Functional and nutritional properties of acylated rapeseed proteins

Abstract

Rapeseed flour was acylated to various degrees with acetic and succinic anhydrides to produce acetylated rapeseed protein concentrates (SRPC) and succinylated rapeseed protein concentrates (SRPC), respectively. With both acylating agents, approximately 5–82% (ARPC‐5 to ARPC‐82) and 5–56% (SRPC‐5 to SRPC‐56) of ε‐amino groups of lysine were acylated. Changes in functional properties were monitored; nitrogen solubility, emulsifying properties and specific viscosity were improved by acylation. The effects on functional properties were more pronounced with succinylation than acetylation. The nutritive value of succinylated rapeseed protein concentrates was determined and compared with those of unmodified rapessed protein concentrate and rapessed flour. Succinylation reduced the availability of lysine and decreased (p<0.05) the net protein ratio (NPR) and apparent digestibility coefficient (ADC) of nitrogen in rapessed protein concentrates. Supplementation of SRPC with lysine improved the NPR compared to that of SRPC‐56.