• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.854-859
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• 2000

A functional yogurt was prepared from whole milk (12%) and skim milk (2%) added with green tea and mugwort tea at 3$0^{\circ}C$ for 24 hors. The yogurt product were evaluated for acid production (pH, titratable acidity), number of viable cell, viscosity, sensory property and quality-keeping property. Addition of green tea and mugwort tea remarkably accelerated acid production of yogurt. After 24 hrs incubation, titratabel acidity of green tea and mugwort tea yogurt was 1.46% and 1.62%, respectively and was higher than that (1.30%) of yogurt made with only milk. The propagation of lactic acid bacteria was not stimulated by green tea and mugwort tea and then the number of viable cell in normal (milk) yogurt green tea yogurt and mugwort tea yogurt groups, after 24 hrs incubation, was about 7.2$\times$$10^{8}$, 7.1$\times$$10^{8}$ and 7.0$\times$$10^{8}$/mL, respectively, Viscosity of green tea yogurt was slightly lower than that of milk yogurt (1,840 cps) and viscosity of mugwort tea yogurt was slightly higher than that of mild yogurt. The overall sensory score of green tea yogurt was the best of tested yogurt. When yogurt with green tea and mugwort tea was kept at 5$^{\circ}C$ for 15 days, its quality-keeping property was relatively good.

• The Korean Journal of Food And Nutrition
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• v.20 no.3
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• pp.289-294
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• 2007

For the purpose of developing a functional yogurt, a new type of yogurt was prepared. To manufacture this new yogurt, 12% skim milk was added to the hot water extract of black soybeans. The yogurt was then evaluated for its acid production(pH and titratable acidity), number of viable cells, viscosity, quality-retention properties, and sensory properties. The titratable acidity of the yogurt with the added 5% black soybean hot-water extract was higher(2.07%) than that of the yogurt without the added extract(1.80%). The viscosity of the yogurt made by adding 5% black soybean hot-water extract was higher(5,040 cps) than that of the yogurt made with only skim milk(2,740 cps). Lactic acid bacteria propagation was stimulated by the addition of the 5% black soybean hot-water extract. When the yogurt prepared with the black soybean hot-water extract was kept at $7^{\circ}C$ for 14 days, its quality-retention was comparatively good. Finally the overall sensory score of the yogurt made with the added 5% black soybean hot-water extract was slightly lower than that of the yogurt made with only skim milk.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.66-72
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• 2014

Quality characteristics of yogurt with added colored barely flour was investigated during fermentation by lactic acid bacteria. Chemical properties such as moisture, crude protein, starch, ash and ${\beta}$-glucan contents was measured. pH, acidity, brix, Hunter color value and growth of lactic acid bacteria in yogurt was investigated during fermentation by L. acidophilus, L. bulgaricus, and S. thermophilus mixed culture. Crude protein contents of Daeanchal and Boseokchal was 16.16 and 12.17%, respectively. Starch contents of daeanchal were shown lower score. The pH of yogurt by addition of barley flour (Daeanchal) addition 0 and 20% were 6.66 and 6.40, respectively. The pH of yogurt supplemented with barley flour tended to be lower than before control which was not added barely flours and oligosaccharide in yogurt. Titratable acidity of yogurt added barley flour was higher compared with that of control. Brix of yogurt was decreased during fermentation by lactic acid bacteria. Lightness of yogurt added barley flour (Daeanchal) addition 0 and 20% were 83.25 and 69.83, respectively. The original microbial population of the yogurt during 0, 5, 8, and 15 hr fermentation were 7.48, 7.79, 8.15, and 8.71 Log CFU/g, respectively. Moreover, the addition of colored barley flour was to promote the proliferation of lactic acid bacteria in yogurt. In our research, addition of colored barley flours added into the yogurt may also have contributed to growth of lactic acid bacteria.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.575-584
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• 2005

