• Journal of the Korean Society of Food Culture
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• v.21 no.2
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• pp.179-186
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• 2006

To investigate the production of yogurt added with desalted bamboo shoots, the component analysis was conducted. Desalted bamboo shoots contained 82.59 % of moisture, 4.56 % of protein, 0.52 % of lipid, 0.50 % of ash and 11.72 % of total dietary fiber. The main mineral elements were Ca, P, S, Na, Mg and K. Yogurt base fermented with 0.005 % ABT-5 starter inoculum at $40\;^{\circ}C$ for 13 hr. For the preparation of bamboo shoots yogurt, various sugaring bamboo shoots were added to the yogurt base. Results of sensory evaluation of the yogurt containing bamboo shoots indicated that color, odor, taste, flesh size, flesh amount, mouth feel, and overall acceptability of the 15 %(w/v) bamboo shoots dicing $(5{\times}5{\times}5\;mm)$ showed higher preference than others. When bamboo shoot yogurt was kept at $4\;^{\circ}C$ for 15 days, pH, titratable acidity, viable counts of lactic acid bacteria and Bifidobacterium bifidum of yogurt were not changed.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.403-414
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• 2013

This study evaluated the physicochemical and microbiological characteristics and antioxidant properties of yogurt samples fermented with lactic acid bacteria (LAB) obtained from pickled cabbage. API 50 CHL systems and 16S rRNA nucleotide sequence analyses revealed that the isolates were Lactobacillus casei PC05 and L. acidophilus PC16. Cell counts, titratable acidity, and viscosity of the yogurt samples fermented with L. acidophilus PC16 were significantly higher than those of the samples fermented with L. casei PC05 (P<0.05). The detected cell counts and physicochemical properties were significantly lower in plain yogurt than in soy yogurt (P<0.05). Yogurt samples fermented with L. acidophilus PC16 exhibited higher antioxidant activity, measured as ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and chelate ferrous ions, than those fermented with L. casei PC05. However, the ability to scavenge superoxide anions and superoxide dismutase (SOD) activity were significantly (P<0.05) higher in yogurt samples fermented with L. casei PC05 compared to those in samples fermented with L. acidophilus PC16. The antioxidant activity of soy yogurt was significantly (P<0.05) higher than that of plain yogurt. The antioxidant activity of the tested strains resulted in lipid peroxidation inhibition (in vitro), which may be related to the elimination of free radicals, chelating ability, and reducing power. There were no significant differences in the physicochemical properties and antioxidant activities of the yogurt samples during cold storage.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.2
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• pp.59-64
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• 2015

Lactic acid-producing bacteria such as Lactobacillus spp. function to ferment carbohydrates and produce ATP. Such Lactobacillus spp. are used for the production of commercial yogurts. Lactobacillus spp. are beneficial to the intestinal tract, and Lactobacillus acidophilus-containing yogurts have received considerable attention because of their preventive effects against early-stage cancer of the large intestine. In this study, lactic acid-producing bacteria were cultured from three different groups: commercial solid yogurt (for eating), commercial liquid yogurt (for drinking), and Lactobacillus acidophilus-containing yogurt. We first determined the optimum culture conditions for Lactobacillus spp. and then analyzed turbidity and pH in order to compare the growth abilities and lactic acid-production capacities among the groups. Finally, high-performance liquid chromatography was used to measure the lactic acid content in the culture supernatants, and the antibacterial activities against Staphylococcus aureus and Escherichia coli were compared among the three groups. The optimum culture conditions for Lactobacillus spp. were MRS medium at $25^{\circ}C$, for 24 h. The highest turbidity was found in L. acidophilus-containing yogurt, followed by liquid yogurt and solid yogurt. Similarly, the highest lactic acid production ability was found in L. acidophilus-containing yogurt, followed by liquid yogurt and solid yogurt. Culture supernatants from the three groups did not show any antibacterial activity towards S. aureus; however, supernatants derived from L. acidophilus-containing yogurt resulted in a 1.8 mm inhibitory zone against E. coli in a paper disk diffusion test. These results revealed the high level of lactic acid-production capacity and antibacterial activity in L. acidophilus-containing yogurt.

