Application of vacuum ultraviolet photolysis reactor and loss of firmness prediction for stored ‘Fuji’ apples

Abstract

Ethylene is beneficial for uniform ripening, but if not properly managed it can induce negative impacts on fruit, such as a decline in firmness or texture profile. Fruit textural profile is one of the most important postharvest quality attributes for apples and it could be influenced by the presence of ethylene during storage. This study investigated the use of a vacuum ultraviolet (VUV) photolysis reactor to degrade ethylene during the retail storage of ‘Fuji’ apples at 15°C for 28 days. A first-order kinetic model was applied to describe the relationship between the measured and predicted apple firmness and used to predict the storage-life of apple fruit. The results showed that the VUV reactor was successful in maintaining low ethylene concentration in storage chamber between 2.5-16.2 ppm, while the ethylene concentration reached a maximum of 181.4 ppm in the control over a period of 28 days. Firmness of apple fruit under both storages was linearly related to storage time but the apples in control lost firmness at a rate that was 2.3 times higher. It was shown that the loss of firmness followed a first order kinetic behavior. The applied model showed that based on firmness the use of VUV reactor for ethylene removal during fruit storage could further extend the shelf-life of apple fruit by 46 days. However, the developed model had a poor correlation with R2 value of less than 0.9.