“Determinación de la actividad bactericida del agua de plata sobre ensaladas listas para el consumo humano en restaurantes cercanos a una institución de educación superior”

Abstract

The present work had as objective to determine the bactericidal activity of the silver water on salads ready for the human consumption in restaurants located near the Technical University of Ambato campus Ingahurco.

Sampling was performed on the total salads sold at the food stalls, and Petrifilm plates were used for contamination indicators: aerobic mesophiles, E.coli / coliforms, molds and yeasts. The first dilution of the samples was processed to determine the initial microbial load present, then it was subjected to a treatment of equal volumes with the concentrations of 5ppm and 10ppm of silver water, at the first minute the first planting was made in the plates for the Contamination indicators and after five minutes the second planting. The cultures were processed according to their requirements and once the incubation time had elapsed, the microbiological count was performed.

Aerobic mesophiles had a higher than permissible microbial load in 45% of samples, total coliforms by 35% and yeasts by 12.5%, whereas E. coli and molds showed no higher than permissible microbial loads. For the statistical part we worked with the comparison of the means of the total of the data obtained in the factors in which we can observe the effect that each concentration had on the initial microbial load according to the contact time.

The silver water managed to reduce considerably more than 80% of the initial microbial load present in the total of the studied salads, being acceptable for the human consumption. The combination of the highest concentration and time of exposure were effective for the reduction of microbial load except for molds, which, despite being greatly reduced, because of their different structure to that of the bacteria did not present a considerable decrease.