• Applied Biological Chemistry
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• v.29 no.2
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• pp.116-121
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• 1986

869 wheat lines were selected and analyzed for protein and lysine composition. Also, high protein-high lysine wheat were evaluated by stability parameter to determine varietal response to environments. Protein content had highly significant positive correlation coefficient of $0.902^{**}$ with lysine content but negatively correlated with lysine per protein content. Bezostaya and Lancota with low regression coefficient provided relatively low response to environment in protein content, while CI 13449 and Centurk with high regression coefficients (1.0) had a relatively high response. High heritability has been formed for protein $(h^2=0.809)$ and lysine content $(h^2=0.647)$.

• Applied Biological Chemistry
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• v.49 no.4
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• pp.304-308
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• 2006

To extract insoluble proteins from silkworm pupa meal, the meal was treated with pretense produced by Bacillus sp. JH-209. The extraction of insoluble silkworm pupa protein was enhanced at alkaline pHs ranged from 7 to 11 by treatment with the protease. The optimum extraction temperature was $40^{\circ}C$ for in soluble protein treated with pretense. The optimum protease treatment time for extraction of protein was 11 hrs and optimum amount of enzyme treated for extraction of protein was 60 Unit, respectively. The treatment of enzyme extracted more protein than ordinary extraction method without pretense. The foaming capacity, foaming stability, emulsion capacity, and emulsion stability of silkworm pupa meal protein extracted by the treatment of the enzymes increased at all pH ranges. Further more oil absorption as well as water absorption capacities of the protein extracted by the treatment of the enzymes were also increased.

• Applied Biological Chemistry
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• v.37 no.3
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• pp.168-174
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• 1994

Effects of filtration and centrifugation on the oxidative stabilities of sesame oils during storage at $70^{\circ}C$ were studied by combination of determining peroxide values and conjugated dienoic acid values of oils and measuring the hexanal formation using headspace gas chromatography. Crude sesame oil from roasted seeds contained more free fatty acids, conjugated dienes, and metals (Fe, Cu, Mg and Zn); on the other hand, higher contents of moisture and ${\gamma}-tocopherol$ were found in the filtered or centrifuged oil. Only filtered oil contained more peroxides than the crude oil in spite of the color advantage of the highest L and b values among three oils. All the oils showed the tendency of increasing in total color difference during storage at $70^{\circ}C$, fatty acid compositions were relatively constant except for decreasing tendency of linoleic acid in filtered oil. No significant difference at 1% in the oxidative stabilities was observed between centrifuged oil and crude oil with higher susceptibility to the oxidation in the filtered oil. Centrifuged sesame oil was the best in the aspect of both oxidative stability and the oil color.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.177-181
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• 1982

This experiment was carried out to investigate the stability of Dicofol solutions which were prepared with various organic solvents such as xylene, toluene, methylisobutyl ketone (M.I.B.K.), cyclohexanone, N.N.-dimetyl formamide (N.N.-D.M.F.) and isophorone under different temperature and storage period. The decomposition rate of Dicofol was increased in the order of cyclohexanone> N.N.-D.M.F.>W.P.>toluene, xylene, M.I.B.K. and isophorone. However, it was shown that precipitation was found in Dicofol solutions such as xylene, toluene and M.I..B.K. except isophorone. Therefore, isophorone was recognized as the best of organic solvents tested for Dicofol in the case of emulsifiable concentrate formulation with it.

• Applied Biological Chemistry
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• v.45 no.3
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• pp.179-184
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• 2002

To examine utilization of Korean black soybean as a natural pigment, the effects of temperature, carbohydrate, organic acid, vitamin C and metal ion were investigated. Korean black soybean pigment was more stable than other anthocyanin pigments when temperature was abused. There was no darkness effect in carbohydrate. In organic acid, the color intensity was increased. The vitamin C addition negatively affected on color of anthocyanin. Among the metal ions tested, $Cu^{2+}$ and $Zn^{2+}$ was not affected but $Mn^{2+}$ makes it unstable. Results indicate that Korean black soybean pigment was more stable than other anthocyanin pigment in various environment at pH 3.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.345-349
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• 2016

