• Journal of Life Science
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• v.28 no.12
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• pp.1501-1506
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• 2018

Edible insects have recently been increasingly promoted as a source of protein. As the number of farms rearing these insect increases, it is important to develop safe and nutritious feed sources to improve their commercial quality. The aim of the current study was to determine the effect of food by-products as feed supplements for the Korean rhinoceros beetle, Allomyrina dichotoma, which has been registered as a general food ingredient in Korea. We compared the effects of waste citrus peel, soybean curd cake, soybean oil meal, and brewers' dried grain on the growth of third instar larvae of A. dichotoma. Groups of larvae were fed with fermented sawdust and nine different combinations of the above by-products and the effects on their growth were measured until pupation. The highest survival rate was with feed supplemented with 10% brewers' dried grain (66.7%, p<0.05), and these larvae were also 26% heavier (p<0.05) than the control group that received no supplementation. In the 10% brewers' dried grain group, the larval period of third instar was shortened by almost 28 days (p<0.01) compared to the control group. Of all the groups, only that which was fed the brewers' dried grain supplement showed more than a 90% pupation rate (p<0.05). Therefore, brewers' dried grain may be useful as a source of feed for A. dichotoma.

• KSBB Journal
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• v.6 no.4
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• pp.327-336
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• 1991

A study on the optimum hydrolysis conditions of fish skin through the aid of enzymes and the development of a natural seasoning using the hydrolysate has been carried out for the effective utilization of fish skin. Using the "pH-drop" techniques the collagenase and pronase were identified as most suitable for this purpose. The $K_m$ and $V_{max}$ values of pronase were 1.82 mgN/ml and 0.06 mgN/mL/min, respectively. The hydrolysis conditions of the cod skin for the pronase were as follows: reaction temperature, $50^{\circ}C$; reaction time, 3hrs; pH 6; enzyme concentration, 0.03%. The degree of hydrolysis at these conditions was 76.8%. But after hydrolyzing cod skin with collagenase for 1hr, when the pronase was treated, the degree of hydrolysis was 83.13%. The molecular weight of the hydrolysate was 8,000 daltons. Among the amino acids in the hydrolysate, glycine(27.95%), glutamic acid(10.94%), proline(7.39%), aspartic acid(9.47%) and serine(7.39%) were responsible for 64.23% of the total amino acids. But valine, methionine, isoleucine, leucine, phenylalanine and histidine having a bitter taste were only 13.05%. From the results of the sensory evaluation, the imitation sauce which was made of 20% fermented soy sauce prepared from the hydrolysate was at least similar to the traditional soybean sauce in product quality. The complex seasoning containing 31.7% of the hydrolysate was nearly equal to complex seasonings on the market, too.

• KSBB Journal
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• v.10 no.5
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• pp.510-517
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• 1995

The hydrolysates of three kinds [FSEH(first step enzymatic hydrolysate), SSEH(second step enzymatic hydrolysate), and TSEH(third step enzymatic hydyolysate)] were prepared by continuous hydrolysis of Alaska pollack(Theragra chalcogramma) skin gelatin with three-step membrane enzyme reactor. The molecular weight distributions of FSEH, SSEH, and THSE are 9,500∼4,800Da, 6,600∼3,400Da, and 2,300∼900Da, respectively. The contents of amino acid having sweet taste (glycine, proline, serine, alanine, hydroxyproline, glutamic acid, and aspartic acid) were about 70% of total amino acid being in the three kind hydrolysates. We also tried preparing of natural seasonings (complex seasoning and enzymeatic hydrolysale sauce) using the hydrolysates. From the results of sensory evaluations, complex seasoning containing TSEH was nearly equal to shellfish complex seasoning on the market. The mixture sauce which was made by mixing of 80% enzymatic hydrolysis sauce and 20% fermented soy sauce, was at least similar to the tradition soybean sauce in product quality, too.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.29-35
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• 2013

Microbiological populations and the sterility of commercial powdered products treated with gamma irradiation at 0~10 kGy were investigated before using them as ingredients for a non-cooked Saengsik product. We evaluated a total of 14 powdered products: 8 powdered cereals, 3 powdered tubers, and 3 powdered leafy vegetables. The total numbers of bacterial populations in non-irradiated powdered cereals, tubers, and leafy vegetables were 2.7~6.9, 5.6~6.0, and $5.3{\sim}6.8\;log\; CFU{\cdot}g^{-1}$, respectively. Moreover, coliform bacteria were not indicated in adlay, millet, germinated brown rice, soybean, and mulberry leaves powder within detection limit ($2.0\;log\; CFU{\cdot}g^{-1}$). The number of Bacillus cereus exceeded $3.0\;log\; CFU{\cdot}g^{-1}$ (the maximum limit for Saengsik products) in all samples, excluding perilla seeds, buckwheat, barley, oat, potato, and Jerusalem artichoke powder. However, a dose of 6 kGy of gamma irradiation reduced the microbiological populations in all samples, and all the powdered products met the microbial requirements for Saengsik products. Futhermore, it was confirmed that all microorganisms in the 9 powdered products, except fermented brown rice, sweet potatoes, and 3 leafy vegetables, were sterilized by 10 kGy of gamma irradiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.149-155
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• 2012

