Study On Double Storage High Thermal Insulation And Simple Cold Chain Logistics Technology Of Sugar-Cored Apple

Known as"Turpan grape hami melon,Aksu apple everyone praises"in Xinjiang,the taste and flavor of sugar apple has been welcomed by the majority of consumers.As a local pillar industry,sugar apple plays an important role in improving the living standard of local farmers.Sugar apples are located in remote Xinjiang region,and in order to ensure that sugar apples have a good sugar rate,the picking time of sugar apples is later than that of ordinary Fuji apples,which results in that sugar apples cannot have a good market share in terms of time.In order not to affect the circulation of sugar apple after harvest in the first-tier city market,it is necessary to ensure the fresh quality of sugar apple from harvest to transportation to storage.There have been in-depth reports on apple postharst storage at home and abroad,but there are few reports on the simple cold chain transportation technology of sugar-core apple.This paper explores the zero-refrigeration simple cold chain logistics technology from four aspects.（1）Optimization of phase change cold storage materials.According to the data,mannitol and ammonium chloride,whose phase transition temperature and latent heat do not change with the change of concentration,were selected and distributed into an aqueous solution.In order to prevent the leakage of the solution,superabsorbent resin was added to the solution for further compounding,so that the solution became gelatinous and delayed the cryogenic freezing time of the refrigerant.By differential scanning method,the phase transition temperature of 0.025mol/L mannitol,0.2mol/L NH₄CI and 2%hyperabsorbent resin complex was-4.3℃,and the latent heat of phase transition was 311.4.4J/g,which met the standard of looking for cold storage agent.（2）The freezing point method of juice was used to determine the pre-cooling and later storage temperature of sugar-heart apple.Through the determination of sugar-core and non-sugar-core parts of sugar-core apple,the pre-cooling temperature of sugar-core apple can not be lower than-1.5℃.（3）Through comprehensive evaluation of thermal conductivity,thermal resistance,moisture content,moisture recovery and unit thermal resistance price of fiber thermal insulation material,flame retardant thermal insulation cotton is selected as thermal insulation material for simple cold chain logistics transportation.Its thermal conductivity is0.0304W/（m.K）,0.7643(m².k.W^-1),unit thermal resistance price is 5.17[m²（m²K）/W],water content is 0.54%,moisture recovery is 0.57%.（4）Analyze the thermal conductivity,thermal resistance and unit thermal resistance price of the five selected bubble films.Aluminum foil bubble film is selected as the thermal insulation material of simple cold chain logistics technology,and its thermal conductivity is0.0312W/（m.K）,thermal resistance is 0.8475（m².K.W-1）and unit thermal resistance price is 12.71[m2（m²K）/W].Belong to high insulation bubble film.（5）the fruit precooling++thermal insulation phase change storage agent bubble film+fiber heat preservation cotton+phase temperature control model to simulation experiment,Lizzie apple from the hardness,color value,respiration intensity,titratable acid,vitamin C content,malondialdehyde content,water soluble pectin,pectin enzyme activity indexes of several aspects such as detecting probe Lizzie apple quality changes during the whole simulation.Compared with the blank group,in terms of hardness,color value and water-soluble pectin,the decline rate of sugar core apple in the treatment group was relatively slow,delaying the emergence of respiratory peak,and TA,SSC and VC contents were maintained well.