Study on the proteolytic ability and ACE inhibitory activity of Lactobacillus delbrueckii QS306 to milk

The growth characteristics of Lactobacillus delbrueckii QS306 in reconstituted skim milk( 10% wt / wt) was observed,and its proteolytic ability and angiotensin- converting enzyme( ACE) inhibitory activity were investigated by the addition of growth promoting substances.The results showed that Lactobacillus delbrueckii QS306 was slow- growing in skim milk,and its acid production and biomass were increased gradually. The titratable acidity,biomass and protein decomposition at 37 ℃ for 4 days were 68.24( ° T),6.91( OD410 nm× 10) and 623.21 μg·m L- 1Tyr,respectively.The proteolytic ability of strain QS306 was increased by 43.7% and the( ACE) inhibitory activity was61.99% when adding Guanine in skim milk.