Influence of Initial Ham Quality and Physical Dimensions on Processing Yield

Abstract

Objective physical measurements and subjective quality scores were obtained on 348 hams to determine the predictability of chilled processed weights and overall processing yields. Analysis of variance and regression analysis were performed to determine the values of these measurements and scores. Hams with darker colored lean, greater fat thickness at the skin-collar interface and smaller specific gravity coefficients produced higher percentages for overall product yield. Muscle color, average fat depth of collar (AFD) and specific gravity exhibited the highest correlation coefficients with yield (.36, .35 and −.32, respectively). AFD was correlated with specific gravity (−.66). Chemical fat also was highly correlated with specific gravity (−.87). Multiple regression equations using objective and subjective measurements predicted 25% of the total variation (best five variables) in overall yield, with color the best single predictor (13.7%). Physical measurements alone accounted for approximately 16% of the total variation in overall yield. The best single objective predictor was AFD in the cushion region. Chilled weight of the final ham product could be predicted with a coefficient of determination of 89.9% with the independent variables green weight, muscle color score, AFD, total ham length and specific gravity coefficient. The higher coefficients of determination for chilled weight than for predicted yield may be partially accounted for by a lesser degree of compounded error in the chilled weight term.