TmIKKß contains a serine/threonine kinase domain and is phylogenetically close to Tribolium castaneum IKKß homolog (TcIKKß). TmIKKß transcripts were highly expressed in the early pupal (P1) and adult (A5) stages. Among the tissues, TmIKKß showed higher expression in the integument of the last instar larvae and the fat body and hemocytes of 5-day-old adults. TmIKKß mRNA was upregulated post-E. coli challenge to the host. Moreover, RNAi-based TmIKKß mRNA silencing increased host larvae' susceptibility against E. coli, S. aureus and C. albicans. TmIKKß RNAi in the fat body led to a downregulation in mRNA expression of ten out of fourteen AMP genes, including TmTenecin1, -2, and -4; TmDefensin, and -like; TmColeoptericinA, and -B; and TmAttacin1a, -1b, and -2, suggesting the requirement of the gene in antimicrobial innate immune responses. Further, a decrease in the mRNA expression of NF-κB factors such as TmRelish, TmDorsal1, and TmDorsal2 in the fat body of T. molitor larvae was observed post-microorganisms challenge. Thus, TmIKKß regulates antimicrobial innate immune responses in T. molitor.

Biodegradation of additive-free polypropylene by bacterial consortia enriched from the ocean and from the gut of Tenebrio molitor larvae.

Accumulation of highly recalcitrant PP wastes has caused a serious environmental pollution. We evaluated the biodegradation of two types of additive-free PP polymers by microbial degraders from different environments. Two bacterial consortia, designated as PP1M and PP2G, were enriched from the ocean and from the guts of Tenebrio molitor larvae. Both consortia were able to utilize each of two different additive-free PP plastics with relatively low molecular weights (low molecular weight PP powder and amorphous PP pellets) as the sole carbon source for growth. After a 30-day incubation, several plastic characterization methods, including high-temperature gel permeation chromatography, scanning electron microscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry, were used to characterize the PP samples. The bio-treated PP powder was covered with tight biofilms and extracellular secretions with significantly increased hydroxyl and carbonyl groups and slightly decreased methyl groups. This suggested that degradation and oxidation had occurred. The altered molecular weights and the increased melting enthalpy and average crystallinity of the bio-treated PP samples all suggested that both consortia preferred to depolymerize and degrade the fractions with molecular weights of ≤34 kDa and the amorphous phase fractions of the two types of PP. Furthermore, low molecular weight PP powder was more susceptible to bacterial degradation compared to amorphous PP pellets. This study provides a unique example of different types of additive-free PP degradation by different culturable bacteria from the ocean and insect guts as well as a feasibility of PP waste removal in different environments.

Molecular Characterization and Functional Analysis of the Dipeptidyl Peptidase IV from Venom of the Ectoparasitoid Scleroderma guani.

Dipeptidyl peptidase IV (DPPIV) is a proline-specific serine peptidase that remains poorly investigated in terms of venom composition. Here, we describe the molecular characteristics and possible functions of DPPIV as a major venom component of the ant-like bethylid ectoparasitoid, Scleroderma guani, named SgVnDPPIV. The SgVnDPPIV gene was cloned, which encodes a protein with the conserved catalytic triads and substrate binding sites of mammalian DPPIV. This venom gene is highly expressed in the venom apparatus. Recombinant SgVnDPPIV, produced in Sf9 cells using the baculovirus expression system, has high enzymatic activity, which can be efficiently inhibited by vildagliptin and sitagliptin. Functional analysis revealed that SgVnDPPIV affects genes related to detoxification, lipid synthesis and metabolism, response to stimuli, and ion exchange in pupae of Tenebrio molitor, an envenomated host of S. guani. The present work contributes towards understanding the role of venom DPPIV involved in the interaction between parasitoid wasp and its host.

Mitigating Effects of Tenebrio molitor Larvae Powder Administration in Mice with Dextran Sodium Sulfate (DSS)- Induced Colitis.

BACKGROUND: Ulcerative colitis (UC) is an inflammatory bowel disease that affects people worldwide. The causes of UC are diverse, and symptoms include diarrhea, weight loss, anemia, rectal bleeding, and bloody stools. Tenebrio molitor larvae have recently gained attention as edible insects with various physiological and medical effects. Research on the anti-inflammatory effects of ingesting Tenebrio molitor larvae powder (TMLP) is being actively conducted. In this study, TMLP was administered to mice with dextran sodium sulfate (DSS)-induced colitis to investigate its effects in reducing colitis symptoms. METHODS: Mice were initially given 3% DSS in water to induce colitis and then feed containing 0%, 2%, or 4% TMLP. Pathologic changes in colon tissues were assessed by histology, and neutrophil levels were measured by myeloperoxidase (MPO) assay. Levels of IL-1ß, IL-6, and TNF-α were measured using real-time PCR and ELISA assays, and IκB and NF-kB protein levels were measured by western blotting. RESULT: Disease Activity Index (DAI) scores and MPO activity were reduced in TMLP-treated mice, and colon length increased as much as normal mice. Pathologic changes in the colon tissues of DSS-induced mice were attenuated, and the expression of inflammatory cytokine genes IL-1ß, IL-6, and TNF-α decreased. Concomitant decreases in the protein expression of IL-1ß and IL-6 were confirmed using ELISA. Western blotting revealed that levels of phosphorylated forms of IκB and NF-κB also decreased. CONCLUSION: These results show that feeding TMLP to DSS-induced mice inhibited the typical inflammatory pathway of colitis. Therefore, TMLP shows potential as a food additive that can help treat colitis.
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Bioactive Compounds and Antioxidant Composition of Nut Bars with Addition of Various Edible Insect Flours.

