羟丙基甲基纤维素基涂膜的制备及香蕉保鲜效果

Preparation of Hydroxypropyl Methyl Cellulose Based Coating and the Effect of Banana Preservation

有些水果采摘后的保鲜期很短,造成运输过程中出现腐烂而浪费。为了延长水果保质期,本研究使用羟丙基甲基纤维素(HPMC)和甘油分别作为成膜基质和增塑剂,添加不同质量分数(0%、0.2%、0.4%、0.6%、0.8%、1.0%)的三颗针提取物(BRE),制备了一种新型水果涂膜。测定了该膜的力学性能、光学性能、阻隔性能和抗菌性能。将成膜溶液分为对照组、HPMC涂膜组、HPMC/BRE-0.6涂膜组、HPMC/BRE-1.0涂膜组,对香蕉进行涂膜后于室温下贮藏,定期进行感官评价,并测定其失重率、V_(C)含量和可滴定酸度。结果表明:随着BRE含量增加,膜的力学强度、断裂伸长率和雾度值总体呈增加趋势。当BRE含量达到0.6%时,膜可以屏蔽波长为200~400 nm的光,水蒸气透过系数达到最小值3.51 gm^(-1)s^(-1)Pa^(-1)×10^(-10),体现了良好的紫外屏蔽性能、水蒸气阻隔性能,同时对金黄色葡萄球菌良好的抑制效果。在香蕉保鲜实验中,不同涂膜处理对香蕉的失重率、V_(C)含量、可滴定酸度均有显著影响(P<0.05)。5 d后,对照组香蕉的失重率、VC含量、可滴定酸度分别为18.08%、2.88 mg/mL、0.31%,HPMC/BRE-0.6涂膜组为11.79%、4.40 mg/mL、0.21%,表明涂膜有效降低了香蕉的失重率和VC的损耗,抑制了可滴定酸度的增加,使其更接近新鲜香蕉。本研究开发了一种可延长水果货架期的新型水果涂膜,在促进水果涂膜行业绿色发展上具有潜在的应用前景。

Some fruits show a short shelf life after being picked,resulting in rotting and wasting during the transportation.In order to prolong the shelf life of fruits,a new type of coating was prepared by using hydroxypropyl methyl cellulose(HPMC)and glycerol as film-forming substrate and plasticizer,simultaneous adding barberry root extractive(BRE)with different contents of 0%,0.2%,0.4%,0.6%,0.8%and 1.0%.The mechanical property,optical property,barrier property and antibacterial property of the films were tested.Moreover,the film-forming solutions were divided into coating groups of control,HPMC,HPMC/BRE-0.6 and HPMC/BRE-1.0 to coat the bananas,respectively,and then stored at room temperature.Sensory evaluation of the bananas was performed regularly,and weight loss rate,V_(C) content and titratable acidity were determined.The results showed that increased BRE content led to a general increase of tensile strength,elongation at break and haze.As it was up to 0.6%,the film had excellent ultraviolet-light shielding,favorable water vapor barrier performance and antibacterial property,which could shield almost light in the wavelength range of 200~400 nm,present the minimum water vapor permeability of 3.5 g m^(−1) s^(−1) Pa^(−1)×10^(−10) and good inhibition on Staphylococcus aureus.In the preservation of bananas,different coatings had significant effects on the weight loss rate,V_(C) content and titratable acidity of bananas(P<0.05).After 5 days,the weight loss rate,V_(C) content and titrable acidity of bananas in control group were 18.08%,2.88 mg/mL and 0.31%,respectively,while those in HPMC/BRE-0.6 group were 11.79%,4.40 mg/mL and 0.21%,indicating that the coating effectively reduced the weight loss rate of bananas,the loss of V_(C) and the increase of titrable acidity,making them more similar to fresh bananas.This study developed a new type of fruit coating which could extend the shelf life of fruit and was promising to promote the green development of fruit coating field potentially.