The Effect of Cooking Process on Ochratoxin A in Commonly Used Rice

Ochratoxin A is one of the fungal secondary metabolites which likely transfer from food such as rice and its derivatives to the human diet. The aim of this study was to evaluate firstly the levels of ochratoxin A in samples of commonly used rice brands collected from Isfahan and Shiraz cities, Iran, and then, the effectiveness of the two methods of cooking (boiling and steaming, vs. boiling, rinsing, and steaming) in reducing the levels of ochratoxin A in the most contaminated samples.
30 samples from 6 commonly used rice brands, including 3 domestic and 3 from-abroad imported rice samples were gotten via using the simple random method. These samples cooked by two different methods (boiling and steaming, and boiling, rinsing and steaming) and then, to assess the amount of ochratoxin A, enzyme-linked immunosorbent assay (ELISA) method was used. The one-way analysis of variance (ANOVA) and Tukey's post hoc test were used to analyze the data.
Findings: 70 percent of the tested rice samples showed contamination of ochratoxin A with the range and mean of 0.94 ± 1.19 and 0-5/61 ng/g, respectively. Domestic rice contamination was 1.2 ng/g and significantly higher than the level of contamination in a variety of from-abroad imported rice (P The results of this study did not show any public health risk in case of the ochratoxin A contamination in rice samples. The cooking process was effective in reducing the fungal toxin levels, and the method with rinsing step after boiling had more efficacy in comparison with just boiling and steaming the rice.