Comparative Evaluation of Puffing Effects on Physicochemical and Volatile Profiles of Brown and Refined Rice

Rice has excellent nutritional quality as a dietary food and is easily puffed. The aim of this study was to investigate the effects of puffing technology on the physicochemical parameters, structure properties and volatile components of brown rice (BR) and refined rice (RR). XRD and FT-IR spectroscopic data demonstrated that puffing under high temperature and pressure conditions triggered starch gelatinization, concurrently reducing starch crystallinity and inducing a V-type polymorphic structure. In addition, it substantially weakened hydrogen bonding networks in rice flour. In detail, 136 volatile compounds of raw and puffed rice were analyzed by HS-SPME-GC-MS, and the results showed that aldehydes, ketones, and pyrazines were the main volatile aroma compounds after puffing. By correlation analysis, benzaldehyde, 2-octenal, 2-methoxy-phenol, and furfural were identified as key contributors. The volatile components, especially ketones and alcohols, were higher in the BR as compared to those in the RR, with a significant difference observed between the two (p < 0.05). Combined with sensory evaluation, 1212CH was found to have a high score (17.63). These results could provide a theoretical basis for understanding the effect of puffing on rice flour and the volatile components of puffed products.