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.