• 미생물학회지
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• 제50권1호
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• pp.8-14
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• 2014

본 연구는 home-made 요구르트에서 분리한 Lactobacillus casei SK-7과 시중에서 판매되고 있는 요구르트에서 분리한 Lactobacillus bulgaricus YK-11의 기능성을 비교 분석하기 위해 실시하였다. 먼저 분리세균인 SK-7과 YK-11의 생리화학적 특성조사를 진행하였다. 이들 균주는 16S rRNA 염기서열을 이용한 계통유전학적 분석방법으로 동정하여, 각각 L. casei SK-7와 L. bulgaricus YK-11로 명명하였다. 16S rRNA 염기서열을 바탕으로 SK-7과 YK-11의 유전적 계통수를 작성하였다. 72시간 동안 SK-7과 YK-11 배양에서 lactic acid와 acetic acid의 생산, 그리고 pH 변화를 조사하였다. 배양기간 동안 L. casei SK-7과 L. bulgaricus YK-11의 몇가지 기능성을 조사하였다. L. casei SK-7과 L. bulgaricus YK-11 배양상등액은 주어진 nitrite를 각각 93.9%와 88.2% 소거하였다. SK-7 and YK-11 배양상등액의 항산화능은 각각 62.6%와 54.9%였으며, ${\beta}$-galactosidase 활성은 14.9 units/mg과 13.1 units/mg로 측정되었다. 항미생물능력은 SK-7과 YK-11 배양의 20배 배양농축액으로 조사되었으며, SK-7은 이 조사에 사용된 모든 미생물에서 명백한 것으로 관찰되었으나, YK-11에서는 관찰되지 않았다. 부가적인 기능성 연구가 이루어져야 되겠지만, 본 연구에서는 home-made 요구르트에서 분리된 젖산균의 기능성은 시판요구르트에서의 기능성과 비교하여 우수한 것으로 조사되었다.

• 미생물학회지
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• 제53권2호
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• pp.103-117
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• 2017

본 연구에서는 된장으로부터 분리된 Lactobacillus acidophilus D11 또는 Lactobacillus fermentum D37 균주로 발효시킨 요구르트의 프로바이오틱로서의 가능성, 물리 화학적 및 기능적 특성에 대한 녹차 추출물의 영향을 조사하였다. 인공 소화액에 대한 저항성과 상피 세포에 대한 부착력과 같은 프로바이오틱활성은 플레인 요구르트보다 녹차 추출물을 첨가한 요구르트에서 다소 높게 나타났는데, 이는 유산균의 수의 증가에 기인하는 것으로 추정되었다. L. acidophilus D11로 발효시킨 플레인 요구르트에 녹차 추출물을 첨가한 경우 유산균수, 유기산 함량 및 점도와 같은 요구르트의 물리 화학적 특성도 유의하게 (P<0.05) 증가하였다. 하지만 녹차 추출물은 L. fermentum D37 균주 발효시킨 요구르트의 물리 화학적 특성에는 유의한 영향을 미치지 않았다 (P>0.05). 한편, Escherichia coli O157 ATCC 43889, Salmonella enteritidis ATCC 13076 및 Salmonella typhimurium KCTC 2514에 대한 항균 활성 및 총 페놀 함량, 라디칼 소거능 및 철 환원력과 같은 항산화 활성은 L. acidophilus D11 보다는 L. fermentum D37로 발효시킨 플레인 요구르트에서 현저히 높았다. 게다가 요구르트의 항균 및 항산화 활성은 녹차 추출물의 농도에 비례하여 유의적으로 증가하였다(P<0.05). 결론적으로, L. acidophilus D11 또는 L. fermentum D37로 발효시킨 녹차 요구르트는 병원성 세균의 성장을 억제하고 체세포 내에 생성된 자유 라디칼을 제거 할 수 있는 유용한 기능성 식품으로 이용할 수 있는 것으로 판단되었다.

• 한국축산식품학회지
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• 제30권4호
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• pp.649-654
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• 2010

In order to develop new functional yogurts using mulberries and mulberry leaves, which were cultivated in Hwasun-gun, Jeonnam Province, Korea, the nutritional compositions, fermentation conditions, sensory properties, and storage stabilities of the yogurts were analyzed. The mulberry powder yogurt contained 87.96% moisture, 3.21% carbohydrate, 4.52% protein, 3.63% lipid, and 0.68% ash, and the mulberry leaf yogurt contained 86.36% moisture, 4.13% carbohydrate, 4.87% protein, 3.79% lipid, and 0.85% ash. A yogurt base was fermented for 13 h with 0.01% ABT-5 starter inoculum at $40^{\circ}C$. To prepare the mulberry jam and mulberry leaf yogurts, a variety of mulberry jam and mulberry leaf samples were added to the yogurt base. The sensory evaluation results of the yogurts containing the mulberry jam and mulberry leaves indicated that a product made with 15% mulberry jam was more strongly preferred than other samples. When the mulberry jam and mulberry leaf yogurts were stored at $4^{\circ}C$ for 15 d, there were no significant changes in pH, titratable acidity, or viable cell numbers of lactic acid bacteria and Bifidobacterium bifidum.

