How does precooling protect raspberries and cherries after harvest?

For highly heat-sensitive fruits like raspberries and cherries, precooling is a critical post-harvest step used to protect quality before cold storage.1

By rapidly removing field heat, precooling slows the natural deterioration that begins immediately after harvest. This process is essential because the respiration of fruit—which involves enzymatic processes—is significantly influenced by ambient temperature; the rate of chemical change in fruit generally doubles with every 10 °C increase in temperature. By lowering the temperature, precooling effectively slows these metabolic rates, inhibits the growth of decay-causing microorganisms, and reduces wilting by retarding water loss.23

Common methods for achieving this include:
* Hydrocooling: Immersing the fruit in cold water.12
* Vacuum cooling: Moistening the fruit and placing it under a vacuum to induce evaporative cooling.12