• Journal of Life Science
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• v.34 no.3
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• pp.191-198
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• 2024

To verify the nutritional value and safety of larvae fed with a soymilk residue-added food source, we compared and analyzed the nutritional components of and harmful substances in Tenebrio molitor larvae reared on wheat bran. Crude protein content based on dry weight was 1.2 times higher in the 10% soymilk residue-fed group (SR) (54.0%) than in the wheat bran-fed group (WB) (43.5%). Dietary fiber also tended to be 1.9 times more in the SR (4.9%) than the WB (2.5%). Among unsaturated fatty acids, the linoleic acid content was found to be 1.1-fold higher in the SR (32.9%) than in the WB (29.0%). Potassium, which was the most abundant among the macro minerals, was 1.1-fold more abundant in the WB (1,074.5 mg/100 g) than in the SR (1,014.0 mg/100 g). Among the micro minerals, zinc content was 1.2-fold higher in the SR (14.5 mg/100 g) than in the WB (11.9 mg/100 g). The results of the analysis of hazardous substances in the WB and SR revealed that the amount of heavy metals met the standards for heavy metals in edible insects, and food poisoning-inducing bacteria such as Escherichia coli and Salmonella spp. were not detected in all groups. These results indicate that mealworm larvae fed with 10% soymilk residue have abundant nutrients and are safe for intake. Thus, food sources with added soymilk residue has the potential to be used as feed ingredients.

• Korean Journal of Food Science and Technology
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• v.51 no.6
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• pp.537-542
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• 2019

Proteins were isolated from four species of edible insects, Bombyx mori, B; Tenebrio molitor, T; Protaetia brevitarsis, P; and Gryllus bimaculatus, G, and their properties were analyzed and compared with those of whey proteins. The yield of the protein isolated from raw materials was 65.0-75.0%. Among three branched chain amino acids (BCAA), the amounts of valine in all the insects were similar to that of the whey protein. The BCAA content was 16.8 and 16.4% in G and T, respectively. The total polyphenolic content and the antioxidant activity of the insect proteins were significantly higher than those of the whey proteins. Based on the sensory test of the protein powder, the whey protein could be replaced by 25% of the isolated protein from the insects, but the taste and flavor needs to be improved. Although the BCAA content of insect proteins was lower than that of the whey protein (by 73-76%), their application could be useful because of high polyphenolic content and the anti-oxidative activity.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.516-523
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• 2020

Supercritical carbon dioxide (_SCO2) extraction was applied for the defatting of mealworm to prepare defatted powder (DP) and protein isolate (PI) and compare the process to press and hexane extraction, with respect to DP and PI physicochemical properties. _SCO2 DP was obtained by extracting 34.40% oil at 41.37 MPa, 40℃ for 180 min, and the product contained 71.66% crude protein, which is similar to that of hexane DP and higher than that of press DP. In using alkali protein extraction to prepare PI from DP, _SCO2 was as effective as hexane and better than press. _SCO2 produced brighter DP and PI than press, but not as much as hexane. Protein solubility was similar in all DP, with minimum values at pH 5. The highest water adsorption capacity was noticeable for _SCO2 PI, and _SCO2 DP showed an oil adsorption capacity comparable to that of hexane DP. _SCO2 DP and PI had better foaming capacity than press DP and PI and showed superior emulsion activity compared to others.

• Korean Journal of Food Science and Technology
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• v.54 no.1
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• pp.94-102
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• 2022

Defatted soybean, larvae of brown mealworm (Tenebrio molitor), and powdered pupae of silkworm (Bombyx mori) were fermented in solid and liquid forms using Aspergillus oryzae and Bacillus subtilis. The protein degradation rate (NDR) through solid fermentation was the highest in the fermented soybean control sample (54.69±6.54%), followed by silkworm pupae (34.82±5.99%) and brown mealworm larvae (30.54±3.80%). When these edible insects were fermented in liquid form, solid extraction yield was 37.73-46.88%, and protein yield was 47.47-63.02%. NDR of fermented liquid form products increased to 58.90, 52.62, and 50.13% for soybean, brown mealworm larvae, and silkworm pupae, respectively. SDS-PAGE of the liquid fermented products confirmed that microbial fermentation decomposed higher-molecular-weight proteins into small polypeptides. In vitro digestibility of liquid forms of edible insects increased by 1.26 to 1.53 times after fermentation. The protein solubility, foaming ability, and foam stability of liquid-fermented edible insects all tended to increase through fermentation.

