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

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 (P0.05). RBPE heated to 40 and 60 degrees 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 degrees C (P0.05). RBPE inhibited browning in potato puree higher than 5, 10 and 20mm ascorbic acid and 5 and 10mm citric acid (P0.05). 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.