Ester content of blueberry fruit can be ruled by tailored controlled atmosphere storage management

This study examines the effects of controlled atmosphere (CA) storage with high CO2 concentration (16 KPa) on the volatile organic compound (VOC) profile of blueberries (Vaccinium spp.), considering their genetic variability. The research focuses on the denovo production of esters and their association with fermentation related VOCs, employing complementary analytical techniques for comprehensive VOC profiling: direct injection mass spectrometry using Proton Transfer Reaction - Time of Flight - Mass Spectrometry (PTR-ToF-MS) and gas chromatography utilizing Solid-phase microextraction coupled to gas chromatography-mass spectrometry (SPME/GC-MS). In the first experiment, PTR-ToF-MS and SPME/GC-MS were applied to analyze the volatilome of seven blueberry cultivars under regular (RA) and controlled (CA) atmosphere storage conditions for 42 days. In the second experiment, 39 cultivars were tested to evaluate genetic variability in response to CA storage using PTR-ToF-MS. The third experiment focused on the effect of different oxygen concentrations during storage (1, 7, and 12 kPa O2), studying four cultivars using PTR-ToF-MS. Results of the three experiments revealed high variability among Vaccinium genotypes for all quality traits, which was amplified during storage, particularly under modified atmosphere conditions. CA storage generally enhanced the positive effects of cold storage by reducing texture decay and water loss and improving VOC profiles. Several ester compounds were synthesized de novo under low oxygen conditions, possibly as a response to hypoxic stress. The study concludes that CA storage offers potential to enhance postharvest fruit quality beyond shelf-life extension. The increase in fruity ester compounds during storage may improve blueberries' organoleptic properties. However, the variability in responses among cultivars needs tailored storage protocols. This research provides valuable insights for market segmentation and breeding programs aimed at enhancing blueberry quality and storability, while also validating PTR-ToF-MS as a rapid phenotyping tool for blueberry assessment