Factors Influencing Heat Loss in Cantaloups During Hydrocooling

Excerpts from the report: Cantaloups are usually precooled by rapidly melting top-ice from the load in a railway car, using the air blast from built-in or auxiliary fans. This method is generally used for melons packed in crates. Rapid and effective precooling is important as a means of attaining early in the transit period temperatures of 35° to 40° F. which melons at maturities now harvested require. Recently a few shippers in California have hydrocooled cantaloups to be packed and shipped in fiberboard containers. Since hydrocooling has only recently been used with cantaloups, little is known of the factors affecting their rate of cooling by this method. Rates of cooling determined for other commodities cannot be applied to cantaloups because of their large size. Moreover, the surface area from which the heat is removed from cantaloups is relatively small in proportion to the volume of the fruit, in contrast to sweet corn or asparagus. Observations by Lipton and Stewart made with a commercial hydrocooler suggested that critical tests should be made to study the factors that might affect heat removal from cantaloups during hydrocooling. Tests were conducted, therefore, at the U. S. Horticultural Field Station, Fresno, Calif. , during the summer of 1959 to determine the effects of (1) initial temperature difference between melons and water, (2) rate of water flow through hydrocooler, (3) number of layers of melons in the cooler, (4) size of melons cooled, and (5) a wetting agent in the water. The pattern of warming of melons after hydrocooling was also studied.