Studies on the Preparation of Food Proteins from Castor Bean Protein

피마자 단백질의 식품화를 위한 연구

  • Yoon, Joo-Ok (Department of Food Technology, Dong Guk University)
  • 윤주억 (동국대학교 식품공학과)
  • Published : 1980.12.30


Detoxified and deallergenized castor bean protein isolate was prepared from defatted castor bean pomace for use in animal feedstuffs and human foods. Succinylation and acetylation of the ${\varepsilon}-amino$ groups of the protein improved markedly the water solubility of the protein at $pH\;7{\sim}8$. The results of the amino acid analysis of the protein isolate revealed that the sulfur-containing amino acids and L-lysine were limiting amino acids and that succinylation and acetylation caused some little loss of the amino acid content. The L-methionine enriched plastein was synthesized from the protein isolate or the acylated protein isolates and DL-methionine ethyl ester by one step process with papain. By this method the extent of incorporation of L-methionine was about 50%. Pepsin hydrolyzed both unmodified and modified protein isolates at the same rate (about 92%). Tryptic hydrolysis, however, was less for the succinylated protein isolates (about 42%) and less for the acetylated protein isolates (about 26%). The protein efficiency ratio of L-methionine enriched protein isolate (about 2.5 weight %) was 90% that of reference casein. The protein efficiency ratio values of succinylated (88%) and acetylated (84%) protein isolate were 55 and 69% of reference casein, respectively.