| Popis: |
Excerpts from the report: Trailers refrigerated with liquid nitrogen and trailers with both mechanical refrigeration and liquid nitrogen for atmosphere modification have been available to lettuce shippers since about 1964. Few critical studies have been made on transit temperatures in such equipment or on the effects of resulting low-oxygen atmospheres on produce quality. The U.S. Department of Agriculture, in cooperation with lettuce shippers, carriers, and suppliers of trailers equipped with liquid nitrogen systems, made tests in 1963, 1964, and 1965 on shipments from California to midwestern and eastern markets. This report gives the results of shipping tests made under commercial conditions to determine comparative effects of liquid nitrogen and mechanical refrigeration on transit temperatures, on the quality of lettuce, and on the various disorders affecting lettuce on the market. |
