Acyl化 大豆蛋白質의 乳化特性 - 7S. 11S의 乳化特性에 及치는 acyl化의 效果

Emulsifying Properties of Acetylated and Succinylated Soy Proteins -Effect of Acylation on the Emulsifying Properties of 7S and 11S Proteins-

  The acid-precipitated protein (APP), the 7S Rich protein (7S RP) and the 11S Rich protein (7S RP) were separated from defatted soybean meal, and they were acetylated and succinylated. Using them, the solubility and some factors affecting the emulsifying properties were studied and the following results were obtained.   1. The aqueous solubility of succinylated APP, 7S RP and 11S RP had generally higher value than that of unsuccinylated soyprotein, and especially increased when they were succinylated at 30% and 60%.   The pH of the minimum solubility of APP was 4.5 and the pH of the succinylated. APP was 4.0 so the isoelectric point(IEP) of APP shifted to the acidic region.   2. The solubility of succinylated soy protein had high value in alkaline region and low value in acidic region.   The solubility of succinylated APP had highest value and that of 7S RP had lowest value in alkaline region.   On the contrary the solubility of 7S RP had highest value and that of APP had lowest value in acidic region.   3. The emulsifying capacity (EC) of acetylated APP, 7S RP and 11S RP, which was effected by the pH, markedly increased than that of unacetylated in weak acidic region and neutral region.   The acetylated soy proteins and unacetylated soy proteins had a similarity in the emulsion stability (ES).   However, the pH at the minimum point of ES of acetylated shifted than that of unacetylated to acidic region.   4. The emulsifying capacity (EC) of acetylated APP and 7S RP clearly increased by the addition of 0.05M sodium chloride while that of acetylated 11S RP was decreased.   The emulsion stability of acetylated APP, 7S RP and 11S RP markedly increased than that of unacetylated by the addition of 0.02M sodium choloride.   5. The emulsifying capacity(EC) of acetylated APP was hardyl affected by heat treatment but that of acetylated 11S RP was markedly decreased by 80℃ heat treatment.   The emulsion stability (ES) of acetylated 11S RP was markedly decreased by 80℃ heat treatment that of acetylated APP and 7S RP was hardly affected by heat treatment.