• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.615-620
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• 2013

To extend the shelf-life of salted Chinese cabbages, electrolyzed water (EW) was used to wash raw Chinese cabbages before the salting process (to control microbial growth), and different storage temperatures evaluated (0, 4, and $10^{\circ}C$). A tap water washing group (TW) was used for comparison. The initial total bacterial population was 5.36 log CFU/g in the TW treatment and 3.50 log CFU/g in the EW treatment. The EW treatment decreased bacterial numbers by approximately 2 log CFU/g compared to the TW treatment and kept this initial population number for 32 days at $0^{\circ}C$. The salinity had no difference during storage. In general, several factors (pH, reducing sugars, hardness, and transmittance) decreased over time, and decreased slowly with EW treatment and $0^{\circ}C$ storage. Overall, the salted Chinese cabbages with EW treatment showed lower bacterial populations compared to TW treatment, and when stored at $0^{\circ}C$, delayed decreases in quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.754-760
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• 2006

This study was conducted to examine the quality characteristics of canned kimchi prepared by minimal thermal processing. Korean cabbage kimchi was fermented at $20^{\circ}C$ for several days up to acidity $0.5{\pm}0.1%$, was packaged in cylindrical can of 115 mL and pasteurized at low temperature. Thermal processing times based on $F_{60}$ value at geometrical center of the can were determined as 23.1, 17.7 and 12.7 min at 65, 70 and $80^{\circ}C$, respectively. The quality changes of the processed kimchi were measured during storage at $20^{\circ}C$. The pH of pasteurized kimchi was higher than that of unpasteurized control. The number of lactic acid bacteria was reduced to about $10^{2}{\sim}10^{3}$ (CFU/mL). The pasteurized kimchi product showed better texture and color values compared to the control, while resulting in the lower carotenoid and ascorbic acid contents. Kimchi preparation by minimal thermal processing had a positive effect for reduction of sour taste and sour flavor in sensory quality, but gave adverse effect in acceptability because of off-taste and off-flavor.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.678-684
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• 2012

The melanin pigment in human skin is a major defense mechanism against ultraviolet light to the skin, but darken skin color. Tyrosinase is mainly responsible for melanin biosynthesis (melanogenesis) in animals and enzymatic browning (melanosis) in plants. The purpose of this study was to optimize the fermented milk process for the melanin formation inhibition by using Lactobacillus plantarum M23 with tyrosinase inhibitory activity. We used 4-factor-3-level central composite design combining with response surface methodology. Yeast extract concentration (%, $X_1$), addition of grape (%, $X_2$), incubation temperature ($^{\circ}C$, $X_3$) and incubation time (h, $X_4$) was used as an independent factor, on the other hand, pH (pH, $Y_1$), overall palatability (score, $Y_2$) and tyrosinase inhibitory activity (%, $Y_3$) was used as a dependant factor. Based on the optimization for the highest tyrosinase inhibitory activity with pH 4.4, the expected data of pH, palatability and tyrosinase inhibitory activity with 14.8 h incubation at $37.1^{\circ}C$ by the addition of 0.127% of yeast extract, 2.95% of grape was 4.42, 7.06 and 86.65%, but the real data was 4.35, 6.86 and 84.05%, respectively. Based on the previous results, fermented milk using Lactobacillus plantarum M23 with the tyrosinase inhibitory activity could contribute for the whitening and antiaging of human skin.

