Abstract:

The effect of cooking temperature during preparation on properties of hot-air dried instant rice were investigated. Results indicated that cooking temperatures of 100, 106 ℃ and 110 ℃ had no significant effect on rehydration rate and ratio of hot-air dried instant rice, but had a significant effect on hardness and viscosity. Instant rice prepared at cooking temperature of 100 ℃ exhibited higher rehydration rate and ratio than at cooking temperature of 106 ℃ or 110 ℃ An increase from 215.199 g to 279.332 g in hardness and an increase from 30.966 g to 43.608 g in stickiness were exhibited in instant rice after rehydration due to increased cooking temperature during preparation. The porous and harsh surface of instant rice prepared at cooking temperature of 100 ℃ was observed under scanning electronic microscope (SEM), in contrast, less porous and smooth surface of instant rice prepared at cooking temperature of 106 ℃ or 110 ℃ was observed. These studies suggest that the appropriate cooking temperature for the preparation of hot-air dried instant rice is 100 ℃.

Key words: cooking temperature, instant rice, property