Flavor evolution in refrigerated tilapia processed by cold plasma: Volatile profiles and odor quality driven by excitation gas-generated reactive species

Rapid flavor deterioration due to lipid oxidation and microbial spoilage is a major challenge during refrigerated fish storage. This study was the first to systematically investigate how cold plasma (CP) gas composition (low-oxygen GasA: 10% O 2 ; air GasB: 22% O 2 ; high-oxygen GasC: 30% O 2 ) drives volatile flavor evolution and enzyme-flavor correlations in refrigerated tilapia. A total of 66 volatile compounds were identified, with aldehydes (hexanal, nonanal) and 1-octen-3-ol as key contributors. GasC-CP increased total aldehydes by 64% (from 20.59 ± 0.22 to 33.74 ± 6.20 μg/kg). GasA-CP balanced flavor enhancement with off-flavor suppression (hexanal OAV = 1.59 at day 8). OPLS-DA confirmed CP elevated desirable compounds while reducing microbial off-flavors (indole, dimethyl tetrasulfide). Correlation analysis revealed a negative association between 1-octen-3-ol and lipolytic enzymes ( r = −0.89, P < 0.05), suggesting enzymatic flavor regulation. From a practical standpoint, GasA-CP is recommended for preserving refrigerated tilapia with balanced flavor quality.