Vacuum Precooling: A Comparison of Cooling of Different Vegetables

Excerpts from the report: Since the start of commercial vacuum cooling of lettuce, research workers and shippers of fresh produce have been interested in using this method to precool other crops. Early investigation showed temperature reduction by vacuum varied greatly among different kinds of crops. Little information is available for a direct comparison of temperatures obtained by vacuum cooling different vegetables. In this study, several vegetables were vacuum cooled under similar conditions to determine the amount of cooling and moisture loss. The effects of cooling time, pre-wetting, and packaging on the final temperature of many of these commodities also were studied. This research is part of a broad program of the Agricultural Marketing Service for preserving high quality in fresh vegetables during marketing