• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.771-778
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• 1995

This study was carried out to produce the oligosaccharides(G2~G7) directly from the culture broth of Bacillus cereous IAM1072. The maximal production of oligosaccharides was obtained after cultivation at $30^{\circ}C$ for 24hrs in the mixture of 12% soluble starch, 1.5% peptone and 0.25% $K_2HPO_4$ adjusted to pH 7.0. Among the oligosaccharides produced $G_5$ oligosaccharide was purified. After methylation, the result of GC analysis was suggested to be oligosaccharide consisting of 5 glucose unit with ${\alpha}-1,4-glucosidic$ bond.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.474-478
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• 2001

Transglutaminase(TGase) 첨가가 튀긴 어묵의 레올로지 특성에 미치는 영향이 평가되었다. 최적의 TGase 함량과 setting시간은 저온$(25^{\circ}C)$ setting에서는 0.1%와 180분이었고, 고온$(40^{\circ}C)$ setting에서는 0.3%와 80분으로 각각 결정되었다. 각각의 최적조건에서의 겔 강도는 $25^{\circ}C$에서는 TGase를 첨가한 겔이 첨가하지 않은 겔보다 최대 750(g cm)도 증가했으며, $40^{\circ}C$에서는 약 800(g cm)정도의 증가를 보여주었다. 동적 점탄성의 setting 측정 결과로부터 TGase 첨가 시료는 $25^{\circ}C$인 경우 G#과 G@ 값이 각각 1.0 kPa과 0.5 kPa 정도 증가하는 것으로 나타났으며, $40^{\circ}C$ 경우는 G#과 G@ 값이 각각 15 kPa과 2.2 kPa 정도 증가함을 보여 주었다. 동적 점탄성의 가열-냉각 측정 결과에서도 $25^{\circ}C$와 $40^{\circ}C$ setting 모두에서 G#, G@ 값이 $5{\sim}15\;kPa$ 정도 증가함을 나타났다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1386-1396
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• 2017

The purpose of this study was to determine the optimum Platycodon grandiflorum root concentrate (PGRC, $65^{\circ}Brix$), fermented P. grandiflorum root extract by Lactobacillus plantarum (FPGRE, $2^{\circ}Brix$), and cactus Chounnyouncho extract (Cactus-E, $2^{\circ}Brix$) for preparation of PGRC stick product with FPGRE using response surface methodology (RSM). The experimental conditions were designed according to a central composite design with 20 experimental points, including three replicates for three independent variables such as amount of PGRC (8~12 g), FPGRE (0~20 g), and Cactus-E (0~20 g). The experimental data for the sensory evaluation and functional properties based on antioxidant activity and antimicrobial activity were fitted with the quadratic model, and accuracy of equations was analyzed by ANOVA. For the responses, sensory and functional properties showed significant correlation with contents of three independent variables. The results indicate that addition of PGRC contributed to increased bitterness and acridity based on the sensory test and antimicrobial activity, addition of FPGRE contributed to increased antioxidant activity and antimicrobial activity, and addition of Cactus-E contributed to increased fluidity based on the sensory test, antioxidant activity, and antimicrobial activity. Based on the results of RSM, the optimum formulation of PGRC stick product was calculated as PGRC 8.456 g, FPGRE 20.00 g, and Cactus-Ex 20.00 g with minimal bitterness and acridity, as well as optimized fluidity, antioxidant activity, and antimicrobial activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1543-1549
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• 2015

Black rice bran, a by-product from rice milling process, is a good natural source of anthocyanin pigment. The purpose of this study was to determine the optimum conditions for anthocyanin extraction from black rice bran as well as the stability of anthocyanin extract according to different storage temperatures. The main anthocyanin in 'Heugkwang' rice bran was identified as cyanidine-3-glucoside (C3G) by HPLC and LC-MS/MS. The yield and C3G content of black rice bran extract were investigated with various extraction solvents, temperatures, and times. The results indicate that the optimum extraction solvent, temperature, and time were 50% ethanol, $70^{\circ}C$, and 2 h, respectively. The stability of anthocyanin extract was studied during a storage period of 168 days at various temperatures ($-20^{\circ}C$, $4^{\circ}C$, and room temperature). Hunter's values (L, a, and b) of anthocyanin extract increased, whereas C3G content continuously decreased up to 168 days. Variations in Hunter's values and C3G content become larger as storage temperature increased. Anthocyanin extract from black rice bran was very stable, as C3G content after storage at all temperatures was maintained at more than 90% of initial content. These results suggest that anthocyanin extract from black rice bran may be useful as a natural food colorant.

