S23 - Session O3 - Spatio-Temporal Metabolomics of Imazalil Postharvest Treatment In Fukumoto Navel and Clementine Mandarin

Authors: Gurreet Brar *, Keeton Montgomery, VV Krishnan

The citrus industry is a major economic contributor to agriculture globally. Millions of citrus products are wasted every year due to post-harvest conditions such as fungal infections, latent physiological disorders that occur in storage, or even over a mature product stays in cold storage due to market conditions. Further, a shortage of labor for harvesters puts pressure on harvest teams to harvest the products as fast as possible, leading to considerable amounts of tissue damage that contribute to fungal infections. To minimize fungal infection loss, packhouses utilize aqueous applications to cure infections that occur during harvest. Penicillium digitatum and Penicillium italicum are the most prominent fungal pathogens of citrus fruit, both commonly treated with imazalil sulfate due to its efficacy for controlling these pathogens, low cost, and ease of handling. Although imazalil sulfate is the most commonly used fungicide in an aqueous application, little is known on how it alters the tissues in the citrus fruit physiology. Metabolomics is the study of the metabolic profile of a targeted biological tissue under specific criteria or experimental conditions. In this study, NMR spectroscopy is utilized to identify and quantify metabolites based on the chemical shifts unique to each metabolite. Experimental conditions include isolating the juice, the albedo and flavedo tissues of both navel and clementine raw fruit initially at harvest, raw fruit stored for ten days at 40 o F, and raw fruit treated with imazalil sulfate and stored for ten days at 40 ° F. Twenty-seven metabolites were identified and several notable changes of metabolite composition due to imazalil sulfate treatment for both the spatial (albedo, flavedo or juice) and temporal levels (days and storage) were found.