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.
Siswoyo
Tri Agus
TA
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.
Morita
Naofumi
N
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