Effect of nano-conversion on morphological, rheological and thermal properties of barley starch

The aim of the present study was to synthesize biodegradable starch nanoparticles (SNP's) from a renewable source like barley starch and to characterize for morphological, crystalline, thermal, and rheological properties. Acid hydrolysis transformed A+V-type round or disc-shaped native starch (NS) granules with an average width of 10 µm and the average length of 22 µm into round or irregular shaped A-type SNP's with an average size of 64 nm with the crystallinity enhanced from 41.75 to 48.08%. The zeta potential of NS and SNP's was - 17.7 and - 21.4 nm, respectively, with the higher stability of SNP's. The gelatinization temperature increased while melting decreased after nano conversion of barley starch. The storage and loss moduli of 12 and 15% suspension of SNP's remained unchanged with a change in angular frequency (0.1-10 rad-s), which indicated a greater tendency to recover after deformation, while 20% SNP's suspension behaved like a viscous fluid. The flow behavior test demonstrated a shear-thinning behavior of SNP's suspension.