Edible insects represent a new functional source of nutrients that can contribute to solving nutritional deficiency problems. The antioxidant potential and bioactive compounds of nut bars with the addition of three edible insects were evaluated. Acheta domesticus L., Alphitobius diaperinus P. and Tenebrio molitor L. flours were used. A 30% share of insect flour in the bars resulted in significantly greater antioxidant activity (TPC increased from 190.19 for standard bars to 309.45 mg catechin/100 g for bars with 30% addition of cricket flour). Insect flour contributed significantly to an increase in 2,5-dihydrobenzoic acid (from 0.12 for bars with a 15% share of buffalo worm flour to 0.44 mg/100 g in the case of bars with a 30% share of cricket flour) and chlorogenic acid in all bars (from 0.58 for bars with a 15% share of cricket flour to 3.28 mg/100 g for bars with a 30% addition of buffalo worm flour), compared to the standard. The highest content of tocopherols was found in bars with cricket flour, compared to standard bars (43.57 and 24.06 mg/100 g of fat, respectively). The dominant sterol in bars enriched with insect powder was cholesterol. The highest amount of it was found in cricket bars, and the lowest in mealworm bars (64.16 and 21.62 mg/100 g of fat, respectively). The enrichment of nut bars with insect flours raises the levels of valuable phytosterols in the final product. The addition of edible insect flours reduced the perception of most sensory attributes of the bars, compared to the standard bar.

Microbacterium tenebrionis sp. nov. and Microbacterium allomyrinae sp. nov., isolated from larvae of Tenebrio molitor L. and Allomyrina dichotoma, respectively.

Two Gram-positive bacterial strains, designated as YMB-B2T and BWT-G7T, were isolated from larvae of Tenebrio molitor L. and Allomyrina dichotoma, respectively, and their taxonomic positions examined by a polyphasic approach. Both of the isolates contained ornithine as the cell-wall diamino acid. The acyl type of murein was N-glycolyl. The predominant menaquinones were MK-11 and MK-12. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. Both of the isolates contained C15 : 0 anteiso and C17 : 0 anteiso as the major fatty acids. Strain YMB-B2T also had C16 : 0 iso as an additional major fatty acid. The 16S rRNA gene phylogeny showed that the novel strains formed two distinct sublines within the genus Microbacterium. Strain YMB-B2T was most closely related to the type strains of Microbacterium aerolatum (99.1 % sequence similarity) and Microbacterium ginsengiterrae (99.0 %), whereas strain BWT-G7T formed a tight cluster with the type strain of Microbacterium thalassium (98.9 %). The phylogenomic analysis based on 92 core genes supported their relationships in 16S rRNA gene phylogeny. Overall genomic relatedness indices warranted that the isolates represent two new species of the genus Microbacterium. Based on the results obtained here, Microbacterium tenebrionis sp. nov. (type strain YMB-B2T=KCTC 49593T=CCM 9151T) and Microbacterium allomyrinae sp. nov. (type strain BWT-G7T=KACC 22262T=NBRC 115127T) are proposed.

The Coincidental Evolution of Virulence Partially Explains the Virulence in a Generalist Entomopathogenic.

PURPOSE: The parasites' virulence is labile after jumping to a new host species, and it might derivate in gaining virulence against a new host as a side effect of living in a non-host environment (coincidental evolution of virulence hypothesis). METHODS: To test this hypothesis, we monitored the experimental evolution of the Rhabditis regina nematode for over 290 generations (4 years) in three environments (strains): (1) the natural host, Phyllophaga polyphylla, (2) an alternate host, Tenebrio molitor, and (3) saprophytic medium (beef; the food that may provide evidence for the coincidental evolution of virulence). Each strain was exposed to P. polyphylla, T. molitor, or Galleria mellonella. We compared the host survival and immune response (proPO, PO, and lytic activity) of infected versus uninfected hosts. RESULTS: The saprophytic nematodes gained virulence only against G. mellonella. However, the P. polyphylla strain was more effective in killing P. polyphylla than T. molitor, and the T. molitor strain was more effective against T. molitor than P. polyphylla. Additionally, one dauer larva was sufficient to kill the hosts. Finally, the immune response did not differ between the challenged and control groups. CONCLUSION: The coincidental evolution of virulence partially explains our results, but they might also support the short-sighted hypothesis. Additionally, we found evidence for immunomodulation because nematodes passed unnoticed to the immune response. It is crucial to analyze the virulence of entomopathogens from the point of view of the evolution of virulence to be aware of potential scenarios that might limit biological control.

