• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.470-476
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• 1992

The curd yogurt was prepared from milk added with skim milk powder or three Tongil rices of different storage period. The effect of storage period of rice on acid production by lactic acid bacteria in milk containing rice of 2%(w/v) was investigated. The effect of storage period of rice on quality of curd yogurt(sensory property, viscosity and keeping quality) was also examined. Addition of rice stimulated acid production by lactic acid bacteria more than control(milk yogurt). Storage period of rice did not significantly affect acid production by lactic acid bacteria though stimulating effect of rice on acid production was slightly different among species. Sensory property of curd yogurt added with rice was not significantly affected by storage period of rice. Apparent viscosity of curd yogurt added with rice increased in proportion to storage period of rice. Curd yogurt showed characteristics of thixotropic flow. When curd yogurt added with rice was kept at $5^{\circ}C$ for 15 days, its keeping quality was relatively good and was not markedly affected by storage period of rice.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.273-281
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• 2021

These days, different types of yogurt are being manufactured by adding various starters and functional ingredients for health. The purpose of this study was to prepare yogurt added with rice followed by fermentation with two types of starters and to examine its attributes. Ten percent of skim milk powder and 0, 2.5, 5.0, 7.5, or 10% rice were mixed in water (w/v) and then inoculated with two types of starter: 1) Type A, Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricus as starter; and 2) Type B, Streptococcus thermophiles, Lactobacillus acidophilus, and Bifidobacteium animalis ssp. lactis as starter. The pH of B type yogurt was lower (p < 0.05) than that of A type yogurt from 6 hours to 14 hours after fermentation. The number of microorganisms in all fermented milk showed maximum increases at 2 and 6 hours of fermentation (p < 0.05). The number of microorganisms in fermented milk peaked at 6 hours after fermentation and maintained this level thereafter. There was no effect of rice addition on microbial growth or acidity of the fermented milk. Sensory attributes of yogurt samples with and without added rice were not significantly different. This experiment showed that the production efficiency of yogurt with added rice was not different when two different types of starters were used to manufacture yogurt.

• Korean journal of food and cookery science
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• v.31 no.4
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• pp.485-496
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• 2015

This study was carried out to establish the optimal conditions for curd yogurt using saccharified rice solution. A central composite design was applied to investigate the effects of pectin (2.8~8.4 g), skim milk (14~70 g) and oligosaccharide (28~84 g) ratio on the physicochemical and sensory characteristics of curd yogurt using saccharified rice solution. pH, total acidity, and color value, were analyzed and sensory evaluation was performed. The pH of curd yogurt decreased with decreasing pectin and oligosaccharide ratio. The addition of pectin had a significant effect on the viscosity while skim milk had a significant effect on the color value (a and b value). The results of sensory evaluation showed that, oligosaccharide and skim milk had significant effects on sweetness and sour taste. Oligosaccharide and skim milk masked the sour taste of curd yogurt. The optimum range of ingredients for curd yogurt using saccharified rice solution was predicted to be 4.27~4.90 g of pectin, 30.80~41.30 g of skim milk, and 28.00~36.10 g of oligosaccharide. Based on the overlapped results of physicochemical and sensory evaluation, the optimal amounts of pectin, skim milk and oligosaccharide were 4.59 g, 36.50 g and 32.05 g, respectively.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.518-522
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• 2005

Yogurt containing high ${\gamma}$-aminobutyric acid (GABA) was developed using lactic acid bacteria and germinated brown rice. Lactobacillus acidophilus, L. plantarum, and L. brevis OPY-1 strains were inoculated into Lactobacillus MRS broth for use as yogurt starter. After treatment with 5% monosodium glutamate in MRS broth, L. brevis OPY-1 strain isolated from Kimchi produced GABA concentration of 8,003.28 nmol/mL. Starter was inoculated into fermentation substrate mixture containing germinated brown rice extract and blend of powdered whole milk and skim milk. Samples were incubated, and viable cell colonies were counted. Highest number of lactic acid bacteria was reached between 16 and 20 hr. Concentrated rice milk fermented with high GABA-producing strain contained GABA concentrations of $137.17\;{\mu}g/g$ D.W., whereas concentrated fermented milk prepared by conventional method contained GABA of $1.29\;{\mu}g/g$ D.W. Sensory evaluation panelists gave favorable ratings to fermented rice milk containing high GABA concentration.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.508-515
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• 2016

This study aimed to investigate the functional and physicochemical properties of yogurt, supplemented with germinated brown rice (GBR) containing γ-aminobutyric acid (GABA), during storage. GBR was produced by soaking brown rice at 30℃, and saccharified germinated brown rice (SGBR) was produced by treating brown rice with α- and β-amylase for 1 h, at 80℃ and 60℃, respectively. Yogurt was manufactured using a commercial starter (YC-X11, CHR. Hansen, Denmark) at 37℃ for 12 h. The fatty acids and GABA contents were analyzed using GC and HPLC, respectively. The fatty acids in the cereal samples consisted of oleic, linoleic, and palmitic acid. The portion of oleic acid was the highest, at 35.65% in GBR, and 32.16% in SGBR. During germination, the oleic acid content increased, whereas linolenic and palmitic acid contents from GBR tended to decrease. Although the portion of saturated fatty acids, such as stearic and myristic acid, decreased significantly (p<0.05), that of unsaturated fatty acids, such as oleic and linoleic acid, increased with an increase in supplementation of BR, GBR, or SGBR in the yogurt. The yogurt, supplemented with cereal samples, showed a tendency of an increase in the concentration of GABA with an increase in the supplementation of the cereal samples. However, yogurt supplemented with GBR showed the highest concentration of GABA, regardless of the supplementation of the cereal samples. These results indicated that yogurt supplemented with BR, GBR, or SGBR could be a promising dairy product.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.587-592
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• 1991

