Susceptibility of vapour heat-treated “B74” mango fruit to internal disorders and mineral nutrient composition

Abstract

Supply of premium quality fruit to export markets is important for consumer satisfaction and repeat purchase. For ‘B74’ mango fruit, vapour heat treatment (VHT) is an export protocol for fruit fly control for market access. However, VHT has been associated with internal physiological disorders in ‘B74’ fruit. Susceptibility of ‘B74’ to internal disorders in association with VHT and flesh mineral composition was investigated. Fruit were sourced from orchards across three climatic regions of Australia: Northern Territory (NT), Far-north Queensland (FNQ), and South-east Queensland (SEQ). They were assessed over two successive seasons for internal disorders associations with mesocarp mineral composition. Flesh browning (FB) and flesh cavity with white patches (FCWP) defects were observed. FCWP was present only in VHT fruit. FB was independent of VHT. Over the two seasons, the highest FB incidence was observed in NT fruit (20 %) and the highest FCWP in FNQ fruit (65 %). FB was not observed in fruit from SEQ in either season. Flesh [Ca] and [Mg] were highest in NT fruit. [N,B], N/Ca, K/Ca, and (K+Mg)/Ca were higher (p ≤ 0.05) in fruit from SEQ. Significant (p ≤ 0.05) positive correlations between FCWP and N/Ca, K/Ca, and (K+Mg)/Ca ratios and a negative correlation between FB and [B] were discerned by linear correlation and principal component analysis. However, strength of correlation and statistical significance levels varied over regions and seasons. This inconsistency suggests that other deterministic factors also influence VHT-induced internal disorders in ‘B74’ mango. ‘Big data’ sets encompassing preharvest factors along with ‘at harvest’ flesh mineral concentrations would potentially better inform predictive modelling of internal disorders expression in ‘B74’ fruit.