• Journal of Dairy Science and Biotechnology
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• v.32 no.2
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• pp.157-161
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• 2014

Quality characteristics of commercial yoghurt powder products marketed in Korea were compared. According to the product type classification, no product met the product identity of "fermented milk powder" (six were identified as "other processed product" and nine as "sugar product"). Titratable acidity of products (10%, w/v) varied from 0.11 to 0.82% while numbers of lactic acid bacteria varied from 0 to $1.4{\times}10^8CFU/g$. There were significant differences in hydration properties and viscosity of yoghurt powder products. Some regulations are required to avoid consumer misunderstanding of beneficial health effects of yoghurt powder products.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.190-196
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• 1996

Kimchi vacuum packaged in PET/AI/PE pouch was stored at $0^{\circ}C\;and\;10^{\circ}C$ to evaluate the effect of vacuumizing conditions on quality changes. The quality of kimchi during storage was investigated in terms of pH, titratable acidity, color, viable counts of lactic acid bacteria including Leuconostoc and Lactobacilli and sensory properties. Titratable acidity and pH were not significantly different for the vacuum degrees. Color index (L b/a) values of crushed kimchi juice decreased exponentially and remained constant during storage, but the resulting color change was not affected by the vacuum degrees. Viable counts of lactic acid bacteria and sensory scores exhibited no significant difference among the kimchi of different vacuum degrees. Consequently, the vacuum degree in packaging of kimchi seemed to influence little on quality of kimchi. For enhancing the commercial value of vacuum packaged kimchi products, it would be appropriate to produce a slight vacuum, eliminating the head space, within packages.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.893-904
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• 2022

It is well documented that the fruit of the vitamin tree, which is rich in vitamins A, C, E, and K, shows anti-diabetic, antibacterial, immune regulation, anti-inflammatory, and anti-aging effects. In some countries including Europe it has been used to develop various functional foods. This study was conducted to elucidate the fermentation properties of fermented milk supplemented with vitamin tree (Hippophae rhamnoides L.) fruit powder. The pH, titratable acidity, number of viable cells, and viscosity of the yogurt made with vitamin tree fruit powder were found to be higher than those of the control group, as the amount of supplemented powder added became higher and the fermentation progressed. Production of lactic, malic, and acetic acids increased relative to that of the control as the amounts of supplemented powder were higher. It was found that the increase in the decomposition of lactose to glucose and galactose was proportional to the amount of supplemented powder added and the elapsed fermentation time. During storage for 15 days the quality of yogurt supplemented with vitamin tree fruit powder was within the proper range of fermented milk quality in terms of pH, titratable acidity, and number of lactic acid bacteria. The yoghurt manufactured with vitamin tree fruit powder has a similar quality to that of the control, and therefore, a new functional yoghurt providing health benefits could be developed.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.319-327
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• 2000

This study was conducted to prolong the edible period of Kimchi by adding chitosan (0.25, 0.5%) and sodium salts of various organic acids(0.01~0.04M citrate, malate, lactate) . The edible period was estimated by measuring changes in pH. titratable acidity(TA), PH/TA ratio, ascorbic acid content and pectin fraction during Kimchi fermentation at 2$0^{\circ}C$. The results were compared by estimating the maturity of Kimchi fermentation. Kimchi with the chitosan showed higher pH and titratable acidity throughout the fermentation period than that without chitosan. The pH decreased during the fermentation in the order of control, 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+Na-citrate, 0.5% chitosan+Na-malate and 0.5% chitosan+Na-lactate. But the titratable acidity increased in the order of control, 0.5% chitosan+Na-malate, 0.25% chitosan. 0.5% chitosan+Na-citrate, 0.5% chitosan and 0.5% chitosan+Na-lactate. The PH/TA ratio decreased in the order of control, 0.25% chitosan, 0.5% chitosan+Na-malate, 0.5% chitosan, 0.5% chitosan+Na-citrate and 0.5% chitosan+Na-lactate. Ascorbic acid content in Kimchi was the highest at the 3rd day and then decreased during fermentation. Ascorbic acid content in Kimchi containing 0.5% chitosan and organic acid salts was higher than others. Alcohol insoluble solids( AIS ) in Kimchi decreased during fermentation in the order of control, 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+Na-palate. 7.5% chitosan+Na-lactate and 0.5% chitosan+Na-citrate. During fermentation, hot water soluble pectin (HWSP) of control increased, whereas HCI soluble pectin (HCISP) decreased. By addition of chitosan, however, the results became reverse. Chitosan addition appeared to be effective in improving preservation quality of Kimchi during fermention. The edible period become extended by using chitosan plus organic acids instead of using chitosan only. Overall. addition of 0.5% chitosan+Na-lactate seemed most effective in prolonging the edible periods during Kimchi fermentation.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.66-75
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• 2003

