Effect of temperatures strategies in the early storage period on weightloss, respiration rate and disease development in carrot (Daucus carota subsp. sativus)

Carrot ( Daucus carota L. subsp. sativus ) is a major vegetable crop in Norway which is stored up to 9 months in refrigerated storage rooms. Postharvest storage losses—primarily from water loss, respiration, and fungal decay—can reach up to 30 %. This study investigated the effects of different postharvest pre-storage strategies involving wound healing (WH) and temperature adaptation (TA) on mass loss, respiration rate, polyacetylene content, and disease development in four carrot cultivars (Nelson, Triton, Nominator, and Romance) during long-term storage. Carrots were subjected to six pre-storage strategies combining WH at 10 °C (60 % or 95–98 % RH) and various TA regimes (directly to 0 °C or 1 °C reduction/day), followed by storage at 0 °C for six months. Data showed that WH at high humidity, followed by gradual cooling, reduced disease incidence and increased the accumulation of antifungal polyacetylenes such as falcarinol and falcarindiol-3-acetate. Respiration rates were initially higher under WH treatments but did not result in increased total storage losses. Rapid cooling without WH led to higher disease levels, particularly in the cultivars Nelson and Romance. The findings support the implementation of a wound healing period prior to temperature reduction as a strategy to reduce postharvest decay and improve carrot storage quality, especially under commercial storage conditions where cooling rates may vary. • Wound healing reduces mass loss of carrots and enhances the accumulation of polyacetylenes. • Gradual temperature adaptation (TA) strategies contributes to maintaining carrot quality. • High respiration rates in the beginning of the storage period does not increase storage losses.