• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.111-119
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• 2004

A new type of drinkable yoghurt was prepared to develop a functional yoghurt. Skim milk containing 0.4-1.0％(w/v) water extract of omija(Schizandra chinensis Baillon) was fermented by the mixed strains of Lactobacillus acidophilus and Streptococcus thermophilus. Quality characteristics of the drinkable yoghurts were evaluated in terms of compositions, keeping-quality(pH, titratable acidity, number of viable cells) and sensory properties. The drinkable yoghurts added with water extract of Schizandra chinensis were composed of 2.92-3.03％ protein, 9.98-10.23％ lactose, 0.81-1.08％ fat, 16.21-16.64％ total solid, and 14.57-15.17％ solid-not-fat. The L values(brightness) were significantly lower in the yoghurts containing water extract of Schizandra chinensis than that of the control which had no water extract of Schizandra chinensis, while the a values(redness) and b values(yellowness) were significantly higher than those of the control. The pH, titratable acidity and number of viable cells of the lactic acid bacteria of all yoghurts were not changed during the storage at 4$^{\circ}C$ for 15 days, while the pH and titratable acidity were remarkedly changed during the yoghurts stored at 20$^{\circ}C$ for 15 days. The drinkable yoghurts containing 0.4％(w/v) water extract of Schizandra chinensis added 15％(w/v) oligosaccharide, or 0.6％(w/v) water extract of Schizandra chinensis added 20％(w/v) oligosaccharide had the highest sensory score in taste and overall acceptability among the treatments. From the results, Schizandra chinensis was a useful natural additive with the bioactive effect by provision of a acceptable physicochemical and sensory properties in the drinkable yoghurt.

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.349-356
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• 2005

For the purpose of making a new type of functional drinkable yoghurt, skim milk containing $0.5\~2.0\%$(w/v) green tea powder was fermented by the mixed stains of Streptococcus thermophilus and Lactobacillus acidophilus. Quality characteristics of the drinkable yoghurts were evaluated in terms of quality-keeping properties(number of viable cells, pH, titratable acidity) and sensory properties. When the drinkable yoghurts added with $0.5\~2.0\%$ green tea powder were kept at $4^{\circ}C\;and\;20^{\circ}C$ for 20 days, the number of viable cell counts of the lactic acid bacteria($2.1\times10^8\~6.2\times10^8$ CFU/mL). pH($4.16\~4.22$) and titratable acidity($0.792\~0.881\%$) were not significantly changed for all drinkable yoghurts during the storage at $4^{\circ}C\;and\;20^{\circ}C$ days, but the number of viable cell counts($4.2\times10^3\~1.8\times10^5$ CFU/mL), pH($3.82\~3.92$) and titratable acidity($1.057\~1.174\%$) were markedly changed f3r the storage at $20^{\circ}C$ for 20 days. Therefore the keeping quality of the drinkable yoghurts with addition of green tea powder was relatively good at $4^{\circ}C$ for 20 days. The results of sensory evaluation of the drinkable yoghurts containing peen tea powder indicated that flavor, sweet taste, mouthfeel and aftertaste of the drinkable yoghurt with $0.5\%$ green tea powder showed higher preference than others. And the drinkable yoghurt containing $0.5\% green tea powder added $20\%$(v/v) oligosaccharide had the higher sensory scores in sweet taste, aftertaste and overall acceptability among the treatments.

• Korean Journal of Agricultural Science
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• v.23 no.1
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• pp.70-79
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• 1996