• Journal of Food Hygiene and Safety
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• v.22 no.2
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• pp.99-104
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• 2007

To defend putrifaction of the processed rice cake from gas-forming yeast during storage and distribution it needed to reduce and remove them. The sanitizers of ethanol and organic acids were applied on Pichia anomala, Candida tropicalis, and isolated yeasts from the putrified cut rice cake. Although growth inhibition effect by the sanitizer of 20% ethanol, 1% acetic acid, or 1% lactic acid respectively were very low, the combined sanitizer of 20% ethanol and 1% acetic acid, or 1% lactic acid showed very high sterilizing effect toward the yeasts. Six log cfu/ml of the yeast was reduced with this combined sanitizers for 30 minutes. In addition, the combined sanitizer heated from 20 to $50^{\circ}C$ had more the increased sterility. Therefore, the sanitizer of the combined ethanol with the acetic acid or the lactic acid for 30 minutes at $50^{\circ}C$ might reduce or sterilize the putrifying yeast at the processed rice cake. The result might be also applied to the effective pre-treatment of many agricultural food stuffs, against yeast, especially unsterilized stuffs, without any hazards from the special sanitizers and nutritional loss from harsh sterilization.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.614-618
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• 2007

The effect of irradiation on the quality characteristics of lyophilized kimchi powder was investigated in order to develop a commercial kimchi seasoning. Fresh and fermented kimchi powders were irradiated at 0, 1.5, 5, 10 and 30 kGy using a Linear Accelerator. By increasing the irradiation dose level, $a^*$ (redness) and $b^*$ (yellowness) values of the kimchi powders were decreased, while $L^*$ (lightness) value remained relatively unchanged as compared to the control. As the main volatile compounds, butanal, 2-butanone and acetic acid were produced in both of the kimchi powders at 30 kGy and dipropyl disulfide was detected only in the fermented kimchi. The viable counts of aerobic bacteria, yeasts, molds, and lactic acid bacteria in the kimchi powder were significantly reduced by all irradiation doses. However, aerobic and lactic acid bacteria were still observed in both of the kimchi powders at 30 kGy. No significant off-odors or off-tastes were produced in either of the kimchi powders by irradiation, while pungency decreased after irradiation. These results suggest that irradiated kimchi powder could be used as a kimchi seasoning.

• Journal of Life Science
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• v.24 no.1
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• pp.46-53
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• 2014

Lactobacillus sakei 383, which showed the highest GABA content in fermented soycurd, survived in artificial gastric fluid (pH 3.0) up to 3 h, and the survival rate was 88%. L. sakei 383 was tolerant to bile juice during incubation in MRS broth with 0.3% oxgall, and the survival rate was 99%. The survival ratio of L. sakei 383 was high in media containing less than 6% NaCl. L. sakei 383 produced an antibacterial substance against various pathogens, including Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella typhi. The quality characteristics of soycurd fermented with L. sakei 383 were measured during the fermentation period. The viable cell number reached a peak ($10^{11}CFU/ml$) 36 h after fermentation and then slowly decreased. According to the fermentation time of L. sakei 383, the acidity of soycurd increased and the pH decreased until 12 h, and they were maintained thereafter. The moisture, crude ash, crude protein, crude fat, and crude fiber content was 94.88, 0.22, 2.38, 1.16, and 0.03%, respectively. The content of total and reducing sugar was comparatively higher in the soycurd fermented with L. sakei 383 than in nonfermented soycurd. The essential and nonessential amino acid content was 11.2 and 38.65 mg/100 g.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.338-344
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• 2001

The effect of gamma-irradiation on the microbiological and general qualities of Kanjang (fermented soy sauce, Korean type) and Shoyu (fermented soy sauce, Japanese type) was studied. Samples were prepared, irradiated at 5, 10 and 20 kGy, and then stored at $25^{\circ}C$ for 18 weeks. The results showed that the Bacillus spp. was inactivated by 3 log cycles with the irradiation dose of 10 kGy and the number of Bacillus cells that survived from 10 to 20 kGy of gamma irradiation was decreased gradually during storage. Yeasts and Lactobacillus were nearly eliminated at 5 to 10 kGy of irradiation. The $D_{10}$ values of Bacillus, yeast and Lactobacillus in Shoyu were 2.67 kGy, 0.81 kGy and 1.30 kGy, in Kanjang were 2.75 kGy, 0.99 kGy and 1.47 kGy, respectively. The general quality of gamma irradiated Shoyu and Kanjang, such as total nitrogen, amino nitrogen, protease activity and pH were more stable than that of control during storage periods. Decolorization was observed just after irradiation, but the color was recovered during storage. The sensory evaluations showed that irradiated samples were more acceptable. Therefore, it was considered that gamma irradiation was effective for maintaining better quality of Shoyu and Kanjang during storage.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.278-284
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• 1990

