REFRIGERATED STORAGE OF PREPACKAGED SALAD VEGETABLES

This study was done to characterize the changes that occur during refrigerated storage of six salad vegetables individually and in a mixture. Salad-cut and intact lettuce, carrot, celery, radish, green onion and endive, and a salad mixture were stored at 4.4°C in packages made from a film having low gas permeability. Respiration of individual vegetables during storage showed two patterns: carrot and celery respired throughout the storage time while respirations by the others was halted after a few days. Respiration of cut vegetables exceeded that of intact. Total plate counts (TPC) for intact vegetables in storage increased slower than for cut vegetables; lettuce and endive showed higher TPC than the others. The cut vegetables were invariably poorer in organoleptic quality. Mixed vegetable salads were sealed with either air or an atmosphere containing 10.5% CO2, 2.25% O2. After 2-wk storage, organoleptic evaluation indicated that the chemical treatments were generally of no value and in some cases were even detrimental but the modified initial headspace was beneficial.