• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.326-330
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• 2005

구기자, 구기엽, 지골피 추출물을 이용한 요구르트를 제조하여 항산화효과, ACE (angiotensin converting enzyme) 저해 효과 및 ${\alpha}-glucosidase$ 저해 활성을 시험하였다. 구기자 첨가 발효유의 Antioxidants activity는 물 추출물보다 methanol 추출물에서 더 많은 항산화 활성능을 보였으며 특히 구기엽 요구르트에서 83.85%의 높은 활성능을 보였다. 구기자와 지골피 요구르트에서는 각각 47%와 54%내외의 활성능을 나타냈다. 구기자 첨가 발효유의 ACE(angiotensin converting enzyme) 저해 효과는 원재료에서는 물 추출물이 angiotensin converting enzyme 저해능이 높았고, 구기자 요구르트의 경우 물 추출물과 methanol 추출물 모두가 angiotensin converting enzyme 저해능이 높은 것으로 나타났다. 구기자 첨가 발효유의 ${\alpha}-glucosidase$ 저해 활성은 구기자, 구기엽 및 지골피 4% 첨가 요구르트에서 methanol 추출물의 경우 각각 8.2%, 5.6%, 7.3%의 ${\alpha}-glucosidase$ 저해능을 나타냈는데 이들 모두 원재료 보다는 활성 저해능이 큰 것으로 나타났으나 물 추출물의 경우에는 활성 저해능이 거의 나타나지 않았다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.103-103
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• 2018

홍경천은 일반적으로 해발 2500~4500m에 자생하는 고원식물이다. 현재 중국에 알려진 홍경천의 종류는 대략 38종으로 알려져 있으며 이 가운데 10종이 보건식품으로 사용되어지고 있다. 중국 홍경천의 생육환경은 동북부지방, 서북부지방, 서남부지방으로 구분되어지고 있다. 이 가운데 동북부지방과 티베트 지방을 중심으로 한 서남부지방의 홍경천이 주로 많이 사용되어지고 있다. 이러한 홍경천은 극한의 생육환경으로 고산병 예방, 피로회복, 작업능력향상, 운동능력향상과 세균의 저항력향상, 진정작용과 강심작용, 조혈작용, 항산화작용등이 신경전달물질의 활동을 증진시키어서 스트레스 해소와 치매 및 인지력을 높여준다고 알려져 있다. 따라서 근무 능력을 향상 시킬 뿐만 아니라 수험생들의 집중력에도 좋은 효과를 나타내는걸로 보고되고 있다. 따라서 본 실험에서는 홍경천의 총 폴리페놀 함량과 항산화 활성을 조사했던 바, 홍경천의 잎과 뿌리에서 양호한 결과를 나타내었으며, 특히 항산화 작용은 뿌리와 잎 추출물에서 양호한 반응을 보였다. 또한 에탄올 추출물 보다 메탄올 추출물 처리구에서 더욱 더 양호한 항산화 활성을 나타났다. 이러한 결과들을 바탕으로 홍경천 추출액을 첨가시킨 요구르트를 만들어서 품질을 조사하였던 바 요구르트 성분, 품질과 보존성이 향상되는 것을 확인할 수 있었으며 항산화 활성도 양호한 반응을 보였다.

• 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.

• Food Science and Preservation
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• v.20 no.2
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• pp.199-206
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• 2013

