Mechanical and Biological Evaluation of Two Fresh Pepper Varieties

Shanwen Zhang ^1* Shaowen Li ¹ Min Dai ¹ Enhui Lu ¹ Sixing Liu ¹ LinQuan Ge ¹ Yongji Zhang ² Chunsong Guan ³ Binxing Xv ³ Wei Su ⁴ Hong Miao ^1*

• ¹ Yangzhou University, Yangzhou, China
• ² Lixiahe Agricultural Institute of Jiangsu Province, Yangzhou, Jiangsu Province, China
• ³ Nanjing Institute of Agricultural Mechanization, Ministry of Agriculture and Rural Affairs, Nanjing, China
• ⁴ Yangzhou Agricultural Technology Comprehensive Service Center, Yangzhou, China

The operation of roller-type pepper harvesters involves striking and pulling the peppers, which may result in incomplete detachment from their stems or cause surface damage or breakage of the peppers. The quality of the harvested peppers is directly influenced by the forces applied during striking and pulling. Therefore, researching the physical and mechanical properties of peppers is crucial for determining the structural and dynamic parameters of the screw rollers. This study selected Round peppers and the 'Bo 15' line pepper from fresh chili peppers as experimental subjects. The moisture content of both pepper varieties was 90% ± 1%. The main stem diameter of Round pepper was 10.196 ± 1.508 mm, significantly smaller than that of 'Bo 15' line pepper at 13.44 ± 0.769 mm. Additionally, the mechanical properties of the two pepper varieties were tested by using tensile, bending, compression, and shear methods. The results showed that, in terms of growth parameters, the average diameter of Round pepper is generally larger than that of 'Bo 15' line pepper. In terms of resistance to mechanical stress, the 'Bo 15' line pepper exhibited stronger resistance, with the following mechanical properties: tensile strength of 0.83 MPa, bending strength of 0.58 MPa, radial compressive strength of 0.25 MPa, and shear strength of 0.28 MPa. This study provides a basis for the selection of low damage harvesting techniques for fresh peppers and the screening of varieties suitable for mechanical harvesting.