Influence of heat–moisture treatment and annealing on functional properties of sorghum starch

Sorghum starch was annealed in excess water at 50 °C for 24 h. Starch was also modified under heat–moisture treatment at 110 °C after adjusting various moisture contents (20, 30 and 40%) for 8 h. Significant decrease in chain lengths of amylose fraction in HMT starches was observed. Heat moisture treated (HMT) and annealed (ANN) starches showed lower granule sizes, swelling power, peak and setback viscosity but higher retrogradation as compared to native starch. HMT starch with addition of 40% moisture showed a decrease in relative crystallinity. HMT and ANN starch gels were observed to be harder than native starch gel.

► Sorghum starch was heat–moisture treated (HMT) and annealed (ANN).
► Amylose got degraded during HMT.
► Granular structure and pasting parameters were altered after HMT and ANN.
► Starch crystallinity decreased at higher moisture application.