• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.420-427
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• 1995

This study was conducted to investigate the preservative effect of low molecular weight chitosans on kimchi(2% salt concentration) during fermentation at $20^{\circ}C$. The pH and total acidity of control kimchi were lower and higher, respectively than those of kimchi samples containing chitosan. Reducing sugar content tended to be lower in control kimchi than in kimchi samples containing chitosan until 6 days of fermentation. Malic acid content was lower in control kimchi than in kimchi samples containing chitosan until 4 days of fermentation. Succinic acid content was higher in control kimchi than in kimchi samples containing chitosan at the 2 days of fermentation. Content of lactic and acetic acid also was higher in control kimchi than in kimchi samples containing chitosan at the 4 days of fermentation. The number of total microorganisms and those of microorganisms of Leuconostoc genus and Lactobacillus plantarum were higher in control kimchi than in kimchi samples containing chitosan. The number of microorganisms of Leuconostoc genus was lower in kimchi samples containing chitosan with the lower molecular weight chitosan than those with the higher molecular weight chitosan. Intensity of sensory sour taste and staled flavor were higher in control kimchi than in kimchi samples containing chitosan. There was not much difference in sensory firmness among kimchi samples, but control kimchi was evaluated slightly weaker than kimchi samples containing chitosan. Off-flavor was evaluated as weak in all the kimchi samples.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.792-798
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• 2002

Investigations on the microbiological, physicochemical, and sensory characteristics of seasoned Galbi using various packaging methods during storage at $-1^{\circ}C$ revealed no significant differences in pH values and acidities of seasoned Galbi depending on packaging methods and storage periods. Increments of thiobarbituric acid values of seasoned Galbi with non-evacuated packaging and modified atmosphere packaging were superior to those of vacuum packaging and double-film vacuum packaging during storage. Seasoned Galbi with non-evacuated packaging showed the highest volatile basic nitrogen value, and total plate count significantly increased compared to other packaging methods after 15 days storage. Coliform bacteria showed an average count of 2.35 log CFU/g at the beginning of storage, which increased slightly from 7 to 15 days, and was maintained under 4.0 log CFU/g after 15 days storage. The sensory evaluation revealed that non-evacuated packaging scored relatively lower than other methods in color, flavor, off-odor, and overall acceptability after storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.921-925
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• 2007

In order to optimize microbial safety and preservation in quality retention of rice flour, commercial hot-air dry (HT, 65/15 min) and microwave dry (MT, 700 watt/30 sec) treatments were developed, and in this study, natural microflora present in rice flour exposed to different storage temperature and periods were monitored. Changes in color (E) appeared to be less on the MT rice flour than on the rice flour. Effectiveness of the MT treatment showed reduction rates for total aerobic bacteria (2.62 log CFU/g), yeasts, and molds (0.37 log CFU/g). Total aerobic bacteria showed similar growth patterns of all the treatments during storage; however, the MT treatment inhibited the growth of this organism in rice flour. In conclusion, the MT treatment was found to be a suitable drying method to substitute the HT treatment in terms of quality of rice flour and microbial safety.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.5
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• pp.759-766
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• 2011

We conducted this study to develop a high value black garlic Makgeolli that was made of black garlic extract (BGE) and Sulgidduk. We investigated the quality characteristics of Makgeolli made with three different combinations of materials (control, Sulgidduk only; A, Sulgidduk combined with 15% BGE and water; B, Sulgidduk combined with 15% BGE instead of water). The pH of A and B were higher than the control, but the titratable acidity of A and B were lower. The sugar and alcohol contents of A and B increased during fermentation. A similar growth pattern was observed invisible cells, yeast, and lactic acid bacteria in all three Makgeolli. In A and B, the quantity of lactic acid bacteria was relatively higher than the yeast. The L value (lightness) was highest in the control, and the a value (redness) and b value (yellowness) were higher in A and B. The antioxidant properties of the three types of Makgeolli were evaluated using DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis[3-ethylbenzthiazoline-6-sulfonic acid]) radical scavenging activities. In these assays, B showed significantly higher radical scavenging activities than the other two Makgeolli.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.5
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• pp.753-758
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• 2011

We investigated the effects of ultra filtration (UF) of Goroshoe (Acer mono Max.) sap collected in March and April. The total bacteria and turbidity of the sap collected in April were higher than in March. However, after UF, the turbidity decreased and bacteria were not detected. The total acidity and total sugar of the sap collected in April were lower than that collected in March. After UF, total acidity and total sugar decreased slightly in sap from both of the collection times. The crude ash and mineral content of the sap collected in April were higher than in March. In particular, the calcium and potassium content of the sap collected in April were 166.38 and 29.47 mg/L, respectively, which was much higher than in March. Again, after UF, the crude ash and mineral content were decreased in the sap from both collection times. We concluded that UF of Goroshoe sap increased its quality regardless of collection time.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.5
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• pp.576-582
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• 2017

