• Journal of Sericultural and Entomological Science
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• v.53 no.2
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• pp.78-81
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• 2015

This study aimed to determine a feed withdrawal duration time of Gryllus bimaculatus (Gb), for removal of intestinal feces. Finally, this species of cricket has been temporarily approved for use as a human food source in Korea. To commercialize Gb as an edible insect, we attempted to prevent the proliferation of micro-organisms and improve taste of Gb by removing intestinal feces of live crickets. Our study showed that weak crickets were damaged in 2 days after feed withdrawal in farm. The microscope findings also revealed that feces of strong crickets' intestine almost disappeared at 1 day after feed withdrawal and instead, some of arms and legs of weak crickets were observed in the former's intestine. The results suggest that 1 day is deemed to be an adequate time for feed withdrawal, when it usually takes 1 day to deliver live crickets from the farm to a destination.

• Food Science and Preservation
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• v.22 no.2
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• pp.218-224
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• 2015

Crickets have been used as crude drug for treating fever and hypertension in East Asia. This study was carried out to investigate the quality characteristics such as the microbial and nutrient contents of crickets (Gryllus bimaculatus) prepared with various processing conditions for use as food. These conditions included the lyophilization process (LP), hot-air process (HP, $90^{\circ}C$ for 7 hr), roasting process (RP, $160^{\circ}C$ for 40 min), and frying process (FP, $180^{\circ}C$ for 30 sec). The total bacterial population of the crickets was 5~7 log CFU/g, but Coliform and E. coli were not detected. The major fatty acids in all the samples were palmitic acid (C16:0), oleic acid (C18:1), and linoleic acid (C18:2). The level of polyunsaturated fatty acids was highest (63.55 g/100 g) in the LP-processed crickets. As for the amino acid content, the glutamic acid level was highest in all the samples, and the RP and FP decreased by 12.01% and 53.88%, respectively, compared to that of the LP. The mineral contents were highest in the LP-processed crickets. Hg was detected at about 1.0 ppb in all the samples, but its level was lower than the residue tolerance level in the Korean Food Code. Such conditions should be considered to better understand the quality characteristics of crickets in food processing.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.133-138
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• 2020

In 2016, the two-spotted cricket was approved as a general food ingredient by the Korean Ministry of Food and Drug Safety. Additionally, the two-spotted crickets have high protein content (60%) and can be reared throughout the year even during the overwintering period. In this study, storage conditions were set in case cricket breeding was not possible due to problems such as breeding space and labor costs, and selection oviposition mats to determine high fecundity rates and low cannibalism rates for the eggs were investigated. The oviposition mat was mostly composed of soil (p < 0.05). Less than 62 crickets per 10 litters were found to be best suited for 1 day of spawning, based on the cannibalism rate of the eggs during the egg laying period. The results from the hatched eggs indicated that the hatching extended 12 to 14 days, and the best hatching rate was approximately 85% when stored at low temperatures(16℃) for 10 days. An efficient production proposed method that established the best oviposition mat and egg storage method for the cricket.

• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.297-307
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• 2018

The aim of this study was to develop a seasoning paste fermented by Aspergillus oryzae and Bacillus subtilis using three edible insects: Tenebrio molitor larvae, Gryllus bimaculatus, and Bombyx mori pupa. No significant changes in pH and titratable acidity were observed between the insect pastes and soybean control during a 5-week fermentation process. The amino nitrogen was 0.35-0.50% (w/w) in the early stage of the fermentation and increased to 0.72-0.78%. The total nitrogen was 2.36-3.62% (w/w) in the early stage and was preserved during the fermentation period. Free amino acids of the insect pastes were similar to those in soybean paste. In general, the fermented insect pastes showed a lower flavor and color than soybean paste but B. mori pupa-fermented paste did not show any significant difference in preference from soybean. Glutamate, aspartate, lysine, phenylalanine, arginine, and serine were found to affect taste preference. It was possible to ferment edible insect protein to produce a fermented seasoning paste like Korean doenjang.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.473-479
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• 2019

Gryllus bimaculatus (GB) has recently been registered as a food variety in Korea. In the present study, we prepared protein hydrolysates from GB and evaluated their antioxidant capacity. Protein hydrolysates were prepared from dried GB using enzymatic hydrolysis using five different proteases, and protein hydrolysates showing high hydrolysis value (alcalase, flavourzyme, and neutrase) were separated further into fractions ${\leq}3kDa$ and then lyophilized. Based on $RC_{50}$ values of hydrolysates (${\leq}3kDa$) obtained from four different antioxidant analyses, the flavourzyme hydrolysates showed relatively high levels of antioxidant capacity among the three hydrolysates, and in particular, it showed considerably strong antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The flavourzyme hydrolysate also significantly inhibited peroxidation of linoleic acid. These results suggest that protein hydrolysates from GB represent potential sources of natural antioxidants. Our current studies are focused on identification of active peptides from the flavourzyme hydrolysate.

