• 한국축산식품학회지
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• 제41권1호
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• pp.122-134
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• 2021

Recently, yogurt has been extensively studied to further enhance its functions using edible plant extracts. This study was conducted to investigate whether safflower petal (SP) as a natural food additive can be used to develop functional yogurt with improved health benefits. SPs were extracted with ethanol (SPE) and hot water (SPW), and then safflower yogurt was prepared by adding 0%-1.0% of those extracts to plain yogurt. With an increase in the fermentation duration, the pH of SPE and SPW yogurt samples was decreased, whereas titratable acidity and microbial counts were increased. The concentration of total polyphenols and total flavonoids, the activity of antioxidants, and the inhibitory effect on reactive oxygen species (ROS) were higher in SPW yogurt than SPE yogurt. Furthermore, α-glucosidase and lipase activity inhibitory effects of SPW yogurt were higher than those of SPE yogurt. In particular, free radical-scavenging activities, ROS inhibitory effect, and α-glucosidase activity inhibitory effects were significantly increased in SPW yogurt in a dose-dependent manner. Overall, these results suggest that SP extract possesses antioxidant activities and that it can downregulate α-glucosidase and lipase activities. The SP extract may have potential benefits as a natural food additive for the development of functional yogurt.

• Journal of Dairy Science and Biotechnology
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• 제24권1호
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• pp.29-42
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• 2006

Recent trend of consumers' for health give rise to the interest in health and functional foods. Functional yogurt is a primary item in USA, EU, and Japan that are leaders in health and functional food industry and its market is going to be enlarged. Also in Korea, functional yogurt has been recognized as health food by consumers. Concept of functional yogurt is various by health of intestine, stomach, and liver, and lowering blood pressure in Korean market. However, functional yogurt is not registered as health and functional foods in Health/Functional Food Act of Korea. Under these circumstances, the results of trustable and scientific research on the efficacy of functional yogurt should be accumulated to obtain the consumers' solid recognition of functional yogurt as health and functional food.

• Journal of Dairy Science and Biotechnology
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• 제38권3호
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• pp.154-160
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• 2020

본 연구에서는 박테리오신을 생성하는 P. acidilactici를 적용한 기능성 요거트를 제조하여 항균활성과 프로바이오틱스로서의 품질을 평가하였다. Yogurt starter로는 시판되는 요거트에서 분리한 혼합 균주 3종(S. thermophilus, Lb. bulgaricus, Lb. rhamnosus GG)을 사용하였으며, 혼합 균주와 P. acidilactici HW01, P. acidilactici JM01, P. acidilactici K10을 각각 혼합 접종하여 각각의 요거트를 제조한 다음 유산균의 생균수, pH, brix를 측정한 결과, 유산균의 생균수는 모두 8.0 Log CFU/mL 이상의 생균수가 검출되어 유산균 발효유로서 기준에 적합하였다. 또한 pH와 brix를 측정한 결과, 발효 후 시간이 지남에 따라 모두 감소하였다. 우유나 유제품의 오염에 있어서 유의해야 할 병원성 균인 L. monocytogenes를 통해 병원성 저해능을 측정하였으며 L. monocytogenes가 발효 후 3일째부터 모두 저해되는 것이 확인되었다. 본 연구 결과를 통해 박테리오신 생성 균주인 P. acidilactici HW01, P. acidilactici JM01, P. acidilactici K10이 발효유제품 제조에 있어서 요거트 제품의 변화 없이 프로바이오틱 효과를 지닌 균주로 기대되며, 식품안정성 및 새로운 프로바이오틱스 유제품 개발에 도움을 줄 것이라 예상된다. 그리고 L. monocytogenes 외의 다른 병원성 균의 저해효과에 대한 연구 및 요거트의 저장온도에 따른 병원성 저해효과 차이에 대한 연구도 기대된다. 따라서 박테리오신 생성 균주를 활용한 기능성 식품을 실제 식품산업에 적용한다면 안전성 및 신제품 개발에 대한 연구가 더 이루어져야 될 것으로 보인다.

