Multivariate analysis of structural and physicochemical properties of different rice starches influenced by apparent amylose content

This study presents an integrated multivariate analysis of physicochemical and structural properties of rice starches across a wide apparent amylose content (AAC) range (2.94–44.43%) by principal component, Pearson’s correlation, and hierarchical cluster analyses. Correlation analysis indicated that AAC showed positive correlations with resistant starch ( r = 0.72), final viscosity ( r = 0.63), setback viscosity ( r = 0.82), and lipid content ( r = 0.64). The AAC also exhibited strong positive correlations ( p < 0.01) with blue value and maximum absorption wavelength. Principal component analysis of 16 variables accounted for 65.5% of total variance, with pasting temperature contributing minimally to the major components. Hierarchical cluster analysis revealed two dominant clusters: one associated with starch composition and retrogradation behavior, characterized by AAC, resistant starch, lipid content, and setback and final viscosities, and another related to structural and pasting properties, including crystallinity, molecular order, swelling power, solubility, and pasting viscosities during heating. These clustering patterns reveal coordinated interactions among starch components that cannot be captured through single-variable analysis. Overall, this study provided an integrated understanding of how amylose content and structural features govern resistant starch formation and pasting behavior, offering a scientific basis for selection and utilization of rice starches in food applications.