Prediction models for the softening of new commercial Actinidia cultivars

Empirical models for the softening of Actinidia deliciosa fruits (exponential decay, complementary Gompertz and modified Boltzmann models) were applied to the ‘Hortgem Tahi®’ and ‘Hortgem Rua®’ cultivars of Actinidia arguta (Seib. Et Zucc.) Planch. Ex Miq, and the ‘Jingold®Jintao’ cultivar of Actinidia chinensis Planch., all of which are emerging cultivars in the baby kiwi and yellow pulp kiwifruit markets. A texture analyser was used to collect firmness data for kiwifruits stored up to 18 days at 2 and 24°C, for use in prediction models. The dry matter, soluble solid and vitamin C content was also determined for these new commercial cultivars, which were compared to the control ‘Hayward’ cultivar. The Boltzmann model, which is known to perform well for the ‘Hayward’ cultivar, was confirmed as the best fit for baby kiwi ‘Rua®’ and yellow ‘Jingold®Jintao’ cultivars for all studied conditions, whereas the exponential decay model was the best fit for the ‘Tahi®’ cultivar.