不同包装材料对龙眼果实贮藏特性的影响

摘要

为了筛选不同贮藏温度下龙眼(Dimocarpus longan Lour.)果实合适的包装袋,以品种‘石硖’(cv.Shixia)为材料,研究了常温(25±1)℃和低温(5±1)℃下,0.025 mm聚乙烯袋(PE)、0.020 mm双向拉伸聚丙烯袋(BOPP)、0.025 mm乙烯-醋酸乙烯共聚物(EVA)、0.025 mm中山气调袋(ZSMA)4种包装材料对果实贮藏特性的影响,以“单层0.010 mm PE膜+托盘”(PF1)作为常温贮藏效果对照,0.025 mm PE包装作为低温贮藏效果对照.结果表明:常温下果皮褐变、果肉自溶、果实质量损失率高低顺序分别为PF1 ＞EVA ＞PE ＞BOPP≈ ZSMA、PF1＞PE＞BOPP＞ZSMA≈EVA、EVA ＞PF1 ＞PE ＞ZSMA≈BOPP;低温下分别为EVA ＞BOPP ＞ZSMA ＞PE、PE ＞ZSMA ＞EVA＞BOPP、EVA＞PE≈ZSMA≈ BOPP.与常温相比,低温下同一种包装内CO2体积分数(V/V)显著降低,O2体积分数(V/V)明显上升.两种贮藏温度下,4种包装中的CO2体积分数高低顺序均为BOPP＞ZSMA＞PE＞EVA,O2体积分数则相反;袋内湿度是影响果皮褐变的最主要因素,EVA的透湿性远高于BOPP、PE、ZSMA;BOPP和PE果实因常温与低温差异表现为部分相反结果,果实的CO2伤害阈值因贮藏温度下降而降低;ZSMA则体现了良好的综合保鲜效果.%The effects of environmental factors within different packagings on the storability of longan fruits (Dimocarpus longan Lour.cv.Shixia) during storage at (25±1)℃ and (4±1)℃ respectively were studied.The treatments including 0.02 mm BOPP bag (Biaxial oriented polypropylene film,marked as BOPP),0.025 mm Polyethylene bag (marked as PE),0.025 mm EVA bag (Ethylene-co-vinyl acetate,marked as EVA) and 0.025 mm ZSMA bag (Zhongshan modified atmosphere packaging bag,marked as ZSMA),and plastic pallet + single layer of 0.010 mm PE (marked as PF1) as the normal storage temperature check and 0.025 mm PE as the the low storage temperature check were used.The results showed that the orders of pericarp browning index,aril breakdown index and mass loss rate at (25±1)℃ storage were PF1 ＞EVA＞PE＞BOPP≈ZSMA,PF1 ＞PE＞BOPP＞ZSMA ≈EVA and EVA＞PF1＞PE＞ZSMA ≈BOPP respectively.Whereas,during storage at (4±1)℃,the orders of them were EVA＞BOPP＞ZSMA＞PE,PE＞ZSMA＞EVA＞BOPP and EVA＞PE≈ZSMA≈BOPP respectively.The volume fraction of CO2 (V/V) in the same bag at (4±1)℃ was significantly lower than that at (25±1)℃,but the volume fraction of O2 (V/V) was higher.Among the 4 treatments,the order of volume fraction of CO2 was BOPP＞ZSMA＞PE＞EVA,while the volume fraction of O2 was reversed;and the moisture permeability of EVA was much more higher than that of other packagings.The RH was the most important factor for pericarp browning.In addition,the fruit storability in BOPP and PE bags showed partly opposite results due to temperature variation,the injury threshold value of longan fruit to CO2 varied with storage temperature.The ZSMA bags showed the best combination storability.