An Assessment of Alkali Degradation, Waxy Protein and Their Relation to Amylose Content in Thai Rice Cultivars

Abstract

In this study, the amount of waxy protein and starch properties including amylose content and alkali digestibility, and their correlation were investigated in a collection of Thai rice cultivars. We found that glutinous rice lacked Wx protein, whereas nonglutinous rice showed a positive correlation between amylose content and the amount of Wx protein (r = 0.97, p<0.01). Starch granules of glutinous rice varieties showed high levels of disintegration in alkali (KOH) solution, while starch granules of nonglutinous rice cultivars were significantly more resistant to alkali digestibility (t = 12.2, p< 0.01).