• Food Engineering Progress
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• v.14 no.1
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• pp.14-20
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• 2010

The objective of the current study was to determine the cryoprotective effects of trehaolse on lactic acid bacteria in the frozen yoghurt during long-term frozen storage conditions. The frozen yoghurts were prepared using starter culture containing Lactobacillus bulgaricus and Streptococcus thermophilus, as well as trehalose and sorbitol as a cryoprotectant. The viable cell numbers of lactic acid bacteria in frozen yoghurt did not significantly decreased during six weeks frozen storage conditions. The MRS broth, which contains either trehalose or sorbitol, cultured with L. bulgaricus and/or S. thermophilus, and then the cultured medium was kept in the frozen condition for six weeks. The results indicated that lactic acid bacteria viability significantly increased with trehalose addition (2 and 5%) in the media compared to those of control and sorbitol supplement groups. The lactic acid bacteria viability in the yoghurts was examined on the effects of repeated freeze and thaw events. The freeze-thaw resistance of lactic acid bacteria significantly increased with trehalose supplement in the yoghurt. The major volatile aroma compounds (acetaldehyde, acetone, ethanol, diacetyl, and acetoin) in yoghurt were separated and indentified by headspace GC-FID analysis. Distinct flavor components and their ratios are known as important quality factors for yoghurt notes. Trehalose addition to the yoghurt was not influenced these factors during lactic acid fermentation. The results in this study demonstrated that trehalose potentially can be applicable as an effective cryoprotectant for lactic acid bacteria in the frozen yoghurt products.

• 우유
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• v.4 no.4 s.15 winter
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• pp.32-36
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• 1983

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.66-75
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• 2003

This experiment was carried out to examine the fermentation properties of yogurt added fresh mulberry, freeze dried-mulberry and heated air dried-mulberry at concentrations of 0%, 0.3%, 0.6% and 0.9%. Lactic acid bacteria was used mixed starter culture(Str.salivarius ssp. thermophilus and Lac. delbrueckii ssp. bulgaricus). We obtained excellent results from the yogurt added fresh mulberry. In yogurt added 0.9% fresh-mulberry, lactic acid contents and titratable acidity were higher than those of 0%, 0.3%, 0.6% fresh-mulberry added. Also, sensory scores of color, taste and overall acceptability of the yogurt with 0.9% fresh mulberry was higher than those of any other groups.

• Journal of Dairy Science and Biotechnology
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• v.14 no.1
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• pp.71-84
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• 1996

This study was conducted to examine the usability of sorbitol for the manufacture as low-calory ingredient and cryoprotectant against frost damage. When frozen yoghrt was made of replacing sucrose by sorbitol at yoghurt mix, the change of physicochemical and lactic acid bacteria, such as Str. thermophilus, L. bulgaricus, and mixed culture of Str. thermophilus, and L. bulgaricus(1:1), was studied during the frozen storage(-20$^{\circ}$C). During the incubation of yoghurt mix, the rapid growth of lactic acid bacteria in all sample was observed as the increase of sorbitol addition, but sample A and D were almost similar. This results suggested that sucrose could play role of effecting the growth stimulator, otherwise, sorbitol could inhibit the death of microorganism, following the genus. At the survival rate between lactic acid bacteria during freezing of -5$^{\circ}$C by ice cream freezer Str. thermophilus showed 26.19 to 34.76%, L. bulgaricus 3.97 to 5.20%, and mixed culture 17.16 to 40.87% respectively. L. bulgaricus showed the greater lethal rate than other genus. Sample C which mixed sucrose with sorbitol (1:2 ratio) was showed the lowest lethal rate. Therefore, it suggested that the use of this ration could be used for better anti-frost damage. During the storage of -20$^{\circ}$C, the number of lactic acid bacteria generally decreased in the stand point of genus and frozen storage period. The survival of lactic acid bacteria might be the addition of sorbitol which could have the effect of anti-forst damage. In all treatment, lactase activity showed the rapid decrease after freezing. During the period of frozen storage, it was shown the slow decreasing trend. In spite· of decreasing, the result during yoghurt mix incubation -5$^{\circ}$C freezing, and -20$^{\circ}$C frozen storage was different at the level. After 80 days of storage, the lactase activity was similar among all genus and sample. Despite differenting viscosity followed by genus, combination of mix, and pH, the ratio of 1 to 2(sucrose : sorbitol) showed the greatest viscosity. The water holding capacity of frozen yoghurt mix was closely related to viscosity. As increasing sorbitol amounts, hardness and cohesiveness were increased, but elastisity was decreased. The significant differences between sample was inoculated with Str. thermophilus. However, there were not significant difference from the sample inoculated with L. bulgaricus and mixed culture.

