1a.Objectives (from AD-416)
1. Determine metabolic pathways that have a direct or indirect role in CO2 injury inception and development. 2. Identify metabolites that may be useful for predicting or diagnosing CO2 injury during the pre-symptomatic stages. 3. Test the capacity of prospective metabolic biomarkers to predict or diagnose CO2 injury under different storage conditions known to affect injury occurrence or severity.

1b.Approach (from AD-416)
Apple fruit will be treated and stored under conditioned known to provoke or reduce scald. Broad untargeted metabolic profiling techniques will be used to track symptom develop from disorder inception, through the asymptomatic development stages, and finally, during symptom development in fruit that are expected to, or not expected to, develop symptoms. Metabolomic data will be compiled and modeled using multivariate data-mining techniques to reveal associations among metabolites from multiple pathways and symptom development. Further experimentation will employ further treatment and storage-based contrasts that are expected to link other metabolites to disorder development while validating already discovered prospective metabolic biomarkers.

3.Progress Report

This project relates to objective 1 of the associated in-house project which seeks to identify factors that influence postharvest fruit quality and development of market limiting physiological disorders. CO2 injury is an apple flesh browning disorder that causes significant annual postharvest losses to susceptible cultivars. Current treatment practices are not available for organic production, are not acceptable in many markets, or do not provide quality assurance along the supply chain. In 2011, biomarkers were characterized and identified from the previous year’s experiment. Differences in metabolism among various browning disorders were evaluated. Progress was reported to the granting agency and a manuscript reporting findings is in preparation.