Abstract:

Fresh-cut pitaya was treated with chitosan alone or together with different concentrations of L-cysteine (0,
0.2, 0.5 g/L and 0.8 g/L) before storage at 12 ℃ to evaluate the effect of combined treatments with both preservatives on
physiological changes of fresh-cut pitaya. Results showed that treatment with chitosan alone or in combination with L-cysteine
at any of the concentration tested inhibited the reduction of total soluble solids and VC contents and the increase of relative
membrane conductivity, respiration intensity and weight loss and effectively inactivated the activities of polyphenol oxidase
(PPO) and peroxidase (POD). The optimal L-cysteine concentration for combination with chitosan that provided the best
effectiveness for preserving fresh-cut pitaya was 0.5 g/L.

Key words: pitaya, fresh-cut, chitosan, L-cysteine