• Journal of Nutrition and Health
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• v.14 no.4
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• pp.175-181
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• 1981

This study was carried out to investigate the feasibility of production of soy yogurt, which is inexpensive and high protein product with an acceptable flavor, from soy milk using lactic acid bacteria. Utilization of various carbohydrates by Lactobacillus acidophilus, Streptococcus thermophilus and Lactobacillus bulgaricus was stuied. Sucrose, the major carbohydrate in soymilk, was fermented by L. acidophilus and S. thermophilus. None of the testing microorganisms was able to ferment melibiose and raffinose. Growth of lactic acid bacteria in soymilk was examined every 4 hour. L. acidophilus exhibited the highest growth rate during the early stage. After 16 hours of incubation, however, all the cultures with the exception of L. bulgaricus grew at nearly equal rates. Microscopic examination of mixed cultures showed that the presence of S. thermophilus was much more pronounced than that of L. bulgaricus. All the cultures with the exception of L. bulgaricus formed acid rapidly during 16 hours of incubation, bringing the titratable acidity to 0.6% and pH to 4.3, which was sufficient to cause coagulation of soymilk. L. bulgaricus produced acid to a much lesser extent and caused coagulation of soymitk after 30 hours at earliest. Three kinds of yogurts were prepared from 100% soymilk, 100% milk and 50% soy-50% milk combination by S. thermophilus and were evaluated by taste panel. Soy yogurt received a significantly lower mean odor score than milk yogurt. Soy yogurt had custardlike texture, while milk yogurt was syrupy. However the scores for texture as well as those for color and flavor did not differ significantly among the treatment. The mean total scores for yogurts were not significantly different and were equivalent to ratings between good and high fair.

• Journal of Food Hygiene and Safety
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• v.12 no.3
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• pp.188-194
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• 1997

The growth inhibition effect of Orally administrated yogurt ACE and Metchnikoffupon E. coli O157:H7 and S. typhimurium inoculated into gastric lumen of rabbits was in vestigated. The rabbits challenged with each 1 $m\ell$ of suspension containing 108 CFU/$m\ell$ of the pathogens were divided into 4 groups by the interval of yogurt administration: A group; preadministrated 7 days before inoculation of the pathogens and fed daily; B group; administrated daily after inocjlation of the pathogens, C group; administrated every 3 days after inoculation of the pathogens; Control group, not fed after inoculation of the pathogens. Each 3 $m\ell$ of yogurt containing 109 CFU/$m\ell$ was orally administrated into rabbits. All yogurt administrated groups (A, B, c) chowed growth ingibition effect on E. coli O157:H7 in one day after inoculation of the pathogen by the level of 0.8~1.0 log CFU/g, compared with the result differences between the control group and the yogurt administrated groups. In the control group after 5 days of inoculation, the number of colonized pathogens was 105~106 CFU/g, whereas 103~104 CFU/g was detected in the yogurt administrated groups. After 10 days of inoculation, the viable pathogen number per gram (g) of the rabbit feces was 103 CFU/g in the control group, whereas the number below 101 CFU/g was detected in the group A, and 102 CFU/g in the control group, B and C. The growth inhibition effect of yogurt administration on E. coli O157:H7 was highly increased in the order of A, B, and C group. The same effect on S. typhimurium was observed at the level of 2 log CFU/g in the Metchnikoff yogurt administrated groups, compared with the control group result in one day after inoculation of the pathogen. In 7 days after inoculation of the pathogen, the viable number was increasingly decreased, and finally after 15 days no viable cell of S. typhimurium was discharged into the fecal samples in the group A, and the mean level of 10* CFU/g was detected in the group B, but there was no growth inhibition effect in the group C. The growth inhibition effect on S. typhimurium was observed at the same level of viable cell number between the yogurt ACE administrated groups and the control group in 5 days after inoculation. But, after 10 days of inoclation the viable cell number was started to decrease, and the viable cell of S. typhimurium was not discharged from rabbit intestinal contents after 15 days of inoculation in the yogurt ACE administrated groups. In such a case that yogurt was administrated in order to prevent the pathogens, pre-administration on a daily basis one week before inoculation of the pathogens exerted considerable effect in growth inhibition. In comparison with two kinds of yogurt tested in this study, the growth inhibition effect on two kinds of pathogens was observed more highly in the Metchnikoff administated group than the ACE administrated group.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.53-59
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• 2004

