Inactivation of membrane‐bound and soluble polyphenol oxidases in apple (Malus domestica Borkh) by radio frequency processing for improved juice quality. (30th October 2018)

• Record Type: Journal Article
• Authors: Tian, Yixiong; Yan, Wenxu; Tang, Yali; Yang, Ruijin; Zhao, Wei
• Is Part Of: Journal of food process engineering. Volume 41:Number 8(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-10-30
• Subjects: Food industry and trade -- Periodicals; Food -- Analysis -- Periodicals; 664.005
• DOI: 10.1111/jfpe.12923
• Languages: English
• ISSNs: 0145-8876

Abstract

Abstract: Radio frequency (RF) processing was proposed to inactivate polyphenol oxidase (PPO) in apple tissue for improved juice quality. PPO in apple tissue exists as membrane‐bound PPO (mPPO) and soluble PPO (sPPO); mPPO is bound in chloroplast membranes and separated from phenolic substrates, preventing catalytic reaction, whereas sPPO is soluble in lumen. When cells break down, mPPO is released and comes in contact with phenolic substrates, contributing to browning and discoloration in juice. Research indicates that after RF treatment, inactivation of mPPO and sPPO in apple tissue was easier to achieve than extracted PPO. In addition, mPPO exhibited a lower thermal stability than that of sPPO. Treatment with RF for 10 min in apple tissue could effectively inactivate PPO and maintain a higher quality of squeezed apple juice than that of freshly squeezed juice treated by conventional thermal methods (65 °C for 10 min and 75 °C for 10 min). Practical applications: In fruit and vegetable processing industry, enzymatic browning is a difficult issue that leads to the deterioration of product quality. RF treatment can inactivate PPO rapidly in food and agricultural products to inhibit browning without heat conduction and overheated food surfaces, keeping high quality of the products. Results in this study could provide references for the application of RF technology on fruit and vegetable processing industry to inactivate endogenous enzyme.