• Title, Summary, Keyword: Yeast-fermented

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A Study on Yeast and Mold Contamination of Fermented Milk Products in Korea (우리나라 유산균 제품의 Yeast, Mold 오염에 관한 조사연구)

  • 홍종해
    • Journal of Environmental Health Sciences
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    • v.7 no.1
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    • pp.51-57
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    • 1981
  • This Study was carried out to investigate yeast and mold contamination in fermented milk products produced by 9 different domestic manufacturers from October 20. to December 5. 1980 The results obtained in the study were as follows 1) pH values of the products were ranged from pH 3.14 to pH 4.20 and average of sour milk drinks was pH $3.66\pm 0.19$ and fermented milks pH $3.74\pm 0.11$. Therefore the difference of pH average among sour milk drinks and fermented milks was statistically significant. (p<0.01) 2) In case of yeast contamination, yeast was found on all the four producted at the same date. From this result, it seemed that yeast contamination occured during the manufacturing progress. 3) Degree of contamination by the indicator organisms was E. coli positive, 3.7%: over 1,000 yeasts/ml, 14.8% over 10 molds/ml, 0.9%. 4) In the range of over 1,000 yeasts/ml, degree of contamination by yeast was 8.4% in fermented milk and 16.7% in sour milk drink. 5) Yeasts in product C increased to the spoilage number within 5 days and in H increased within 10 days at 5C. At 15$\circ$C, yeast increased to the spoilage number within 15 days in product A.D. 6) It seems that the yeast number of initial contamination should be important than the increase rate as criteria on the fermented Milk products.

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Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels

  • Hao, W.;Wang, H.L.;Ning, T.T.;Yang, F.Y.;Xu, C.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.6
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    • pp.816-826
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    • 2015
  • The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR). The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML), 450 g/kg (medium moisture level, MML), and 500 g/kg (high moisture level, HML), and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM) basis, yeast populations significantly increased from $10^7$ to $10^{10}cfu/g$ during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to $10^9cfu/g$ DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR.

Effect of a Fermented Rice Protein Residue on the Taste Property of Yeast Extract (쌀단백질 잔사발효물이 효모추출물의 맛특성에 미치는 영향)

  • Park, Gang-Seok;Han, Gwi-Jung;Chung, Ha-Yull
    • Food Engineering Progress
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    • v.15 no.4
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    • pp.413-419
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    • 2011
  • For producing a high added-value natural seasoning ingredient, a yeast extract (Yx) was supplemented with a rice protein residue fermented with Bacillus licheniformis (Rfl) or with Bacillus subtilis (Rfs). A rice protein residue was obtained after enzymatic hydrolysis of rice protein which was used for preparing a yeast culture medium. Overall acceptabilities of the supplemented yeast extracts (YxRfl or YxRfs) were higher compared to pure yeast extract. Savory taste like umami was found to increase noticeably by adding a fermented rice protein residue to yeast extract, which was confirmed in taste sensor analysis and in sensory test. Beyond the presence of savory tasting amino acids such as Glu and Asp in a fermented rice protein residue, it is assumed that other soluble peptide fractions remained play an important role in enhancing taste of the supplemented yeast extracts. Thus, the yeast extract added with a fermented rice protein residue could be applied to manufacture a natural seasoning ingredient.

Production of Fermented Tea with Rhodotorula Yeast and Comparison of its Antioxidant Effects to those of Unfermented Tea (적색효모를 이용한 발효차의 제조 및 발효차와 비발효차의 항산화능 비교)

  • Kang, Ok-Ju
    • Korean journal of food and cookery science
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    • v.26 no.4
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    • pp.422-427
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    • 2010
  • This study was conducted to investigate the antioxidant effect and properties of unfermented tea and fermented tea made with Rhodotorula yeast. The levels of crude fat and crude protein in the fermented tea were higher than those in the unfermented tea. The water-soluble phenol levels of unfermented tea and fermented tea were 912.5 and 2,445.24 ppm, respectively. The total amino acid content of fermented tea was greater than that of unfermented tea;,- the amino acid concentrations of alanine, valine, leucine, and lysine were 25.58, 24.38, 27.96, and 14.14 ${\mu}g/mL$, respectively. The DPPH radical scavenging activities of the unfermented and fermented teas were 32.14 and 41.57%, respectively; this is in contrast to 29.73% for L-ascorbic acid(150 ppm). The reducing power activity of fermented tea was 41.57%, and that of unfermented tea was 32.14%.

