• Food Science and Preservation
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• v.17 no.6
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• pp.770-776
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• 2010

Sarcodon aspratus (Berk.) S. Ito is a wild mushroom commonly consumed in Korea due to its beneficial effects on health. However, only limited information on the volatile and nonvolatile constituents of S. aspratus is available. In the present study, the total concentration of mushroom soluble sugars, including glucose, trehalose, sucrose, and xylose, was found to be 202.5 mg/kg. The total contents of free and essential amino acids were 2,592.1 mg/kg and 1,249.5 mg/kg, respectively; arginine, lysine, methionine, and valine were the major amino acids present. The contents of total 5'-nucleotides and flavor 5'-nucleotides in S. aspratus were 2,510.7 mg/kg and 773.4 mg/kg, respectively. The volatile components of S. aspratus were collected by simultaneous distillation-extraction (SDE) and analyzed by gas chromatography-massspectrometry (GC-MS). A total of 27 volatile compounds were isolated and identified. The most abundant was l-octen-3-ol, which accounted for more than 68% of total volatiles; other important compounds were 2-octen-1-ol, 1-octen-3-one, and 2-octenol. Our results provide preliminary data for the development of S. aspratus as a food material.

• Food Science and Preservation
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• v.16 no.4
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• pp.499-505
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• 2009

Quality changes in fresh-cut potatoes during storage at $4^{\circ}C$ after treatment with low-temperature blanching and antibrowning agents were studied. Fresh-cut potatoes were treated by dipping for 1.5 min in a browning inhibitor solution containing 0.5% (w/v) ascorbic acid, 0.5% (w/v) citric acid, 0.5% (w/v) sodium chloride, 0.1% (w/v) trehalose, and 0.005% (w/v) biotin, at $60^{\circ}C$, with subsequent cooling for 1.5 min and storage at $4^{\circ}C$. The browning properties of fresh-cut potatoes were examined by measurement of polyphenol oxidase (PPO) activity and total phenolic content. Changes in quality attributes over a 14-day period were assessed in terms of titratable acidity, pH, water-soluble solid level, and gas analysis at $4^{\circ}C$. During storage, PPO activity increased, with the lowest activity seen after about 7 days of storage. Treatment with antibrowning solution at $4^{\circ}C$ increased visual sensory attributes during storage. Low-temperature blanching in distilled water more effectively inhibited browning compared with exposure to browning inhibitor solution, as assessed after 7 days of storage. Fresh-cut potatoes respired aerobically after different treatments during storage at $4^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.739-748
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• 2021

This study focuses on the use of rice in the production of gluten-free rice udon (GFU) through an optimized mixing ratio, using the Box-Behnken response surface methodology (RSM). Different additional levels of rice flour (A, 40-60 g), acetylated distarch adipate (B, 10-20 g), and trehalose (C, 0-3 g) were used as variables, while water absorption level, volume, cooking loss, solid yield, lightness, texture properties, proximate compositions of GFU and turbidity of cooking water were set as responses in the RSM design model. The optimum mixing ratio for the preparation of gluten-free rice udon was obtained for 60.00 g of rice flour, 18.81 g of acetylated distarch adipate without the addition of trehalose. The response values of the optimized samples were water absorption (60.94%), volume (34.94%), turbidity of the cooking water (0.37), cooking loss (4.77%), solid yield (1.55 g), lightness value (70.04), hardness (2.53 N), springiness (0.18), gumminess (10.45 N), chewiness (1.83 N), and cohesiveness (2.89). This study has shown that rice flour can replace wheat flour to manufacture udon at an optimized mixing ratio successfully derived by statistical estimation method.

• Research in Plant Disease
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• v.30 no.2
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• pp.148-156
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• 2024

Ralstonia pseudosolanacearum, a plant pathogenic bacterium that can survive for a long time in soil and water, causes lethal wilt in the Solanaceae family. Sigma S is a part of the RNA polymerase complex, which regulates gene expression during bacterial stress response or stationary phase. In this study, we investigated the role of sigma S in R. pseudosolanacearum under stress conditions using a rpoS-defective mutant strain of R. pseudosolanacearum and its wild-type strain. The phenotypes of rpoS-defective mutant were complemented by introducing the original rpoS gene. There were no differences observed in bacterial growth rate and exopolysaccharide production between the wild-type strain and the rpoS mutant. However, the wild-type strain responded more sensitively to nutrient deficiency compared to the mutant strain. Under the nutrient deficiency, the rpoS mutant maintained a high bacterial viability for a longer period, while the viability of the wild-type strain declined rapidly. Furthermore, a significant difference in pH was observed between the culture supernatant of the wild-type strain and the mutant strain. The pH of the culture supernatant for the wild-type strain decreased rapidly during bacterial growth, leading to medium acidification. The rapid decline in the wild-type strain's viability may be associated with medium acidification and bacterial sensitivity to acidity during transition to the stationary phase. Interestingly, the rpoS mutant strain cannot utilize acetic acid, D-alanine, D-trehalose, and L-histidine. These results suggest that sigma S of R. pseudosolanacearum regulates the production or utilization of organic acids and controls cell death during stationary phase under nutrient deficiency.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1324-1329
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• 2007