To evaluate peanut sprouts as a functional food material, the quality characteristics and antioxidant activities of soybean yoghurt with different percentages (0.5, 1.0, 2.0, and 3.0%) of peanut sprout powder (PSP) contents were investigated. The pH of soybean yogurt with PSP decreased in a time- and dose-dependent manner during fermentation, whereas the titratable acidity increased under the same conditions. The Hunter L value (lightness) decreased while the b value (yellowness) and a value (redness) increased as the PSP concentration in soybean yogurt increased. Prior to fermentation, the sugar content of the soybean yogurt increased as the PSP level increased, but the contents decreased as fermentation progressed. Meanwhile, the viscosity of the soybean yogurt increased during fermentation, and the lactic acid bacteria population was higher than that of the control. The sensory properties, including the flavor, color, taste, and overall acceptability, of the soybean yogurt containing 0.5 and 1% PSP, respectively, were higher than those of other tested yoghurts (with 0, 2.0, and 3.0% PSP contents). The antioxidant activity of the soybean yogurt significantly increased at the PSP concentrations of over 1.0%. These results suggest that the addition of PSP has beneficial effects on the quality and functionality of soybean yogurt, and that the addition of 1.0% PSP is the most suitable for manufacturing soybean yogurt.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1051-1058
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• 2005

This experiment was carried out to investigate the biological function of Lycium chinence Miller yogurt. Antioxidant activity was higher in methanol extract yogurt than in water extract yogurt. The antioxidant activity was shown at 83.9% in Lycii folium extract yogurt, 47.0% in Lycii fructus extract yogurt and 54.0% in Lycii cortex extract yogurt. Angiotensin converting enzyme inhibitor activity was shown highly both in water extract and methanol extracts from the Lycii folium. The $\alpha$-glucosidase inhibitor activity was shown at the 4.0% concentration of Lycii folium extract yogurt, Lycii fructus extract yogurt and Lycii cortex extract. In an orally administrated rat, normal yogurt, Lycii fructus extract yogurt and Lycii cortex extract yogurt have no effect on blood cholesterol content. IgG production in blood is more increased in Lycii cortex extract yogurt than in normal yogurt and Lycii fructus extract yogurt.

• Journal of Food Hygiene and Safety
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• v.8 no.1
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• pp.63-68
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• 1993

The healthy yogurt containing pumpkin was developed and evaluated an antioxidant effect of pumpkin in yogurt during storage. For the preparation of pumpkin yogurts, 15, 20 or 25 g of pumpkin level. and 5, 6 or 7 g of sugar level were added to 100 ml milk. There was a trend for more desirable color and texture of pumpkin yogurt at 20 g pumpkin level than 15 or 25 g pumpkin level. Pumpkin yogurt contained 7 g sugar level had a more desirable flavor, texture and overall accetability than those contained 5 or 6 g sugar level. To evaluate antioxidant effect of pumkin in yogurt during stroage, yogurts were prepared by milk alone, with pumpkin, with sugar, and with sugar and pumpkin. The sugar and pumpkin levels in yogurt were 7 g and 20 g per 100 ml milk. The malondialdehyde(MDA) content of yogurt prepared by milk alone were significandy affected by days of storage. During 13 days storage of yogurt, pumpkin and sugar exhibited antioxidant effect.

• Food Science and Preservation
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• v.25 no.1
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• pp.71-78
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• 2018

This study was carried out to investigate the quality characteristics and antioxidant activity of yogurt dressing prepared with different amounts (0, 5, 10, 15, and 20%) of black currant (Ribes nigrum L) extract. All samples were evaluated for chemical composition, pH, viscosity, sugar content, color, organic acid content and antioxidant activity. Our findings revealed that with increasing amounts of black currant extract in yogurt dressing, the moisture, crude protein and crude lipid contents decreased. The pH and viscosity gradually decreased, whereas the sugar increased with increase in black currant extract. Further, the lightness (L) value decreased, while the redness (a) and yellowness (b) values increased with increase in added black currant extract. Among the organic acids, the contents of citric acid, malic acid, succinic acid and acetic acid increased, while that of tartaric acid and lactic acid decreased with increasing levels of added black currant extract. The total polyphenol and total anthocyanin contents were 5.90-245.97 mg/100 g and 0.62-190.09 mg/100 g, respectively. In addition, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-thylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities significantly increased with increase in added black currant extract.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.113-118
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• 2020

