The Study On Relationship Between Electrical Properties And Physiological Characteristics Of Apple Fruit During Storage

Taking‘Fuji’and‘Qinguan’apple fruit as experimental materials, fruits were treated with1-MCP and ethephon, then stored separately at (20±2)℃and (0±1)℃. With electricfrequencies of0.1～3980KHz during apple fruit storage period，the change rules of electricalproperties and physiological characteristics of ‘Fuji’and ‘Qinguan’ apple fruit weresynchronously measured by using electronic instrument of Japan3532-50LCR andphysiological and biochemical technology and the relationship between them compared. Thegeneral goal of this study were:1) to seleet sensitive electric parameters to quantize qualityparameters of fruits.2) to accumulate the data on the change regularity of apple electricproperties and provide evidence for developing new non-destruetive method.Main research results are as follows:1. When stored at (20±2)℃,both‘Fuji’and ‘Qinguan’ apple fruits presented a downswingof Z value as the electric frequency increased and the storage time extended. Thecharacteristic frequency of aech sample was3980KHz, under which the Z value of Fuji applecould be significantly associated with titration acid content,so regression equation was builtby correlation between electrical parameters of Z and physiological indexes of titration acidcontent; also regression equation was built between electrical parameters Z of Qinquanapple(1-MCP) and physiological indexes of firmness; moreover, ε′and Z could predict thechange of peel chromaticity of b*, and thus can measure for nondestructive-testing apples.2. When stored at (20±2)℃,the characteristic frequency of Fuji apple(ck) and Qinguanapple(ck) was0.1KHz, Fuji apple(1-MCP) was39,8KHz.As storage time extended, X、a*andTSS presented downswings, b*and D showed upward trends. The X value of Fujiapple(1-MCP) could be significantly associated with titration acid content,so regressionequation was built by correlation between them;also, deg and D could predict the change ofpeel chromaticity of b*and a*, and thus can measure for nondestructive-testing ofrefrigeration apples.3.Treatments with1-MCP or ethylene could cause electrical parameters changes, butdidn’t change the overall trends of fruit electrical parameters.4.Through contrast analysis of Fuji apple(ck) and Fuji apple(1-MCP), this study also concluded that fruit with different treatments had different characteristic frequency. Fromanother point of view, it verified Nelson’s(1993～1995) results on the study of some fruits atfrequency of0.2～20GHz that different kinds of fruit exerted different trends of electricalcharacteristics, because of their different organization structures and chemical compositions;even the same kinds of sample with different treatments showed various electrical parameters.