Evaluating Contamination Level of Raw and Roasted Nuts Distributed in Commercial Markets in Mazandaran Province, Iran

Raw and roasted nuts are one of the most popular snacks consumed in Iran but mishandling and poor storage conditions and practices may lead to promote the growth of microorganisms and foodborne intoxications and infections.

The purpose of this study was to investigate the microbial quality of raw and roasted (salted and unsalt- ed) nuts, distributed in commercial markets in Mazandaran province, Iran.

The moisture content, total colony counts, total coliform, fecal coliform, Staphylococcusaureus, and fungal contamination were evaluated according to procedures of Iran national standards.

The moisture content of raw and roasted hazelnut, pistachio, almond, and cashew nut samples were above the standard limits. The moisture content of the raw peanuts was within the standard approved limit (maximum 9%). But the moisture content of the roasted peanut was higher than the permissible limit of 5%. For yeasts and moulds, except for all almond samples and 56% of cashew nut samples, all products tended to be loaded with unsatisfactory limits. The total viable count was within the standard limits in hazelnut, almond, and cashew nut samples (less than 4log cfu/gr). Satisfactory limits of coliforms (lower than 1log cfu/gr) were observed in all almond samples, 91.6% of hazelnut, and 16.7% of pistachio samples. No fecal coliforms were detected in samples. S.aureus contamination was observed in 6.5% of hazelnut, 8% of almond, 25% of cashew nut, and 33% of peanut samples.

According to the findings, almond and hazelnut showed the least, and pistachio and peanut samples showed the highest microbial contamination.