We investigated the quality characteristics and antioxidant capacities of Korean commercial yogurt. Twenty commercial yogurt samples exhibited a pH of 4.05-4.51, titratable acidity of 0.80-1.45%, viable counts of 6.65-9.39 log CFU/g, and total phenolic content of 0.71-2.92 mg gallic acid equivalent/g dry weight (dw). Lactic acid was the major organic acid detected by HPLC with UV detection, and its content was 5.4 times and 46.5 times higher than that of malic acid and citric acid, respectively. The tested commercial yogurt samples exhibited antioxidant potential (1.62-8.95 mM trolox equivalent/g, dw) measured based on scavenging activities of DPPH and ABTS radicals. The average antioxidant potentials of commercial set yogurt containing fruit syrup were significantly (p<0.05) higher than that of cream and plain yogurt. A positive linear correlation was observed between the total phenolic content and the antioxidant capacities, suggesting that phenolic components are likely to contribute significantly to the antioxidant potential of commercial yogurt.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.690-697
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• 2014

This study was conducted to investigate the effect of mulberry powder on the antioxidant activities and quality characteristics of yogurt. The samples were fermented with different amounts (0, 0.5, 1, and 3% to the yogurt quantity) of mulberry powder for 24 hr. The total phenol content, anthocyanin content, and DPPH radical scavenging activity of yogurt significantly increased with higher mulberry powder content. The pH decreased with higher mulberry powder content until 16 hr, whereas the treated groups showed higher pH levels than the control group after 20 hr. Acidities of the treated groups were higher than that of the control group upon addition of mulberry powder. Citric acid, succinic acid, and lactic acid contents of the treatment group were higher than that of the control until 16 hr, whereas the free organic acid content of the control group increased after 20 hr. The amount of lactic acid bacteria increased with higher mulberry powder content until 12 hr, whereas that of the treated group tended to decrease compared to the control group after 16 hr. Color values of mulberry yogurt were lower in terms of brightness and yellowness, whereas redness value was higher compared to the control. Mulberry yogurt groups showed higher sensory attributes than the control, except for 3% added yogurt. Consumer acceptability score of yogurt with 1% mulberry powder was ranked higher than those of other yogurts in terms of overall preference, sourness, color, flavor, and sweetness. We suggest that mulberry powder can be used to improve the quality characteristics, functionality, fermentation, and sensory evaluation of yogurt.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.103-117
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• 2017

The aim of this study was to evaluate the effect of green tea extract on probiotic potential, physico-chemical and functional properties of yogurt fermented with Lactobacillus acidophilus D11 or Lactobacillus fermentum D37 strains isolated from Doenjang. Probiotic activities such as the resistance to artificial digestive juices and the ability to adhere to epithelial cells were slightly higher in yogurt supplemented with green tea extract than in plain yogurt, which may be attributed to the increase in the number of lactic acid bacteria (LAB) by green tea extract supplementation. Furthermore, the microbiological and physico-chemical properties such as the number of LAB, organic acid production and viscosity were significantly (P<0.05) increased in yogurt added green tea extract compared to plain yogurt fermented with L. acidophilus D11. However, the green tea extract did not significantly (P>0.05) affect these properties of yogurt fermented with L. fermentum D37 strain. Meanwhile, the antibacterial activities against Escherichia coli O157 ATCC 43889, Salmonella enteritidis ATCC 13076, and Salmonella typhimurium KCTC 2514 and antioxidant activities including total phenol content, radical scavenging ability, and ferric-reducing antioxidant power were significantly higher in plain yogurt fermented with L. fermentum D37 than with L. acidophilus D11. The antibacterial and antioxidant activities of the yogurt were significantly (P<0.05) increased in proportion to the concentration of green tea extract added to plain yogurt. Consequently, green tea yogurt fermented with L. acidophilus D11 or L. fermentum D37 was considered to be a useful functional food that can inhibit the growth of pathogenic bacteria and scavenge the free radicals from the body cells.