Microbiological and safety evaluation of green table olives marketed in Italy

Abstract

The microbiological and safety conditions of green table olives sold on the Italian market were evaluated on 40 samples, 20 loose and 20 packed in containers, purchased at street markets and supermarkets. The olives were analyzed for microflora and food safety indices, and for aflatoxin B1 and ochratoxin A occurrence, and the results showed acceptable security. There was wide heterogeneity in the microflora, the numerical values being in relation to the olive type. The microbial population was dominated by the yeasts and lactic bacteria responsible for the fermentation process, and their numbers, together with the metabolic activity, led to conditions unfavorable for the development of pathogenic microflora; hence, such microflora were always absent. However, fecal coliforms were occasionally found in cracked olives. Lactic Acid Bacteria and yeast classification was performed at the species level by molecular techniques. The mycotoxin aflatoxin B1 was detectable in 25% of the olive samples, in the range of 0.40–0.55 μg/kg, while ochratoxin A, present in 58% of the samples, was in the range of 0.20–3.90 μg/kg.