PP/PBAT薄膜阻隔性对沙葱采后品质及菌相结构的影响

Barrier Properties of PBAT/PP Blend Films and the Effects on Postharvest Quality and Microbiological Population of Allium Mongolicum Regel

目的探讨不同组成的共混膜阻隔性对沙葱采后品质和微生物菌群结构的影响。方法采用熔融共混法制备不同组分的聚对苯二甲酸-己二酸-丁二醇酯(PBAT)和聚丙烯(PP)共混薄膜,分析共混膜的阻隔性能;采用共混膜包装沙葱,分析沙葱的生理指标和微生物群落结构的变化。结果当PBAT的质量分数为30%时,CO_(2)透过系数(CDP)提高了49.7%,CO_(2)和O_(2)透过比(CDP/OP)提高了50.7%,H2O透过系数(WVP)提高了145.5%。厚度为35μm的PP/PBAT(30%)(PBAT质量分数为30%)薄膜包装沙葱,能够形成与沙葱匹配的气体环境(O_(2)体积分数为0.48%~0.66%,CO_(2)体积分数为5.98%~6.53%);低浓度O_(2)高浓度CO_(2)环境有效抑制了沙葱表面嗜温菌(Aerobic Bacterial Count,ABC)、嗜冷菌(Psychrophile Plate Count,PPC)、假单胞菌(Pseudomonas Count,PC)、霉菌和酵母菌(Yeast and Molds,YAM)的增殖,与PP包装比较,ABC降低了1.1 lg CFU/g,PPC降低了1.3 lg CFU/g,PC降低了1.47 lg CFU/g。结论厚度为35μm的PP/PBAT(30%)薄膜包装沙葱能够有效降低呼吸速率和微生物的增殖侵染,维持稳定的采后品质。

The work aims to investigate the effect of different compositions of co-blended film on the post-harvest quality and microflora structure of Allium Mongolicum Regel(A.mongolicum).The PBAT/PP blend films was prepared by melt extrusion,then barrier properties and the effects on postharvest quality and microbiological population of A.mongolicum of PBAT/PP blend films were studied.The results showed that PBAT/PP blend system was incompatible.With the increase of PBAT content,the transmission properties of CO_(2)and H2O were enhanced.When the addition of PBAT was increased to 30%,the CO_(2)transmission coefficient,CDP/OP and H2O transmission coefficient were increased by 49.7%,50.7%and 145.5%.PP/PBAT(30%)film of 35μm thickness could formed gas environment that matched the physiological characteristics of A.mongolicum,with O_(2)ranging from 0.48%to 0.66%and CO_(2)ranging from 5.98%to 6.53%.It also could significantly reduce respiration rate,under low O_(2)and high CO_(2)environment,bic bacterial count(ABC),Psychrophile plate count(PPC),Pseudomonas count(PC)are effectively inhibited on the surface of A.mongolicum.Compared with PP packaging,ABC decreased by 1.1 lg CFU/g,PPC decreased by 1.3 lg CFU/g,PC decreased by 1.47 lg CFU/g.It was concluded that A.mongolicum packed in PP/PBAT(30%)film with a thickness of 35μm was effective in reducing respiration rate and microbial proliferation infestation and maintaining stable postharvest quality.