Identification and Inhibition of Key Off-Odorants in Boiled Greenfin Horse-Faced Filefish (Thamnaconus septentrionalis) Subjected to Perilla Polyphenols Extract

The generation of off-flavor during boiling significantly hampers the acceptability and popularity of the greenfin horse-faced filefish (BFF). Adding perilla to Chinese fish dishes can enhance the flavor of fish. A total of 72 volatile compounds were quantified in BFF with different addition of Perilla polyphenol extract (PPE) (i.e., 0, 0.1 %, 0.3 %, 0.5 %, w: w) by headspace solid phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS). Based on the gas chromatography-olfactometry (GC-O), odor activity value (OAV) and recombination omission testing, (Z)-4-heptenal, (E,E)-2,4-heptadienal, (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, heptanal, nonanal, octanal, decanal, (E)-2-hexenal, (E)-2-octenal, (E)-2-nonenal were identified as volatiles contributing to the off-flavor, while linalool and β-ionone exhibited a mitigating effect. Moreover, the antioxidant capacities of PPE assessed through 2,2-diphenyl-1-picrylhydrazyl (DPPH) and thiobarbituric acid reactive substances (TBARs) assays, exhibited a positive correlation with perilla polyphenols contents. Orthogonal partial least square discriminate analysis (OPLS-DA) and partial least-squares regression (PLSR) results indicated a significant relationship between the off-flavor of BFF and lipid oxidation, adding 0.3% PPE resulted in a marked improvement in flavor profile, with a reduction in off-flavors associated with fishy, oily/fatty and marine, while simultaneously enhancing the freshness, herbal flavors, and overall acceptability of the product.