Effects of knife edge angle and speed on peak force and specific energy when cutting vegetables of diverse texture

Abstract

Cutting tool parameters such as edge-sharpness and speed of cut directly influence the shape of final samples and the required cutting force and specific energy for slicing or cutting operations. Cutting force and specific energy studies on different vegetables help to design the appropriate slicing or cutting devices. Peak cutting force and specific energy requirements for the transverse cutting of nine vegetables, differing in their textural characteristics of rind and flesh, were determined at cutting speeds of 20, 30, 40 mm min^-1 and single-cut knife-edge angles of 15, 20 and 25° using a Universal Testing Machine. Low speed (20 mm min^-1) cutting with a sharper knife-edge angle (15°) required less peak force and specific energy than that of high-speed cutting (40 mm min^-1) with a wider knife-edge angle (25°). The vegetables with the maximum and minimum variation in the average peak cutting force were aubergine, at 79.05 (for knife speed 20 mm min^-1 and edge angle 15⁰) to 285.1 N (40 mm min^-1 and 25⁰), and cucumber, at 11.61 (20 mm min^-1 and 15⁰) to 21.41 N (40 mm min^-1 and 25⁰), respectively. High speed (40 mm min^-1), with a large knife-edge angle (25°), required the highest force and specific energy to cut the vegetables, however, low speed (20 mm min^-1), with a small knife-edge angle (15⁰), is preferred. Effects of cutting speed and knife-edge angle on peak force and specific energy responses were found significant (p<0.05). Linear or quadratic regressions gave a good fit of these variables.