Fig.1.

Effects of (a) the ratio of enzyme to substrate, (b) reaction temperature, (c) reaction solvent pH, (d) reaction time, and (e) ethanol concentration on the polyphenol extraction from unripe apples

Reaction: (a) pH 4.5, 40 °C, 12 h; (b) the ratio of enzyme to substrate 0.02, pH 4.5, 12 h; (c) the ratio of enzyme to substrate 0.02, 40 °C, 12 h; (d) the ratio of enzyme to substrate 0.02, pH 3.7, 50 °C; (e) the ratio of enzyme to substrate 0.02, pH 4.5, 40 °C, 12 h. Extraction: (a)~(d) 80% ethanol, 85 °C, 12 h; (e) 85 °C, 12 h. Values are the means of triplicates. TPC: total phenolic content