Lactobacillus casei와 Bacillus subtilis의 첨가에 의한 두유요구르트 발효에 관한 연구

다국어 초록 (Multilingual Abstract)

In order to characterize chemical and physical changes of soy yogurt which was fermented by Lactobacillus casei and Bacillus subtilis, two kinds of soy yogurt were prepared. The first group was prepared with Lac. casei and the second group was prepared with Lac. casei and Bac. subtilis.
Chemical and physical changes of each group of soy yogurt were found during 36 hours of fermentation period. These groups of soy yogurt were analysed pH, titrable acidity, viscosity, protease activity, free amino acids, and organic acids regularly at 6 hours' interval.
The results of the study were summarized as follows;
1. pH was decreased during the soy milk fermentation in all of the two groups.
The final pH value of soy yogurt showed 4.5 at the last stage of fermentation. On the other hand titrable acidity was increased during the soy milk fermentation.
2. Viscosity during the soy milk fermentation by Lac. casei was increased up to 24 hrs fermentation, after that decreased. Viscosity of mixed culture group was decreased slightly up to 24hrs, after that decreased drastically.
3. Protease activity during the soy milk fermentation by Lac. casei was increased by insensible degree, and that decreased after 24 hrs. Protease activity of mixed culture group was maintained similar value from 32 to 40 until 24 hrs, and that increased substantially. Changes in two groups were big difference.
4. Lactic acid content during the soy milk fermentation had a close relationship to titrable acidity. In addition to mixed culture group was showed higher correlation between lactic acid content and protease activity.
5. Amount of amino acid in Lac. casei culture group was decreased slightly. Amount of amino acid in mixed culture group was maintained the first value about 480 ㎍ / mI and that increased after 24 hrs.
Correlation between content of amino acid and protease activity of Lac. casei group was irrespective. By contrast, amino acid content of mixed culture group was very closely related with protease activity and content of lactic acid. The higher protease activity was, being accelerated protein hydrolysis, the more increase content of amino acid and lactic acid.

목차 (Table of Contents)

• 목차
• I. 서론 = 1
• II. 실험재료 및 방법 = 3
• 1. 실험재료 = 3
• 1) 대두 = 3
• 2) 사용균주 = 3
• 2. 실험방법 = 3
• 1) 두유 요구르트의 제조 = 3
• (1) 두유 제조 = 3
• (2) 균주 사용 = 4
• (3) 두유 요구르트 제조 = 6
• 2) 분석 및 측정 = 6
• (1) 일반 성분 분석 = 6
• (2) pH 및 적정산도 측정 = 6
• (3) Viscosity 측정 = 6
• (4) 효소활성 측정 = 6
• (5) 유리아미노산 정량분석 = 8
• (6) 유기산 정량분석 = 10
• 3) 통계 자료의 처리 방법 = 12
• III. 결과 및 고찰 = 14
• 1. 두유 요구르트 발효 중의 pH 및 적정산도의 변화 = 14
• 2. 두유 요구르트 발효 중의 Viscosity의 변화 = 16
• 3. 두유 요구르트 발효 중의 Protease Activity의 변화 = 18
• 4. 두유 요구르트 발효 중의 유기산의 변화 = 20
• 5. 두유 요구르트 발효 중의 유리아미노산의 변화 = 23
• IV. 요약 = 29
• 참고문헌 = 31
• Abstract = 34
• Appendix = 36