• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.511-517
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• 1988

Kimchi, a traditional vegitable fermented food in Korea, was prepared and fermented at $5^{\circ}C$ in order to analyze the taste and flavor compounds. Major flavor components were identified as dimethyl-disulfide, dimethyl-trisulfide, dipropyl-disulfide, 1-butane 1-isothiocyanate, diallyl-disulfide by GC and GC/MS. Some organic acids such as lactic acid and citric acid increased from 1.2mg/100g and 5.4mg/100g in the initial stage to 33.3mg/100g and 44.4mg/100g at the end of fermentation, respectively. Free amino acids in kimchi were found to play an important role for the taste. The contents of total free amino acid increased from 316.3mg/100g to 600mg/100g in the fermented kimchi and glutamic acid, alanine, valine, leucine, lysine and arginine were abundant in kimchi. The results of sensory evaluation showed that the taste of kimchi was closely related to the contents of non-volatile organic acid, free amino acid and pH.

• Food Engineering Progress
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• v.13 no.1
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• pp.1-7
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• 2009

Fermented functional onion juice was developed using lactic acid bacteria as a fermentation starter of onion. From the preliminary studies, we selected the bacterium KC-007 (named as Pediococcus pentosaceus based on morphological and physiological characteristics, carbon utilization pattern, and molecular genetic characteristics) as a fermentation starter. The optimum recipe of functional fermented onion juice based on manufacturing process and sensory evaluation were determined as 27% of fermentation liquer, 27% of apple juice, 3.7% of HFCS, 1.86% of $\beta$-cyclodextrin, 0.9% of oligosaccharide, 0.2% of apple flavor, 0.09% of citric acid, and 39.25% of water.

• Preventive Nutrition and Food Science
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• v.16 no.2
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• pp.165-173
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• 2011

Five types of meju were prepared from 100% defatted soybean (DFSG0), a mixture of 90% DFS and 10% glasswort (DFSG1), a mixture of 80% DFS and 20% glasswort (DFSG2), a mixture of 70% DFS and 30% glasswort (DFSG3), and a mixture of 60% DFS and 40% glasswort (DFSG4). Five types of kanjang were separately prepared from the 5 types of meju by ripening in brine for 6 months. The contents of certain minerals (Mg, Ca, Fe, Mn, and Zn), organic acids (citric acid, malic acid) and the antioxidative effects in the kanjang were increased in proportion to the glasswort content in the meju. However, the free amino acid contents in the kanjang were reduced in proportion to the glasswort content in the meju. DFSG1- and DFSG2-kanjang did not show distinct differences from DFSG0-kanjang based on aroma, flavor, and taste that were compared simply by panel tests. The bacterial and fungal community in the fermented meju and kanjang was not affected by the addition of glasswort to the meju-making process. Bacteria belonging to the Lactobacillus and Bacillus genera and the Lactobacillus family predominated, and yeasts belonging to the Saccharomyces genus and fungi belonging to the Aspergillus genus predominated in the fermented meju and kanjang. In conclusion, the glasswort was a supplement that nutritionally improved the kanjang (except for free amino acid contents) but didn't influence the growth of microorganisms that are responsible for the fermentation of meju and kanjang.

• Journal of the Korean Society of Food Culture
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• v.31 no.5
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• pp.489-497
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• 2016

Kunrak, a type of Korea traditional cheese, is made using Tarak, a yogurt produced with makgeolli as the fermentation source. Kunrak is produced by removing whey from Tarak, followed by drying process for safe storage and consumption over a longer period. In this study, we produced kunrak based on the method described in "Imwonsibyukji". Prepared Kunrak was ripening for 96 hours at 20, 30, and $40^{\circ}C$. In order to study characteristics of Kunrak, physiochemical properties (pH, acidity, water contents) and contents of metabolites (organic acids, sugars, amino acids, and fatty acids) were analyzed. During ripening, water contents decreased. The main organic acids in Kunrak were citric acid and lactic acid, and the main free sugar was lactose. Main amino acids were glutamate and phenylalanine, and main fatty acid was saturated capric acid. At later ripening, all metabolites increased immediately after preparation. The sensory evaluation score of overall preference was highest for Kunrak, which was ripening at $40^{\circ}C$ for 96 hours. This study was aimed to assay metabolites of Kunrak under various ripening conditions. The results provide basic data to produce conditions for standardized manufacturing of Kunrak.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.176-181
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• 2004

This study was carried out to investigate the effect of yucca extract on the quality characteristics of Chungkookjang using Bacillus subtilis p01. The changes in the contents of amino-type N, ammonia type N, volatile compounds and organic acids, and those in the activities of ${\alpha}-amylase$ and protease were also determined during aging of Chungkookjang. The amount of amino-type N increased gradually with time for aging. The content of amino-type N was slightly higher in Chungkookjang fermented by adding yucca extract than in the control without yucca extract. The content of ammonia-type N was slightly lower in Chungkookjang with yucca extract than in the control without yucca extract. The activities of amylase and protease were higher in Chungkookjang with yucca extract than in the control and the highest in Chungkookjang containing 0.5 mg/g of yucca extract. Organic acid contents in Chungkookjang was the highest at the initial period of fermentation. The contents of organic acids in Chungkookjang with yucca extract was higher than that in control for 48 hr of aging. The amounts of 2,5-dimethylpyrazine were increased by addition of yucca extract, while those of cis-3-hexanol were decreased.

