Volatile Organic Compounds as Key Indicators for Rice Freshness and Quality Assessment during Storage Using GC-IMS

Rice storage is always accompanied by changes in nutrition and safety, making the evaluation of freshness and quality essential. This study investigated the changes in the quality properties and volatile organic compounds (VOCs) of five rice cultivars under different storage conditions, aiming to identify common VOC indicators that reflect rice freshness and quality. A total of 109 major volatiles were identified from the rice samples during the 6-month storage, and changes in the VOCs effectively differentiated their quality properties. Furthermore, partial least-squares regression models were constructed and evaluated to predict fat acidity, freshness value, and taste value based on the VOCs, with 5-methylfurfural, dimethyl disulfide, and acetoin identified as key compounds. The R2 of the freshness value and taste value models were 0.76 and 0.63, respectively, indicating the effectiveness of the models. This study provides VOC indicators reflecting rice quality and proposes new methods for rapid rice quality and freshness evaluation.