• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.261-266
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• 1979

This experiment was carried out to evaluate the sanitary quality of cultured vegetables and to check the removing rate of bacteria by treating methods such as washing with tap water or commercial detergent, or blanching. Samples collected from farm land located at Busan suburbs and markets were Fragaria chiloensis var. ananasa, Lycopersicum esculentum, Capsium longum, Cucumis sativus, Lactuca scariola var. sativa leaf of Perilla frutescens var, japonica, Oananthe stolonifera and Allium odoium. Fecal coliform MPN was ra god from less than 30 to 430,000 per 100 grams of samples examined while plate count was $7.2\times10^3\;to\;2.2\times10^7$ per gram. Usually contamination rate of fecal coliform of leaf vegetal)les was much higher than that of fruit vegetables. Removing rate of bacterial density of vegetables by washing three times with tap water was about $70\%$ in fruit vegetables, about $20\%$ in leaf vegetables but it was about $80\%$ in leaf vegetables by washing with a commercial detergent. Sirvival rate of viable cell count of leaf vegetables was less than $0.1\%$ after blanching for one minutes in boiling tap water, Composition of coliform was $18\%$ Escherichia coli group, $22\%$ Citrobacter freundii group and $60\%$ Klebsiella aerogenes group, among Escherichia coli, type I being $16\%$ in total. The coliform detection from BGLB gas positive tubes being planted with various vegetables was about $80\%$ in the result of IMViC reaction.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.194-200
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• 2008

This study was performed to examine the properties of takju containing added Glycyrrhiza uralensis ethanol extract (GUEE) at 10$^{\circ}C$ for 12 days. Change in TBARS values was lower in the takju with GUEE as compared to control. The total viable cell count and yeasts cell count of all samples remained constant over the storage period. The brix of the takju treated with 0.5% GUEE (3.8-4.3) was higher than that of the control (3.8-4.0). Suspension stability and yellowness increased as the added concentration of GUEE increased. After 12 days of the storage, the pH level of the 0.5% GUEE takju was 3.9, which was 0.2 higher than that of control. In terms of acidity, the 0.5% GUEE takju ranged from 0.269 to 0.282, whereas the acidity of the control ranged from 0.294 to 0.302. In treated Takju with GUEE represented at treated takju with GUEE had the positive effects toward improving its preservation and quality.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1341-1349
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• 2000

The addition of 5% NaCI to standard plate count (SPC) and bromcresol purple (BCP) agar showed the highest viable cell counts for Jeot-kal samples. The use of 15% glycerol as cryoprotectant showed the highest microbial survival rate at both temperatures, $-20^{\circ}C$ and $-170^{\circ}C$, and on both colony count media, SPC and BCP. During the aging, the pH of Bajirak Jogae-Jeot (fermented clam) decreased from 6.8 to 5.0. Crude protein content was 10% for Bajirak Jogae-Jeot and $6{\sim}7%$ for Myeolchi-Jeot (fermented anchovy). Microbial population of Bajirak Jogae-Jeot was $10^9\;CFU/g$ after 4 weeks of aging, but was only $10^{3-5}\;CFU/g$ in the case of Myeolchi-Jeot. The proportion of Gram positive and catalase negative bacteria in Bajirak Jogae-Jeot increased drastically during the 4 weeks of aging, which showed typical lactic bacterial fermentation. After 2 years' storage of Jeot-kal in liquid nitrogen tank, the cell counts of total aerobic or lactic bacteria were decreased, resulting in about 10% survival rate. Microbial floral change of Jeot-kal was also investigated. In the case of Bajirak Jogae-jeot, the ratio of rod to cocci and that of Gram negative to positive increased after liquid nitrogen storage. But, rod to cocci ratio of Myeolchi-jeot decreased after liquid nitrogen storage. The ratio of yeasts decreased in both cases after storage.

• Korean Journal of Human Ecology
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• v.6 no.2
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• pp.57-65
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• 2003

To investigate quality characteristics of kimchi prepared for the winter around Chonnam area, home made kimchi samples collected from 22 area, and they were stored at -1${\pm}$1$^{\circ}C$. The results were as follows : The pH and acidity of kimchi samples were 4.75 and 0.84%. respectively. Salt concentration was 3.50% and in Redox potential measurement, Eh value was -134.08mV. Ascorbic acid and reducing sugar contents were 10.l8mg% and 13.25mg%, respectively, In color measurement, L value was 52.29 and a and b values were 19.68 and 27.69, respectively. Total viable count was 5.5${\times}$10$\^$6/ and lactic acid bacteria count and yeast were 4.6${\times}$10$\^$5/ and 8.8${\times}$10$\^$5/. respectively. Properties of hardness of kimchi measured instrumentally was 9.26kgf. Alcohol insoluble solids(AIS) content was 5.53% and hot water soluble pectin(HWSP) content and sodium hexametaphosphate soluble pectin(NaSP) content were 17.35% and 29.65%, respectively, also hydrochloric acid soluble pectin(HClSP) content was 53.0%.

