Effectiveness of different concentrations of ozonated water in the sanitization of fresh-cut green pepper

Abstract

Green pepper is a popular vegetable in Brazil.  It is consumed mainly in raw salads or their complements, and therefore should be given special attention as to sanitization.  Sodium hypochlorite is currently the sanitizer most used for this purpose, but the formation of by-products is an inconvenience.  Thus, the search for techniques to minimize and/or replace this product in the fresh-cut industry has been increased.  Ozonated water can be an alternative because it is a potent sanitizer and does not create by-products.  The aim of this work was to define the most effective concentration of ozonated water in reducing microbial contamination of fresh-cut green pepper.  The raw material was purchased in a local trade of Campinas-SP, selected and minimally processed.  The sanitization consisted of immersion in tap water (T₂) and ozonated water at concentrations of 1.6 mg/L(T₃), 1.8 mg/L (T₄) for one min.  The processing consisted of washing, manual cutting, taking up the stalk and the internal parts and slicing into strips (± 3 mm in thickness).  The control treatment (T₁) was the product minimally processed without washing. The ozone concentration was measured by a commercially available kit (CHEMetrics, Vacu-vials, Ozone K-7402, Calverton, Va., U.S.A.).  It was performed physical-chemical (pH and soluble solids) and microbial analysis (mesophilic and psychrotrophic aerobic bacteria, total coliforms, Escherichia Coli, yeasts and molds, besides the presence of Salmonella spp.).  The average initial contamination of samples were 1.3×10⁵ CFU/g to mesophilic aerobic bacteria, >1.1×10³ CFU/gto total coliforms, <1 (est.) to psychrotrophic and yeasts and molds.  After the treatment, the results were 1.3×10⁴, 9.2 and <1 (est.) CFU/g, respectively.  The presence of E.coli and Salmonella spp. were not observed.  The concentration of 1.6 mg L^-1 was found to be the most effective treatment in reducing the microbial contamination of fresh-cut green pepper.

Keywords: microbial contamination, safe food, postharvest, chemical methods, green-cut peppers