METABOLIC ADAPTATION DURING INITIATION OF CA STORAGE OF 'JONAGOLD' APPLES

Metabolic adaptation of ‘Jonagold’ apples during the initial period of controlled atmosphere (CA) storage was studied using GC-MS based metabolic profiling. The physiological status of the apples was assessed by measuring respiration rate, ethylene production rate, firmness and total soluble solids. The fruit were stored in CA either immediately or after 14 days of intermediate cold storage. Cold storage suppressed the respiration rate while ethylene production continued to increase exponentially. However, this rate is very low as compared to the level during climacteric ripening of ‘Jonagold’ apples. Irrespective of the delay in CA application, respiration rate immediately dropped and stabilized upon transfer to CA. In contrast, ethylene production gradually decreased in delayed CA, however, for immediate CA, a slight increment was observed after an initial drop. PLS-DA analysis revealed differential metabolic changes attributable to the differences in the CA conditions. A broad spectrum of metabolic changes was observed in the glycolysis, TCA cycle, ethylene biosynthesis, and other pathways branching from the central carbon metabolism.