• Food Science and Preservation
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• v.24 no.3
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• pp.387-393
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• 2017

The objective of this study was to investigate the effect of hot water extract of Welsh onion root (HEWO) on growth of lactic acid bacteria and fermentative characteristics of yogurt. The physiochemical characteristics of HEWO such as pH, soluble solid, reducing sugar, total polyphenol content and DPPH radical scavenging activity were studied. The lactic bacterial count in brain heart infusion (BHI) broth with HEWO was about 1 log cycle higher than in control for 24 h at $37^{\circ}C$. The pH of yogurt prepared with HEWO (WY100) and 50% HEWO (WY50) was gradually decreased significantly but increased the viscosity of yogurt with increasing HEWO concentration during fermentation. The viable cells of lactic acid bacteria after fermentation for 24 h were 8.03 (control), 8.77 (WY50), 8.84 (WY100) log CFU/mL, respectively. The DPPH radical scavenging activity of yogurt increased with increasing HEWO concentration. Sensory quality of yogurt prepared with HEWO was higher than that of control. The pH and lactic acid bacteria of all tested yogurts decreased during storage for 10 days at $4^{\circ}C$ but lactic bacterial count of yogurt prepared with HEWO maintained $10^8CFU/mL$ during storage. These results indicated the potential use of HEWO as a valuable resource to improve fermentation and functionality of yogurt.

• Food Science and Preservation
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• v.15 no.4
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• pp.606-611
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• 2008

Myungran Jeotkal, Korean fermented seafood, and its ingredients(hot red pepper powder, ginger, garlic, and seasoning mix) were irradiated with 0, 0.5, 1.0, 2.0, and 5.0 kGy of gamma rays and stored at 4C for 4 weeks to determine changes in microbiological and sensory characteristics. Water activities of Myungran Jeotkal, hot red pepper powder, ginger, garlic, and seasoning mix were 0.89 0.56, 0.98, 0.99, and 0.07, respectively. Myungran Jeotkal was observed to be initially contaminated. Total aerobic bacteria, yeast and mold, and coliform levels were 6.7, 4.3, and 3.6 log CFU/g, respectively. Irradiation at 2 kGy afforded approximately a 4 log reduction in total aerobic bacteria, and a 3 log drop in both yeast and mold levels and coliform bacteria(P<0.05). No viable microbial cells were detected in Myungran Jeotkal after 5 kGy of irradiation(at a detection limit of 101 CFU/g). The total aerobic bacterial level in red pepper powder was 6.3 log CFU/g and this component, of the tested ingredients, contributed most to the microbial contamination of Myungran Jeotkal. The initial count of total aerobic bacteria, 6.3 log CFU/g, was significantly reduced to 4.5 log CFU/g after irradiation(P<0.05). Sensory evaluation showed that gamma irradiation of up to 5.0 kGy did not adversely affect overall acceptability of Myungran Jeotkal or its ingredients during cold storage. Therefore, gamma irradiationwas effective to extend the shelf-life of Myungran Jeotkal.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.105-114
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• 1974

Identification and change of microflora during the fermentation of anchovy Engraulis japonica, under the halophilic circumstance were investigated. The change of salinity and pH in meat and juice which decide the environment for microorganism and decomposition of nitrogenous compound which functions as a nutrient source were also discussed by measuring the content of total-N, amino-N, nonprotein-N, TMA and VBN, The fresh anchovy was mixed with rock salt (20 percent w/w) and stocked for six months. Through the fermentation lag phase of viable cells extended for 20 days that was obviously larger compared with other circumstances, hereafter increased to reach the maximum value of $5\times10^4$ total count per gram at 35 day stock. The stationary phase proceeded for 25 days. 540 strains were isolated and among them 11 genus of bacteria, 3 genus of yeasts, were identified and other 2 yeast strains of unidentified. At the initial stage of fermentation, Pseudomonas, and Helobacterium prevalently grew, at the middle stage, they disappeared rapidly and Pediococcus and yeasts completely dominated, where they are assumed to get directly involved with fermentation of fish, The PH value tended to decrease in the progress of fermentation and at 100 day stock it showed the minimum value of 5.5 to 5.6 in both meat and juice. The highest salinity of meat decreased to 18 percent, while in juice it decreased to 28 percent since 50 days stock. The content of total-N in meat gradually decreased to 2.8 percent, while in juice it increased to 2.3 percent at 100 day stock, However nonprotein-N was 1.8 percent and amino-N was 1.1 Percent. Since 100 days stock, the increasing rate of amino-M is too low it could be judged to entered the final stage of fermentation, In the first 20 days stock, the increase of VBN and TMA can be explained by the growth of putrefactive bacteria such as pseudomonas on the meat before salts penetrate into the fish meat, while reincrement after 100 days stock, is explained by decomposition of free amino acid due to the reactions of bacteria and enzymes.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.513-520
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• 2006