• Bulletin of Food Technology
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• v.15 no.1
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• pp.55-61
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• 2002

장내 균총 개선을 위하여 조합시킨 prebiotics와 probiotics는 최고의 건강 증진을 제공할 잠재성을 갖지만, 알맞은 균주선발이 필수적이다. 기능성 식품시장은 연간 15∼20% 성장하고 있고, 그 산업은 33백만 달러의 값어치가 있다(Hilliam, 2000). 기능성 식품은 nutraceuticals, designer foods, medicinal foods, therapeutic foods,superfoods, foodiceuticals와 medifoods로 알려져 있고 그 정의는 전통적인 영양소개념을 넘어선 건강증진 성분을 함유한 식품이라고 할 수 있다(Berner와 O'Donnell,1998). 식품은 phytochemicals, bioactive peptides, $\omega$-3 불포화 지방산, 그리고probiotics 또는 기능성을 갖게 되는 prebiotics의 부가에 의하여 변형될 수 있다(Berner와 O'Donnell, 1998)(표 1). 장관에서 살수 없는 균을 함유한 요구르트의 경우와 같은 다양한 발효 낙농식품 제조에 젖산균을 사용한 이래, 오늘날에는 발효식품에Lactobacillus acidophilus와 bifidobacteria 같은 probiotic 균을 사용하는 경향이다. Probiotic 식품은 살아 있는 미생물을 함유한 식품이고, 그 미생물은 충분한 양이살아 있는 상태로 장 속에 공급되었을 때에 미생물 균총을 개선하여 소비자 건강을 증진시키는 것이라고 할 수 있다(Fuller, 1992). 전통적으로, probiotics는 요구르트와 기타 발효식품에 사용되어 왔지만, 최근에는 드링크, 알약형, 캡슐형, 동결건조물과 같은 형태로도 공급되고 있다. 오늘날, 전세계에 sour cream, buttermilk, 요구르트, 분유와 frozen desserts 같은 식품에 bifidus acidophilus를 함유한 제품이 70개를 넘고 있으며, 일본에서만도 probiotic 미생물을 함유한 형태의 우유제품이 53종류 이상 개발되어 있다. Probiotics는 유럽에서도 매우 인기가 있지만, 주로 요구르트에 한정되어 사용되고 있다(Hilliam, 2000).

• 축산식품과학과 산업
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• v.6 no.2
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• pp.30-33
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• 2017

• Food Science of Animal Resources
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• v.29 no.4
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• pp.437-444
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• 2009

${\gamma}-Aminobutyric$ acid (GABA) producing lactic acid bacteria, Lactobacillus acidophilus RMK567 was cultivated in 50 L of sterilized MRS broth using a fermenter at $40^{\circ}C$ for 24 h. The cell number was increased to $10.04{\pm}0.13$ Log CFU/mL with a growth rate constant (k) of 0.454 generation/h and a generation time (g) of 2.303 h after a lapse of a lag phase (L) of 5.16 h. A total of 487 g of cell paste with 40.5% moisture was harvested with viable cell number of 12.48 Log CFU/g cell paste. The cell pastes after preparation with glycerol, glucose, and polydextrose as cryo-protectants were lyophilized under a vacuum of 84 m torr. A total of 408 g of freeze dried (FD) cell powders were mixed with a commercial strain of Streptococcus thermophilus to prepare of three types FD starter cultures with the viable cell numbers of 12.42 (FDA-GY), 12.60 (FDBGG) and 12.91 (FDC-GP) Log CFU/g. During preservation the FD cultures at -$18^{\circ}C$, the cell viability of the FD starter cultures were rapidly dropped to below 3.24% of the day of storage. No significant difference was found in the cell viabilities among three types of FD starters cultures, but significant difference (p<0.01) was found in storage periods. Yoghurts fermented through FD starter culture of L. acidophilus RMK567 were determined to contain $155.16{\pm}8.53$ ppm, $243.82{\pm}4.27$ ppm, and $198.64{\pm}23.46$ ppm of GABA, respectively. This study shows that GABA production activity of L. acidophilus RMK567 is not affected during the freeze drying process and would be available for commercial production of yoghurt containing high GABA content.

