تعیین افلاتوکسین در نمونه های پسته با روش ELISA در تربت حیدریه (شمال شرق ایران) Determination of Aflatoxin in Pistachio samples by ELISA Technique in Torbat-e-Heydarieh (North-east of Iran)

ABSTRACT The aim of this study was to detect the amount of aflatoxin total (AFT) in raw pistachio samples in Torbat-e-Heydarieh in north-east of Iran. For this purpose, 48 raw pistachio samples were collected from Karimi farm in Torbat-e-Heydarieh during October 2014 and analyzed for AFT content by enzyme linked immune-sorbent assay (ELISA) technique. Results showed that the the minimum, maximum and average ± standard deviation of AFT was respectively 0.27, 0.3, 0.95±۰٫۶۲ng/g in the raw pistachio samples. The AFT concentration in the samples was lower than the national (15ng/g) and EU (10ng/g) standards. The situation seems to be suitable in the raw samples, but the storage condition must be in mind to prevent the contamination and production of the mycotoxin. Keywords: Aflatoxin, Pistachio, ELISA, Torbat-e-Heydarieh. INTRODUCTION Mycotoxins are secondary metabolites of molds which are associated with certain disorders in animals and humans. In addition to being acutely toxic, some mycotoxins are now linked with the incidence of certain types of cancer, and it is this aspect which has evoked global concern over feed and food safety (1). The major types of aflatoxins are B1, B2, G1, G2 and M1. Among them aflatoxin B1 is a very potent carcinogen to humans and animals, the main metabolite produced by fungi of the genus Aspergillus, particularly A. flavus, A. parasiticus, and A. nomius (2). The Pistachio nut is a commodities with the highest risk for aflatoxin contamination (3). The knowledge that mycotoxins can have serious effects on humans and animals has led many countries to establish a maximum tolerable level (MTL) on mycotoxins in food and feedstuffs in the last decades to safeguard the health of humans, as well as the economic interests of producers and traders. Currently, worldwide range for the limits of AFB1 and Aflatoxin total are 1-20 ng/g and 0-35 ng/g, respectively (4). More details about the current standards in different countries are presented in Table 1. Previous studies have shown that the aflatoxin content in exported lots did not meet the required standards (6, 7, and 8). The purpose of this study was to determine the AFT levels in the pistachio samples collected from the pistachio farm of Karimi in Torbat-e-Heydariyeh in Khorasan-Razavi province in Iran. MATERIALS AND MTHODS Materials In this study the AFT content of 48 raw pistachio samples collected in October 2014, from Karimi farm, in Torbat-e-Heydariyeh in Khorasan Razavi in northeast of Iran determined by ELISA technique. Methods Samples treatment Samples were analyzed by the ELISA method. Euro-Diagnostic ELISA test kits (Sweden) was used for analysis. AFT extraction was carried out according to the manufacturer’s instructions For this purpose, 10g of grinded samples was taken and 50mL of 33% methanol solution (methanol: distilled water, 30:60) added, shaken for two minutes and then let settle for 15 minutes at room temperature. Then, the extract was filtered through a Whatman No 1 filter paper, the clear supernatant was diluted 1:2 with 33% methanol solution (1mL+1mL) and samples were tested through ELISA kits instructions. The topical density was measured at 450 nm using ELISA plate reader (ELx 800, Bio-Tek USA). Evaluation of the ELISA data as well as the AFT concentration was performed using the software program (EuroDiagnostic). Statistical Analysis SPSS program version 11.5 was used for statistical analysis (SPSS Institute Inc. Chicago, Illinois). Descriptive statistical analysis was reported as mean ± SD.