IMPACT FORCE MODEL RELATED TO PEACH FIRMNESS

Abstract

ABSTRACT Impact testing of fruit is a good compromise between applying a realistic and yet repeatable, controlled load. Features of the impact force versus time curve are related to firmness and can be utilized in non-destructive grading and sorting of fresh fruit. An improved model taking into account the asymmetry of the force-time curve was developed for peaches. Two of the model parameters were correlated with peach properties and drop characteristics; one is more sensitive than previously used firmness predictors. Data from 50 peach impacts representing three cultivars, two degrees of ripeness, two storage times, and three drop heights fit the model within 0.6% for peak force, 3.7% for time-to-peak force, and 4.1% for initial slope of the forcetime curve.