Exploring effect of uniform dry ball-milling duration on pasting and rheological properties of pink potato and maize starch mixtures

Abstract

This study examined the potential effect of ball milling on maize starch (MS), pink potato starch (PPS), and their blends in various ratios (90:10, 80:20, and 70:30) on the pasting and rheological properties. Ball-milling led to changes in the particle size, ranging from 652.9 to 6488 nm, and a decrease in relative crystallinity (RC), as confirmed by XRD. Ball-milling increased amylose concentration in blend with the ratio of 90:10 up to 32.53 %, indicating structural alterations and molecular interactions. FESEM analysis confirms significant changes in the surface and particle sizes and starch gels with honeycomb structures. FTIR and Raman spectroscopy revealed a decrease in the intensity of the 1044 cm−1 and 480 cm−1 bands, respectively, signifying structural changes. Pasting parameters like peak viscosity and gelatinization behavior varied with PPS incorporation. The 80:20 blend had the highest viscosity, demonstrating PPS's capacity for high-viscosity starch paste. Rheological measurements of starch blends exhibited shear-thinning behavior, whereas the viscoelastic properties of the blends are influenced by particle size and the ratio of pink potato starch. Ball-milling treatment affects the granules and causes molecular-level interactions between the particles. This results in unique rheological properties of the starch blends, making them suitable for various applications.