Physical and mechanical properties of cassava (Manihot esculenta Crantz) cultivars: Implications for the design of mechanical peeling machines

摘要

The data on physical and mechanical properties of short and long-duration cassava cultivars are limited to design an efficient continuous type peeling machine for small-scale processing. Short duration cultivars included Sree Jaya, Sree Vijaya, and Sree Swarna, as well as long duration cultivars included M-4, Sree Athulya, Sree Suvarna, H-226, Sree Raksha, Sree Pavithra, and Sree Vishakam, were investigated. The moisture content, girth, proximal diameter, middle diameter, cylindricity, and tuber surface taper angle were the highest for long-duration cultivar H-226. The maximum length was observed in the short-duration cultivar Sree Swarna. The periderm thickness was the highest for Sree Suvarna, whereas the highest proximal cortex thickness, middle cortex thickness, and distal cortex thickness were observed in Sree Athulya, Sree Vijaya, and M-4 cultivar, respectively. The highest bulk density, true density, and porosity were observed in the long-duration cultivars; Sree Raksha, Sree Athulya, and Sree Suvarna, respectively. The highest hardness, shear force, and rupture force were recorded for cassava peelings in the cultivar Sree Athulya. Similarly for cassava flesh, the highest hardness, shear force, and rupture forces were recorded in the Sree Suvarna cultivar. A strong positive correlation for true density with bulk density and proximal diameter and moisture content with cylindricity and middle-end diameter was found from the multivariate correlation analysis. Statistical analysis showed that the reported physical and mechanical properties of the cultivars were highly significant (p .01). Practical Applications Engineering properties such as physical and mechanical properties are important for designing machines, storage structures, and processes. Cassava tuber peeling by the manual method is time-consuming, labor-intensive, and has a low capacity. Thus, the design of a peeling machine for small-scale processing becomes important. The physical and mechanical characteristics of cassava flesh and peelings are critical design considerations for developing peeling machines for small-scale processing. The physical and mechanical properties investigated here would provide technical and scientific data for designing continuous shearing type cassava peeling machine units such as tuber feeder length, peeling knife selection, peeling knife angle, and adjustable spring with required tension for holding rotary type peeling knife.