Yogurts were prepared with skim milk powder added with jujube extract of 0%, 1%, 2%, 3%, 4%, 5%, respectively and fermented by mixed culture(Str. thermophilus, and Lac. bulgaricus). The fermented yogurts were evaluated for acid production(pH, titratable acidity), number of viable cell, change of sugars, sensory properties. 1. Addition of jujube extract increased acid production and decreased pH. Acid production was increased in proportion to concentration of jujube extracts added to milk and pH was decreased. 2. In yogurt fermentation, the lactic acid bacteria of yogurt added with jujube extract, increased in proportion to jujube extract concentration added to milk. 3. The viscosity was increased in proportion to concentration of jujube extract during 6 hrs. of fermentation. The viscosity of yogurt added with 4% and 5% jujube extract remarkably decreased for the first 12 hrs. Yogurt added with 5% jujube extract is lowest in its viscosity among the treatments. 4. The concentrations of glucose and fructose were higher in proportion of jujube extract add at 0 hrs. the concentration of lactose was decreased simultaneously, and those of galactose was increased in all the samples at 12 hrs. 5. The taste and odor of yogurt added with the jujube extract of 4% and 5%, respectively, were better than other samples. The color of control was better than other samples. The texture of control yogurt was better than orther samples, but was not clearly difference with the yogurts added with jujube extract of 4% and 5%. In the overall acceptability, the sensory scores of yogurt added with jujube extract of 3% and 4% were higher than other samples.

• Food Science and Preservation
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• v.24 no.6
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• pp.865-870
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• 2017

Yogurt is produced by fermentation of milk using bacteria known as "yogurt cultures". Most of these bacteria are probiotics such as Lactobacillus delbrueckii subsp. bulgaricus, Lb. rhamnosus, Streptococcus thermophilus, and Bifidobacterium. The domestic fermented milk market is increasing, and about 30 companies are producing yogurt. The purpose of this study was to analyze the quality characteristics of domestic commercial liquid yogurt. Total 30types of commercial yogurts were sampled and their physicochemicial properties, including pH, sugar content, acidity, viscosity, and microbial characteristics of lactic acid bacteria counts, were measured. Commercial liquid type yogurt showed a pH of 4.5, sugar content of 7.4-21.2%, total acid content of 0.4-0.9%, and viscosity of 0.1-250 cP. In terms of microbial populations, lactic acid bacteria counts were 7.2-11.3 log CFU/mL and anaerobic lactic acid bacteria counts were 8.0-11.5 log CFU/mL. The quality characteristics differed depending on the constituents of the sample and the microorganisms used. These results are related to the quality characteristics of yogurts and are useful for identifying new trends in the domestic fermented milk industry.

• Journal of Dairy Science and Biotechnology
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• v.37 no.2
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• pp.115-128
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• 2019

Lactic acid bacteria obtained from traditional Kimchi were selected on the basis of their caseinolytic activity and lactose usability and examined for availability as a starter in probiotic activity. Thirty-two strains were selected as lactic acid producing bacteria in BCP agar, and two strains (KC23 and KF26) with more than 90% resistance for both acid and bile salts were selected. The two strains were identified as L. plantarum (KC23) and L. paracasei (KF26) by API 50 CHL system and 16S rRNA sequence analysis. L. plantarum (KC23) was finally selected based on its biochemical characteristics for lactose and raffinose usability. Free tyrosine content increased rapidly in 10% skimmed milk medium, from $24.1{\mu}g/mL$ after 8 h to $43.9{\mu}g/mL$ after 16 h. Additionally, the caseinolytic clear zone of 12 mm of L. plantarum (KC23) was greater than the 9 mm zone of commercial L. acidophilus CSLA. The bacterium exhibited mesophilic growth and yielded $8.9{\times}10^8CFU/mL$ when incubated at $37^{\circ}C$ for 12 h at pH 4.25. Moreover, L. plantarum KC23 exhibited antibacterial activity as it formed a clear zone of 8-13 mm for the 5 pathogens. Adherent activity was 2.23 fold higher than that of LGG. The acidity of 10% skimmed milk fermented for 12 h was 0.74%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.4
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• pp.458-463
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• 2007

This study was carried out to investigate potential use of Scutellaria bicalensis Georgi (SBG) as an ingredient for extending the shelf life of tofu. The spore of Bacillus sp. KN-4 was isolated from commercial tofu and inoculated to soybean milk to prepare artificially contaminated tofu. The contaminated tofu was stored in the presence of 0.05 and 1% of SBG extract at $25^{\circ}C$ for 72 hrs. The pH changes of contaminated tofu with SBG extract was slower than those of control during storage. The degree of pH change decreased as the concentration of SBG extract was increased from 0.05% to 0.1%. The change of titratable acidity of the tofu showed the same tendency as pH change during storage. Total cell number of the SBG extract added tofu was lower about $1{\sim}2$ log cycle (0.05% SBG extract) or $2{\sim}3$ log cycle (0.1% SBG extract) than that of control after storage for 12 hrs at $25^{\circ}C$. The color changes of the tofu did not show any difference with and without SBG during storage at $25^{\circ}C$. The strength and hardness of the tofu was improved by the addition of SBG extract. Especially, the strength and hardness of tofu in the Presence of 0.1% SBG extract did not change during storage time. The sensory Qualify of SBG extract added tofu was better than control in texture, but not in taste and color. The overall acceptability of the SBG extract added tofu was similar to control.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.386-390
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• 1993

