Soluble Solid Content, Mineral Nutrition, and Harvest Maturity Affect Flavor Deterioration of Sweet Cherries during Storage/Shipping

In the US Pacific Northwest and Chile, producing sweet cherries with 4-5 weeks postharvest storage/shipping life is desirable especially for ocean transport. With protracted shipping, flavor deterioration is a significant arrival issue. The flavor deterioration includes bland flavor and bitter taste and is often associated with internal browning (IB). ‘Skeena’ fruit harvested at commercial maturity from 9 orchards were hydro-cooled and packed in a modified atmosphere packaging (MAP) liner and stored at 0°C for 5 weeks. Atmospheres in MAP were equilibrated at O₂ ≈ 9.5% and CO₂ ≈ 10.6%. Cherry fruit of the 9 lots retained varied degrees of sensory flavor and developed varied degrees of bitter taste and IB. It was found that soluble solids content (SSC), titratable acidity (TA), K, Ca and B were positively correlated with sensory flavor score and negatively with bitter taste and IB scores. Fruit respiration rate, N, P, Mg, S, and other micronutrients were not found to be associated with fruit flavor. The bland flavor might be a result of TA reduction and have little correlation with volatile compounds. IB was positively and negatively correlated with malondialdehyde (MDA) (a lipid peroxidation product) and total antioxidant capacity (determined by DPPH and FRAP), respectively. From one orchard, ‘Skeena’ fruit were harvested when average skin color as described by CTIFL color chips was 4.0, 5.5, or 6.5. Compared to early harvests, the late harvested fruit had lower titratable acidity (TA) and sensory flavor score, higher amounts of ethanol and MDA contents, higher bitter taste and IB scores after 5 weeks at 0°C. Fruit with varied SSC (17.8-21.5%) were obtained in the same trees by manipulating crop loads (fruit densities) of 2-3, 5-7, or >10 fruit/spur generated on scaffolds 30 d after bloom. After 5 weeks at 0°C, fruit with higher SSC retained higher sensory flavor, lower bitter taste and IB scores. In conclusion, fruit quality, nutrition, and harvest maturity affect arrival flavor quality of sweet cherries for long-distant transport.