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

Area of Science:

• Food Science
• Sensory Analysis
• Analytical Chemistry

Background:

• Cooked glutinous rice flavor is susceptible to degradation during frozen storage.
• Understanding flavor changes is crucial for preserving product quality and consumer acceptance.

Purpose of the Study:

• To investigate the dynamic changes in volatile aroma compounds during frozen storage of cooked glutinous rice.
• To identify key aroma contributors and markers of flavor deterioration.
• To explore cultivar-specific differences in aroma stability.

Main Methods:

• Gas Chromatography-Olfactometry-Mass Spectrometry (GC-O-MS) for aroma compound identification and characterization.
• Electronic Nose (E-nose) for comprehensive aroma profiling.
• Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) to identify key aroma compounds influencing overall flavor.

Main Results:

• Frozen storage significantly reduced most volatile aroma compounds, while aldehydes and ketones associated with rancidity increased.
• Nineteen aroma-active compounds with an odor activity value (OAV) greater than 1 were identified.
• Hexanal, (Z)-2-nonenal, 1-octen-3-one, and 2-aminopyridine (2-AP) were identified as primary markers of aroma deterioration.
• Cultivars JT, ZK, TN, and ZZ demonstrated superior aroma retention compared to others.

Conclusions:

• Lipid oxidation is the primary mechanism responsible for aroma degradation in frozen glutinous rice.
• Specific aroma compounds serve as reliable indicators of flavor deterioration.
• Cultivar selection is critical for maintaining the desirable flavor profile of frozen glutinous rice products.
• Findings provide a scientific basis for developing high-quality frozen glutinous rice.