Abstract:Effects of temperature,pH,drying methods and in vitro digestion of intestinal enzyme on the stabilities of angiotensin-Ⅰ converting enzyme(ACE) inhibitory peptides from silkworm pupae were studied.Furthermore,the inhibitory mechanism of ACE-inhibitory peptides from silkworm pupae against ACE was preliminarily studied based on the analyses of Lineweaver-Burk plots and ultraviolet spectrum.The results showed that,ACE-inhibitory peptides from silkworm pupae were instability and easy inactivation under the conditions of high temperature,acidic or alkaline.The effects of freeze-drying and spray-drying on the peptides activity were smaller.The peptides were resistant to digestion by pepsin,trypsin and α-chymotrypsin.After co-digestion by pepsin,trypsin and α-chymotrypsin,the peptides activity could maintain 94.0% of their initial activity.Moreover,the inhibition pattern against ACE revealed that the peptides were competitive inhibitors with inhibition constants(Ki) 0.06 mg/mL.After the inhibition by the peptides,the ultraviolet absorbance values of ACE at 240～280 nm were significant increase,and these changes of ultraviolet absorbance values initially revealed that ACE molecular structure has been changed.
