Microbial contamination and concentration of aflatoxin in pistachio by-product

Each year, large amount of pistachio by-product (PBP) was produced after the processing of fresh pistachio. PBP has suitable nutritional value and is used as a feed stuff in animal nutrition. The objective of this study was to determine the microbial contamination and concentration of aflatoxin in PBP. The samples of PBP were collected from two types of processing system (traditional and industrial), three stage of pistachio harvesting, and three different intervals time of picking up the skin (1-2 hours, 5-6 hours and ≥13 hours). All samples were dried under the sun and then were milled. All of the samples were cultured in a sterile culture and total mould, Aspergillus moulds and Coliform, and E.coli bacteria were counted. The concentration of total aflatoxin was measured by HPLC via extraction. Results showed that the means of microbial population of total moulds, Aspergillus moulds and Coliforms, and E.coli bacteria count were 21000, 3892, 3094 and 1.1 CFU/g, respectively, that were below a critical level to interfere in animal nutrition. Although microbial population were different in sampling area (P