• Journal of Bio-Environment Control
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• v.33 no.3
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• pp.139-147
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• 2024

Mealworms are used as food, so it is preferable if the larval stage lasts longer. On the other hand, to accelerate the population growth of mealworms, it is preferable if the larvae become adults quickly. The purpose of this study is to explore the effects of population density on development time of mealworms. We used a container size of 7 cm at the top, 5 cm at the bottom, and 3 cm in height. Mealworms lived in the containers at densities of 1, 2, 5, 10, and 20 per container. The containers were bedded with 1 g of wheat bran and formed two groups, fed and not fed, at each density levels. The experiments were performed three times. In all of the experiments, higher population densities resulted in shorter transformation times from larva to pupa, but the time from pupa to imago was not significantly different. In addition, given the same density, the presence of food accelerated the time to transformation to pupa, but not to imago. The data supported that a lower density is needed to prolong the larval stage, and if adults are needed at a faster rate, the density should be higher. Therefore, we conclude that the development time of mealworms can be controlled by the density which is useful information for mealworm farmers.

• BMB Reports
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• v.34 no.1
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• pp.15-20
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• 2001

One of the innate immune reactions in invertebrates is the pro-phenoloxidase (pro-PO) activation system that is involved in the generation of superoxide, melanin synthesis, and the subsequent sequestration of foreign matter entering the hemocoel of the invertebrates. However, the molecular mechanism of this biological reaction is still obscure. To expand our understanding of the biological roles of the pro-PO activation system in invertebrates, we performed a yeast two-hybrid screening by using three regions of pro-PO as bait and a yeast two-hybrid cDNA library from Tenebrio molitor larvae as prey We isolated a novel partial cDNA clone that encodes a glycine-rich protein that interacted with the active phenoloxidase (termed phenoloxidase interacting protein, POIP). POIP consists of two domains: One is an N-terminal unique domain and the other is a C-terminal glycine-rich domain. The C-terminal glycine-rich domain showed sequential homology with those of insect antifungal proteins. Also, the yeast two-hybrid screen in a reverse orientation (using POIP as bait) yielded PO, suggesting that the PO-POIP interaction is specific. By using a 315 bP PCR fragment of the N-terminal unique region of POIP, we cloned the full-length cDNA of POIP from the Tenebruo cDNA library constructed by using E. coli injected larvae. The interaction analysis between PO, and a truncated fragment lacking the N-terminal unique region of POIP, indicated that the N-terminal unique region is necessary for interaction between PO and POIP. The expression level of the POIP mRNA is increased by bacterial injection into T. molitor larvae. This suggests that POIP might be engaged in the humoral defense reaction.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.155-163
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• 2022

The application of fungicides is indispensable to global food security, and their use has increased in recent times. Fungicides, directly or indirectly, have impacted insects, leading to genetic and molecular-level changes. Various detoxification mechanisms allow insects to eliminate reactive oxygen species (ROS) toxicity induced by agrochemicals including fungicides. In the present study, we analyzed the mRNA expression levels of detoxifying enzymes in Tenebrio molitor larvae following exposure to non-lethal doses (0.2, 2, and 20 ㎍/µL) of a fungicide captan. Transcripts of peroxidases (POXs), catalases (CATs), superoxide dismutases (SODs), and glutathione-s-transferases (GSTs) were screened from the T. molitor transcriptome database. RT-qPCR analysis showed that TmPOX5 mRNA increased significantly 24 h post-captan exposure. A similar increase was noticed for TmSOD4 mRNA 3 h post-captan exposure. Moreover, the expression of TmCAT2 mRNA increased significantly 24 h post-treatment with 2 ㎍/µL captan. TmGST1 and TmGST3 mRNA expression also increased noticeably after captan exposure. Taken together, these results suggest that TmPOX5 and TmSOD4 mRNA can be used as biomarkers or xenobiotics sensors for captan exposure in T. molitor, while other detoxifying enzymes showed differential expression.

