Prediction of storage potential and firmness loss of 'Hayward' kiwifruit along the supply chains in India : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Food Technology, Massey University, Albany campus, New Zealand

Abstract

The ‘Hayward’ kiwifruit (Actinidia deliciosa, C.F. Liang and A.R. Ferguson) is one of the most common commercial varieties grown in New Zealand. The long shelf-life of the ‘Hayward’ kiwifruit along with its inherent properties such as flavour, colour, texture and high content of vitamin C has allowed the development of New Zealand kiwifruit exports. However, the quality of the fruit can be affected by factors such as storage time and temperature along the supply chains to different markets. This study investigated changes in physiochemical parameters of kiwifruit along three supply chains to Indian markets, as well as development of predictive mathematical models for the loss of flesh firmness and storage potential of ‘Hayward’ kiwifruit along the supply chains. At each analysis point along the three supply chains, the ‘On arrival’ and ‘At departure’ quality of twenty kiwifruit were analysed for flesh firmness (kgf), soluble solids content (% Brix) and core temperatures (°C). The variation in the environmental temperature during storage and transportation along the supply chains were recorded. Three firmness loss models: Simple Exponential, Boltzmann and Inverse Exponential Polynomial were used to characterise the flesh firmness data collected along each supply chain. Three storage potential models: Reciprocal, Power and Reciprocal Quadratic, were fitted to the flesh firmness and core temperature data collected along each supply chain. The Akaike Information Criteria (AIC) test was used to determine the most suitable model that characterised the flesh firmness loss along the supply chains. The flesh firmness decreased (P<0.05) in all the grower lines along the three supply chains, while the soluble solids content increased (P<0.05) with temperature variation during storage and transportation. The Simple Exponential model best characterised the firmness data collected along supply chains 1 and 3. Changes in flesh firmness of fruit along supply chain 2 were best characterised by the Boltzmann model. The Reciprocal model best fitted the data on flesh firmness and core temperature. The Power model was the second best storage potential model that characterised the data collected along the three supply chains. The developed storage potential models may be used to determine the shelf-life of kiwifruit along similar supply chains in other markets.