Isochoric Cold Storage for Postharvest Preservation of Green Grapes

The study evaluated the effects of isochoric cold storage (ICS) on preserving green grapes ( Vitis vinifera ). Grapes were stored in an impregnation solution within isochoric chambers at −1.5°C and 16 MPa for 7 days. After this, they were stored either with or without the solution at 4°C for up to 3 weeks. A separate set of grapes was stored in the same solution in a refrigerator at 4°C for 7 days, and then also stored either with or without the solution at 4°C for up to 3 weeks. Fresh grapes served as a control group, with direct storage at 4°C for 4 weeks. The study found that after 4 weeks of storage, microbial counts in isochoric impregnated grapes were 1.5 log colony‐forming unit (CFU) g −1 for those stored without the solution and 2.1 log CFU g −1 for those stored with the solution, indicating a lower incidence of decay. In contrast, the refrigerated grapes showed significantly higher microbial counts, reaching 3.2 log CFU g −1 without the solution and 4.4 log CFU g −1 with the solution. The refrigerated grapes experienced rapid weight loss, softening, color changes, and shifts in soluble solids to titratable acidity (TA) ratios, while grapes that underwent isochoric treatment and those refrigerated in solution maintained better quality. This study demonstrates that isochoric impregnation effectively preserves grape quality and ensures microbial safety, presenting a promising alternative to synthetic fungicides. The combination of isochoric impregnation and refrigerated storage in a solution can significantly extend the shelf life of grapes.