S-Ethyl thioacetate as a natural anti-browning agent can significantly inhibit the browning of fresh-cut potatoes by decreasing polyphenol oxidase activity

Enzymatic browning drastically affects the acceptability and marketability of fresh-cut potatoes. The browning inhibitory effects and mechanisms of S-Ethyl thioacetate (S-Et) in fresh-cut potatoes were investigated. The results showed that S-Et treatment could delay the browning of fresh-cut potato chips, alleviate both the decrease of total phenol contents and the increase of soluble quinones contents, and inhibit the synthesis of browning pigment of potato mashes, but could not transform the browning pigment into colorless compounds. S-Et was a reversible mixed polyphenol oxidase (PPO) inhibitor with the property of chelating Cu 2+. S-Et decreased PPO activity mainly by chelating Cu 2+, and acting on the amino acid residues of PPO. The results indicated that S-Et could be a promising natural anti-browning agent, which inhibited enzyme browning of potatoes mainly by decreasing PPO activity.