Authors

Abstract

In order to enrich the apple quality evaluation system, TPA mechanical tests were carried out on Fuji, Guoguang and Golden delicious apple pulp at 10 loading speeds of 0.01, 0.1, 0.5, 1, 2, 5, 9, 13 and 17mm/s, and the mechanical characteristic parameters of pulp were obtained. The effects of loading speed on pulp hardness, elasticity, cohesiveness, chewiness and resilience were analyzed. The microstructure of pulp of different varieties pulp was observed by laser confocal microscope. Based on the Voronoi model of pulp tissue structure, the compression test was simulated to construct the relationship between microstructure and mechanical properties. The results showed that the loading speeds had a certain effect on the cohesiveness and chewiness, and had a linear relationship with the cohesiveness of Guoguang variety and the chewiness of Golden delicious. The microstructure of pulp directly determines its mechanical properties, the smaller the roundness of cells and pores, the greater the hardness, cohesiveness, chewiness and resilience. Using Abaqus for compression test simulation, the maximum deviation of stress is 4.3%, which proves that the model is effective and the accuracy is improved. The results provides technical parameters for mechanical system improvements for apple during harvesting, storing and transporting and perfect evaluation system of apple texture.

Abstract in Chinese

为了丰富苹果品质评价体系，选用0.01 、0.1 、0.5 、1 、2 、5 、9 、13 、17mm/s 10个加载速度，对富士、国光、金冠苹果果肉进行了TPA力学试验，获得果肉力学特性参数，分析加载速度对果肉硬度、弹性、内聚性、咀嚼度、回复性的影响；采用激光共聚焦显微镜对不同品种果肉微观结构进行观测，得到不同品种组织结构差异；基于果肉组织结构的Voronoi模型模拟仿真压缩试验，构建微观结构与力学特性的联系。结果表明，加载速度对内聚性、咀嚼度有一定影响，与国光品种内聚性、金冠品种内聚性、咀嚼度成线性关系；果肉微观结构直接决定了其力学特性，细胞及孔隙圆形率越小，硬度、内聚性、咀嚼度、回复性越大；运用Abaqus软件进行压缩试验仿真，应力最大值偏差度为4.3%，证明模型有效，且精确度提升。研究结果为苹果采收、贮藏、运输等相关机械系统的改善提供数据支持，完善苹果贮运品质评价体系。