S23 - Session P7 - Fruit maturity and vapour heat treatment influence flesh cavity with white patches disorder in Calypso mango

Authors: Amit Khanal *, Daryl Clifford Joyce, Muhammad Asad Ullah, Donald E Irving, Andrew J Macnish, Priya Joyce, Neil A White, Richard I Webb

In Australia, Calypso TM mango is an economically important export cultivar that can express internal disorders after phytosanitary vapour heat treatment (VHT). Internal disorders (IDs) adversely affect consumer satisfaction and repeat purchasing of the fruit. The incidence and severity of fruit disorders are typically influenced by genetic, environmental, and management factors. Among these, harvest maturity is generically important. In a study of nine export supply chains, fruit were sampled upon arrival at a commercial VHT facility. Half of the sampled fruit were kept as controls and the remainder were collected following VHT. Individual fruit maturity was assessed initially as dry matter (DM) by near-infrared reflectance (NIR) handgun. Thereafter, all fruit were kept at 20-22°C and 90% relative humidity (RH) until eating ripe as determined by hand firmness. Thereupon, each fruit were cut and assessed for incidence and severity of IDs. Fruit maturity in the different supply chains and within each harvest batch varied by up to 5.5% DM. A Flesh Cavity with White Patches (FCWP) disorder was identified consistently by VHT. Expression was related to fruit maturity at harvest. Comparatively less mature fruit ( < 15% DM) were prone to FCWP post-VHT. The incidence and/or severity of FCWP could potentially be minimised by harvesting or sorting for DM prior to VHT.