THE MICROBIOLOGY OF MIXED SALAD CONTAINING RAW AND COOKED INGREDIENTSWITHOUT DRESSING

Growth of aerobic mesophilic bacteria in mixed salad without dressing, containing cooked sweet corn and raw endive, was similar to that of r aw endive alone. At 9 degrees C, sweet corn permitted the growth of th e lactic acid bacterium Leuconostoc mesenteroides, whenever the bacter ium was present on raw endive, whereas no growth of lactic acid bacter ia was recorded on raw endive alone. Listeria monocytogenes, artificia lly inoculated in the samples, grew more in the mixed salad than in th e raw endive alone, for products stored at 6 degrees C and 9 degrees C . Acidification of sweet corn to pH 5.0 was proposed to reduce the dev elopment of L. monocytogenes in the mixed salad to a level similar to that recorded in the raw endive alone. Acidification with citric acid reduced spoilage of sweet corn, whereas acetic acid caused necrosis on the leaves of raw endive.