Effect of style of cut and storage on phenolic composition and antioxidant activity of fresh-cut sweetpotatoes

Abstract

Three different style fresh-cut (shredded, French fry, and sliced) sweetpotatoes [Ipomoea batatas (L.) Lam.] were stored at 0 and 5°C for 4 and 8 days. At specified storage intervals, the fresh-cut sweetpotatoes were analyzed for total phenolics, individual phenolic acids, and antioxidant activity. Sweetpotato tissue analyzed immediately after cutting was considered the control. Storage at 5°C resulted in an increase in total phenolics in all types of fresh-cut sweetpotatoes, except in shredded tissue analyzed after 4 days of storage. However, at 0°C, only sliced tissue accumulated higher total phenolics than the control. In general, antioxidant activity in all fresh-cut sweetpotatoes held at 5°C was higher than in the control. No significant increase in antioxidant activity was observed in shredded sweetpotatoes stored at 0°C. Chlorogenic acid followed by 3,5-dicaffeoylquinic acid were the predominant phenolic acids present in fresh-cut sweetpotatoes. The highest content of chlorogenic acid (539.9 μg·g-1 dry weight) in sliced tissue stored for 8 days at 5°C was ≈6-fold higher than in the control (88.3 μg·g -1 dry weight). No significant development of tissue browning, off-odors, or off-flavors were observed after 8 days of storage and the products were considered to be marketable.