Hydration behavior and kinetic studies of paddy cultivars: optimization of process variables for improved physical, milling and textural properties.

Unlabelled: The optimization of hydration temperature and duration were determined in six and non- paddy cultivars varying in grain size, shape, and amylose content based on kinetic parameters and effect of hydration temperature on physical, milling, textural and color attributes. Based on higher R, lower Chi square and RMSE values, Peleg model fitted more suitably compared to Singh and Kulshrestha model. Hydration process significantly altered geometric, gravimetric and mechanical properties as evident by regression analysis. Physical properties except length and L/B ratio positively correlated with increasing hydration temperature. Head rice yield significantly improved in the hydrated treatments and showed a linear increase with the increase in hydration temperature. Head rice yield significantly correlated with hardness of grain ( = 0.684,  ≤ 0.01). Variable physico-chemical properties of cultivars led to establishment of cultivar specific optimum hydration temperature. Based on improvement in hardness, milling efficiency, head rice yield, color and textural attributes, the optimized temperature emerged as 75 °C for long slender grained cultivars (PB1509, PB1718, PS17) and 80 °C for medium grained cultivars (PD18, KJ, AL). The results revealed that optimum hydration temperature should be cultivar specific to get better output of parboiling process.

Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-024-05925-1.