• Journal of Mushroom
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• v.19 no.4
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• pp.285-293
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• 2021

The purpose of this study was to identify and characterize the laccase genes of Flammulina velutipes var. lupinicola. Five laccase genes (g1934, g1937, g2415, g2539, g5858) were selected based on the copper binding site and signal peptide analysis results using the laccase gene selected from the F. velutipes var. lupinicola genome. The size of the laccase genes of F. velutipes var. lupinicola were 1,488 bp~1,662 bp. As a result of cDNA sequence analysis, 14 to 17 introns were identified in the laccase genes. The cleavage site predicted as the signal peptide of the laccase gene was found to be located between 20 bp and 34 bp from the N-terminus. In addition, separation and purification were performed to characterize the F. velutipes var. lupinicola laccases, and the optimal activity of the separated and purified proteins were analyzed by pH, temperature and time. Five bands with laccase activity were found from zymogram analysis. The optimal pH of the reaction was 5.5, the optimal temperature was found to be 40℃. Therefore, characterization of the laccase genes identified in this study should help in better understanding the biomass decomposition of F. velutipes var. lupinicola.

• Journal of Environmental Science International
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• v.2 no.4
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• pp.271-278
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• 1993

Optimal biodegradation kinetics models to the initial nonylphenol ethoxylates-30 concentration were investigated and had been fitted by the linear regression. Microorganisms capable of degrading nonylphenol ethoxylates-30 were isolated from sewage near Ulsan plant area by enrichment culture technique. Among them, the strain designated as EL-10K had the highest biodegradability and was identified as Pseudomonas from results of taxonomical studies. The optimal conditions for the biodegradation were 1.0 g/ι of nonylphenol ethoxylates-30 and 0.02 g/ι of ammonium nitrate at pH 7.0 and 3$0^{\circ}C$. The highest degradation rate of nonylphenol ethoxylates-30 was about 89% for 30 hours incubation on the optimal condition. Biodegradation data were fit by linear regression to equations for 3 kinetic models. The kinetics of biodegradation of nonylphenol ethoxylates was best described by first order model for 0.1 $\mu\textrm{g}$/ι nonylphenol ethoxylates-30 ; by Monod no growth model and Monod with growth model for 0.5 $\mu\textrm{g}$/mι and 1.0, 5.0 $\mu\textrm{g}$/mι, respectively.

• Journal of the Korean Ceramic Society
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• v.39 no.2
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• pp.164-170
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• 2002

Measurements of sedimentation, solid loading, zeta potential, and viscosity were employed to determine a proper dispersant and its amount for a well dispersed alumina powders in aqueous alumina tape casting using acrylate as a binder. Polycarboxylic acid was the most effective one among various dispersants considered in the present study and its amount was 0.23∼0.24 g per 100 g alumina for a dispersion. Better dispersion was obtained as an increase of dispersant addition. However, the dispersion was hindered as the amount of dispersant was higher than the optimum amount because of bridging or tangling of polymer chains. Excellent aqueous alumina tapes were prepared from the slurry containing the optimum amount of the polycarboxylic acid (0.2g), alumina powders(100 g), acrylate and Benzoflex as binder and plasticizer, respectively. The viscosity of the slurry was 570 cps and the alumina loading in the tape was 57 vol%.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2003.10a
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• pp.73-73
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• 2003

느티떡은 멥쌀가루에 느티잎을 첨가하여 시루에 찐 떡이다. 본 연구에서는 멥쌀가루에 느티잎의 양, 설탕의 양, 물의 양을 달리하여 느티떡을 제조하여 관능검사와 기계측정을 하여 최적 배합비를 얻는데 목적이 있다. 관능검사 결과 Color는 멥쌀가루 200g에 느티잎 20g(10%), Flavor와 Moistness는 느티잎 30g (15%), 설탕 30g(15%), Chewiness는 느티잎 20g(10%), 설탕 30g(15%), 물 35m1, Sweetness는 느티잎 20g(10%), 설탕 30g(15%), 물 25ml 첨가한 떡이 가장 높게 평가되었다. (중략)

• Journal of Korean Society for Quality Management
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• v.21 no.2
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• pp.140-155
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• 1993

The characteristics of $I_{\lambda}$-optimality, one of the linear criteria suggested by Fedorov (1972) are investigated with respect to the D-and heteroscedastic G-optimality in case of non-constant variance function. Though having limited results obtained from simple models, we may conclude that $I_{\lambda}$-optimality is sometimes preferred to the heteroscedastic G-optimality suggested newly bv Wong and Cook (1992) in the sense that the experimenter's belief in weighting function exists in $I_{\lambda}$-optimality criterion, not to mention its computational simplicity.

• The Korean Journal of Applied Statistics
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• v.6 no.2
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• pp.303-309
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• 1993

In this paper we have defined two approaches to be error-robust when the precise form of error-structure is unknown. An experiment is optimal by the first criterion if it maximizes the minimum effciency over all candidates of error structure and is optimal by the second if it maximizes the minimum average of the efficiency over all candidates of error structure. In order to appreciate the basic implications of each design criterion, these approaches are applied to two different experimental situations, D- and heteroscedastic G-optimalities.