Study on Puncture Mechanical Properties of Apple Peel Under Different Loading Speeds

The mechanical properties of apple peel puncture were studied to provide reference for fruit quality evaluation and theoretical basis for improving the means of harvesting, transportation and storage and reducing fruit damage. Methods To Danxia, Fuji, Guoguang three varieties of apple as the research object, adopting TA. XT plus type structure, selection of 0.01, 0.1, 0.5, 1, 1.5, 2, 5, 9, 13, 17 mm/s ten loading rate on the apple peel to puncture the mechanics characteristic test of yin and yang, analysis of the same species under the same loading speed puncture and different loading speed skin puncture strength, different varieties under the same loading speed puncture strength of the skin. The microscopic structure of pericarp was observed by scanning electron microscopy, and the reasons for the difference of pericarp puncture intensity were analyzed. Results Under the same loading speed, the puncture strength of the yang-side pericarp of the same variety was greater than that of the yin-side pericarp, and the puncture strength of the yin-side pericarp of the same variety was significantly different（P＜0.01）. Under different loading rates, there were two peaks on the positive side curve and no obvious trend on the negative side curve of the same cultivar. Under the same loading speed, the puncture intensity of Danxia pericarp of different varieties was the highest, while that of Fuji pericarp was the lowest. Conclusion The intensity of pericarp puncture was significantly correlated with the location of puncture and loading speed, but had no correlation with variety.