Figure 2. UPLC chromatograms of phenolic compounds in the purple
tomato before (a) and after (b) hydrolysis and mixed standards (c) at
320 nm. Peaks: 1 = protocatechuic acid; 2 = chlorogenic acid ; 3 =
gentistic acid ; 4 = caffeic acid; 5 = p-coumaric acid; 6 = ferulic acid; 7 =
rutin; 8 = naringenin; and uk = unknown.