Development and Effectiveness Evaluation of a Propolis Hydroalcoholic Solution With Glycine in Reducing Microorganisms and Removing Helminth Eggs in Leafy Greens

Abstract

The main goal of this study was to evaluate the effectiveness of a propolis hydroalcoholic solution with glycine on the reduction of microorganisms and removal of helminth eggs in lettuce leaves. Three experimental groups were evaluated in triplicate or replicates: microbiological (ME), parasitological (PE), and microbiological and parasitological (MPE). Prior to the experiments, the initial concentration of native microbiota was assessed by counting mesophilic aerobes, molds and yeasts, using conventional microbiological techniques. Lettuce leaves were washed in tap water and subjected to different immersion treatments: in propolis hydroalcoholic solution (PHS), in propolis hydroalcoholic solution at pH 5.5 (PHS2), and in propolis hydroalcoholic solution with glycine (PHS-glycine). In ME, the propolis hydroalcoholic solution combined or not with glycine, was evaluated on the reduction of native microbiota. Residual microbiological contamination was assessed. In the PE, the effect of PHS2 and PHS-glycine was evaluated on the removal of a known number of Ascaris suum eggs on leaves artificially contaminated. In MPE, PHS-glycine was evaluated on the reduction of native microbiota and removal of eggs. A reduction of more than 2 log CFU/g were observed in ME. In PE, PHS-glycine removed 37.22% of eggs. In MPE, the PHS-glycine reduced 3.3 CFU/g mesophilic aerobes, 5.0 log CFU/g fungi, and 35.53% of eggs from vegetable. The results highlight the efficiency of the solution on reducing or eliminating different contaminants in vegetables and reinforce the need for the development of hygiene methods that do not harm human health and are reproducible at household level.