Effect of Postharvest Treatment with Chitosan Hydrochloride on the Storage Quality and Chlorophyll Metabolism of Fresh-Cut Broccoli

A comparative analysis of the preservation effects of different concentrations of chitosan hydrochloride (CHC) and chitosan (CTS) was done on fresh-cut broccoli. Furthermore, the effect of CHC on the storage quality and chlorophyll metabolism of fresh-cut broccoli was explored. The results showed that CHC provided good preservation of fresh-cut broccoli; this effect was concentration-dependent, being most pronounced at 5 g/L CHC. On the 20th day of storage, the mass loss and respiration intensity of broccoli treated with 5 g/L CHC decreased by 56.87% and 36.12% compared with the control group treated with distilled water, and by 13.44% and 1.18% compared with the 5 g/L CTS-treated group, respectively. Moreover, 5 g/L CHC treatment effectively delayed the yellowing, significantly the increase of chlorophyllase (CLH), Mg-dechelatase (MDcase), pheophytinase (PPH) and pheophyllase a oxygenase (PAO) activities, and maintained high total chlorophyll, chlorophyll a and chlorophyll b, and carotenoid contents. On the 15th day of storage, the chlorophyll content of the 5 g/L CHC treated-group was 62.13% higher than that of the control group. These findings suggest that 5 g/L CHC maintains the storage quality and delays the degradation of chlorophyll in fresh-cut broccoli, showing its potential in extending the storage period.