Aroma Changes in Cooked Glutinous Rice During Frozen Storage: A Comprehensive GC-O-MS, E-Nose, and Chemometrics...

This study investigated the dynamic evolution of volatile aroma compounds in cooked glutinous rice during frozen storage, aiming to elucidate the flavor degradation mechanism and provide theoretical support for flavor preservation in glutinous rice products. By integrating E-nose and GC-O-MS analyses, aroma profile variations in seven glutinous rice cultivars were comprehensively characterized. Frozen storage led to a marked decline in most aroma compounds, while oxidation-derived aldehydes and ketones, such as hexanal and (Z)-2-nonenal, increased substantially, generating undesirable rancid notes. A total of 19 compounds of OAV>1 were identified to be aroma-active compounds, representing important contributors to the overall aroma profile. Subsequent analysis employing OPLS-DA revealed nine key aroma compounds (VIP > 1) which significantly influence the overall aroma of frozen glutinous rice. Among them, hexanal, (Z)-2-nonenal, 1-octen-3-one, and 2-AP were confirmed as the primary markers of aroma deterioration, strongly correlating with the loss of characteristic fragrance. Importantly, significant cultivar-dependent differences were found: JT, ZK, TN, and ZZ exhibited notably superior aroma retention. These findings not only highlight lipid oxidation as the central pathway of aroma deterioration during frozen storage but also provide a scientific basis for selecting optimal rice cultivars, thereby guiding the development of high-quality frozen glutinous rice products.