Temperature kinetics of texture changes in actinidia chinensis 'Hortl6A' during storage

Kinetic models describing softening during storage of 'Hortl6A' kiwifruit at different temperatures are useful tools for the development of pre-conditioning and ripening protocols. Magness-Taylor firmness, compression firmness, and stiffness were assessed for their usefulness as tools to monitor and predict softening of 'Hortl6A' kiwifruit during storage at six storage temperatures ranging from 1.5 ° C to 25 ° C. Softening showed the same general biphasic pattern for all three measures, similar to that for green 'Hayward' kiwifruit, and could be described using simple exponential decay models. Magness-Taylor firmness reached an asymptotic minimum rapidly, whereas compression firmness and stiffness still decreased measurably at the end of storage. The rate of softening increased with temperature, and the biphasic pattern of the softening curves became more pronounced with later harvest dates. The effects of orchard, cane, and fruit position on parameter estimates such as rate constant, activation energy, and asymptotic firmness value, were negligible.