To increase the nutritional and economic value of commercial peanut yogurt, a peanut yogurt was prepared by 12% skim milk added defatted peanut powder(DPP). The proximate compositions of DPP were moisture 2.3%, crude protein 31.39%, crude lipid 38.84, ash 2.89% and carbohydrate 24.58, respectively. The yogurt product were evaluated for acid production(pH, titratable acidity), number of viable cell, viscosity, color, quality-keeping property and sensory property. By addition of 5% and 10% DPP, the titratable acidity of yogurt was higher than that of yogurt not added DPP. The propagation of lactic acid bacteria was stimulated by adding 5% DPP, and the number of viable cells were about 8.9 log cfu/ml. On the other hand, the number of viable cells in control were 8.3 log cfu/ml. Viscosity of yogurt made from adding 5% and 10% DPP was higher than that of yogurt with only skim milk. When yogurt added with DPP was kept for 15 days at 5$^{\circ}C$ its quality-keeping was relatively good. As the DPP increased, L value(lightness) decreased and a value(redness) increased obviously but the b value(yellowness) of 5% peanut yogurt increased and 10% and 15% again decreased. The overall sensory scores of yogurts added with DPP showed lower than that of yogurt with only skim milk.

• Journal of Dairy Science and Biotechnology
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• v.37 no.1
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• pp.57-68
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• 2019

The effects of yogurt supplementation with enzyme-bioconverted ginseng (EBG), ascorbic acid, and yeast extract on the bacterial counts of Streptococcus thermophilus, Lactobacillus acidophilus LA-5, and Bifidobacterium BB-12 were investigated to develop healthy yogurts with high probiotic counts during storage. In addition, the colors and viscosities of the yogurts were determined. EBG, ascorbic acid, and yeast extract did not affect S. thermophilus counts. EBG and ascorbic acid enhanced the viabilities of L. acidophilus LA-5 and Bifidobacterium BB-12 during storage. Yeast extract improved growth of L. acidophilus LA-5 and Bifidobacterium BB-12 during fermentation. EBG turned the yogurt into brown color. We conclude that supplementation of yogurt with EBG, ascorbic acid, and yeast extract may enhance its health-promoting functions by increasing the viability of probiotics, which can thus promote consumption of the yogurt.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1025-1031
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• 2008

S-Adenosyl-L-methionine (SAM) exerts several beneficial effects on depression, chronic diseases, and cognitive impairments. Bifidobactrium bifidum BGN4 reportedly produces higher amounts of SAM than any other lactic acid bacterium used in yogurt. The aim of this study was to develop a SAM-reinforced probiotic yogurt using Bifidobacterium. The sensory aspects of the yogurt via response surface methodology (RSM) and the texture and SAM content of the yogurt were assessed. Based on the sensory assessments for sweetness, sourness, and thickness evaluated by 48 panelists, the optimized conditions for preparation of SAM-reinforced yogurt were 4.0-4.4%(w/w) sugar, 3.2-3.5%(w/w) skim milk, and a pH of 4.7-4.8. The SAM content of the developed yogurt was 0.05 nmol/mL. In conclusion, SAM-reinforced probiotic yogurt may provide a vehicle for the potential exploitation of the benefits of increased dietary SAM.

• Food Science of Animal Resources
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• v.36 no.1
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• pp.90-99
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• 2016

This study evaluated the effects of two Korean traditional plant extracts (Diospyros kaki THUNB. leaf; DK, and Nelumbo nucifera leaf; NN) on the fermentation, functional and sensory properties of herbal yogurts. Compared to control fermentation, all plant extracts increased acidification rate and reduced the time to complete fermentation (pH 4.5). Supplementation of plant extracts and storage time were found to influence the characteristics of the yogurts, contributing to increased viability of starter culture and phenolic compounds. In particular, the increase in the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was highest (2.95 and 1.14 Log CFU/mL respectively) in DK yogurt. Furthermore, supplementation of the plant extracts significantly influenced to increase the antioxidant activity and water holding capacity and to produce volatile compounds. The higher antioxidant activity and water holding capacity were observed in NN yogurt than DK yogurt. Moreover, all of the sensory characteristics were altered by the addition of plant extracts. Addition of plant extracts increased the scores related to flavor, taste, and texture from plain yogurt without a plant extract, as a result of volatile compounds analysis. Thus, the overall preference was increased by plant extracts. Consequently, supplementation of DK and NN extracts in yogurt enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt. These findings demonstrate the possibility of using plant extracts as a functional ingredient in the manufacture of herbal yogurt.

• 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.