• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1470-1476
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• 2001

Kou Woan Lao is an oriental-style dairy product, which is coagulated by milk-clotting enzyme from the culture filtrate of lao-chao. The product appears smooth, sweet, slightly wine flavour, and the flavour differs from yogurt. The aim of this study was to search for the optimum model to shorten the period of manufacture, and to improve the quality of Kou Woan Lao. A response surface design was used for studying the effects of addition of carrageenan, locust bean gum, and culture filtrate from lao-chao on the curd firmness, viscosity, and syneresis. Results indicated that the best rheological property, preservative quality and acceptability of Kou Woan Lao could be obtained by the combination of 0.22% carrageenan, 0.21 % locust bean gum and 12% culture filtrate from lao-chao. The curd firmness, viscosity and syneresis of resultant product were 29.3 g, 21,347.7 cps, and 8.92%, respectively and the microstructure of the curd revealed a relatively complete three-dimensional spider web-like structure.

• Korean Journal of Food Science and Technology
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• v.17 no.1
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• pp.45-50
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• 1985

Soy yogurt beverage(SYB) was prepared from soy protein concentrate and the effect of stabilizers on the sedimentation of SYB curd and the microbiological quality of SYB during storage were investigated. The curd in SYB precipitated significantly during the first one hour of storage and the sedimentation of curd was reduced by the addition of CMC of over 0.6%, PGA of over 0.2% or Na-alginate of over 0.05%. SYB could be kept for 66 days at $5^{\circ}C$ without significant change in viable cell count of lactic acid bacteria. pH, titratable, acidity and viable cell count of SYB were significantly changed from 42 days of storage at $25^{\circ}C$. Some of SYB samples were contaminated by fungi and the growth of fungi was greatly inhibited by the addition of K-sorbate of 0.005%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1579-1585
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• 2005

The aim of this study was to propose utilization of tofu whey concentrates separated by ultrafiltration (UF) for yogurt production. The curd yogurt was prepared from whole milk added with skim milk Powder in which UF powder was substituted 0$\%$, 6.25$\%$, 12.5$\%$ or 25$\%$ for skim milk powder. The quality characteristics of yogurt in terms of pH, titratable acidity, viscosity, color and viable cell counts were evaluated. There were no significant differences in pH and titratable acidity between control (yogurt added with only skim milk powder) and yogurt added with UF powder after 24 hr of fermentation at 37$^{\circ}C$. Apparent viscosity of yogurt added with UF powder was lower (2,623 $\∼$ 3,189 cps) than that of the control yogurt (3,196 cps). Lightness and redness value of yogurt added with UF powder were not significantly different from control yogurt, while yellowness value increased as the amount of UF powder increased. Addition of UF powder stimulated the growth of lactic acid bacteria. Gas chromatographic analysis detected acetaldehyde, diacetyl, and organic acids, and more volatile compounds were detected in yogurt added with UF powder. Sensory analysis showed that yogurt added with UF powder were evaluated as acceptable as control yogurt. Therefore, UF powder could be substituted for skim milk powder without depressing yogurt qualify.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.863-866
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• 1994

This study was carried out to estimate aluminum contents of commercial beverage foods by atomic absorption spectrophotometer. The contents of aluminium in drinking yogurt, curd yogurt, fruit beverage, carbonated beverage, fruit canned food and commerical teas ranged from 161.667 to 173.333ppm 139, 300 to 293, 925ppm, 1.481 to 7.130 ppm, 1.803 to 6.026ppm, 4.600 to 7.053ppm 194.437 to 846.056 ppm, respectively.

• 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.20 no.3
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• pp.317-325
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• 1988

The effects of various heat treatments of soy milk prepared from soy protein concentrate on growth and acid production by five species of lactic acid bacteria were investigated. Sensory property and sedimentation characteristics of soy yogurt prepared from heat-treated soy milk were also evaluated. Heat treatment of soy milk stimulated acid production by all cultures. Acid production was generally proportional to degree of heat treatment and acid production by all cultures except Streptococcus lactis was maximum in soy milk heated at $121^{\circ}C-1min$. However, viable cell count was not changed markedly by heat treatment of soy milk. Sensory property of soy yogurt beverage (SYB) prepared from soy milk heated at $95^{\circ}C-30min$ was better than that of unheated sample while sensory property of SYB prepared from soy milk heated at $121^{\circ}C-15min$ was inferior to that of unheated sample. Heat treatment of soy milk generally retarded sedimentation of curd in SYB.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.765-771
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• 2015

