Thermal properties of partially hydrolyzed starch-glycerophosphatidylcholine complexes with various acyl chains.
Complexes of starch and monoacyl-sn-glycerophosphatidylcholine (GPC) containing various acyl (myristoyl, palmitoyl, and stearoyl) chains were subjected to hydrolysis with glucoamylase (EC 3.2.1.3). The enzyme hydrolyzed approximately 40% of starch control and 20-28% of starch-GPC complexes. Among the GPCs examined, 1- and 2-monomyristoyl-sn-GPC showed the highest resistance to enzyme hydrolysis, and the hydrolysis rate of starch-GPCs was greater with longer chains. Enzymatic hydrolysis strongly affected the thermal properties of the starch. After enzymatic hydrolysis of starch-GPC complexes for 24 h, their thermograms had broader peaks with lower enthalpies than the corresponding starch without enzyme; however, the starch-GPC complexes showed little change. The surface of starch-GPC granules was less eroded. These results showed that the increasing amount of starch-GPC complexes could be more resistant to hydrolysis.
Laboratory of Food Chemistry, Division of Applied Biological Chemistry, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai 599-8531, Japan.
Tri Agus
TA
Siswoyo
Naofumi
N
Morita
D000215:Acylation; D005087:Glucan 1,4-alpha-Glucosidase / Q000378:metabolism*; D005997:Glycerylphosphorylcholine / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D008855:Microscopy, Electron, Scanning; D019814:Myristic Acid / Q000032:analysis; D019308:Palmitic Acid / Q000032:analysis; D013213:Starch / Q000378:metabolism*; D013229:Stearic Acids / Q000032:analysis; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D013229:Stearic Acids; D019814:Myristic Acid; D019308:Palmitic Acid; C031183:stearic acid; D005997:Glycerylphosphorylcholine; D013213:Starch; D005087:Glucan 1,4-alpha-Glucosidase