Antioxidant and antihypertensive activities of autolysate and enzymatic hydrolysates from yam (Dioscorea opposita Thunb.) ichyoimo tubers

Author: Takeshi Nagai ^1*, Nobutaka Suzuki ², Yasuhiro Tanoue ³, Norihisa Kai ³ and Toshio Nagashima ¹

Received 5 May 2007, accepted 29 July 2007.

Abstract

Autolysate and enzymatic hydrolysates from yam ichyoimo tubers were prepared by autolysis and digestion using three peptic enzymes. The potential antioxidant capacity and angiotensin I-converting enzyme (ACE) inhibitory activity were also investigated. Among these sample species, autolysate and trypsin hydrolysate exhibited extremely high antioxidant activities. In addition, high ACE inhibitory activities were detected in the same sample species similar to peptides derived from food proteins, for example fish muscle, casein, zein, sake and other food proteins. Yam ichyoimo tubers is an excellent source of antioxidant compounds and exhibited great efficiency in scavenging against active oxygen species. The discovery of our research is helpful to produce processed foods with high antioxidant activity and antihypertensive activity and high health benefits in food industry.