Cold plasma treatment modulates reactive oxygen species metabolism and improves storage quality of fresh-cut yam slices.

Cold plasma (CP), a novel non-thermal preservation technology, was studied for its impact on fresh-cut yam's oxidative stress response, focusing on color, texture, reactive oxygen species (ROS) accumulation and antioxidant enzyme activities. The results showed that CP treatment effectively delayed browning and reduced the hardness decline by 50 %. Notably, CP treatment significantly suppressed ROS accumulation, reducing surface superoxide anion (O(2) (-)) by 51.9 % and hydrogen peroxide (H(2)O(2)) by 80.6 % on day 7. CP treatment enhanced antioxidant enzymes, with an increase of superoxide dismutase (SOD) activity by 184 % and catalase (CAT) activity by 48 % in surface tissues, crucial for scavenging excess H(2)O(2) and O(2) (-). CP treatment reduced the activities of phenylalanine ammonia-lyase (PAL) by 39 %, cinnamyl alcohol dehydrogenase (CAD) by 67.3 %, and peroxidase (POD) by 34 %, thereby effectively reducing yam lignification and browning. Effects were most pronounced on surfaces (<5 mm thickness). CP at 20 kV extended shelf-life by balancing ROS-enzyme responses.