• The Korean Journal of Food And Nutrition
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• v.30 no.5
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• pp.1042-1047
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• 2017

In order to improve the usability of mealworm and the nutritional quality of acorn Mook mostly composed of carbohydrates, we prepared acorn Mook using with different levels of mealworm powder, and the physico-chemical and sensory evaluation were investigated. In the content of proximate chemical composition, moisture content did not show any significant difference. But crude protein, crude ash, and crude fat contents were increased with increasing mealworm content. Carbohydrate content was reduced as mealworm content increased. Lightness showed no significant difference among treatments, redness was increased, and yellowness was decreased as the amount of mealworm powder increased. In physiological properties, hardness, gumminess, chewiness, and springiness were significantly increased as the amount of mealworm powder decreased. However, adhesiveness and cohesiveness were not significantly different. Ascorbic acid content, activities of DPPH and ABTS radical scavenging activities were decreased with increasing amount of mealworm in acorn Mook. In sensory evaluation, acorn Mook containing 0.75% of mealworm powder showed highly preference compared with the control.

• The Korean Journal of Food And Nutrition
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• v.34 no.3
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• pp.272-288
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• 2021

Mealworm is the most widely used edible insect in Korean traditional food. In this study, the quality characteristics and antioxidant activity of Garaedduk containing different proportions of powdered mealworm (0%, 3%, 6%, 9%, and 12%) were evaluated in order to enhance the utilization of mealworm. The results revealed that moisture content decreased while pH and starch elution increased, with increasing amount of mealworm. Furthermore, the amount of total amino acids, essential amino acids, and non-essential amino acids increased with increasing amount of mealworm. Regarding chromaticity, the L value decreased while the a and b values increased as the amount of mealworm increased. The addition of 6% mealworm showed slight differences in the pore size and surface smoothness as compared to plain Garaedduk. Texture, hardness, chewiness, and gumminess increased, but cohesiveness decreased with increasing amount of mealworm. The preference test evaluating the appearance, flavor, taste, texture, and overall preference showed that 6% mealworm additive group had the highest preference. In addition, antioxidant activity of the newly developed Garaedduk increased with increasing amount of mealworm. In conclusion, Garaedduk enriched with 6% mealworm showed promising results for developing rice cake with improved nutrition and antioxidant activity and excellent overall preference and quality.

• Animal Bioscience
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• v.35 no.2_spc
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• pp.347-355
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• 2022

Among edible insects, black soldier fly (Hermetia illucens), yellow mealworm (Tenebrio molitor), and common housefly (Musca domestica) have been considered as an alternative protein source for pigs. Because they are easy to breed and grow in the organic wastes, and they have well-balanced nutritional value as a protein source for pigs. The black soldier fly larvae and mealworm could replace the fish meal in the diets for weaned pigs without adverse effects on growth performance and nutrient digestibility. Black soldier fly could also be included in the finishing pig's diet without any negative effects on the growth performance and pork quality of the market pigs. Insect products showed a greater standardized ileal digestibility value of amino acids than conventional animal proteins in growing pigs. Due to the limited amount of insect products used for pig feeding study, most previous pig studies have been conducted in weaned pigs. Thus, further study is needed about the optimal inclusion level of insect products in every phase diet from weaned pigs to sows. The use of insect products in swine diets has some challenges in terms of cost, supply, and safety. Lastly, intrinsic differences among insect species, processing method, and feeding phase should be taken into consideration for the use of insect products in the swine diets.