Effects of Spraying Bacteriostatic Agents on Postharvest Quality of ‘Zihonglong’ Pitaya

Purpose In order to understand the effect of spraying bacteriostatic agents on postharvest quality of pitaya.

Method The bacteriostatic agents, including Trichoderma combined with nisin, nisin combined with natamycin, and crude extract of camellia cake, were sprayed at 10 and 20 days after anthesis, the postharvest quality, including pericarp characteristics, color, pulp characteristics, nutritional components, enzymes and antioxidant activities of ‘Zihonglong’ pitaya were investigated.

Results Spraying bacteriostatic agents could significantly improve the b^* in flesh, firmness in pericarp, and betacyanins in flesh of ‘Zihonglong’ pitaya, and significantly decrease the b^* in peal, PPO, and the DPPH· scavenging ability. The rise of rot index with L^* in peal, a^* in flesh, pectin in peal, titratable acid, and reducing sugar reduced, the rise of rot index with relative conductivity, PPO, POD, the DPPH· and ABTS·⁺ scavenging ability increased during storage.

Conclusion Compared with the control group, spraying bacteriostatic agents could maintain the total flavonoids of ‘Zihonglong’ pitaya, can significantly accelerate the decline of a^* and the increase of POD, can significantly reduce the rot index and respiration rate, delay rises in thinning in peal, firmness in flesh, viscosity, betacyanins, PPO, the DPPH· and ABTS·⁺ scavenging ability, to postpone the rot of ‘Zihonglong’ pitaya during storage.