The curd yogurt was prepared from milk or milk added with skim milk powder or four types of rice powder. Acid production by lactic acid bacteria in milk containing additive of 2% (w/v) was investigated and quality of curd yogurt (sensory property and keeping quality) was examined. Some organic acids in curd yogurt were analyzed by HPLC. Four types of rice powder, particularly brown rice, stimulated acid production by lactic acid bacteria more than control (milk yogurt). Among four organisms tested, Leuconostoc mesenteroides and Lactobacillus bulgaricus produced more acid than L. casei and L. delbrueckii. HPLC analysis of organic acids in curd yogurt showed that the amount of lactic acid markedly increased during the fermentation by L. bulgaricus for 24 hours while the amount of citric acid markedly decreased. Addition of rice powders to milk slightly reduced sensory property of curd yogurt. Among four types of rice powder tested, tongil rice added sample showed better sensory acceptability than other samples. When curd yogurt was kept at $5^{\circ}C$ for two weeks, acidity and number of viable cells of curd yogurt were not changed.

• Korean Journal of Agricultural Science
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• v.37 no.3
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• pp.387-392
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• 2010

This studies were carried out to assess fermentation properties of amylase activity and added rice yogurt of Enterococcus faecium KHM-11 isolated from Korean human milk. The amylase activity of Enterococcus faecium KHM-11 was above 23 units. Characterization of carbohydrate fermentation of Enterococcus faecium KHM-11 has D-ribose, D-lactose, L-arabinose and starch. Titratable acidity and viable count of lactic acid bacteria of 4% rice yogurt was higher compared to the 0%. Therefore we were discussed Enterococcus faecium KHM-11 is suitable microorganism for fermented milk added rice powder. Hydrolysates of sugars of fermented milk with 4% rice powder cultured Enterococcus faecium KHM-11 were analyzed by TLC and HPLC. Hydrolysates of lactose and galactose were revealed and hydrolysates of glucose was not revealed in results of TLC and HPLC.

• Culinary science and hospitality research
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• v.20 no.4
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• pp.37-48
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• 2014

The purpose of this study is developing a formulation with an optimum sensory point by using yogurt added with rice flour and pregelatinized rice flour(alpha rice flour) optimized by response surface method(RSM). The pH, acidity, sugar content, viscosity and number of lactic acid bacteria during fermentation of two types of yogurt(added with rice flour and pregelatinized rice flour) optimized by RSM were analyzed As the fermentation time of both types of yogurt increased, pH showed decreasing trend. The titratable acidity showed increasing trend as fermentation time increased. Sugar content decreased as fermentation time increased. The reasons are believed to be the sugar decrease during glycolysis and lactic acid fermentation. Viscosity was the highest at 6 hours of fermentation. After 10 hours of fermentation, the viscosity was higher than it was before the fermentation. The number of lactic acid bacteria of yogurt added with rice flour and pregelatinized rice flour was 7.43~9.00 log CFU/mL, which is more than optimum value. Therefore, it is possible to confirm that adding rice flour during yogurt manufacturing increases the number of lactic acid bacteria.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.345-349
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• 2016

This study was performed to evaluate the quality characteristics of curd yogurt with different contents [0.5~2.0% (w/w)] of Korean rice wine lees powder (KRWLP). Yogurt was fermented with commercially available mixed lactic acid bacteria (Lactobacillus acidophilus, Bifidobacterium longum, Streptococcus thermophiles) at $40^{\circ}C$ for 15 h. Acid production (pH and titratable acidity) of yogurts increased with increasing KRWLP content. After 12 hours fermentation, titratable acidity of KRWLP yogurt was 1.19~1.29 % and was higher than that (1.07 %) of yogurt made without KRWLP. And also, the number of viable lactic acid bacterial cell increased and the culture time to obtain maximum number of lactic acid bacteria cell decreased with the addition of KRWLP. The curd stability in yogurt was significantly enhanced by repression of whey separation in KRWLP yogurt. In sensory evaluation, there was a similar preference for KRWLP yogurts and the control. These results suggest that KRWLP can be used as foodstuff to improve the quality characteristics of yogurt.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.315-320
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• 2018

This study was carried out to determine the effect of enzymatically saccharified Korean rice wine lees powder (eKRWLP) on the quality characteristics and storage stability of curd yogurt. Yogurt with different contents [0.5-2.0% (w/w)] of eKRWLP was incubated with commercially available mixed lactic acid bacteria (Lactobacillus acidophilus, Streptococcus thermophilus, Bifidobacterium longum) at $40^{\circ}C$ for 18 h. The production of acid measured at pH and titratable acidity of yogurts increased with increasing eKRWLP content. After 12 h fermentation, titratable acidity of eKRWLP yogurt was 0.77-0.90% and was higher than that (0.72%) of yogurt made without eKRWLP. The viable cell counts of lactic acid bacteria in eKRWLP yogurts were increased in proportion to the addition of eKRWLP, and increased up to 8.01-8.13 log CFU/g after 12 h incubation. The repressive effect of whey separation in eKRWLP yogurt curd significantly decreased than that in Korean rice wine lees powder (KRWLP) yogurt. With sensory evaluation, yogurt with 0.5% eKRWLP obtained the highest scores among all eKRWLP yogurts. When eKRWLP yogurts and the control preparations fermented for 12 h were incubated at $4^{\circ}C$, their pHs and titratable acidities were slightly changed and the number of viable lactic acid bacteria were well maintained above $10^7CFU/g$ for 16 days.