Investigation of volatiles and quality attributes of indica-japonica hybrid paddy by radio frequency combined hot air drying

The study was aimed at investigating the effects of radiofrequency combined hot air drying (RF-HAD) on volatiles and quality attributes of indica-japonica hybrid paddy. The results indicated that RF-HAD reduced the drying time by 40% compared to hot air drying (HAD). In addition, HA-RF-dried samples showed significantly higher color, vigor, and taste value but less fatty acid value than HA dried-ones. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that RF-HAD did not affect the protein profile of rice protein. Gas chromatography-ion mobility spectrometry characterized changes in volatile components of paddy before and after drying, results showed that the content of aldehyde and ester aromatic compounds increased after drying and the content of most volatile components in RF-HA-dried paddy was higher than in HA-dried samples. Thus, the inference was that RF-HAD technology may be an innovative alternative to existing drying methods such as microwave, HA, and other drying technologies.