Cold shock precooling improves the firmness of chili pepper during postharvest storage and the molecular mechanisms related to pectin

This research was conducted to explore the influence of cold shock on the firmness, a quality marker in chili pepper during 0-21 d storage and determine mechanism by cold shock impacted pectin. Chili peppers were exposed to cold shock precooling (0 +/- 2 degrees C water/ice mixture) for 0-, 30-, 90- and 150-min, respectively. Results showed that cold shock alleviated loss of firmness throughout storage. Firmness was positively associated with sodium carbonate-soluble pectin content (r = 0.44), methylation degree of CDTA-soluble pectin (r = 0.82) and water-soluble pectin (WSP, r = 0.87), but negatively associated with WSP content (r = - 0.76), and the activities of beta-galactosidase (r = -0.72) and pectinlyase (r = - 0.74). Cold shock for 90 min was determined to be optimal. This study confirms the applicability of cold shock precooling to maintain firmness and thereby to extend the shelf life of chili pepper.

Automated summary

This research aimed to investigate the impact of cold shock on the firmness of chili pepper during storage and determine the mechanism by which cold shock influenced pectin. Chili peppers were subjected to cold shock precooling for different durations. Results revealed that cold shock helped to maintain the firmness of the peppers throughout storage. Firmness was found to be positively correlated with certain pectin contents and negatively correlated with other pectin content and enzyme activities. Cold shock for 90 minutes was determined to be the optimal duration. This study confirms the effectiveness of cold shock precooling in preserving the firmness and extending the shelf life of chili pepper.