Fate of Salmonella in Salpicon, a Mexican Cold Shredded Beef Salad

Abstract

The fate of Salmonella during the preparation and storage of salpicon, a cold shredded beef salad commonly consumed in Mexico, was evaluated. Salmonella contamination was introduced by a person shredding the cooked beef, who previously had handled raw pork containing several native serotypes of Salmonella at 9,000 salmonellae per g. The salad was prepared with 0, 2, or 4% vinegar and was held for 48 h (8 at 24–26°C and 40 at 5–7°C). The optimal concentration of vinegar for acceptable salad flavor was 4%. The initial number of salmonellae in salads prepared with 0 or 4% vinegar was 20/g. Salmonella populations increased to 5,000 after 48 h. Salmonella did not grow in salad containing 4% vinegar (pH 5.3); however, the organism was isolated at levels of 7 cells per g at 48 h of incubation. Fourteen different serovars of Salmonella were isolated from the salads. Critical control points in the preparation and storage of salpicon are shredding the beef, the concentration of vinegar, and rapid cooling of salad before serving.

Frequency and Behavior of Salmonella and Escherichia coli on Whole and Sliced Jalapeño and Serrano Peppers

“…For instance. Salmonella Typhimurium inoculated on shredded cooked beef and stored at 20°C for 8 h increased from 2.3 to 3.4 log CFU/g (18); whereas, after 22 h of incubation on sliced tomatoes. Salmonella Montevideo increased by 1.5 log CFU/g at 20°C and 2.5 log CFU/g at 30°C (40).…”

Survival of Vibrio cholerae O1 in Ceviche and Its Reduction by Heat Pretreatment of Raw Ingredients

“…Adding chemicals such as lactic or acetic acid has been proven effective in reducing pathogens on beef carcasses (9). Fernandez-Escartin et al (6) were able to reduce Salmonella in a cold beef salad by increasing the concentration of acetic acid in the recipe. However, in the case of ceviche, adding a new ingredient might affect the acceptability of the food.…”