Study On The Relationship Between Compressive Properties And Quality Of Pear Fruits

The thesis aims at the following targets : mechanical menace caused damages which take place during picking,storing and shelf life; further processing technics including compression and slicing up ;designing and choice of parameter of related equipments.This paper takes apple-pear and Zaosu pear which abound in Hetao Region of Inner-Mongolia as experimental material. The following results were obtained by reseaching into change pattern of quasi-static compression characteristics, compressive properties in storing period and quality .1) with the enhancement of pear maturity, five parameters of mechanical properties reduced, sugar content decreased and the titratable acidity and moisture content fell down ,with same rigidity ,Zaosu pear has more moisture content than apple-pear while apple-pear has more compresive property parameters than crisp pear. This means apple-pear which keep moisture longer has stonger anti damage ability than crisp pear during picking,transportation and storing .2) Established multi-dimensional equation of motion between the pear fruit mechanical characteristics parameters and the quality target and carried through the significance examination.3) Storing in low temperature , pear fruits will be ripe slowly with no appreciably hard level reducing, storing in room temperature ,ripeness become fastest and hardness reduce obviously. In 13℃,conditions are between above both.4) The change of the compressive properties parameters of Zaosu pear with relate to the storage temperature and time were as follows; The change of the compressive properties was not obviously in the storage of 40days at 4℃; The change of the compressive properties reduced in the storage of initial stage at 13℃,and then to accelerate relatively 20days later ,the Compressive of Zaosu pear go down the most quickly at the room temperature.5) The change of the quality index of the Zaosu pear with relate to the storage temperature and time were as follows; soluble solid content first rise and then go down; the content of titratable acidity are increased obviously in the storage of initial stage and began to decrease in its later stage. while low temperature could slow down the changing process obviously; Water content could be dissipation quickly during the storage of first 15days at the room temperature, and then dissipation slowly, water dissipation of Pear fruits was Stable at the storage of 13℃,while water dissipation of pear fruits was slow in the storage of first 20days at the storage of 4℃,and then begin to accelerate relatively.