This experiment was carried out to examine the fermentation properties of yogurt added fresh mulberry, freeze dried-mulberry and heated air dried-mulberry at concentrations of 0%, 0.3%, 0.6% and 0.9%. Lactic acid bacteria was used mixed starter culture(Str.salivarius ssp. thermophilus and Lac. delbrueckii ssp. bulgaricus). We obtained excellent results from the yogurt added fresh mulberry. In yogurt added 0.9% fresh-mulberry, lactic acid contents and titratable acidity were higher than those of 0%, 0.3%, 0.6% fresh-mulberry added. Also, sensory scores of color, taste and overall acceptability of the yogurt with 0.9% fresh mulberry was higher than those of any other groups.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.60-64
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• 2005

Yogurt base was prepared from skim milk added with $0.2{\sim}1.0%\;(w/v)$ chlorella powder and fermented with lactic acid bacteria (the mixed strain of Lactobacillus acidophilus, Bifidobacterium longum and Streptococcus thermophilus) at $40^{\circ}C$ for $12{\sim}18\;h$. Quality characteristics of the yogurt were evaluated in terms of acid production (pH and titratable acidity), number of viable cells, viscosity and sensory properties. The addition of chlorella powder stimulated the growth of lactic acid bacteria and remarkably enhanced the acid production. After 12 h incubation, titratable acidity of chlorella yogurt was $1.16{\sim}1.33%$ and was higher than that (1.02%) of yogurt made with only skim milk. However, the viscosity of yogurt was decreased by the addition of chlorella powder. The sensory score of yogurt added with 0.2% chlorella powder was similar to ordinary yogurt in taste and overall acceptability. When chlorella yogurt was kept at $4^{\circ}C$ for 15 days, its quality-keeping properties except for number of viable cells were relatively good. According to sensory score and storage ability, the optimum concentration of chlorella powder was around 0.2%.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.666-671
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• 1993

Mixtures (total solid content: 15%) prepared with whole milk added with skim milk powder and/or sweet potato and/or pumpkin were fermented with 0.205% gelatin, 2% sugar and yogurt bacteria. The fermented mixtures (curd yogurt) were evaluated for acid production (pH, titratable acidity), number of viable cell, sensory property and keeping quality. The acid production of all mixtures remarkably increased for the first 12 hours and there is no significant difference among the mixtures. The lactic acid bacteria counts in the all products after 24 hours incubation were above $6.4{\times}10^{9}cfu/ml$. In organic acids, the mixture added with skim milk powder was higher ratio of lactic acid content to total acidity than those added with sweet potato and/or pumpkin. The sensory score of mixture containing sweet potato was best but curd yogurt containing pumpkin reduced the sensory property. When each mixtures were kept at $5^{\circ}C$ for 15 days, pH, titratable acidity, and number of viable tells of yogurt were not changed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.439-443
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• 2001

The effect of fermentation of peanut milk with lactic acid bacteria on n-hexanal content was investigated. Changes in pH, titratable acidity and viable cell populations indicated that Streptococcus salivarius subsp. thermophilus was adapted better than Lactobacillus delbrueckii subsp. bulgaricus during fermentation. Analysis of headspace volatiles revealed that n-hexanal, which is one of the compounds responsible for undesirable green/beany flavor in peanut milk, completely disappeared as a result of fermentation. S. salivarius subsp. thermophilus was more effective than L. delbrueckii subsp,. bulgaricus in reducing the n-hexanal content. No significant difference was found in water sorption between fermented and unfermented peanut milk.

• Journal of the Korean Society of Food Culture
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• v.9 no.4
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• pp.329-333
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• 1994

Physicochemical Properties of dough for Jeungpyun(Korean steamed rice cake) were analyzed during fermentation in the ranges of 0 to 10 hours. As fermentation time went by, pH of Jeungpyun dough was decreased while its titratable acidity and lactic acid content were increased continuously. Total sugar content was decreased continuously during fermentation. Reducing sugar content was increased greatly at the early stage of fermentation, reaching maximum value, 101 mg/g-dry matter at 4 hours, but it was decreased thereafter.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.1
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• pp.41-48
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• 2008

This study focused on the alcohol fermentability of traditional Nuruk, as well as yeast containing traditional Nuruk, in the production of Yakju. The fermentation performed with 30% Nuruk was effective with regard to alcohol yield. In addition, the fermentation containing 70% Nuruk showed the highest titratable acidity due to increased amounts of organic acids (succinic acid, oxalic acid, malic acid, acetic acid), which, however, negatively influenced the Yakju quality. Moreover, microbiological contamination always occurred in the fermentations using only Nuruk. In contrast, in the experiments with the yeast containing Nuruk, higher alcohol content and lower titrable acidity were obtained, independent of the Nuruk ratio used, positively effected the Yakju taste and flavor. Overall, the fermentation performed using the yeast containing 30% traditional Nuruk showed the best results for Yakju production.