EFFECT OF ANTIMICROBIAL SOLUTIONS ON Salmonella POPULATIONSAND COLOR OF CLADODES OF NOPAL VEGETABLE

During the production and post-harvest handling of the nopal vegetable(Opuntia ficus-indica) there is a risk of contaminating this product withpathogenic microorganisms such as Salmonella. Currently, there is noeffective product to eliminate Salmonella from fresh nopal vegetable. Toprevent illnesses to consumers of this fresh product, it is important to havean effective disinfectant that eliminates the bacteria without affecting thecolor of the cladode. This research aimed to evaluate the effect of organiccompounds such as hibiscus (Hibiscus sabdariffa) calyx extracts, a mixtureof white vinegar and lemon (Citrus × latifolia) juice 1:1 (v/v), and 1.5 % lacticacid solution on Salmonella cultures, as well as identify their effect on thecolor of fresh vegetable nopal tissue, without thorns. Nopal cladodes of theAtlixco, Copena V1, Milpa alta and Villanueva varieties were used for the tests,inoculated with a mixture (7.6 log10 CFU) of strains of the serotypes S. Javianaand S. Typhimurium, resistant to Kanamycin (Km50). After the incubation time,cladodes were put in contact with the disinfectant solution for 10 min, theywere immediately washed with sterile distilled water and the bacterial countwas performed by inoculating the previously treated samples in boxes withHektoen enteric agar added with Km50. Results obtained showed a significantreduction (P ? 0.05) of 2.4 log10 mL-1 in the Salmonella population with all thesolutions evaluated (extracts of hibiscus calyces, a mixture of white vinegarand lemon juice, and lactic acid). The luminosity of the tissue was affected (P? 0.05) only with the mixture of vinegar and lemon juice; thus, it is concludedthat all the disinfectants tested are suitable to maintain the safety and qualityof the nopal vegetable