Physical And Mechanical Properties Of Peanut Kernel From Four Cultivars Grown In Ecuador

Peanut postharvest processing in developing regions often suffers from equipment mismatches due to lack of varietal specific engineering data. The objective of this study was to determine the physical and mechanical properties of four peanut cultivars (INIAP 380, Charapoto, Caramelo, and Rosita) grown in Manabí, Ecuador, to establish engineering parameters for design and optimization of postharvest equipment. Through standardized measurements and statistical analyses, was characterized kernel dimensions (length, equatorial diameter, mass, density, sphericity, flow properties (angle of repose), friction coefficients and rolling resistance coefficients (rubber, stainless steel, carbon steel). Key findings include: (1) 90.5% of kernels within the 6.8-10.28 mm diameter range ideal for mechanical sorting, but for accurate classification, gravimetric or densimetric methods should be employed instead of dimensional sorting (2) 33.7% lower dynamic friction on stainless steel versus rubber surfaces, and (3) Barriga de Sapo's superior sphericity (0.65) and rolling resistance (ρₑ=0.554±0.007). These results provide the first complete engineering dataset for Ecuadorian peanut varieties, enabling the design of adapted seeders, conveyors, and storage systems. The study particularly supports small-scale processors in Manabí through: (a) DEM/CFD modeling inputs, (b) evidence-based material selection (e.g., stainless steel for energy efficiency), and (c) quality control standards using density thresholds.