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¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥1,000,000 (Direct Cost: ¥1,000,000)
Anti-oxidization peptides in fermentation milk were studied, and their structure and the formation mechanism were investigated, gettig the following result.
1. After various lactic acid bacteria were cultivated by using the skim milk, the antioxidative activity of those cultivation was measured. The highest antioxidative activity was found in Lactobacillus delbruekii subsp. Bulgaricus IFO13953 culture. Two peptides with antioxidative activity were found in fermented milk by Lactobacillus delbruekii subsp. Bulgaricus IFO13953, that is, αs2-CN (f113-126) and κ-CN (f96-106) which were separated with HPLC.
2. It is considered that these peptides were involved in cell envelope associated protease as enzyme for the formation of them. Casein was mixed with cells which could be harvested after the cultivation of the strain, and incubated for 3 hours. Peptides formed was then analyzed by using the reverse-phase HPLC. Most of them were form αs2 and β-casein. The peptides were also originated from κ-casein, but not αs1-casein. Αs2-CN(f113-126), one of the peptides which was appeared in fermented milk was known to be antioxidative.
3. The properties of cell envelope associated protease, which was related in formation of these peptides, were studied using resting cell. The activity from pH5.0 to 7.0 was not affected. It was most active at 45 ℃. The enzyme was estimated to be serine protease, being strongly inhibited by PMSF.