Addition of starch syrup, table sugar, potato powder, skim milk powder an parched soybean powder to melon flesh was suitable as fermented melon base. The manufacturing process of fermented melon was as follows: Pasteurization for 10 min at $95^{\circ}C$, use of 1% starter culture, fermentation for 12 hours at $35^{\circ}C$ and ripening for 3 days at $8^{\circ}C$. The growth and acid production of Pediococcus acidilactici among several starter cultures were most active for the first 12 hours, but such activities were disappeared during ripening. In the case of Lactobacillus plantarum, the activities were not high during fermentation, which, however, increased during ripening. Throughout the whole manufacturing process, the fermented melon with a mixed culture of P. acidilactici and L. plantarum showed more cell number of each bacterium and higher titratable acidity than that with single cultures. Also P. acidilactici surpressed the growth of L. plantarum during ripening.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.721-726
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• 2013

In this study, a yogurt containing skim milk powder and whole barley flour was fermented with lactic acid bacteria, and its quality and properties were estimated. The yogurts with 1% and 3% barley flour had lower pH values, higher titratable acidity, and higher Brix values than the control. In addition, the viable cell counts were lower and viscosity was higher. The value of L was low, and the values of a and b were high. The yogurt with 3% barley flour had more lactic acid than the control and showed a substantial increase in the amount of acetic acid. ${\beta}$-Glucan content and antioxidant activity increased with the amount of barley flour added. In sensory evaluation, there was a similar preference for the yogurt with 3% barley flour and the control, and as the barley flour content increased, the preference decreased. Moreover, the preference for the yogurt was higher among old people.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.408-413
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• 2005

Rheological properties and sensory characteristics of prickly pear jelly made from κ-carrageenan and glucomannan were examined. Prickly pear extract (PPE) fermented by Lactobacillus casei LS (isolated from soy milk curd residue) exhibited pH 3.12, 1.15% acidity (lactic acid) and 2.7 × 10/sup 9/ CFU/mL lactic acid bacteria. In the effect of concentration of fermented PPE, the jelly containing 4% fermented PPE had higher springiness and slightly lower hardness than that without fermented PPE, and was superior to color and taste. The hardness and brittleness of jellies were enhanced by the addition of 0.25% citric acid. The addition of 0.25% ascorbic acid resulted in the production of soft jelly like pudding. In the effect of concentration of κ-carrageenan, the hardness and springiness of jellies were increased by adding 0.75% κ-carrageenan, but was decreased by adding at the 0.9% level. In the overall preference of jellies including sweet and sour taste, higher score was obtained by the fortification of 0.6% and 0.75% κ-carrageenan, 0.25% citric acid and 30% fructose syrup.

• Journal of agriculture & life science
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• v.44 no.2
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• pp.49-56
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• 2010

Yogurt base was prepared from skim milk added with 0.1, 0.3 and 0.5% (w/v) garlic powder and fermented with Lactic acid bacteria (the mixed strain of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus) at $42^{\circ}C$ for 24 h. The yogurt products were evaluated for acid production such as pH and titrable acidity, number of viable cell, viscosity, color value and sensory properties. The titrable acidities of yogurt added with garlic powder were higher than that of control(0.73%). There was no significant difference in viable cell counts among samples except 0.3% garlic powder. The viscosity of 0.5% garlic yogurt was the highest than any other garlic yogurt. There was no significant difference in color difference among experimental groups. The overall sensory scores of yogurt added with 0.1% and 0.3% garlic powder were not significantly different with those of control. These results suggest that the added amounts of garlic powder to prepared yogurt are adequate below 0.3%.