• Korean journal of applied entomology
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• v.58 no.1
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• pp.69-76
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• 2019

This study was evaluated to increase the production efficiency of Gryllus bimaculatus De Geer, which are recently increasing attention as industrial insects in Korea. In this study, the hatching rate and larval period were investigated along with temperature and humidity, as well as the survival rate and ovipositional temperatures along with rearing density. The optimum relative humidity for hatching was highest at 90%, which shows the hatching rate of 90%. The highest hatching rate was 98.3% at $20^{\circ}C$. The hatching period was shortest at $35^{\circ}C$ incubation, which shows 7.1 days in average. The survival rate at 3,000-20,000 individuals in the breeding container was 34-18% after rearing for 35 days. In the effect test of feeding vegetables, the survival rate was 1.8 times and the biomass weight 2.5 times higher than that of normal individuals respectively. The number of laying eggs by temperature was highest at $25^{\circ}C$, which shows 1,710 eggs after reading for 30 days.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.171-178
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• 2022

In this study, the quality characteristics of rice cookies supplemented with different types of insect powder (Tenebrio molitor, Protaetia brevitarsis, and Gryllus bimaculatus) were assessed according to the quantity of insect powder used (0, 1, 2.5, 5, and 7.5 g). No significant differences were observed in rice cookie densities or water content. The pH value and spread factor decreased with increasing insect powder content (p<0.05); however, a significant increase was observed in the loss rate (p<0.05). Crude ash, crude fat, and crude protein content significantly increased with higher concentrations of insect powder (p<0.05). Moreover, lightness and yellowness decreased, whereas redness increased with higher insect powder concentrations (p<0.05). Hardness significantly decreased, whereas the antioxidant capacities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals increased with higher insect powder concentrations (p<0.05). Finally, insect powder can prove a valuable resource in rice cookie production, considering its nutritional value, consumer preference, and antioxidant properties.

• Journal of Nutrition and Health
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• v.56 no.6
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• pp.615-628
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• 2023

Purpose: Increasing levels of domestic fine dust (DFD) have emerged as a serious problem that threatens public health by causing chronic respiratory diseases and skin aging. The present study was performed to investigate the inhibitory effects of Gryllus bimaculatus (the two-spotted cricket), which has recently attracted attention as an edible insect in South Korea, on DFD-induced aging and inflammation. Methods: To verify that DFD causes skin aging and investigate the anti-aging effect of an aqueous ethanolic-Gryllus bimaculatus extract (AE-GBE), human diploid fibroblasts (HDF) were treated with 100 ㎍/mL of European reference material (ERM)-CZ100 dust for 24 hrs in the presence or absence of 100 ㎍/ml AE-GBE. Aging and cellular toxicities were assessed by measuring reactive oxygen species (ROS) levels, DNA fragmentation, and β-galactosidase activity. The protein levels of cyclooxygenase (COX) 2, matrix metalloproteinase (MMP)-1, and collagen were measured by western blot, and the mRNA expressions of inflammation-related genes were assayed by quantitative reverse transcriptase polymerase chain reaction. Results: Treatment with ERM-CZ100 induced an aged phenotype in HDF cells, as evidenced by increased ROS levels, DNA fragmentation, and senescence-associated β-galactosidase activity, but cotreatment with AE-GBE significantly reduced these inductions. The mRNA expressions of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, induced by ERM-CZ100 were also reduced by AE-GBE cotreatment, which also reduced COX2 expression. Moreover, ERM-CZ100-induced MMP-1 expression and reduced collagen type I expression were recovered by AE-GBE treatment. Conclusion: These results suggest that AE-GBE is a potential treatment for domestic fine dust-induced skin inflammation and inflammaging.

• Toxicological Research
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• v.31 no.2
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• pp.173-180
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• 2015

Extract from Gryllus bimaculatus crickets inhibits oxidation at the DNA level, with reduced production of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Microarray analyses were performed with a rat 28K cDNA clone set array to identify the gene expression profiles of aged (10 months old) Wistar Kyoto rats treated for one month with 100 mg/kg G. bimaculatus ethanol extract to assess the effects. The extract produced a meaningful anti-edema effect, evident by the inhibition of creatinine phosphokinase activity. The weights of abdominal and ovarian adipose tissues were reduced and the proportion of unsaturated fatty acids in adipose tissues was increased in an extract dose-dependent manner. Compared with untreated control rats, rats treated with the extract displayed the upregulation of 1053 genes including Fas (tumor necrosis factor receptor superfamily, member 6), Amigo3 (adhesion molecule with an immunoglobulin-like domain), Reticulon 4, 3-hydroxy-3-methylglutaryl-coenzyme (Hmgcr; a reductase), related anti-fatigue (enzyme metabolism), and Rtn antioxidant, and the downregulation of 73 genes including Ugt2b (UDP glycosyltransferase 2 family), Early growth response 1, and Glycoprotein m6a. Data suggest that G. bimaculatus extract may have value in lessening the effects of aging, resulting in a differential gene expression pattern indicative of a marked stress response and lower expression of metabolic and biosynthetic genes.

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.176.3-176
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• 2003

No Abstract, See Full Text