The objective of this study was to develop bioactive ginseng yogurt, fermented by B. minimum KK-1 and B. cholerium KK-2, which showed transforming activity of ginseng extract to compound K. Among older people, 3% ginseng yogurt fermented by B. minimum KK-1 and mixed with Bifidobacterium KK-1, KK-2 showed the highest overall acceptability(6.80, 6.80) among 1%(3.87, 3.67), 2%(4.40, 4.53) and 3% ginseng yogurt. The pH of ginseng yogurt was lower than that of plain yogurt. During 9 days of storage, the pH of each yogurt slightly decreased and then increased until 15 days of storage. The 3 8.25 log CFU/g and B. cholerium KK-2; 7.78 log CFU/g). Therefore, ginseng might be used as a growth factor during the fermentation of yogurt. The L value of ginseng yogurt decreased, and the a and b values increased, with increasing ginseng concentration.

• The Korean Journal of Food And Nutrition
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• v.13 no.1
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• pp.71-77
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• 2000

New type yogurt base were prepared from milk added with skim milk powder or purple sweet potato, and fermented by lactic acid bacteria (Streptococcus thermophilus and Bifidobacterium infantis, 1:1, v/v). The yogurt proudcts were evaluated for acid production(pH, titratiable acidity), number of viable cell, viscosity, sensory properties, and color value. The composition of some organic acids was also analyzed by GC. The acid production slightly decrerased by addition with purple sweet potato. There was no significant difference in viable cell counts between control (yogurt added with only skim milk powder) and yogurt added with purple sweet potato, and viable cell counts of all samples were above 9.08 log cfu/ml. Viscosity of yogurt added with purple sweet potato(36,800∼46,000 centipoise) was higher than that of yogurt added with only skim milk powder(32,200 centipoise). The overall sensory score of yogurt added with purple sweet potato(38.6%, dry base) was the best of tested yogurt. The major organic acid of yogurt added with purple sweet potato was lactic acid. its content was 0.997∼1.203%. malic acid, succinic acid, oxalic acid, and fumaric acid were analyzed out a little. Lightness and yellowness decreased by addition with purple sweet potato but redness increased. Total color difference($\Delta$E) with yogurt addition with purple sweet potato and only skim milk powder were very high(above 11.46).

• Food Science of Animal Resources
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• v.35 no.2
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• pp.205-210
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• 2015

The objective of this study was to develop yogurt-cheese using cow’s milk, ultrafiltrated cow’s milk, and soy milk. The addition of soy milk and ultrafiltrated milk increased the amount of protein in the yogurt-cheese. Yogurt-cheeses were made using cheese base using 10% and 20% soy milk with raw and ultrafiltrated cow’s milk, and stored at 4°C during 2 wk. The yield of yogurt-cheeses made with added soy milk was decreased and the cutting point was delayed compared to yogurt-cheese made without soy milk. Yogurt-cheese made using ultrafiltrated cow’s milk showed the highest yield. However, yogurt-cheese made with added soy milk had higher protein content and titratable acidity than yogurt-cheese made using raw and ultrafiltrated cow’s milk. Fat and lactose contents in the yogurt-cheese made with added soy milk were lower. Yogurt-cheeses made with added soy milk contained several soy protein bands corresponding to the sizes of α₂-, β-, and κ-casein band. Yogurt-cheese made with added soy milk had similar elasticity to yogurt-cheese made without soy milk but had lower cohesiveness. There was no significant difference in the number of lactic acid bacteria in the different cheeses, as all had over 8.0 Log CFU/g. Considering these data and the fact that proteins and fats of vegetable origin with high biological value were observed as well as unsaturated fats, yogurt-cheese made with added soy milk can be considered to be a functional food.

