Survival of Salmonella Enteritidis and Escherichia coli in cactus cladodes under domestic marketing conditions in Mexico

In Mexico, during domestic marketing of cactus cladodes, called “nopalitos”, there is a tendency not to provide refrigerated storage, and sometimes dealers do not take care of the hygienic conditions of the product during commercialization. Therefore, the objective of this study was to evaluate the survival of Salmonella Enteritidis and Escherichia coli on cladodes of Opuntia ficus-indica Var. Atlixco under conditions associated with domestic marketing in Mexico. Some phenolic compounds present in cladodes, which could influence the survival of these pathogens in the vegetable were analyzed at the same time. For the survival experiment, a 2x2 factorial design was used; treatments included two presentations of cactus cladodes (without spines and with spines) and two storage temperatures. Viable cells were counted during 16 days of storage using specific culture media. Phenolic compounds were determined using HPLC. E. coli did not survive on cactus without spines during 16 days at 4°C, while S. Enteritidis was able to survive until 16 days in all the treatments. The analytic results obtained indicated higher contents of caffeic and protocatechuic acid. The results showed the importance of refrigerated storage of nopalitos during their commercialization to reduce the risk of presence of foodborne illness and provide good practices during marketing. Key words: Opuntia ficus-indica, human pathogens, handling, storage temperature.