MODELING BLUEBERRY FIRMNESS AND MASS LOSS DURING COOLING DELAYS AND STORAGE

Abstract

Blueberry mass and firmness losses were measured to determine the effect of cooling delays at selected temperaturesin postharvest environments. Models were developed from the slopes of firmness and mass values plotted against timefor four temperatures (4C, 21C, 27C, and 32C) and 95% relative humidity. The models were validated by holding othersets of blueberries at three temperatures (21C, 27C, and 32C) and at 95% relative humidity for cooling delays of 0, 2,4, 8, 12 and 24 h before storage at 4C and 95% RH up to 96 h. The models developed were suitable for evaluating the benefitof lowering temperature during cooling delays of selected durations or the benefit of reducing cooling delays at specifiedtemperatures. The impact of cooling delays was less than expected when compared with losses caused by low-temperaturestorage for only four days. Additional studies are needed to model the effect of various relative humidity levels and to learnthe extent of variation in the rate constants for different cultivars and different crops.