Effect of rice bran protein extract on enzymatic browning inhibition in potato puree

Summary Effect of rice bran protein extract ( RBPE ) on enzymatic browning inhibition in potato puree was studied by colour measurement and polyphenol oxidase ( PPO ) inhibition. RBPE inhibited browning in potato puree and showed a higher per cent potato PPO inhibition at pH 4.0 and 5.0 than those at pH 3.0, 6.0 and 7.0 ( P  ≤ 0.05). RBPE heated to 40 and 60 °C had browning inhibition in potato puree and per cent potato PPO inhibition at a similar extent to unheated RBPE ( P  > 0.05). Browning inhibition and per cent potato PPO inhibition of RBPE were decreased when it was heated to 80 °C ( P  ≤ 0.05). RBPE inhibited browning in potato puree higher than 5, 10 and 20 m m ascorbic acid and 5 and 10 m m citric acid ( P  ≤ 0.05). Regarding the kinetics study, RBPE exhibited a mixed‐type inhibition for potato PPO . Therefore, RBPE has a potential to be used as a natural antibrowning agent in the potato industry.