• 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.

• International Journal of Industrial Entomology and Biomaterials
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• v.32 no.2
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• pp.69-79
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• 2016

Distillers dried grain (DDG) and makgeolli spent grain (MSG) are agricultural byproducts to produce alcoholic beverage. However, they are known to contain enough nutrients. Mealworm is a promising insect resource for an animal feed ingredient as well as alternative human food. With low cost, DDG and MSG were investigated as a feed ingredient for rearing high quality mealworms. DDG and MSG were mixed with wheat bran and compared to control feed (only wheat bran) for its effects on larval survivorship, larval weight, duration for developmental period, pupation rate, and pupal weight. When DDG added, larval survivorship was reduced to 50~70% compared to the control group. Larvae fed on DDG were heavier from third to sixth week. Especially, larvae with 50% DDG were 28% heavier than the control group at the third week. For the larval period, the 50% DDG group was 11% less than that for the control. The pupal weight for the 30% DDG group was 7% heavier than that for the control group. Pupation rates for all the DDG groups were higher than 90%. When compared to the control, larval survivorship for the 70% MSG group was low, but the 50% and 70% MSG groups were high during the seventh and eighth weeks because of delayed development. After the eighth week, larvae with 70% MSG showed the highest larval weight increase as 9~18% compared to the control group. Except 70% MSG group, all of MSG groups showed more than 90% pupation rates. We confirmed that adding 30~50% of DDG or MSG to conventional wheat bran have a strong potential to replace the conventional wheat bran insect feed for quality insect production.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.849-859
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• 2016

Edible insects have gained recognition worldwide as complementary protein sources. Recently, four edible insects were newly allowed to be used as food materials in Korea: the mealworm (Tenebrio molitor), the cricket (Velarifictorus asperses), the white-spotted flower chaffer beetle larva (Protaetia brevitarsis seulensis), and the rhinoceros beetle larva (Allomyrina dichotoma). In this study, we evaluated the oxidative stabilities of these four edible insects during cold storage. The insects were sacrificed by blanching for 3 minutes in boiling water. The blanched insects were then stored at $4^{\circ}C$ in an incubator for 42 days. The color values, titratable acidity, peroxide values, acid values, TBARS, contents of VBN, and total plate counts of the insects were measured at days 0, 2, 4, 7, 10, 14, 21, 28, 35, and 42, respectively. Blanching decreases oxidative stresses during storage. At day 0, the white-spotted flower chaffer beetle larva showed the highest values for acid value, TBARS, VBN, and microbial counts. Most of the oxidative indicators were significantly changed at day 14 in all four insects, possibly related with the growth on all microbial plates. Based on microbial safety and the oxidative stabilities of lipids and proteins, optimal storage conditions for the cricket, the white-spotted flower chaffer beetle larva, and the rhinoceros beetle larva were 10~14 days at $4^{\circ}C$. Likewise, the mealworm showed rapid oxidation after day 14, but poor qualities were not observed until day 28.