Physico-chemical, sensory quality and flavor compounds of Philippine rice wine (tapuy) prepared by traditional and multi-parallel fermentation

This study was conducted to determine the physico-chemical properties and the organic acid and fatty acid profiles of: (i) commercial rice wine tapuy and; (ii) tapuy prepared by traditional and multiparallel fermentation methods using two different types of bubod starters. The organic acid and fatty acids of these samples were identified and quantified using high pressure liquid chromatography (HPLC) and gas chromatography (GC) methods, respectively. Results of analysis from nine (9) commercial tapuy samples indicated variability in terms of pH, titratable acidity, total soluble solids, reducing sugar and alcohol content. Significant differences in the amounts of organic acids and fatty acids in tapuy samples were also observed. High concentrations of lactic acid, malic acid, and succinic acid were detected in commercial tapuy wines while acetic acid and oxalic acid were present at low concentrations. In terms of fatty acid, all commercial tapuy contained the short chained butyric acid (C4) and medium chain fatty acids caproic acid (C6) and caprylic acid (C8). The type of fermentation method and type of starter applied did not significantly affect the physico-chemical properties of tapuy samples, but appears to have significant interaction effect on the concentrations of acetic, citric, oxalic and succinic. The concentrations of malic and tartaric acids were found to be significantly lower in tapuy produced by multiparallel fermentation method (MPM) compared to tapuy prepared by traditional method (TM). The fatty acid contents in tapuy produced by Atok bubod were higher regardless of the fermentation method applied. Except for capric and caprylic, an interaction effect between the type of fermentation methods and type of starters were observed in the concentrations of fatty acids. In general, the type of fermentation method and starter culture used did not affect the sensory qualities of the produced rice wines. The produced tapuy samples were characterized as having a bright light yellow color, with a sweet medium-heavy mouth feel. Caramel flavor was the predominant flavor observed in the wine with perceptible notes of banana and apple flavor. Rice wine utilizing Atok bubod was rated as the most favorable with an overall acceptability rating of 7.58.