Abstract:Ascorbic acid and L-cysteine were applied in the fresh-keeping treatments for purple sweet potatoes. Changes in quality attributes and antioxidant activity of purple sweet potatoes during storage were evaluated by determining browning index，polyphenol oxidase （PPO） activity，peroxidase （POD） activity，firmness，weight loss rate，and soluble solids content. The results showed that both ascorbic acid and L-cysteine treatments effectively inhibited PPO and POD activities，reduced browning rate，decreased weight loss，maintained soluble solids content，and preserved the texture of purple sweet potatoes. Among the treatments，the 0.1% L-cysteine treatment exhibited brighter color，lower browning degree，and firmer texture，indicating superior preservation effects.