Raw material characteristics affect enzymatic browning of pre-peeled potato tubers.

Potatoes are extremely sensitive to enzymatic browning caused by polyphenol oxidase (PPO) during minimal processing. To investigate the difference between potato cultivars in the enzymatic browning in peeled potatoes, eleven potato cultivars were grown and their quality of minimal processing products was evaluated. For determining the difference between tubers with different maturities, two cultivars, ‘Atlantic’ and ‘Shepody’ were harvested four times at 10 days interval from 90 days after planting. The potato tubers were analyzed for browning potential, activity of PPO, and concentration of total phenolic compounds. Among them, the lowest value in browning rate, total phenol content, and PPO activity were found in pre-peeled potatoes of ‘Atlantic’ and ‘Jowon’. In experiment on tuber maturities, browning rate of ‘Shepody’ increased gradually as delaying harvest date, but changes in ‘Atlantic’ was insignificant. These results were caused by the difference in mainly PPO activity between the two cultivars. Our results will contribute the selection of cultivars and determination of harvest date for minimal processing of potatoes.