Experimental Study On Mechanical Damage During Storage And Transportation Of Blueberries

Reducing the loss of fruit after harvest has become one of the most important issues in the development of agricultural products.In the circulation and transportation,the fruit will cause mechanical damage due to various forms of load.The three main forms are vibration,static pressure and drop impact,and the damage characteristics are different.Mechanical damage is the most important cause of fruit loss after harvest,leading to fruit decay and economic loss.In this study,under the simulated transportation conditions,the damage characteristics of blueberry and its packaging under vibration stress,static pressure load and drop impact were studied and analyzed,and suggestions for ensuring the quality of blueberry were provided.Mainly carry out the following three aspects of analysis:The natural vibration frequency of blueberry package was obtained by sweep frequency test.According to the selection of three different frequencies,the blueberry package was subjected to constant frequency vibration test,and then stored in three different temperature environments to detect the changes of physiological indexes of blueberry fruit.The effect of comprehensive vibration and temperature on the physiological indexes of blueberry fruit.The natural vibration frequency of blueberry is 85Hz.The storage quality of blueberry is affected by mechanical vibration and storage temperature.Vibration and high temperature accelerate the decay rate of blueberry.When the storage temperature is the same,the natural frequency vibration is transported,and the quality of blueberry is the most obvious.After storage at 4?,it is more conducive to the stability of various indicators of blueberry fruit,delaying fruit senescence.Through the main effect analysis of variance,the effects of vibration stress and storage temperature on the quality of blueberry fruit were studied.The equations of some physiological indexes,temperature and frequency of blueberry were obtained by regression analysis,which could provide the prediction of the maturity and decline of blueberry.Learn from.The blueberry single fruit was subjected to a compression test,and the relationship between the static load and the deformation of the blueberry was determined by the force-deformation curve,and the rupture force of the blueberry was 11-19N.The elastic modulus of the blue and horizontal directions of the blueberry was calculated by the single-sided plate compression equation to be 0.26 MPa and 0.22 MPa,respectively.The results show that the smaller force can cause the blueberry to deform.Further construct the rupture force and blueberry diameter and pressure loading speed model to provide a reference for the minimum load that blueberry can bear.The vertical impact test of the blueberry package was carried out by the face drop method,and the brittle value of the blueberry package was 44.82.The blueberry package was further subjected to face drop,edge drop and corner drop test,and the maximum drop height of the blueberry package was measured.The results show that the maximum drop height of the package used in the test is 775mm,which provides a design basis for the subsequent development of buffer packaging for effectively protecting blueberry fruit.