Survey of ochratoxin A in rice from Iran using affinity column cleanup and HPLC with fluorescence detection

Mycotoxin Contamination of Consumed Rice in Iran: A Review

: Mycotoxin contamination of rice has been introduced as a big challenge for public health in developing countries in numerous studies. Rice consumption is also considered the main source of secondary metabolites in Iran. Given the diversity of climatic conditions in this region as well as unsuitable storage conditions, including high temperature and humidity, rice can be extremely contaminated via various fungi. The current study is a review of the occurrence of mycotoxins in rice in Iran. In this regard, some investigations had revealed that rice could be contaminated by mycotoxins such as aflatoxins (AFTs) (B1, B2, G1, and G2), deoxynivalenol (DON), fumonisin (FM) (B1 and B2), ochratoxin A (OTA), T-2 toxin, and zearalenone (ZEN). Moreover, the amount of mycotoxins in rice was reported in varying ranges in different provinces and regions and normally less than Iranian maximum tolerated dose (MTD). Given the importance of rice in the Iranian diet, it was finally recommended to screen consumed rice to find about fungal contaminations and mycotoxins.

Optimization of washing and cooking processes of rice for Ochratoxin A decrement by RSM

In this research, effects of washing and cooking processes on the decrease in ochratoxin A (OTA) residue in rice were investigated. Rice samples were washed one, two, and three times in the washing stage. Results showed that the washing stage was effective on OTA residue as 42.68% of OTA was removed. In the cooking stage, the effects of boiling time, salt content, and water-to-rice ratio on OTA residue were studied employing response surface methodology (RSM). The results showed that time and salt content, interaction between time and salt content, and interaction between salt content and water-to-rice ratio were effective on the amount of OTA residue. According to the results, the optimum levels for boiling time, salt content, and water-to-rice ratio were 9.6 min, 3.5% salt, and 4:1, respectively. At these conditions, 76% of the OTA in rice was reduced.

Ochratoxin A in dried grapes in Hamadan province, Iran

The occurrence of ochratoxin A (OTA) in dried grapes was surveyed in this study. Sixty-six samples of dried grapes (40 currants, 16 sultanas and 10 raisins) were collected from dried grapes factories in Hamadan province, Iran, from October 2012 to March 2013. High-performance liquid chromatography (HPLC) was used to determine OTA in these samples. OTA was detected in 23 (57.5%) currants, 10 (62.5%) sultanas and 6 (60%) raisins samples. Levels in five samples exceeded the Institute of Standards and Industrial Research of Iran (ISIRI) maximum level of 5 µg/kg. However, OTA content in none of the samples exceeded the maximum limit prescribed in the European Union (EU) regulations, which is 10 µg/kg. The obtained data contribute to information on OTA levels in Iranian dried grapes.

The occurrence of ochratoxin A in rice in six provinces of Iran

Three hundred and eight samples of rice purchased from retail markets in six different provinces in Iran from March 2012 to January 2013 were surveyed for the presence of ochratoxin A (OTA) using enzyme-linked immunosorbent assay. The recovery percentages of OTA from spiked rice samples at concentrations of 5 and 10 ng/g were found to be 85.3% and 86.7%, respectively. Analytical results showed a 9.4% frequency of contamination from total analyzed rice samples with a mean OTA level of 3.60 ± 2.66 ng/g. Concentrations of OTA in positive samples ranged from 0.84 ng/g to 11.37 ng/g, and in 17.3% of contaminated rice samples the concentrations exceeded the maximum tolerance limit set by European regulations for OTA in cereals (5 ng/g). Based on the results of this study, the estimated daily intake of OTA in rice was 0.62 ng/kg body weight/day for Iranian consumers.