• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.136-144
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• 1989

The purification of myrosinase from radish roots was performed using Concannavalin A-Sepharose affinity chromatography and gel permeation HPLC, which gave a 22-fold-purification(S.P.A.=39,000 units/mg) with 50% recovery, SDS-polyacrylamide gel electrophoresis showed a single major band, suggestive of a relatively pure myrosinase, and the M.W. of the enzyme determined on gel permeation HPLC was ca. 124K. The enzyme showed on optimum pH of 6.5 and was stable at pH 6 to 7 at room temperature, but unstable below pH 4. The enzyme possessed an optimum temperature of $37^{\circ}C$, and gave a Vmax value of $40\;{\mu}moles/mg{\cdot}min$ and a Km value of 0.12mM for sinigrin. The purified myrosinase was activated maximally by 0.6mM of ascorbic acid, but somewhat inhibited by more than 2 mM ascorbic acid. The activities of myrosinase present in the peelings and the peeled radish amounted to approximately 1,333 units/g and 140 units/g weight, respectively and the peelings contained much more myrosinase activity than the peeled radish.

• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.252-258
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• 1972

Methods of separating yeast cells from oil-water-cell emulsion and subsequent purification of the recovered yeast have been studied. In addition, the results of preliminary feeding experiments in which a yeast grown on gas oil was incorporated into chick rations are reported. According to the present study, it appears that the recovery of the yeasts would be easier at pH 9, since the emulsion is relatively more unstable. A class of surface active agent at a concentration of 0.3% was found to facilitate the separation of the yeast from the emulsion. The use of electrolytes such as NaCl and KCl were found to be most effective in breaking the emulsion. Solvent treatment using iso-propyl alcohol and its azeotropic mixture with hexane at $58^{\circ}C$ are particularly suitable for purification of the yeast. In the feeding experiment it was found that 5 percent of the fishmeal in the control ration could be replaced by the yeast with no adverse effect on performance. However, when 8 percent of the fish meal in the control ration was replaced by the yeast, some effect on live-weight gain of the chicks was observed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.609-614
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• 1991

Thermal stability and quality change during storage of red pepper oleoresin were studied. Upon heat treatment, carotenoids in oleoresin from red pepper were more stable under nitrogen than air. In the thermal stabilities, the presence of air at $100^{\circ}C$ for 3 hours and 10 hours were 69.1% and 42.3%, respectively ; whereas, in the presence of nitrogen, 95.4% and 92.3%, respectively. In contrast, capsaicin was comparatively stable upon heat treatment in the presence of air. The retentions of capsaicin at $100^{\circ}C$ for 3 hours and 10 hours were 84.7% and 81.3% with air, those were 90.7% and 87.5% with nitrogen, respectively. Color appearance showed close relation to the stability of total carotenoids during 60 days storage at varying temperatures ; $5^{\circ}C,\;25^{\circ}C\;and\;40^{\circ}C$ were 69.4%, 48.0% and 35.1%, respectively. The degradation of total carotenoids during storage could be interpreted as a first order reaction. The activation energy obtained from the Arrhenius plot was 5.03 kcal/mole. Conversely, capsaicin was very stable under storage temperatures. More than 90% of capsaicin was remained upon completion of storage. In the mean time, pH of oleoresin was increased slightly as increasing storage temperatures.

• Food Science and Preservation
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• v.9 no.4
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• pp.429-433
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• 2002

The D-xylulokinase from Candida sp. L-16 was purified through a sequence of ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-100 and Sephadex G-200 gel filtration. The specific activity of the purified Dxylulokinase was increased to 23.2 fold and the yield was 11.2%. The enzyme was showed to be a single protein band by SDS-PAGE. The molecular weight of the enzyme was 150,000 dalton, this enzyme was identified to be a dimer with two subunits. The optimum conditions of the enzyme were pH 8.0 and 40$\^{C}$, respectively. The enzyme was relatively stable between pH 7.0 to pH 9.0, but it was unstable over 30$\^{C}$. The enzyme showed substrate specificity on D-xylulose, D-arabinose and D-ribose, Km value and Vmax for D-xylulose were 0.042 mM and 117 units/ml, respectively. The activation energy of the enzyme was 4.75 Kcal/mol. The one was inhibited by metabolic intermediates such as 6-phosphogluconic acid, 2-keto-gluconic acid. The enzyme was activated by EDTA and thiol compounds such as cysteine-HCI, DTT and glutathione.

• Food Science and Preservation
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• v.14 no.4
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• pp.369-377
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• 2007