This study evaluated the microbial quality of dried and powdered foods during storage with increased humidity because of climate change. Five types of dried and powdered foods (dried shredded squid, wheat flour, Sunsik, red pepper powder, and roasted sesame seed) were stored at different relative humidities (RH 23%, 43%, 68%, 85%, and 100%) and changes in water activity and microbial populations were measured during storage at $35^{\circ}C$ for 15 days. The results revealed that water activity values of dried and powdered foods were significantly increased during storage when samples were stored at RH 85 and 100%. In addition, levels of total mesophilic bacteria, yeast, and mold were significantly increased after storage for 6 days or 9 days at RH 85% and 100%. However, levels of Escherichia coli and coliform did not increase significantly during storage. Based on these findings, dried and powdered foods should not be stored at high RH because the increased water activity enables microbial growth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1964-1968
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• 2014

This study investigated the quality characteristics of mulberry cultivated under greenhouse and open field conditions. Quality characteristics such as the number of aerobic bacteria, pH, acidity, soluble solid content, and contents of free sugar, polyphenol, and anthocyanin were investigated. The number of aerobic bacteria in mulberry cultivated in open fields was higher than that of mulberry cultivated in the greenhouse. The average pH was significantly higher in greenhouse mulberry whereas acidity was higher in mulberry grown in open fields. The average soluble solid content of mulberry cultivated in open fields was slightly higher than that of mulberry cultivated in the greenhouse, although the difference was not significant. Fructose and glucose were detected in mulberry as free sugar. The free sugar content of mulberry was not affected by cultivation conditions. The average polyphenol contents of mulberry cultivated in the greenhouse and open fields were 393.36 and 514.47 mg%, respectively. The average anthocyanin contents of mulberry cultivated in the greenhouse and open fields were 205.00 and 265.56 mg%, respectively. The average polyphenol and anthocyanin contents of mulberry cultivated in open fields were significantly higher than those of mulberry cultivated in the greenhouse.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1095-1101
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• 2001

Spinach was minimally processed into the unseasoned side dish to be used for Korean food service industry, using the techniques of cook-chill and sous vide. Spinach was blanched at 10$0^{\circ}C$ for 6 minutes, vacuum-packaged in the unit of 500 g by plastic film of low gas permeability, pasteurized at 9$0^{\circ}C$ and then cooled rapidly at 3$^{\circ}C$. The chilled products were then stored at 3 and 1$0^{\circ}C$ with measurement in their quality. Six log cycle (6D) inactivation of Listeria monocytogenes and 13 log (13D) thermal destruction of Streptococcus faecalis were compared as two pasteurization conditions, which corresponded to heating for 22.8 and 30.0 minutes at 9$0^{\circ}C$, respectively. Milder heat processing based on 6D process of L monocytogenes gave better quality of color, texture, ascorbic acid and chlorophyll than the conditions of 13D process of S. faecalis. Any microbial growth in total aerobic, psychrophilic and anaerobic bacteria was not observed until 8 days at 1$0^{\circ}C$ and 14 days at 3$^{\circ}C$, which might be regarded as strict guidelines of shelf life. Storage times based on the changes in physical and chemical quality were longer than those based on strict microbial quality in case of the products pasteurized by 6D process of L. monocytogenes. The seasoned vegetables prepared from sous vide processed spinach were found to be inferior in sensory quality to those from freshly blanched one.

• Food Science and Preservation
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• v.20 no.4
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• pp.518-523
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• 2013

This study was performed in order to evaluate the quality properties of Kimchi containing 0%, 10%, 20%, and 30% of oriental melon peel parts. The Kimchi was fermented for 28 days at a temperature of $15^{\circ}C$. The pH, titratable acidity, total microbial counts, and lactic acid counts were measured, and the sensory characteristics including taste, color, chewiness, and overall acceptability were evaluated. During the 28 days of fermentation, the pH dramatically decreased between the 7th and 21st day of the fermentation period, and maintained thereafter in control (0%). However, the pH in peel-added groups slightly increased up to the 14th day and decreased up to the 21st day with 4.13~4.41. The total microbial counts in control were significantly higher than those in the peel-added groups. This trend was maintained throughout the fermentation period. A similar trend was found in the lactic acid microbial counts throughout the fermentation period. During the sensory analysis, the values of taste were significantly higher in the 20% and 30% peel-added Kimchi, while the chewiness and overall acceptability were significantly higher in the 20% peel-added Kimchi than those in control. This study showed an improvement in the storage period of Kimchi products with 20% of oriental melon peel, as well as the possibility of a commercial Kimchi manufacture.

• Food Science and Preservation
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• v.15 no.3
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• pp.340-346
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• 2008

This study investigated the microbial safety of apple snails and intermediate-moisture-content apple snail products subjected to various treatments, according counts of total bacteria, Escherichia coli, mold and yeast during storage at 4C Heating of raw apple snails at 95C for 5 min increased the storage period in relation to total bacteria, E. coli, mold and yeast-cell growth. Addition of 10% NaCl and 50% vinegar increased the microbial safety of apple snails. Microorganisms were not detected for 14 weeks in vacuum-packaged intermediate-moisture-content apple snail products stored at either 4C or 30C. These results suggest that heat treatment of raw apple snails, soaking in 10% NaCl and 50% vinegar solutions, and vacuum-packaging increases the shelf-life and microbial safety of apple snail products.