A study relating the soluble-solids (S.S.) contents of Chinese cabbages to the final titratable acidities(TA) of kimchis was conducted. The S.S. contents of Spring-sowed Chinese cabbages were in the range from $1.20-3.40^{\circ}$ Brix while those of Autumn-sowed Chinese cabbages were in the range from $3.8-6.6^{\circ}$ Brix. The S.S. contents of Chinese cabbages were varing depending on their varieties and the cultivating seasons. However, seasonal variations were much more significant than the varietal variations. The final TAs of kimchis after complete fermentation were found to be directly proportional to the S.S. contents(x) of Chinese cabbages, showing that TA equals to 0.30x+07779. From the equation, a Chinese cabbage of a S.S. content with up to $0.02^{\circ}$ Brix, which is practically impossible to obtain, will make a kimchi which will not be overacidified during the prolonged storage period without any preservative measures.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.109-119
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• 1989

To improve the storage method of Kimchi, optimum ripening Kimchi for an irradiation treatment(the time of around 0.3% in total acidity of Kimchi) was irradiated by doses of 1, 2, 3 kGy with Co-60 ${\gamma}-radiation$ and stored at $10^{\circ}C$. Total aerobic bacteria increased in the beginning of storage and then decrease slowly as the number of total lactic acid bacteria increased. Total lactic acid bacteria initially loaded by $10^8\;cells/ml$ in Kimchi shortly after irradiation reduced to $10^4-10^6\;cells/ml$ with 1-3 kGy doses and decreased gradually through the whole storage period. The initial load of yeast, $10^3\;cells/ml$, increased steadily during Kimchi storage and led to more than $10^4\;cells/ml$ after 30 days of storage. While it maintained tha the load in 2-3 kGy irradiated groups after 30 days of storage was less than that at the beginning of storage. pH, acidity and volatile acid in the nonirradiated group were 4.0, 0.7% and 0.06%, respectively at the 15th day after storage, but at the 30th day after storage, 2-3 kGy irradiated groups showed different values, 4.1, 0.58-0.63%, and 0.04-0.05%, respectively. The texture(firmness) of Kimchi reduced along with storage time, and 2 kGy irradiated group proved most favourable in its texture during storage. In the sensory evaluation of Kimchi, nonirradiated group was inedible after 15 days of storage, whereas 2-3 kGy irradiated groups could proling the storage-life of Kimchi over 2 times compared with the nonirradiated Kimchi, showing the good sensory quality even after 30 days of storage.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.100-108
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• 1989

A study relating the sugar contents of radishes to the final titratable acidities(TA) after complete fermentation was conducted to get an idea of selecting radish varieties to improve storage stabilities of fermented pickled radish cubes. Thirty six varieties of spring-sowing and thirty four varieties of autumn-sowing radishes were chosen to ferment to measure their final TA in relation to their sugar contents. The sugar contents of spring-sowing radishes were in the range from 2.40 to $3.71^{\circ}\;Brix$ and the final TA ranged from 1.15 to 1.65%. The sugar contents of autumn-sowing radishes were in the range from 4.00 to $5.53^{\circ}\;Brix$ and the final TA ranged from 1.45 to 2.00%. The final TA obtained after complete fermentation were found to be directly proportional to the sugar contents of radishes, showing that TA equals to 0.29x+0.4428, where x is sugar content of radish. From the equation, since a properly aged fermented pickled vegetable is believed to have a TA range from 0.6 to 0.8%, a radish of a sugar content ranging from 0.6 to $1.3^{\circ}\;Brix$ will make fermented pickled radish cubes which will not be overacidified during the prolonged storage period.