Effects of acylation on the functional properties and in vitro trypsin digestibility of red kidney bean (Phaseolus vulgaris L.) protein isolate.
The effects of succinylation and acetylation on some functional properties and the in vitro trypsin digestibility of kidney bean protein isolate (KPI) were investigated. The extent of succinylation or acetylation progressively increased from 0% to 96% to 97%, as the anhydride-to-protein ratio increased from 0 to 1 g/g. Polyacrylamide gel electrophoresis (PAGE) and zeta potential analyses indicated that acylation, especially succinylation, considerably increased the net charge and hydrodynamic radius of the proteins in KPI, especially vicilin. Acylation treatment at various anhydride-to-protein ratios (0.05 to 1 g/g) remarkably improved the protein solubility (PS) and emulsifying activity index (EAI) at neutral pH, but the improvement by succinylation was much better than that by acetylation. Succinylation resulted in a marked decrease in mechanical moduli of heat-induced gels of KPI, while the mechanical moduli were, on the contrary, increased by acetylation. Additionally, in vitro trypsin digestibility was improved by the acylation in an anhydride-type and level-dependent manner. The results suggest that the functional properties of KPI could be modulated by the chemical acylation treatment, using succinic or acetic anhydride at appropriate anhydride-to-protein ratios.
Yin
Shou-Wei
SW
Dept. of Food Science and Technology, South China Univ. of Technology, Guangzhou 510640, PR China.
Tang
Chuan-He
CH
Wen
Qi-Biao
QB
Yang
Xiao-Quan
XQ
D000089:Acetic Anhydrides / Q000737:chemistry; D000215:Acylation; D000465:Algorithms; D004044:Dietary Proteins / Q000302:isolation & purification / Q000378:metabolism*; D004063:Digestion; D055119:Elastic Modulus; D004591:Electrophoresis, Polyacrylamide Gel; D045703:Emulsifying Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D005782:Gels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D027805:Phaseolus / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry; D012995:Solubility; D013387:Succinic Anhydrides / Q000737:chemistry; D013997:Time Factors; D014357:Trypsin / Q000378:metabolism*
D000089:Acetic Anhydrides; D004044:Dietary Proteins; D045703:Emulsifying Agents; D005782:Gels; D010940:Plant Proteins; D011506:Proteins; D013387:Succinic Anhydrides; C048826:phaseolin protein, Phaseolus vulgaris; C031800:acetic anhydride; C031801:succinic anhydride; D014357:Trypsin