This study was performed to evaluate the quality characteristics of curd yogurt with different contents [0.5~2.0% (w/w)] of Korean rice wine lees powder (KRWLP). Yogurt was fermented with commercially available mixed lactic acid bacteria (Lactobacillus acidophilus, Bifidobacterium longum, Streptococcus thermophiles) at $40^{\circ}C$ for 15 h. Acid production (pH and titratable acidity) of yogurts increased with increasing KRWLP content. After 12 hours fermentation, titratable acidity of KRWLP yogurt was 1.19~1.29 % and was higher than that (1.07 %) of yogurt made without KRWLP. And also, the number of viable lactic acid bacterial cell increased and the culture time to obtain maximum number of lactic acid bacteria cell decreased with the addition of KRWLP. The curd stability in yogurt was significantly enhanced by repression of whey separation in KRWLP yogurt. In sensory evaluation, there was a similar preference for KRWLP yogurts and the control. These results suggest that KRWLP can be used as foodstuff to improve the quality characteristics of yogurt.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1516-1524
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• 2014

Flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) can utilize a variety of external electron acceptors and also has stricter substrate specificity than any other glucose oxidoreductases, which makes it the ideal diagnostic enzyme in the field of glucose biosensors. A gene coding for a hypothetical protein, similar to glucose oxidase and derived from Aspergillus terreus NIH2624, was overexpressed in Pichia pastoris GS115 under the control of an AOX1 promoter with a level of 260,000 U/l in the culture supernatant after fed-batch cultivation for 84 h. After a three-step purification protocol that included isopropanol precipitation, affinity chromatography, and a second isopropanol precipitation, recombinant FAD-GDH was purified with a recovery of 65%. This is the first time that isopropanol precipitation has been used to concentrate a fermentation supernatant and exchange buffers after affinity chromatography purification. The purified FAD-GDH exhibited a broad and diffuse band between 83 and 150 kDa. The recombinant FAD-GDH was stable across a wide pH range (3.5 to 9.0) with maximum activity at pH 7.5 and $55^{\circ}C$. In addition, it displayed very high thermal stability, with a half-life of 82 min at $60^{\circ}C$. These characteristics indicate that FAD-GDH will be useful in the field of glucose biosensors.

• Applied Biological Chemistry
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• v.38 no.3
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• pp.259-262
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• 1995

Oxidative stabilities of fat in DHA(cis-4,7,10,13,16,19-docosahexaenoic acid)-added dry milk and ordinary dry milk during storage were studied by determining thiobarbituric acid values of samples. Two kinds of milk powder samples were purchased in the local supermarket and $2{\pm}0.05\;g$ of samples were transferred into serum bottles, which were stored under the light or under dark The oxidation of fat in DHA-added milk powder was higher than that of fat in ordinary milk powder and the acceleration was more evident in the presence of light Light and unsaturated fats accelerated synergistically oxidation of milk fat Addition of DABCO(diazabicyclooctane), which is an efficient singlet oxygen quencher, significantly decreased the photooxidation of milk fat This result clearly suggested that singlet oxygen oxidation (Type II reaction) was involved in the system. Deceleration of milk fat oxidation by DABCO was higher in the DHA-added milk powder.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.193-199
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• 1988

This study was conducted to investigate the possibility of emulsifiable concentrate(EC) development and the stability and acaricidal activity of the formulated emulsifiable concentrate. Cyhexatin could be formulated into 9% EC by using phenol as a cosolvent and E-ASC as an emulsifier. Cyhexatin EC was stable in 0.5% moisture content, pH 4.5 and 7, but it was unstable in more than 1% moisture content and the alkaline condition of pH 9.5. The emulsion of cyhexatin EC was unstable in hard water of pH 10. The acaricidal activity of 500 fold of 9% EC was shown to be as good as that of 27% wp of 1500 fold.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.12-17
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• 2007

A biosurfactant-producing strain, Bacillus subtilis TBM 3101 was isolated from the soil sample at Tae-Baek Mountain through an antifungal test and emulsification assessment. The strain was assessed, regarding to the microbial growth, by physical and chemical test, surface tension, emulsification activity and stability. The surface tension of the isolate sharply decreased to the minimum 29mN/m at 48 h growth. Of note, its emulsification was stabilized to the highest degree when tributyrin was utilized as a substrate, indicating that in comparison to a variety of synthetic surfactants, the biosurfactant produced by the isolate was significantly similar to synthetic surfactant, tween 20. In addition, the biosurfactant showed high emulsification activity when soybean oil, crude oil and tetradecane were used as a substrate. Thus, these studies could contribute to the detection and development of biosurfactant beneficial to the environment and humans.