Characterization and Immobilization of Purified Alliinase Produced from Shallots

Abstract

In this study, Alliinase extracted and purified from shallots was comprehensively examined. Its molecular weight was determined as 50 kDa, and its optimal working conditions were identified as pH 8 and 40 º C. Its activity was significantly and positively affected by the metals K + , Na + , Ga 2+ , Mg 2+ and Fe 2+ . Purified Alliinase was immobilized by alginate and the optimized conditions for this process were: a sodium alginate concentration of 2.5%, a CaCl 2 concentration of 4.0%, a Glutaraldehyde concentration of 0.75%, and a ratio of sodium alginate solution and Alliinase solution (by volumn) of 4:3. The ability for free Alliinase and immobilized Alliinase to release flavours from shallots was compared. It was found that immobilization did not compromise Alliinase's flavor releasing ability. They both released 36 flavouring chemicals from the flavouring precursor, with a similar ratio. This study provided fundamental information for further commercial development of Alliinase produced from shallots.