Spray-dried (SD) and freeze-dried (FD) takju powders were stored at 5, 15 and $25^{\circ}C$, and various quality characteristics such as moisture, amino nitrogen, color value, total viable cell count, total sugar, reducing sugar organic acid, and flavor compounds were measured for 50 days at 10-day intervals. After 50 days of storage, the moisture content was increased from an initial 6.64% to 7.24-7.38% in the SD powder, and from an initial 4.86 to 5.43-5.61% in the FD powder. pH, total acid content and total viable cell counts were slightly increased. Organic acid content was decreased in the SD powder from an initial 3,949.9 mg% to 805.9-922.3 mg%, and in the FD powder from an initial 5,171.5 mg% to 3,646.0-4,110.2 mg%. Amino nitrogen content was increased in the SD powder from an initial 1.2% to 1.9-2.2% and in the FD powder from an initial 1.9% to 2.2-2.5%. Total sugar and reducing sugar contents were increased in the SD powder from an initial 17.2% and 4.0% to 25.9-27.3% and 5.8-6.9%, and in the FD powder from an initial 19.1% and 5.2% to 29.2-30.2% and 8.3-8.8%, respectively. With increasing storage time, L and b values in the SD powder increased slowly, while L value in the FD powder tended to decrease and b value tended to increase. About 20 major volatile flavor components were identified in the SD and FD powders by GC-MS and all such component levels were decreased with increasing storage time.

• Food Science and Preservation
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• v.21 no.6
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• pp.917-924
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• 2014

Normal- and late-harvested Fuji apples were fermented using the rapid-fermenting yeast strain Saccharomyces cerevisiae SS89. The late-harvest apples showed a slightly higher soluble-solid content with a lower level of total-acid and moisture (p<0.05) contents as well as hardness (p<0.05) than the normal-harvest apples. During the fermentation, the apples had similar changes in the pH and total-acid content regardless of the harvest time, but the increases in the alcohol content and yeast viable count with the decrease of the soluble-solid content were more rapid in the late-harvest apples than in the normal-harvest apples. After the completion of the fermentation, the soluble-solid and alcohol contents became very similar. The late-harvest cider showed a high total phenolic-compound content and a high DPPH radical scavenging effect, although these were slightly lower than those of the normal-harvest cider. It also showed a higher malic-acid content and higher hue color (p<0.05), Hunter's L, and b (p<0.05) values than the normal-harvest cider. In the sensory evaluation, the late-harvest cider obtained a higher score in taste and a lower score in color compared to the normal-harvest cider.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.223-228
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• 2011

Korean traditional rice wine, Makgeolli, has been widely consumed with increasing popularity in Korea. Also, there has been an increase in the varieties of Makgeolli for the younger generation. In this study, we examined the physicochemical and microbial properties of Makgeolli supplemented with cucumber during fermentation. Four hundred grams of cucumbers (20% of the total amount of rice) were grinded and added to the rice solution (2 kg rice and 3.12 L distilled water) along with the Nuruk (40 g) and yeast (14 g). After mixing the solution, it was fermented for six days in a water bath ($28^{\circ}C$). During the fermentation, the pH value of the cucumber Makgeolli fell from 5.88 to 3.94 on day-1, and steadily increased to a pH value of 4.48 by day-6. The total acidity of the cucumber Makgeolli sharply increased from 0.02 to 0.20% on day-1, and then slowly increased thereafter to 0.28% by day-6. After the 6-day fermentation, the L values of the control and the cucumber Makgeolli were similar. The total viable cell, lactic acid bacteria and yeast count of the control and the cucumber Makgeolli increased considerably after the 6-day fermentation process. Free sugar analysis showed that glucose contents decreased with increasing fermentation periods. The succinic acid content was the highest among all the organic acids. Thirty-nine volatile compounds were observed on the final day of fermentation in the cucumber Makgeolli.