This study was performed to examine the quality characteristics and antioxidant activity of the curd yogurt with different contents (0.5-2%, w/w) of acanthopanax powder (AP). The pH decreased with increasing AP content until 16 h, whereas the treated groups showed higher pH levels than the control group after 20 h. The viscosity and the viable cell counts of the yogurt with 2% AP were lower than those of the control group during fermentation, significantly. Color values of AP yogurt were lower in terms of brightness, whereas redness and yellowness values were higher compared to the control group. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and soluble content significantly increased with increasing AP content. Consumer acceptability score of yogurt with 0.5% AP was ranked higher than other yogurts. Yogurt added with 0.5% AP showed no differences in pH, titrable acidity, and viable cell counts compared to the control group after storage at $4^{\circ}C$ for 14 days.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.602-609
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• 2002

Lao-chao is a traditional Chinese fermented rice product with a sweet and fruity flavor, containing high levels of glucose, a little alcohol and milk-clotting characteristics. In order to optimize commercial production of lao-chao, Rhizopus javanicus and Saccharomyces cerevisiae were selected as the mold and yeast starter, respectively. A commercial mixed starter (chiu-yao) was used as control. Fermentation of the experimental combination revealed a sharp drop in pH (to 4.5) on the fourth day, remaining constant thereafter. Content of reducing sugars gradually decreased throughout the entire fermentation period. Of the free amino acids, higher quantities of alanine, leucine, proline, glutamic acid, glutamine and $NH_3$ were noted. For sugars, glucose revealed the highest concentration, while organic acid levels, including those for oxalic, lactic, citric and pyroglutamic acid, increased throughout the fermentation period. Twenty-one compounds were identified by gas chromatography from aroma concentrates of the lao-chao culture filtrate, prepared using the headspace method. For the flavor components, higher quantities of ethanol, fusel oil and ester were determined in both culture filtrates. In regard to the evaluation of yogurt-like product, there were significant differences in alcoholic smell, texture and curd firmness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1229-1236
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• 2009

This study was performed to examine the quality characteristics of the curd yogurt with different contents (0.5$\sim$2.0% (w/v)) of cherry powder (obtained from freeze-dried fruit of Prunus serrulata L. var. spontanea Max. wils.). Yogurt was fermented with two kinds of lactic acid bacteria (Streptococcus thermophilus, Lactobacillus bulgalicus) at $40^{\circ}C$ for 18h. During the period of 14 days of storage ($4^{\circ}C$, 14 days), acid production (pH and titratable acidity) of the yogurts increased significantly with the addition of cherry powder. The sugar content of the yogurts prepared with cherry powder increased but cherry powder yogurts presented lower viscosity values than the control. Hunter color values, lightness (L) and yellowness (b) of yogurt colors decreased as the concentration of cherry powder increased, whereas the redness (a) increased. Lactic acid bacteria of yogurts increased with the addition of cherry powder and all samples had increasing levels of lactic bacteria over the storage period. The sensory properties, such as flavor, taste, viscosity, and overall acceptability, of the yogurts containing the 1.0% cherry powder were superior to the control sample. Consequently, the optimal quality achieved in these experiments was yogurt with 1.0% cherry powder added.

• Food Science and Preservation
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• v.18 no.5
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• pp.714-720
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• 2011

Sweet Pumpkin (Cucurbita maxima) is rich in minerals, vitamins, and dietary fibers and has less fat. It is thus effective for dieting and for preventing constipation. Sweet Pumpkin contains vitamin A, particularly beta-carotene, which is turned into retinol in the body and helps protect the vision. It is currently on the spotlight as a vision care, anticancer, and diet food, among others, but because it is hard to find yogurt made of Sweet Pumpkin, in this study, Sweet Pumpkin powder was added to yogurt for promotion as a new health food. Yogurt was made with 0, 0.5, 1, 2, and 3% Sweet Pumpkin powder, and the color properties (brightness, redness, and yellowness), viscosity, pH, and acidity were measured through a sensory test (color, flavor, taste, overall acceptability). The storage stability at five-day intervals for one day, five days, ten days, 15 days, etc. was also experimented on. For the color properties, the greater the amount of Sweet Pumpkin powder added, the greater the decrease in the lightness (L) value, but the redness (a) and yellowness (b) values increased (p<0.001). For the viscosity, it was decreased for five days and then increased by 47-68% for ten days. This showed a significant difference in storage stability period: one day (p<0.001), five days (p<0.01), and ten days (p<0.01) (except 15 days). Further, there was a significant difference in pH and acidity [pH: for one day (p<0.001), five days (p<0.01), and ten days (p<0.01); acidity: one day (p<0.001), ten days (p<0.05), 15 days (p<0.001)]. No significant difference in pH was shown, however, for 15 days, and in acidity for five days. The results of the sensory test are highly estimated in the order of 1%>2%.3%>0%>0.5%. The study results indicate that the addition of 1% Sweet Pumpkin powder is most suitable for manufacturing Sweet Pumpkin yogurt.