| Summary: | 碩士 === 中州科技大學 === 保健食品系 === 101 === The purpose of this study is to develop a suitable enzymatic method for producing sesame peptides with angiotensin I-converting enzyme inhibitory (ACEi) activity by using the defatted sesame as substrate. Various commercialized proteases were preliminarily tested for their yields of peptides and ACEi activities. The results showed that bromelain was the most suitable protease for producing ACEi peptides from defatted sesame. Our further studies found that the optimal condition for producing ACEi peptides from defatted sesame was as follows: 10g of defatted sesame (containing about 42% protein) mixed with 10-fold volumes of distilled water and digested with 20000 units of bromelain at 55℃ for 4 hours. The yield, protein recovery and ACEi-IC50 were 35.4%, 50.7% and 0.26mg/mL, respectively. Treatment with pepsin at 37℃ and pH 2 for 2 hours could increase the ACEi activity of the crude peptides. Extraction of the dried crude peptide product with methanol could remove a lot of impurities and increased the ACEi activity by two times. The sesame peptide was fractionated by a Sephadex G-25 column, and the fractions with the highest ACEi activies were analyzed by LC/MS. Three peptides were identified as tetra-peptides of Leu-Pro-Asn-Leu and Leu-Pro-Val-Leu, and a penta-peptide of Asp-Ala-Arg-Pro-Ala with ACEi- IC50 of 0.61, 0.80 and 7.74mg/mL, respectively.
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