Milling properties of peas in relation to texture analysis. Part 1. Effectof moisture content

A new efficient method to evaluate the milling behaviour of peas in a class ifier hit mill has been developed. The energy uptake to split a pea in a te xture analyser with a Stanley knife set-up was compared with energy uptake of pea in a classifier hit mill as function of moisture content. Drier peas showed a less elastic and ductile behaviour in the texture analyser and we re found to be harder than wet peas. However, the increase of brittleness a t lower moisture contents decreases the total energy uptake to create a fra cture. The same energy decrease was found for the milling experiments and p eas with lower moisture contents needed less energy to create new surfaces in a hit mill. The total energy uptake in the mill was higher than in the t exture analyser, but of the same order of magnitude and with the same relat ion with the moisture content. Small deviations from the linear correlation between energy uptake of the texture analyser and the classifier hit mill could be explained by the difference in the deformation rate during breakin g. Consequently, a lower milling speed showed a better correlation than a h igher milling speed. (C) 2001 Elsevier Science Ltd. All rights reserved.