• The Microorganisms and Industry
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• v.19 no.3
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• pp.46-48
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• 1993

현재 유산균은 요구르트, 치즈, 케피어(kefir), 에시도필러스 밀크(acidophilus milk), 비피더스 밀크(bifidus milk), 쿠미스(kumiss), 발효버터(fermented butter), 유산균음료, 빵 등 식품의 천연 방부제, 채소절임, 발효두유(fermented soy milk), 정장제, 구강염증치료제, 사료 첨가제 등등 다양하게 이용되고 있다. 이것은 유산균에 대한 동결건조, 유전자 조작 등 첨단기술이 산업화로 연결되면서 그 이용성이 더욱 확장되고 있다. 유산균을 이용한 건강보조식품도 최근 몇년 사이에 선을 보이고 있지만 아직은 초보적인 단계이며 현재로선 유산균 발효식품과 유산균제제(의약품) 사이에서 뚜렷한 자기자리를 찾지 못하고 있는 실정이다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.926-934
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• 2006

The base for preparing oyster hydrolysate-added yogurt was consisted of whole milk (1,000 mL), skim milk (44.05 to 42.05 g), enzymatic oyster hydrolysates powder (OHP, 0 to 2.0 g) and pectin. The yogurt base was fermented with 7 kinds of starter cultures (3% based on yogurt volume), such as Lactobacillus acidophilus, lactobacillus bulgaricus, lactobacillus casei, Lactobacillus fermentum, Lactobacillus pentosus, Streptcoccus thermophilus and the mixed starters (L. bulgaricus and S. thermophilus) at optimal temperature. Processing condition and quality characteristics of the yogurt were evaluated by analyzing pH, titratable acidity, viscosity, viable cell count, functional properties and sensory evaluation. The results suggested that the optimal conditions for preparing the good quality yogurt revealed the mixed starters (L. bulgaricus and S. thermophilus) for starter culture, 1.0 g of 3 kDa hydrolysate for amount, and 5.5 hrs for fermentation time. The good quality yogurt showed 4.31 for pH, 1.07% for titratable acidity, 469 cps for viscosity and $4.9{\times}10^8\;CFU/mL$ for viable cell count. The hydrolysate-added yogurt was 2 times higher in ACE inhibitory and antioxidant activities than commercial yogurt, and kept good quality during storage of 15 days at $5^{\circ}C$.

• Journal of Life Science
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• v.25 no.2
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• pp.206-213
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• 2015

Sunsik has been popular as well-being and healthy food to some Asian people, but it still has a limit to other foreigners because of its taste and appearance. This study tried to modify Sunsik into smoothie type for foreigners and investigate its physicochemical characteristics. Germinated black and brown rice was prepared. The germination condition of two cereals was steeping for 24 hr at room temperature, and then germinating for 24 hr at $30^{\circ}C$. After germination, the ${\alpha}$-amylase activity of germinated grains was 13~15 times higher than before germination. The enzyme activity of brown rice was 9.16 CU/g, but germinated brown rice was 152.63 CU/g. In case of black rice, enzyme activity before germination was 7.47 CU/g, and enzyme activity after germination was 97.96 CU/g. The lactic acid bacteria was grown in 50 g germinated brown rice powder with 100 ml malt solution, 30 g tomato juice, and 1.5 g rice bran. After manufacturing beverage using milk and Sunsik and the cell count of lactic acid bacteria was $1.3{\times}10^5CFU/ml$ enough to use starter. According to sensory test, the optimal concentration of Sunsik smoothie was 30 g Sunsik in 200 ml of milk. The viscosity was $5.97{\pm}1.2$ centipoise. The color of Sunsik beverage was evaluated as L value : $63.50{\pm}0.41$, a value: $-0.35{\pm}0.06$, and b value: $8.85{\pm}0.19$.