• 한국축산식품학회지
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• 제40권4호
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• pp.613-627
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• 2020

Paprika is known to contain polyphenolic compounds that have good antioxidant properties. This study was conducted to investigate the benefits of adding paprika juice of different colors to yogurt and to determine how paprika affects the quality characteristics of yogurt. Stirred yogurt samples supplemented with different levels of red, orange, or yellow paprika juice were inoculated with mixes of Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus. Paprika addition decreased the pH but increased titratable acidity, lactic acid bacteria (LAB) counts, total polyphenol content (TPC), levels of vitamin A and C, and antioxidant activity. Proteolysis and viscosity of paprika-containing yogurts were significantly higher than those of the control yogurt without paprika juice (p<0.05). In particular, the viscosity of red paprika yogurt was significantly higher than that of yogurts containing 5% orange and yellow paprika juices (each p<0.05). The antioxidant activity of the methanol extract of the yogurt containing 2.5% orange paprika juice was the highest. Storage at 4℃ for 15 days only slightly altered LAB counts, antioxidant activity, and TPC of paprika yogurt. These results indicate that paprika could be used as a natural food additive for the development of functional yogurts.

• 한국식품영양학회지
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• 제21권2호
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• pp.135-142
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• 2008

This study investigated to develop new functional yogurt added domestic yuza(Citrus junos). In order to make the most effective yogurt, yuza extract and fructose were mixed at different proportions. DPPH free radical scavenging activity of yuza yogurts increased dependent on concentration. The results of the DPPH free radical scavenging activity, the 1% yuza yogurt was proven to be the best. The overall sensory score for yogurt made from adding 1% yuza ethanol extract was the best of tested yogurts. The antioxidant activity(DPPH free radical scavenging activity) was the highest in 1% yuza yogurt. The quality characteristics of prepared yogurt were evaluated in terms of acid production(pH and titratable acidity), viscosity, color and levels of lactic acid bacteria during storage period. During storage, the quality of yogurt made from adding yuza extract was better than control(without yuza extract). The sedimentation of curd was repressed a little by adding 1% yuza extract.

• 농업과학연구
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• 제48권2호
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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.

• 한국축산식품학회지
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• 제32권5호
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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.

• Journal of Dairy Science and Biotechnology
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• 제40권1호
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• pp.48-56
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• 2022

Enterococcus species have been reported to produce unique flavoring ingredients in fermented dairy products. Generally, they were found in cheese and fermented dairy products. Enterococcus spp. produce extracellular polysaccharides and reduce blood cholesterol levels in humans. This study used heat-killed E. faecalis and E. faecium in yogurt production to increase safety during consumption. The addition of heat-killed E. faecalis and E. faecium to milk did not affect the fermentation time of yogurt production, the growth of starter cultures, and the viscosity of yogurt. These results concluded that heat-killed Enterococcus, rather than live Enterococcus, is sufficiently possible and even safer to be added to milk products. Enterococcus species could be used as a safe and functional food additive to fermented milk products and supplements in health foods.

• 한국축산식품학회지
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• 제31권1호
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• pp.66-73
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• 2011

Physicochemical and sensory properties of Dioscorea opposita Thunb. (yam) powder-added yogurts (1, 3, 5, and 7%, w/v) were examined when stored at $4^{\circ}C$ for 16 d. When the yam concentration increased, the pH increased with 16 d storage. The lactic acid bacteria counts in all yogurt samples showed an increase during storage period, and the highest counts were appeared with 7% yam powder addition. The dramatic decrease was found in viscosity with higher concentrations of yam powder-added yogurt samples. No change was found in allantoin and diosgenin contents for 16 d storage periods. A significantly strong bitterness and astringency and decreased viscosity were found with 5 and 7% yam powder addition. However, less than 3% yam powder-added yogurt samples did not show a significant difference compared with the control (p>0.05) and overall acceptability score was the highest in 3% yam powder-added yogurt throughout the storage. The present study indicated that the concentrations (1 and 3%, w/v) of yam powder could be used to produce yam powder-added yogurt without significant adverse effects on physicochemical, microbial and sensory properties, and enhance functional components from the supplementation.

• 한국식품조리과학회지
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• 제24권1호
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• pp.59-67
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• 2008

In an effort to make a functional and stable yogurt, this study investigated the improvement effects of sea tangle extract and sea tangle yogurt on intestinal function. The intestinal improvement effect of the extract was measured by the charcoal meal transit method, employing Balb/C mice. And constipation relief was compared utilizing the loperamide-induced constipation method, employing SD rats. Charcoal meal transit was remarkably increased in the mice receiving sea tangle extract as compared to the controls. The constipation relief effects of the sea tangle and sea tangle yogurt were evaluated by measuring fecal amounts in the rats after adding them to water. The fecal contents increased remarkably in the sea tangle administered rat groups as compared to the control group. In addition, different yogurt samples were used to evaluate the characteristics of the sea tangle yogurt. During storage, pH slightly decreased in the yogurt with sea tangle as well as without. At the same time, acidity slowly increased as the storage duration increased. As time elapsed, the amounts of viable cells increased in both yogurts (with and without sea tangle). In the sensory evaluation, significant differences were shown between the sea tangle yogurt and the control for color, flavor, sweetness, and overall quality. Overall, based on the combined results of the intestinal function effects and sensory evaluation, the 0.25% sea tangle yogurt proved to be superior.