Influence of pine nut (Pinus koraiensis) oil fractions on physicochemical properties of rice starch solutions

摘要

The physicochemical properties of rice starch suspensions effected by interactions with pine nut oil fractions were investigated. Oil fractions (crude pine nut oil, glycolipid, nonpolar lipid, gums, and degummed oil) from pine nut (Pinus koraiensis) were prepared by solvent extraction and addition of boiling water. The influence of the fractions on the physicochemical properties of rice amylose solution (5%, w/w) was determined by measuring the complexing index, absorbance ratio (630/520 nm), colour, rheological characteristics, and microscopic structure at various concentrations. Their effect on rice starch swelling power was also determined. The glycolipid fraction had the highest complexing index with rice amylose. Rice amylose solutions containing the glycolipid fraction exhibited greater pseudoplastic fluid (n < 0.7) behaviour, higher colour difference values, and lower absorption ratios (1.64-1.48) than did those containing other fractions. Hydrated oil fraction (gums) complexed with amylose only poorly, if at all, but amylose solutions containing them had rheological properties similar to those containing the glycolipid fraction. The addition of oil fractions increased the swelling power value compared to the control.