三种涂膜材料对番荔枝采后生理和贮藏品质的影响

Effects of Three Different Coating Materials on Post-harvest Physiology and Storage Quality of Custard Apples

为了探究适合不耐贮藏的番荔枝的保鲜技术,分别采用3种不同涂膜材料梯度浸泡(10、20、30 g/L普鲁兰多糖,5、10、15 g/L壳聚糖以及5、10、20 g/L硫酸壳聚糖)处理1 min,以蒸馏水清洗果实为对照(CK),然后置于13℃、相对湿度85%条件下贮藏,每3 d测定1次果实的呼吸强度、多酚氧化酶(PPO)活性、过氧化物酶(POD)活性、可溶性固形物含量,并统计裂果率和失重率。结果表明:普鲁兰多糖、壳聚糖和硫酸壳聚糖涂膜处理均能推迟番荔枝果实呼吸跃变发生时间,有效延缓果实糖类等营养物质的损失,更好地保持番荔枝的水分,降低果实的裂果率,抑制果实PPO活性的升高和提高果实贮藏后期POD活性,具有较好的贮藏保鲜效果。3种涂膜材料最佳质量浓度分别为20 g/L普鲁兰多糖、5 g/L壳聚糖、20 g/L硫酸壳聚糖,而综合各项指标进行分析后发现经20 g/L硫酸壳聚糖涂膜处理的番荔枝保鲜效果最佳,果实贮藏12 d时外观、口感等均与鲜果无显著差异,但实际应用还需更多的试验探究。

This study aimed to explore the preservation technology suitable for custard apples storage.The fruits were gradient soaked for 1 min in three different coating materials:pullulan polysaccharides of 10,20,30 g/L,chitosan of 5,10,15 g/L,and chitosan sulfate of 5,10,20 g/L.The fruits washed with distilled water were set as control(CK)and stored at 13℃and 85%relative humidity.Respiration intensity,polyphenol oxidase(PPO)and peroxidase(POD)ac⁃tivities,soluble solid contents were measured every 3 days after the treatments,and fruit cracking rates and weight loss rates were also calculated.The results showed that the coating treatments of pullulan polysaccharides,chitosan and chitosan sulfate could delay the occurrence time of respiratory climacteric,effectively postpone the loss of carbohy⁃drate and other nutrients,better maintain the moisture of fruits,reduce the fruit cracking rates,inhibit the increase of PPO activities and improve the POD activities at later stage of storage,which presented good storage and fresh-keep⁃ing effects.The optimal concentrations of these three coating materials were determined as follows:Pullulan polysac⁃charides of 20 g/L,chitosan of 5 g/L,chitosan sulfate of 20 g/L,respectively.After comprehensive analysis of various indices,it was found that the custard apples coated with 20 g/L chitosan sulfate exhibited the best preservation effects,and the appearance and taste after 12 days storage were not significantly different from that of fresh fruits.However,the practical applications still needed more experiments and exploration.