This study investigated the effect of ginseng products on the baking properties of white breads. Flour was substituted by ginseng products (ginseng at levels 2, 4, 6, and 8%, all w/w, of flour levels). Both ginseng powder (GP) and red ginseng powder (RGP) were used. Similarly, red ginseng extract (RGE) was substituted at levels of 1, 2, 3, and 4% (all w/w) of flour. The physical properties of each dough were assessed using farinograms, extensograms, and amylograms. Water absorption increased as the proportions of ginseng products rose. The dough surface areas and R/E (resistance/extensibility) values decreased, as did peak viscosities, at the proportions of ginseng products increased. The pH values during fermentation decreased as the proportions of ginseng products increased. The fermentation power of dough with GP was lower than that of control, and higher than that of dough with RGP or RGE, but the addition of ginseng products beyond certain levels weakened the gas retention power: The specific loaf volumes of breads with 2% GP were the highest at 5.41 mL/g. In breads with RGE, the specificloaf volume increased from 5.52 mL/g to 5.82 mL/g as RGE levels rose from 0% to 4%. Hardness increased with rising GP and RGP levels in breads with GP and RGP, but decreased with RGE levels in breads with RGE. The moisture contents of breads during storage tended to be higher than control in breads with ginseng products. Lightness increased with addition of GP and decreased upon addition of RGP or RGE, while redness and yellowness increased after addition of any ginseng products. In sensory evaluation tests, the sensory scores for texture, color, mouth feel, and overall acceptability, were high, when any ginseng product (GP, RGP or RGE) was present at 2%. Of these breads, the bread with 2% RGE attained the highest sensory score.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.678-684
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• 2005

Extraction conditions, spectrometric, and sensory properties of pigment extracts from green discolored garlic (GDG) were studied for development of green index to evaluate degree of green discoloration of garlic. GDG pigments were extracted using polar solvents, such as methanol, ethanol, and water. Methanol with 1% HCl resulted in highest extraction of green pigments. Extraction of pigments was affected by temperature, and extracted pigments were partially destroyed at high temperatures. Optimum conditions for extraction of green pigments were $20^{\circ}C$ for 30 min. Because green pigments are unstable at room temperature, and no method has been reported to evaluate degree of green discoloration of garlic, color chart was designed by mixing varying amounts of control and GDG. High correlation was observed between sensory scores and "a" value of color chart samples (y=-3.465x - 11.676) with $R^2$ of 0.993. Green index (GI) was developed based on linear regression equation between sensory scores and "a" values. Sensory panel recognized green discoloration of garlic at $GI{\geq}3.0$. GI developed in this study could be utilized to evaluate degree of green discoloration of garlic during cold storage and distribution of garlic.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.705-713
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• 2010

This study was carried out to investigate the physicochemical properties of bread dough with added mulberry leaf powder. The crude protein, fiber and ash contents of the mulberry leaf powder were 21.25%, 7.70% and 9.27% respectively. The mulberry leaf-mixed powder showed low lightness and redness values and high yellowness. Farinograph water absorption increased as the mulberry leaf powder content increased. Both arrival and development times of the mulberry leaf powder-added dough were longer than those of wheat flour dough. As the mulberry leaf powder content increased, the degree of weakness increased. Maximum viscosity by amylograph analysis increased gradually with the addition of mulberry leaf powder, while gelatinization temperature was not affected. Degree of extension decreased as shown in extensograph analysis with increasing content of mulberry leaf powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.350-356
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• 1983

Ginseng is one of the most important plant drugs which has been used as a medicine in Asia. Main effective components of ginseng have been recently believed to be saponins which have been isolated and identified from Panax ginseng C. A. Meyer. Decrease in total saponin content of white ginseng by storage years was remarkable in contrast with red ginseng. In storage for three years, decrease in red and white ginsengs were 12% and 27% for total saponin content, and 16.8% and 42.2% for major saponin content, respectively. The PT/PD ratios of red and white ginseng saponins were ranged 0.646 to 0.694% and 0.414 to 0.428%, respectively. According to the result of PT/PD ratios, red ginseng was greater than 50% in compare with white ginseng. The change of PT/PD ratio would greatly influence on the biochemical and pharmacological effects of ginseng.

• Food Engineering Progress
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• v.15 no.2
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• pp.136-142
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• 2011

The objective of this research was to classify intact soybeans and foreign objects using near-infrared (NIR) spectroscopy. Intact soybeans and foreign objects were scanned using a NIR spectrometer equipped with scanning monochromator. NIR spectra of intact soybeans and foreign objects in the wavelength range from 900 to 1800 nm were collected. The classification of intact soybeans and foreign objects were conducted by using partial least-square discriminant analysis (PLS-DA) and soft independent modelling of class analogy (SIMCA) multivariate methods. Various types of data pretreatments were tested to develop the classification models. Intact soybeans and foreign objects were successfully classified by the PLS-DA prediction model with mean normalization pretreatment. These results showed the potential of NIR spectroscopy combined with multivariate analysis as a method for classifying intact soybeans and foreign objects.

• Journal of Life Science
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• v.33 no.5
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• pp.383-390
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• 2023

The goal of this study was to identify new bioactive peptides in extracts derived from Tenebrio molitor (T. molitor) larvae for the development of functional foods. After extraction from freeze-dried T. molitor larvae with various solvents on time course, the extracts showed the highest 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity at 5 and 10 hr per total protein and solid contents, respectively. When the water extract was fractionated, a high methanol concentration led to a reduced level of high-molecular-weight proteins in the centrifugal supernatant, whereas increased DPPH activity in the supernatants suggests low-molecular-weight peptides may mediate antioxidant activity in the supernatant. Most of the organic solvent partitions, excluding butanol, showed similar activities in the water phases, and the organic solvent partition fraction exhibited a 28~44% decrease in activity following heat treatment, implying that some components in the fraction become unstable in the presence of heat. The addition of proteinase K to the water extract increased DPPH activity by 10~20%, suggesting that peptides, when released from total proteins, partially increase antioxidant activity. Therefore, we suggest that the antioxidants in T. molitor larval extracts make them a potential source of functional animal food.