Study On The Preparation And Application Of Breathable Packaging Films Based On The Preservation Of Mushroom

At present,the packaging of Flammulina velutipes in the market has dew,package swelling and other phenomena which affect its shelf life quality.Therefore,water vapor,gas permeability and packaging methods are particularly important for the preservation of Flammulina velutipes.In this study,polypropylene(PP)was selected as the basic material according to material characteristics,and blended with high moisture permeability(PBAT)resin.By adjusting the proportion of PBAT to water vapor and gas permeability,combined with packaging form,Flammulina velutipes could achieve good storage and fresh-keeping effect.Firstly,the feasibility observation and performance test of the prepared film are carried out,such as mechanics,thermodynamics,water vapor transmittance performance,gas transmittance,and then the fresh-keeping test of the mushroom is carried out.The test results show that the transverse elongation and tensile strength of the PBAT increase,the Young's modulus is reduced by 3.7 times,when the 20%is added,and the addition of 30%is 2.7 times,Longitudinal tensile test results show that the elongation at break decreases with the increase of PBAT,contrary to that at transverse direction.The elongation at break of PPT2(20%PBAT/PP)film after longitudinal tension is higher than that of PPT3(30%PBAT/PP).The blending of PBAT and PP improves the toughness,decreases the brittleness and improves the deformation resistance of the material.The best blending ratio is 20%PBAT/PP.With the decrease of the oxygen permeability of PBAT films,the CO2 permeability increased from 19.1×10-7 cm 3 m/m2 D Pa to 28 × 10-7 cm 3 m/m2 D Pa,and the water vapor permeability increased to 2.1 times.The fresh-keeping experiment of the mushroom was carried out by using different packaging methods after the feasibility of mixing the film.The results show that:Market packaging group,sealed packaging group,vacuum packaging group compared to the market packaging group in the 18th day of the soluble solids content decline and in the senses appear condensation,the phenomenon of rising packets and other phenomena lost the value of goods.The content of soluble solids in the PPT2 sealed packaging group was the illusion of sudden rise due to the unstable respiration intensity in the early stage of the atmosphere control.The content of Vc in vacuum packaging of PPT2 mixed film and the weight loss rate,the content of soluble solids decreased more gently,there was no condensation phenomenon,to the 27th day,the mushroom rot lost value,and the effect of fresh preservation was excellent.The free space in the bag can regulate the post-ripening effect of the mushroom,and the vacuum packing group is superior to the other groups in the elongation of the fungus handle caused by the posterior ripening of the mushroom.Therefore,adding 20%PBAT combined with vacuum packaging can effectively control the elongation of the fungus caused by the post-ripening effect to prolong the shelf period and accord with the short-term storage and storage and transportation of mushrooms on various preservation indexes.