Production of Sikhae Fermented Beverage using a Dextran Producing Isolate from Kimchi and Takju Yeast (김치에서 분리한 Dextran 생성균 및 탁주 효모를 이용한 식혜 발효음료 제조)

  • Hwang, Seung-Hwan;Chung, Chang-Ho
    • Journal of the East Asian Society of Dietary Life
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    • v.21 no.1
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    • pp.82-87
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    • 2011
  • A fermented alcoholic beverage made from Sikhae, a Korean traditional fermented rice beverage, has been developed using a dextran producing isolate from Kimchi and Takju yeast. When both of yeast and the isolate inoculated for fermented beverage production it produced around 4% (w/v) ethanol and oligosaccharides during fermentation. Inoculation of Takju yeast and the dextran producing isolate showed a similar fermentation profile with case of yeast inoculation only, but the rate of sucrose use was slower than the case of yeast only. TLC analysis showed that oligosaccharides were produced during the fermentation of Takju yeast and the isolate from Kimchi. Therefore, it is possible to produce a functional fermented beverage by modification of dextran fermentation.

Quality Changes in 'Hayward' Kiwifruit Wine Fermented by Different Yeast Strains (효모에 따른 참다래 'Hayward' 와인의 품질 변화)

  • Towantakavanit, Korsak;Park, Yang-Kyun;Park, Yong-Seo
    • Korean Journal of Food Preservation
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    • v.17 no.2
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    • pp.174-181
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    • 2010
  • The yeast strains used for fermentation are known to influence the qualities of wine. We investigated the effects of fermentation using different yeast strains on the properties of wine produced from 'Hayward' kiwifruit (Actinidia deliciosa). The physicochemical characteristics of wine produced using various yeast strains for fermentation were also analyzed. Saccharomyces cerevisiae Gervin No.5 strain (GVN), S. bayanus Lavin strain EC1118 (EC1118), and S. cerevisiae Red star Davis No. 796 (No.796) are commercial dry yeast strains selected for optimization of fermentation. Although the soluble solid contents of samples fermented by all three yeast strains decreased by a similar extent, the levels of alcohol production differed, particularly during the first week of fermentation. Use of the GVN strain resulted in the highest alcohol concentration (13.8%, v/v), whereas fermentation with No.796 and EC1118 strains yielded alcohol contents of 13.0% and 12.5% (both v/v), respectively. Upon sensory evaluation, GVN-fermented wine had a strong taste and bitterness, with high acid and alcohol contents. Wine fermented using No.796 had a chemical profile similar to that of GVN-fermented product, but the taste remained sweet, consistent with the lower alcohol content. EC1118-fermented wine was soft and sweet in taste, high in flavor, and had a low alcohol content. Total phenolic levels and antioxidant activities in wine fermented by EC1118 were significantly higher than in wines prepared using No.796 or GVN. When previously described characteristics were additionally considered, EC1118 was selected as an optimum strain for further study. In conclusion, fermentation of kiwifruit using different yeast strains yielded wines with distinct characteristics. The yeast strain EC1118 had the most desirable properties, and is considered suitable for kiwifruit fermentation. Valuable attributes of wine fermented by this yeast include overall sensory acceptance, an appropriate level of total phenolics, and good antioxidant activity.

Quality Characteristics of Baguette using Fermented Rice Bran Sourdough (발효미강 Sourdough를 이용한 바게트 빵의 품질특성)

  • Hwang, Gum-Hee;Yun, Hai-Ra;Jung, Hee-Nam;Choi, Ok-Ja
    • Korean journal of food and cookery science
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    • v.30 no.3
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    • pp.307-316
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    • 2014
  • This study was carried out in order to investigate the quality characteristics of baguette with different amounts of yeast and fermented rice bran sourdough(Control: Yeast 30 g + Fermented rice bran sourdough 0 g, A sample: Yeast 20 g + Fermented rice bran sourdough 150 g, B sample: Yeast 10 g + Fermented rice bran sourdough 300 g, C sample: Yeast 0 g + Fermented rice bran sourdough 450 g). The pH of fermented rice bran sourdough by fermentation time was decreased as the fermentation time was longer. The pH of baguette dough was decreased as the fermented rice bran sourdough increased; the volume was the highest in control at the 1st fermentation, and in the B sample at the 2nd fermentation. The weight of baguette was the highest in the C sample, and the volume and specific volume were the highest in the B sample. The microstructure of the cross section analysis indicated that the air cell of baguette crumb was large and regular in the B sample. The moisture content and water binding capacity were the highest in the B sample, although significantly different. The L value was decreased as there was an increasing addition ratio of fermented rice bran sourdough; further, the a and b values were decreased with an increase in baguette volume. Hardness, gumminess and chewiness were decreased as volume and specific volume were increased; yet, springiness was increased. According to the result of the sensory evaluation, the flavor, taste, appearance and texture were the highest in the B sample.

