The effect of various compounds, (i.e., reducing agents (ascorbic, sodium sulfite, bisulfite and thiosulphate), thiol (L-cysteine), and organic acids (glycine, aspartic, glutamic, oxalic, succinic, phthalic, tartaric, citric, adipic, fumaric, and benzoic) on the browning process and polyphenol oxidase activity of fresh-cut of butterhead lettuce and two potato cultivars (Spunta and Desiree) were evaluated. Results indicated that slices slightly elevated enzyme activity and browning index (BI) in both cultivars more than those of sticks. Mechanistic study indicated that ascorbic acid reduced...