Study on the Preparation of High gas Permeable Film and its Application in Fruit Preservation

摘要

Fresh produces still maintain respiration after be harvested, they would be perishable if appropriateprocesses are not took in storage and transportation. The most common means of keeping fruits and vegetablesfresh is Modified Atmosphere Packaging (MAP), which can extend the shelf life of fresh produces byway of controlling concentration levels of oxygen and carbon dioxide in-package to restraint respiration ofthe tissue cell. A kind of film with micropore structure was obtained by oriented extrusion stretching method.A series of films with five different filler concentrations were prepared in this paper, mechanical properties,barrier properties and application properties in fruit preservation of these films were also studied. One LDPEfilm without additive was used as control. Experiment results showed that Young's modulus of these filmswas moderately lower, and compared with the control, tensile strength of these films decreased by 40%~50%at most. Breaking strength and elongation at break decreased with increasing filler concentration. The OTR ofOne with 2% filler concentration of these films was applied in fruit preservation as package of pear. Afterbeing stored at room temperature for 6 weeks, firmness dropped from 4.2×105Pa to 3.6×105Pa in sample filmpackage in contrast to 3.0×105Pa in control package. Weight loss of pear stored in sample and control filmswas 1.45% and 2.24%. Gas contents (O2,CO2) in-package were determined every week, the results showedthat a appropriate levels of oxygen and carbon dioxide in-package were obtained by using these kind of highgas permeable films. Fruits stored in these films package have better quality and longer shelf life.