• Korean Journal of Food Science and Technology
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• v.23 no.3
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• pp.267-271
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• 1991

The chemical and organoleptic properties of dongchimi studied for their changes during fermentation at $4{\sim}35^{\circ}C$ in 7% NaCl solution with seasonings. It was found that pH decrease showed three variation points in its slope at about pH 5.2, 4.7 and 4.1 during fermentation. A negative linear relationship between total acidity and logarithmic value of pH was obtained. The slope of the relationship curve was increased as the fermentation temperature increased. The reducing sugar was increased until pH reached$4.0{\sim}4.2$ followed by a small decrease and its amount was lowered as the temperature increased from $4\;to\;25^{\circ}C$ The major nonvolatile organic acids were lactic and citric acids. The increase in lactic acid were more marked at $25^{\circ}C$ than at $4^{\circ}C$. As fermentation proceeded the fresh radish odor significantly decreased while sourness and yeast-moldy odor increased. The crispness of the radish decreased slightly during fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.690-697
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• 2014

This study was conducted to investigate the effect of mulberry powder on the antioxidant activities and quality characteristics of yogurt. The samples were fermented with different amounts (0, 0.5, 1, and 3% to the yogurt quantity) of mulberry powder for 24 hr. The total phenol content, anthocyanin content, and DPPH radical scavenging activity of yogurt significantly increased with higher mulberry powder content. The pH decreased with higher mulberry powder content until 16 hr, whereas the treated groups showed higher pH levels than the control group after 20 hr. Acidities of the treated groups were higher than that of the control group upon addition of mulberry powder. Citric acid, succinic acid, and lactic acid contents of the treatment group were higher than that of the control until 16 hr, whereas the free organic acid content of the control group increased after 20 hr. The amount of lactic acid bacteria increased with higher mulberry powder content until 12 hr, whereas that of the treated group tended to decrease compared to the control group after 16 hr. Color values of mulberry yogurt were lower in terms of brightness and yellowness, whereas redness value was higher compared to the control. Mulberry yogurt groups showed higher sensory attributes than the control, except for 3% added yogurt. Consumer acceptability score of yogurt with 1% mulberry powder was ranked higher than those of other yogurts in terms of overall preference, sourness, color, flavor, and sweetness. We suggest that mulberry powder can be used to improve the quality characteristics, functionality, fermentation, and sensory evaluation of yogurt.

• Journal of Life Science
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• v.29 no.6
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• pp.688-696
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• 2019

This study investigated changes in triglyceride and cholesterol synthesis and tyrosinase activity induced by ice plant (Mesembryanthemum crystallinum L.) extract, which cannot be stored for long periods of time due to its high moisture content when it was fermented to improve its storage stability. The accumulation of triglyceride and cholesterol in HepG2 cells inhibited the accumulation with a relatively large magnitude in n-butanol and aqueous fractions that generally have high polarity, however, changes in inhibition potency due to the fermentation were not significant. As for the effect to inhibit tyrosinase activity, when L-tyrosine was used as a substrate, the inhibitory activity was the highest for the aqueous fraction at $60.58{\pm}4.03%$ and $63.35{\pm}4.35%$, before and after fermentation, respectively, which amounted to 72% of that of the positive control group (arbutin, $100{\mu}g/ml$). In addition, when L-3,4-dihydroxyphenylalanine (L-DOPA) was used as a substrate, the inhibitory activity was also found the highest for the aqueous fraction at $56.85{\pm}1.57%$ and $59.38{\pm}1.74%$, before and after fermentation, respectively, which amounted to at least 88% of that in the positive control (kojic acid, $100{\mu}g/ml$). Overall, the activity of the fermented ice plant extract was similar or a little higher compared to that of the one without fermentation, indicating that fermentation can be a good approach to improve the storage stability of the ice plant.

• Food Science and Preservation
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• v.19 no.6
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• pp.933-938
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• 2012

The quality characteristics of rice wine seed mash and rice wine made with different lactic acid concentrations were investigated. The pH decreased along with the lactic acid concentration. The total titratable acid content of the rice wine seed mash was lowest when 0.5% lactic acid was added, and the ethanol contents of the mash samples were not significant. The results of the measurement of the microorganism number, C (cell numbers of the total bacteria and the lactic acid bacteria), decreased along with the lactic acid concentrations of the mash samples. The yeast cell numbers of the rice wine seed mash samples according to the lactic acid concentrations were high (0.5, 0.3, 1.0, control, and 0.7%, respectively). The pH and total titratable acid levels of rice wine according to the lactic acid concentration were stable during fermentation, according to the increase in the amount of lactic acid. The organic acids in the rice wines were highest in the lactic acid. The rice wines to which lactic acid had been added had lower acetic acid contents than the control. Also, the acetic acid contents decreased along with the lactic acid concentrations, except in the rice wine treated with 1.0% lactic acid. The ethanol contents of the tested rice wines were not significant. All in all, in the sensory evaluation, the rice wines treated with 0.5 and 0.7% lactic acid scored higher than the other treatments.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.202-208
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• 2006

Since abnormal fermentation and short storage duration of oriental melon are the main problems causing loss in commercial value, it is necessary to develop a food processing method using uncommercial melon. In this study, we suggested the effective pretreatment and storage conditions of melon as the material for alcoholic beverage production. Abnormally fermented melon had smaller carbohydrate and larger moisture content than normal one, indicating that carbohydrate in normal melon was probably converted to fermented products during fermentation. The sugar content of oriental melon was increased after fruiting and the highest value $(12.4^{\circ}Brix)$ was found at 5 weeks of storage. The maximum storage duration of normal and fermented oriental melons were 25 and 7 days at $4^{\circ}C$, and 8 and 4 days at room temperature, respectively. The oriental melon for fermentation-use could be conserved after slicing for 30 days at $4^{\circ}C$ with the addition of 1.5% citric acid and for one year at $-20^{\circ}C$ with the plastic film sealing, respectively.