Abstract
This work is a new attempt to modify the functionality of food proteins by the use of a potential activity of papain. Fish protein concentrate, soy protein isolate, casein, ovalbumin and gelatin were succinylated prior to using them as substrates. Each of the L-leucine n-alkyl esters with different alkyl-chain lengths was covalently incorporated into each substrate by applying the unusual papain-catalyzed reaction [Agric. Biol. Chem., 43, 1065 (1979)]. The resulting products posessed high whippability and/or emulsifying activity. The highest whippability was observed when leucine butyl ester or hexyl ester was incorporated, while the incorporation of higher alkyl esters generally caused an increase in emulsifying activity.
