Correlation of volatile and nonvolatile components with the total antioxidant capacity of tartary buckwheat vinegar: Influence of the thermal processing

Shanxi aged tartary buckwheat vinegar differs from other vinegars in that it has a unique thermal processing (6 days at 85 °C) which is helpful to create its typical flavor and functional properties. The present study evaluated the relationship between some volatile and nonvolatile compounds, the total antioxidant activity of tartary buckwheat vinegar, and the influence of thermal processing on the vinegar. Correlation analysis showed that 1-(2-furanyl)ethanone, isoamyl acetate, ethyl valerate, tetramethyl pyrazine, benzothiazole, browned compound and total polyphenolic content were highly significant while 3-methylbutanoic acid, 3-hydroxy-2-butanone, benzyl methyl ketone, and total flavonoid content were significantly associated with total antioxidant capacity measured by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and redox potential methods. Principal component analysis allowed tartary buckwheat vinegar separation according to volatile and non-volatile compounds (PC1) and antioxidant capacity (PC3). Comparing with alcoholic and acid fermentation, thermal processing not only contributed to the characteristic aromas of the vinegar, but also retained its antioxidant capacity. The result of this study suggested that aromas from thermal processing of the vinegar may be served as natural antioxidants.

► Detect antioxidant activity of tartary buckwheat vinegar and relationship with total polyphenols and flavonoids. ► Found volatile compounds significantly correlated with antioxidant activity of the vinegar. ► Demonstrate influence of processing on aromas and antioxidant activity of the vinegar.