酸溶技术脱除大米粉中重金属镉的工艺优化

摘要

以镉含量0.647 9 mg/kg的大米为研究对象,研究利用酸液浸泡大米粉脱除大米粉中重金属镉的技术.探讨酸的种类、浸泡温度、浸泡时间、液料比和酸液浓度等因素对大米粉中镉脱除率的影响,确定选用乳酸为浸泡液,并采用三因素三水平Box-Behnken试验设计进一步优化了酸溶技术脱除大米粉中镉的技术参数.结果表明:浸泡温度、液料比和酸液浓度对镉脱除率的影响极显著(P＜0.01),浸泡时间影响不显著(P＞0.05);影响因素的主次顺序为:液料比＞酸液浓度＞浸泡温度;优化得到的最佳工艺参数为浸泡温度44.4℃,酸液浓度40％(V/V),液料比10∶1 (mL/g).在此条件下,大米粉中镉的残留量为0.018 92 mg/kg,镉的脱除率达97.08％,与预测值之间有较好的拟合性.%Taking the rice with the Cd content of 0.647 9 mg/kg as research object,the technology that the Cd was removed from the rice power by using the acid liquor to soak the rice power was researched.Base on the effects of acid species,soaking temperature,soaking time,liquid-to-solid ratio and acid concentration.on the removal rate of Cd in rice powder,lactic acid was selected as soak solution,and the technical parameters that the acid soluble technology removed the Cd in the rice power was further optimized by using a three elements and three level Box-Benhnken test design.The results showed that soaking temperature,liquid-to-solid ratio and acid concentration could significantly affect the removal rate of Cd (P ＜ 0.01),and the effect of soaking time(6 ～36 h) was not significant (P ＞ 0.05).Then,the main orders of the influence factors were liquid-to-solid ratio ＞ acid concentration ＞soaking temperature.The soaking temperature of 44.4 ℃C,acid concentration of 40％ (V/V) and liquid-to-solid ratio of 10∶1 (mL/g) were gained from the optimum technology parameter optimized,Under this condition,the residual content of Cd in rice powder was 0.018 92 mg/kg and the removal rate of Cd in rice was 97.08％,which was consistent with the predicted value.