• Preventive Nutrition and Food Science
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• v.21 no.4
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• pp.330-337
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• 2016

We investigated the quality characteristics and antioxidant activities of yogurt supplemented with 1%, 2%, and 3% aronia juice and fermented for 24 h at $37^{\circ}C$. The total acidity increased with increasing levels of aronia juice and incubation time. Lightness and yellowness of the yogurt decreased, but redness increased, with increasing aronia juice content and incubation time. The number of lactic acid bacteria (LAB) increased with increased incubation time, and yogurt containing 2% and 3% aronia juice showed higher LAB counts than 1% aroinia juice-supplemented yogurt. The total polyphenol and flavonoid contents increased proportionally with increasing levels of aronia juice. Antioxidant activity of aronia-containing yogurt was significantly higher than that of the control and increased proportionally with aronia juice concentration. Yogurt with 2% aronia juice had the best taste (P<0.05). Aronia juice may be a useful additive for improving the taste and antioxidant potential of yogurt.

• Journal of Dairy Science and Biotechnology
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• v.18 no.1
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• pp.61-72
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• 2000

Consumers primarily consider flavor when they take yogurt. Recent researches on yogurt flavor productron its analytical technique have been extensively developed. These studies have provided a better understanding on the role of starter culture microorganisms on flavor formation and degradation. Yogurt volatile flavor compounds produced by the lactic cultures include acetaldehyde, diacetyl, ethanol and organic acid. Among them, acetaldehyde is recognized as a principal flavor component. since yogurt contains a delicate and low intense flavor, mild sample isolation techniques and sensitive identification means might be used. This paper attempts to discuss recent findings in yogurt flavor and to describe the application of yogurt flavor separation techniques. The section on practical aspects of culture selection based on flavor compound production and flavor analysis is also included.

• Journal of Dairy Science and Biotechnology
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• v.24 no.1
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• pp.65-73
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• 2006

This study was to review recent reports in effects of various starter cultures on the viscosity in stirred yogurt. The rheological properties of yogurt have received considerable attention in the literature. Most yogurts are typically made by mixed cultures of Lactobacillus bulgaricus and Streptococcus thermophilus. The viscosity of yogurt made by mixed cultures was much higher than that of yogurt by single cultures. Since texture of stirred yogurt is the result of both acid aggregation of casein micelles and production of exopoly-saccharides, it is suggested that yogurt be made by the exopolysaccharide-producing cultures in order to increase viscosity, Both types of exopolysaccharides are capsule and loose slime(ropy). But it is desirable to use encapsulated nonropy strains. And Bifidobacteria affects adversely to the viscosity of yogurt. Therefore, starter cultures which have an effect on yogurt viscosity have been widely demonstrated. This review is the search for the development of viscosity in stirred yogurt.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.553-560
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• 2012

This study was conducted to compare the physicochemical and sensory properties of yogurt containing nanopowdered peanut sprouts (NPPS) and powdered peanut sprouts (PPS) at different concentrations (0.05-0.20%, w/v) during storage at $4^{\circ}C$ for 16 d. The pH values of NPPS (0.05-0.20%, w/v)-added yogurt were lower than those of PPS-added yogurt. The antiradical scavenging activity and LAB counts were significantly higher in NPPS-added yogurt than in PPS-added yogurt during the storage period of 16 d (p<0.05). Higher concentrations (0.15, and 0.20%) NPPS-added yogurt showed greater antiradical scavenging activity. The LAB counts were ranged from $9.00{\times}10^8$ to $1.10{\times}10^9$ and $1.30{\times}10^9$ to $9.10{\times}10^8$ CFU/mL in 0.05% and 0.20% NPPS-added yogurts, respectively. In sensory testing, 0.05 and 0.10% NPPS-added yogurt showed similar results to the control in whey-off, grainy texture, and overall acceptability. Yellowness and astringent scores increased with increasing addition of NPPS or PPS to the yogurt irrespective of its storage times. Peanut and beany flavors were lower during the storage for 0.05 and 0.10% NPPS-added yogurt. Based on the data obtained from the present study, it was concluded that 0.05 and 0.10%, w/v of NPPS could be used to produce NPPS-added yogurt without significant adverse effects on the physicochemical and sensory properties, but with an enhanced functional value added to the yogurt.