Resveratrol (3,5,4'-trihydroxystilbene) is a naturally occurring, multi-biofunctional chemical existing in grapes and various other plants as a polyphenol type, and it is one of the best known natural anticancer and antiatherosclerosis reagents. In this study, we investigated the antifungal action by resveratrol in Candida albicans, which is a human infectious fungi as an agent of candidiasis. Resveratrol displayed potent fungicidal activity in an energy-dependent manner, without any hemolytic effects against human erythrocytes. It was found that the serum-induced mycelial forms, which playa crucial role in the pathogenesis of C. albicans during host tissue invasion, were disrupted by resveratrol. To understand the correlation between lethal effects and resveratrol action, we examined the physiological changes of C. albicans. A significant accumulation of intracellular trehalose was induced by stress responses to resveratrol action, and a remarkable arrest of cell-cycle processes at the S-phase in C. albicans occured. Therefore, the fungicidal effects of resveratrol demonstrate that this compound is a potential candidate as an antifungal agent in treating infectious diseases by candidal infections.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.106-111
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• 2003

A novel carbohydrolase, which is a DXAMase, containing both dextranase and amylase equivalent activities, was purified from Lipomyces starkeyi KSM22. The purified DXAMase was also found to hydrolyze cellobiose, gentiobiose, trehalose and melezitose, while disproportionation reactions were exhibited with various di- and tri-saccharides, such as maltose, isomaltose, gentiobiose, kojibiose, sophorose, panose, maltotriose, and isomaltotriose with various kinds of oligosaccharides produced as acceptor reaction products. Furthermore, the purified DXAMase hydrolyzed raw waxy rice Starch and produced maltodextrin to the extent of 50% as a glucose equivalent.

• Reproductive and Developmental Biology
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• v.32 no.4
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• pp.245-248
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• 2008

In the present studies, we have intended to compare the EDS (20% EG + 20% DMSO + 0.4 M sucrose + 10% FCS) and EDT (20% EG + 20% DMSO + 0.3 M trehalose 10% FCS) methods for vitrification of canine oocytes, in order to improve the vitrification methods. The survival rate of vitrified-thawed oocytes using the EDS method was $15.1{\pm}1.8%$ (p<0.05), which was lower than that of the control group $(66.7{\pm}2.5%)$. About $45{\sim}55%$ of the vitrified-warmed oocytes showed normal morphology, as assessed by PI staining. However, the ratio of survival rate of oocytes showed lower than that of normal morphology in comparison between EDS method and control group. The survival and developmental rates of vitrified-warmed oocytes by the EDS and EDT methods were $16.7{\pm}1.4%\;and\;11.1{\pm}0.8%$ and $8.3{\pm}1.4%\;and\;4.4{\pm}1.8%$, respectively (p<0.05). The results were significantly lower than the control group $(66.7{\pm}2.5%\;and\;16.7{\pm}3.7%)$. However, the survival rate of vitrified-warmed oocytes using EDS method showed higher than that in the ETS group.

• Culinary science and hospitality research
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• v.20 no.5
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• pp.34-42
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• 2014

The study explores the sensory properties of Backsulgi prepared with dry non-glutinous rice flour sweetened with various sweeteners(sugar, honey, oligosaccharide, trehalos, erythritol and accesulfame K). Sensory attributes of Backsulgi were evaluated by quantitative descriptive analysis(QDA), PCA and PLSR. The QDA results revealed that the sample sweetened with trehalose showed highest value in dryness, and samples with accesulfame K, honey and erythriol had relatively high levels in moisture and springiness. Principle component analysis (PCA) results showed 78.89 % of the total variation with PC1 (54.92%) and PC2 (23.98%), respectively. The samples with accesulfame K(AF) and honey, which showed high values in moisture level, springiness and sweet taste, showed similar attributes which led to a positive direction of PC1. The correlation between the sensory attributes and consumer acceptance showed that the most important factors for high consumer acceptance were moistness, springiness, sweet taste and sweet flavor. Overall, the samples with accesulfame K(AF) had the closest position in the PLSR results with highest overall consumer satisfaction.

• Food Science and Preservation
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• v.2 no.2
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• pp.225-232
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• 1995

In order to study the effect of modified atmosphere packaging(M.A.P.) and controlled atmosphere(C. A.) storage on keeping freshness of mushrooms (Agricus-bisporus). Mushrooms was packaged with polyethylene(P.E.) film (40${\mu}{\textrm}{m}$, 60${\mu}{\textrm}{m}$, 80${\mu}{\textrm}{m}$) and C.A. conditions(CO2 concentration of 2%, O2 concentration of 2%) and storage at 0$\pm$1$^{\circ}C$, RH(relative hummidity) 92$\pm$1%. Gas composition in film was changed rapidly at early of storage, but it kept a constant level after 14 days of storage, and then kept at the level of 6~9% CO2 and 2~5% O2. Weight loss was 5% in non-packed mushrooms after 3 days of storage, but P.E. film, CO2 treated, C.A. conditions were 5% after 21 days of storage. Flesh firmness of the mushrooms was continuously decreased throughout storage period and the lowest of flesh firmness changed was 80${\mu}{\textrm}{m}$-P.E. film packing. Discoloration of the piteous of mushrooms appears to be the most Important factors to determine its marketability, L value of it appears to be of the high values at P.E. film packing and C.A. conditions during period. Large amount of ethanol and acetaldehyde were produced from the 7 days during storage, large contents of mannitol and trehalose were at the 14 days and 7 days during storage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1723-1727
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• 2004

We investigated the activity and stability of alcohol dehydrogenase from horse liver (HLADH) under the electric stimulation. The activity and stability of alcohol dehydrogenase depended on electric output voltaqe, stimulation time, pulse duration and pulse interval, and temperature. HLADH retained about 23% of its activity in buffer but 78% in 10% trehalose solution under electric stimulation with 10V, 10min, The stabilizing of enzymes against electric stimulation by stabilizing additives showed a great potential use of enzymes in biotechnology and medical engineering fields.