In this study, the functional properties of royal court (RC) soy sauces, Gungjung-kanjang, were analyzed in vitro. RC soy sauces, traditional soy sauce, and commercial soy sauces were fractionated based on an MW cut-off of 1,000. The total phenolic compounds smaller than and larger than 1,000 MW (low and high fraction) in RC soy sauces were determined to be $101.55{\pm}1.49\sim114.00{\pm}0.11$ mg/L and $32.51{\pm}0.32\sim113.47{\pm}0.43$ mg/L, respectively. The low fraction of RC soy sauces showed around 51% superoxide dismutase (SOD)-like activity, which was higher than other soy sauces. Among RC soy sauces, Cheong-jang showed significantly high activity. Significant differences in fibrinolytic and antibacterial activities were not observed between soy sauces. ${\alpha}$-Glucosidase inhibitory activities in the low and high fractions of RC soy sauces were in the range from $6.34{\pm}1.51\sim8.79{\pm}0.81$% and $5.72{\pm}1.29\sim7.94{\pm}0.34$%, respectively. However, ${\alpha}$-glucosidase inhibitory activity in the high fraction of Kot-jang soy sauce was 75.88%${\pm}$1.20%. Lipase inhibitory activities in the low fractions of RC soy sauces, especially Cheong-jang, Deot-kangang, Jin-jang, and Euyeuk-kanjang, were also measured.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.75-82
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• 1999

The hydrolysate of desalinated tuna boiled extract (TBE) were prepared by continuous hydrolysis of TBE using a membrane reactor. TBE and tuna boiled extract hydrolysate (TBEH) were isolated depending on molecular weights. The major molecular weight distributions of TBEH-l0K, TBEH-5K and TBEH-lK were 9,800Da, 3,000Da and 990Da, respectively. The amounts of nucleotides and their related compounds of TBE were 3.47 $\mu$mole/g AMP, 23.75 $\mu$mole/g IMP, 9.07 $\mu$mole/g inosine and 1.89 $\mu$mole/g hypoxanthine. Total content of amino acids having desirable taste (glycine, glutamic acid, alanine, proline, aspartic acid, serine) was about $63\%$ of total amino acid from TBE and about $62\%$ from TBEH. The natural seasoninings were prepared with TBE and TBEH. From the results of sensory evaluations, complex seasoning containing TBEH-1K was almost equal to the shellfish complex seasoning obtained from the market. The mixed sauce which was made by mixing of $50\%$ TBEH sauce and $50\%$ fermented soy sauce was similar to the tradition soybean sauce in product quality and it showed the possibility to be used for the substitute product for acid hydrolyzed soysauce.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.438-446
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• 2007

The fermented soybean product, cheonggukjang, is favored by many people, partly due to its bio-functional ingredients. Since the fermentation process of cheonggukjang is mediated by enzymes, including proteases, produced by microbes, analysis of the proteome profile changes in cheonggukjang during fermentation would provide us with valuable information for fermentation optimization, as well as a better understanding of the formation mechanisms of the bio-functional substances. The soluble proteins from cheonggukjang were prepared by a phenol/chloroform extraction method, in order to remove interfering molecules for high resolution 2-D gel analysis. Proteomic analysis of the cheonggukjang different fermentation periods suggested that most of the soluble soy proteins were degraded into smaller forms within 20hr, and many microbial proteins, such as mucilage proteins, dominated the soluble protein fraction. The proteomic profile of cheonggukjang was very different from natto, in terms of the 2-D gel protein profile. Among the separated protein spots on the 2-D gels, 50 proteins from each gel were analyzed by MALDI-TOF MS and PMF for protein identification. Due to database limitations with regard to soy proteins and microbial proteins, identification of the changed proteins during fermentation was restricted to 9 proteins for cheonggukjang and 15 for natto. From de novo sequencing of the proteins by a tandem MS/MS, as well as by database searches using BLASTP, a limited number of proteins were identified with low reliability. However, the 2-D gel analysis of proteins, including protein preparation methods, remains a valuable tool to analyze complex mixtures of proteins entirely. Also, for intensive mass spectrometric analysis, it is also advisable to focus on a few of the interestingly changed proteins in cheonggukjang.