A Non-yeast Kefir-like Fermented Milk Development with Lactobacillus acidophilus KCNU and Lactobacillus brevis Bmb6

  • Lee, Bomee;Yong, Cheng-Chung;Yi, Hae-Chang;Kim, Saehun;Oh, Sejong
    • Food Science of Animal Resources
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    • v.40 no.4
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    • pp.541-550
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    • 2020
  • The use of yeast assist kefir fermentation, but also can cause food spoilage if uncontrolled. Hence, in this study, the microbial composition of an existing commercial kefir starter was modified to produce a functional starter, where Lactobacillus acidophilus KCNU and Lactobacillus brevis Bmb6 were used to replace yeast in the original starter to produce non-yeast kefir-like fermented milk. The functional starter containing L. acidophilus KCNU and L. brevis Bmb6 demonstrated excellent stability with 1010 CFU/g of total viable cells throughout the 12 weeks low-temperature storage. The newly developed functional starter also displayed a similar fermentation efficacy as the yeast-containing control starter, by completing the milk fermentation within 12 h, with a comparable total number of viable cells (108 CFU/mL) in the final products, as in control. Sensory evaluation revealed that the functional starter-fermented milk highly resembled the flavor of the control kefir, with enhanced sourness. Furthermore, oral administration of functional starter-fermented milk significantly improved the disease activity index score by preventing drastic weight-loss and further deterioration of disease symptoms in DSS-induced mice. Altogether, L. acidophilus KCNU and L. brevis Bmb6 have successfully replaced yeast in a commercial starter pack to produce a kefir-like fermented milk beverage with additional health benefits. The outcome of this study provides an insight that the specific role of yeast in the fermentation process could be replaced with suitable probiotic candidates.

Characteristics of Peach Wine with Different Commercial Yeast Strains (시판 와인 효모에 대한 복숭아주의 발효 특성)

  • Park, Hyun-Sil
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.4
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    • pp.531-535
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    • 2010
  • This study investigated the effects of different commercial yeast strains on the characteristics of peach wine. Peach fruit was inoculated with Fermivin, K1-V1116, EC-1118, D-47 and AR2. Peach wines fermented with the D-47, K1-V1116, and AR2 strains showed faster fermentation than wines fermented with the other strains. Wine fermented with EC-1118 had the lowest titratable acidity and highest pH. The ethanol content of wines fermented with different commercial yeast strains was in the range of 13~14%. In sensory evaluation, the wine made with EC-1118 showed the highest overall scores in color and acceptability.

Optimal Cultivation Time for Yeast and Lactic Acid Bacteria in Fermented Milk and Effects of Fermented Soybean Meal on Rumen Degradability Using Nylon Bag Technique

  • Polyorach, S.;Poungchompu, O.;Wanapat, M.;Kang, S.;Cherdthong, A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.9
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    • pp.1273-1279
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    • 2016
  • The objectives of this study were to determine an optimal cultivation time for populations of yeast and lactic acid bacteria (LAB) co-cultured in fermented milk and effects of soybean meal fermented milk (SBMFM) supplementation on rumen degradability in beef cattle using nylon bag technique. The study on an optimal cultivation time for yeast and LAB growth in fermented milk was determined at 0, 4, 8, 24, 48, 72, and 96 h post-cultivation. After fermenting for 4 days, an optimal cultivation time of yeast and LAB in fermented milk was selected and used for making the SBMFM product to study nylon bag technique. Two ruminal fistulated beef cattle ($410{\pm}10kg$) were used to study on the effect of SBMFM supplementation (0%, 3%, and 5% of total concentrate substrate) on rumen degradability using in situ method at incubation times of 0, 2, 4, 6, 12, 24, 48, and 72 h according to a Completely randomized design. The results revealed that the highest yeast and LAB population culture in fermented milk was found at 72 h-post cultivation. From in situ study, the soluble fractions at time zero (a), potential degradability (a+b) and effective degradability of dry matter (EDDM) linearly (p<0.01) increased with the increasing supplemental levels and the highest was in the 5% SBMFM supplemented group. However, there was no effect of SBMFM supplement on insoluble degradability fractions (b) and rate of degradation (c). In conclusion, the optimal fermented time for fermented milk with yeast and LAB was at 72 h-post cultivation and supplementation of SBMFM at 5% of total concentrate substrate could improve rumen degradability of beef cattle. However, further research on effect of SBMFM on rumen ecology and production performance in meat and milk should be conducted using in vivo both digestion and feeding trials.