Comparison the level of Aflatoxin in different varieties of internal and imported rice in different collection seasons and effect of cooking methods on the level of toxins

Subject Areas : Molecular Microbiology

Mahmood  Najafian ¹ (استادیار، دانشگاه آزاد اسلامی، واحد جهرم، گروه زیست شناسی)

Received: 2012-12-30 Accepted : 2013-04-30 Published : 2014-03-01

Keywords: ELISA, Rice, Aspergillus, aflatoxin, Methanol,

Abstract :

Background and Objectives: Nowadays, rice is the foodstuff for half the populations, worldwide. Rice is exposed to fungal and aflatoxin contaminations like other cereal. This study was aimed to investigate and to compare the amount of aflatoxin in rice samples in Rasht city and effects of cooking on the level of toxin. Material and Methods: This cross-sectional study was carried out on 72 samples of consumed rice from domestic and imported productions bought from six stores in Rasht city in both summer and winter. At first aflatoxin was extracted using 80% methanol in three different types of samples including raw, boiled and water cooked. Then aflatoxin content was determined in each sample using the ELISA technique. Results: Domestic samples were less contaminated than imported ones. Samples collected in the summer were less contaminated than winter. Also, in all cases, the cooked rice was less contaminated than seen in raw rice. This reduction rate of contamination was more effective in cooked water rice than in boiled. Conclusion: The results showed that all rice was contaminated in different levels. Therefore the needs for constant control and supervision over the contamination of rice must be considered. Since the contamination rate of imported rice was more than domestic one, for the purpose of reduction imported rice, the basic steps in order to increase domestic production of rice should be supported.