乳酸浸提去除大米粉中镉的研究

Study on the Removal of Cadmium in Rice by Lactic Acid Leaching

以镉超标大米为原料，尝试用乳酸浸提方法脱除大米粉中的重金属镉，并对试验条件进行了优化研究。通过单因素试验分析了浸提剂种类、浸提剂浓度、大米粉粒度、浸提时间和浸提温度对镉脱除率的影响，确定最佳试验条件为：浸提剂乳酸、浸提剂浓度0．4％、大米粉粒度40目、浸提时间8h及浸提温度25℃。在此条件下，镉含量在0．25-0．82mg／kg的大米粉中镉的脱除率达85％以上，其残留量均低于0．10mg／kg（米粉类制品国家标准限量标准）。

In order to resolve the problem of ＂excessive cadmium＂ polished rice utilization,this paper tried to reduce the con- tent of cadmium in ＂excessive cadmium＂ polished rice by lactic acid leaching, and the experimental conditions were studied and optimized.The effects of type of leaching agent, concentration of leaching agent, leaching time, leaching temperature on the removal rate of cadmium in polished rice were evaluated by single-factor significantly affect the removal rate of cadmium. The optimum experimental conditions were as follows,the concentration of lactic acid was 0.4%,the grain size of 40 mesh, the ex- traction time of 8 hours and the temperature of 25 degrees.Under these conditions,the removal rate of cadmium in rice powder- cadmium content of 0.25---0.82 mg/kg was more than 85%,and the residual amount of cadmium was lower than that of 0.10mg/kg （the national standard for rice flour products）.