• Preventive Nutrition and Food Science
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• 제18권1호
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• pp.45-49
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• 2013

This study was carried out to determine a possibility of adding Corni fructus extract (CFE) into yogurt for improving the neutraceutical properties of yogurt and the effects of adding CFE (2~6%, v/v) on the physicochemical and sensory properties of the products during a 15-day storage period at $4^{\circ}C$. Incorporation of CFE into the yogurt samples resulted in a significant pH reduction and a significant increase in titratable acidity. When evaluating the color of the yogurt, the $L^*$-values were not significantly influenced by CFE supplementation; however, the $a^*$- and $b^*$-values significantly increased with the addition of CFE during storage. The power law and Casson models were applied to assess the flow behavior of CFE-added yogurt samples. The magnitudes of apparent viscosity (${\eta}_{a,100}$), consistency index (K), and yield stress (${\sigma}_{oc}$) for 4~6% CFE yogurt samples were significantly greater than those for the control, indicating that CFE can be used as a thickening agent for yogurt. The sensory test revealed that addition of CFE (2~4%) to yogurt did not significantly affect the overall scores, but the overall preference score for 6% CFE yogurt was significantly decreased. Based on the data obtained from the present study, we concluded that the concentrations (2~4%) of CFE could be used to produce a CFE-added yogurt without the significantly adverse effects on the physicochemical and sensory properties.

• 한국식품영양과학회지
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• 제24권2호
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• pp.254-260
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• 1995

Yogurt base were prepared from milk added with skim milk powder or Aloe vera powder and femented with lactic acid bacteria(the single or mixed strain of Lactobacillus bulgaricus and Streptococcus thermophilus). The yogurt product were evaluated for acid production(pH, titratable acidity), number of viable cell, viscosity, sensory property and quality-keeping property. The composition of organic acid were also analyzed by HPLC. Addition of Aloe vera remarkably accelerated acid production, and titratable acidity of Aloe vera yogurts(1.293∼1.407%) after 24 hours incubation was higher than that of yogurts added with only skim milk powder(9.98∼1.110%). Yogurt fermented with the mixed strain of L. bulgaricus and Sc. thermophilus was more acidic than that of single strains. The propagation of lactic acid bacteria was stimulated by Aloe vera and the number of viable cell after 24 hours incubation were above 9.87log CFU/ml. Viscosity of Aloe vera yogurt(3,860∼4,300CPS) was higher than that of yogurt with only skim milk powder(2,402∼2,604CPS). The overall sensory score of Aloe vera yogurt femented by mixed strain was the best of tested yogurt. When yogurt with Aloe vera was kept at 5℃ for 15 day, it's quality-keeping property was relatively good. The major organic acid of Aloe vera yogurt was lactic acid and lactic acid content of yogurt increased by addition of Aloe vera powder. The citric acid content decreased wtih fermentation and malonic acid, pyroglutaric acid and α-ketoglutaric acid were analyzed out a little.

• 한국축산식품학회지
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• 제39권1호
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• pp.162-176
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• 2019

This study was performed to evaluate the antioxidant activity of yogurt fermented at low temperature and the anti-inflammatory effect it has on induced colitis with 2.5% dextran sodium sulfate (DSS) in Balb/c mice. Yogurt premix were fermented with a commercial starter culture containing Lactobacillus acidophilus, Bifidobacterium lactis, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. bulgaricus at different temperatures: $22^{\circ}C$ (low fermentation temperature) for 27 h and $37^{\circ}C$ (general fermentation temperature) for 12 h. To measure antioxidant activity of yogurt samples, DPPH, $ABTS^+$ and ferric reducing antioxidant potential (FRAP) assays were conducted. For animal experiments, inflammation was induced with 2.5% DSS in Balb/c mice. Yogurt fermented at low temperature showed higher antioxidant activity than that of the yogurt fermented at general temperature. In the inflammatory study, IL-6 (interleukin 6) was decreased and IL-4 and IL-10 increased significantly in DSS group with yogurt fermented at general temperature (DYG) and that with yogurt fermented at low temperature (DYL) compared to that in DSS-induced colitic mice (DC), especially DYL had higher concentration of cytokines IL-4, and IL-10 than DYG. MPO (myeloperoxidase) tended to decrease more in treatments with yogurt than DC. Additionally, yogurt fermented at low temperature had anti-inflammatory activity, although there was no significant difference with general temperature-fermented yogurt (p>0.05).