Frying dough with yellow mealworm oil: Aroma profile and consumer perception at a central location test and at home.

Insect oil is a valuable fraction that is obtained from insect processing. The aim of this study is to evaluate the impact of yellow mealworm oil (YMW) oil (crude, deodorized, and blended with vegetable oil) on the sensory evaluation and aroma profile of fried dough. The sensory evaluation was performed in a sensory lab (central location test, CLT) and at home in order to examine how the evaluation environment or context impacts consumer perceptions. The strongest liking and preference were found for the donuts that were fried in 100% deodorized YMW oil and in YMW oil blended with vegetable oil. The evaluation environment did not affect overall liking scores but had an impact on sensory profiling, with more discriminating sensory terms observed for the test that was conducted at the sensory lab than for the test that was conducted at home. A distinctive profile of volatile organic compounds (VOCs) was found for every fried dough. The discrimination between VOCs and other frying oils that were observed is well in line with the sensory descriptors and the consumer test results. Acetic acid, acetic acid ethenyl ester, and tetrahydro-6-propyl-2H-Pyran-2-one were present in the doughs that were fried in crude YMW oil and in its blend with vegetable oil. They were absent from deodorized YMW oil and from its blend with vegetable oil. This study shows that, as far as fried donuts are concerned, deodorized YMW oil is an alternative to a vegetable oil-the two lead to similar sensorial experiences and preferences. PRACTICAL APPLICATION: Yellow mealworm oil (YMW) oil is a co-product of insect protein that can be valorized in the food industry. In the present study, it is demonstrated that the deodorization of YMW oil produces positive sensorial experiences and increases consumer acceptance of insect-based food. Furthermore, findings indicate that consumer testing at home yields similar acceptance and preference ratings suggesting that this type of testing may be an alternative means of collecting reliable consumer data.

Lesser mealworm (Alphitobius diaperinus L.) larvae oils extracted by pure and binary mixed organic solvents: Physicochemical and antioxidant properties, fatty acid composition, and lipid quality indices.

Insect oil is one of the most sustainable lipid sources with remarkable health effects. Herein, the type of organic solvents (i.e., n-hexane, ethanol, and isopropanol) and their binary mixtures was evaluated based on the quantity (e.g., yield extraction) and quality (e.g., bioactive compounds, thermal stability, DPPH scavenging rate, fatty acid profile, and nutritional indices) of lesser mealworm oils. The oils extracted by ethanol/isopropanol and ethanol/n-hexane significantly showed the highest extraction yield and efficiency, lightness, accelerated thermal stability, phenolics, tocopherols, vitamin D, campesterol, ß-sitosterol, phosphatidylinositol and phosphatic acid, linoleic acid, and hypocholesterolemic/hypercholesterolemic ratio, while these organic mixtures meaningfully extracted lipids with the lowest peroxide value, free fatty acid, and atherogenicity and thrombogenicity indices. These solvents compared to pure ones could dissolve membrane and internal lipids with the complete disintegration of external structures. The ethanol/isopropanol mixture would be a promising solvent for n-hexane substitution to extract this oil on an industrial scale.

Antheraea peptide and its analog: Their influence on the maturation of the reproductive system, embryogenesis, and early larval development in Tenebrio molitor L. beetle.

In recent years, many new immunologically active peptides from insects have been identified. Unfortunately, in most cases, their physiological functions are not fully known. One example is yamamarin, a pentapeptide isolated from the caterpillars of the Antheraea yamamai moth. This peptide has strong antiproliferative properties and is probably involved in the regulation of diapause. Additionally, antiviral activity was discovered. The results of the research presented in this paper are, to our knowledge, the first attempt to characterize the biological effects of yamamarin on the functioning of the reproductive processes and embryonic development of insects using a model species, the beetle Tenebrio molitor, a commonly known pest of grain storage. Simultaneously, we tested the possible activity of the molecule in an in vivo system. In this research, we present the multifaceted effects of yamamarin in this beetle. We show that yamamarin influences ovarian growth and development, maturation of terminal oocytes, level of vitellogenin gene transcript, the number of laid eggs, duration of embryonic development, and larval hatching. In experiments with palmitic acid-conjugated yamamarin (C16-yamamarin), we also showed that this peptide is a useful starting molecule for the synthesis of biopharmaceuticals or new peptidomimetics with gonadotropic activity and effects on embryonic development. The data obtained additionally provide new knowledge about the possible function of yamamarin in insect physiology, pointing to the important role of this pentapeptide as a regulator of reproductive processes and embryonic development in a heterologous bioassay with T. molitor.