Abstract

Pyroligneous Acid (PA) contains biostimulatory compounds that have been explored to improve crop productivity and nutritive value of vegetables. However, little is known of its effect on the metabolic profiles of fruits or their extracts. This study investigated the biostimulatory effects of varying concentrations of PA (i.e., 0, 2, 4, 8, and 12%) application on grape wine (Vitis vinifera cv. KWAD7-1). We identified 52 metabolites following varying rates of PA application. Principal component analysis (PCA) demonstrated that the 2%, 4%, and 8% PA had similar metabolic profiles. The 12% PA increased the concentrations of glycine (574-fold), proline (0.46-fold), glutamic acid (0.29-fold), glucose (0.25-fold), fructose (1.40-fold), ethanol (0.44-fold), myo-inositol (0.53-fold), catechin (1.02-fold), acetone (0.31-fold), choline (0.31-fold), betaine (0.17-fold), and 2, 3- butanediol (0.53-fold) compared to the control. However, the 12% PA reduced the concentrations of acetic (0.60-fold) and malic (0.16-fold) acids in the wine compared to the control. Thus, the application of 12% PA led to a notable shift in the metabolic profile of the wine grapes, which may have potential impact on the sensory attributes and overall quality of the wine. Further studies should be conducted to evaluate the effect of PA on grape wine sensory quality.

Keywords:  Wood Vinegar; Biostimulant; Wine Quality; Vitis Vinifera Vineyard