• Journal of Animal Science and Technology
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• 제47권6호
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• pp.1051-1058
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• 2005

본 연구는 구기자 요구르트의 생리활성 기능을 확인하기 위하여 항산화 활성, ACE 저해효과, $\alpha$-glucosidase 저해 활성을 조사하였고, 실험동물을 이용한 혈중 콜레스테롤 및 혈중 면역글로블린 함량도 조사하였다. 구기자 추출액 첨가 요구르트의 항산화 활성은 물 추출물보다 methanol 추출물에서 더 높은 항산화 활성능을 보였으며, 특히 구기엽 추출액 첨가 요구르트에서 83.85%의 높은 활성능을 보였다. ACE 저해효과는 구기자 추출액 첨가 요구르트의 경우 물 추출물과 methanol 추출물 모두가 ACE 저해능이 높은 것으로 나타났다. $\alpha$-glucosidase 저해 활성은 구기자, 구기엽 및 지골피 추출액 4% 첨가 요구르트에서 methanol 추출물의 경우 각각 8.6%, 7.3%, 8.8%의 $\alpha$-glucosidase 저해능을 나타냈다. 구기자 추출액 4% 첨가 요구르트 및 지골피 추출액 4% 첨가 요구르트를 섭취한 rat의 혈중 콜레스테롤 농도 측정 결과는 일반 요구르트 섭취군, 구기자 추출액 첨가 요구르트 섭취군 및 지골피 추출액 첨가 요구르트 섭취군은 대조구인 요구르트 무섭취군 혈중 콜레스테롤 농도보다 약 25% 정도 줄어 들었으나, 일반 요구르트 섭취군, 구기자 추출액 첨가 요구르트 섭취군 및 지골피 추출액 첨가 요구르트 간의 콜레스테롤 농도는 거의 변화가 없었다. 혈중 면역글로블린(IgG) 측정결과는 지골피 추출액 첨가 요구르트 섭취군은 무첨가 요구르트 섭취군과 구기자 추출액 첨가 요구르트 섭취군 보다 일정한 수준으로 30일간 혈중 면역글로블린 수치가 다소 높은 것으로 나타났다.

• 한국지역사회생활과학회지
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• 제25권4호
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• pp.601-608
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• 2014

This study evaluates changes in yogurt with Ulmus davidiana var. japonica (U. davidiana) in terms of its physicochemical, microbial, and sensory properties during storage. The pH value and mean microbial counts of this yogurt with 0.2 to 0.8% of U. davidiana added ranged from 4.1 to 4.3 and from $1.4{\times}10^8$ to $2.3{\times}10^8cfu/mL$, respectively, during storage at $7^{\circ}C$ for 16 d. In terms of its color, the L value was significantly higher in the control and U. davidiana yogurt 0.2 to 0.4% up to 4 d, than other yogurt samples, and the b value was influenced by the addition of U. davidiana over 0.6% throughout the storage. According to a sensory test, there was a significant difference in the yellowness score between U. davidiana yogurt and the control, but earthy, and bitterness, and viscosity scores were similar. Overall acceptability was not significantly influenced after 8 d of storage in all yogurt samples, including the control. According to these results, concentrations (0.2 and 0.4%) of U. davidiana yogurt had no significantly adverse effects on its physicochemical, microbial, and sensory properties.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• 제33권2호
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• pp.323-331
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• 2020

Objective: The present work was undertaken to determine the possibility of using xanthan and guar gums as stabilizers to enhance the yogurt quality. Methods: Yogurt was manufactured from standardized milk (3.5% fat, 8.5% solid-not-fat contents) with the addition of 2% to 3% starter culture. Enzyme-hydrolyzed xanthan gum (0.1%, 0.5%, 1.0%) and guar gum (0.1%, 0.5%, 1.0%) were added to the yogurt as stabilizers. Prepared yogurt samples were kept at refrigeration temperature (4℃±2℃) for 21 days and various quality and sensory parameters were studied at regular intervals (7 days). Results: Results showed that yogurt with 0.5% xanthan gum (T5) was best in terms of preventing syneresis and improving the viscosity, water holding capacity and texture of the product. Additionally, adding gums did not adversely affect the sensorial attributes of the product. Conclusion: Modified gums were found useful in augmenting yogurt quality and therefore addition of gums is highly recommended for manufacturing yogurt.