利用同相等差感应电压检测面包中的山梨酸钾

采用同相等差感应电压法即45～60 V激励电压及300～500 Hz频率为初级线圈的激励参数,测定并分析次级线圈中山梨酸钾溶液的电信号特性。结果发现,0～200 mg/kg山梨酸钾溶液的瞬时绝对电位不随频率的变化而改变,与激励电压大小呈正相关。当山梨酸钾含量增加时,在不同频率及激励电压作用下,次级线圈中山梨酸钾溶液电势差增大。山梨酸钾含量、激励电压、频率及体系电势差呈线性相关,相关系数R²为0.916。采用同相等差感应电压法与化学法检测5种市售面包样品的山梨酸钾含量,检测结果相对误差均在4%以内。该研究将面包预处理后的料液作为次级线圈,通过同相等差感应电压法测定其电学参数来量化山梨酸钾含量,为面包中山梨酸钾的检测提供了一种新方法。

Study on detection of potassium sorbate in bread by in-phase equal difference induction voltage

The electrical signal characteristics of potassium sorbate solution in the secondary coil were measured and analyzed by in-phase equal difference induction voltage method with the electrical excitation parameters of the primary coil of 45-60 V excitation voltages and 300-500 Hz frequencies.The results showed that the instantaneous absolute potentials of 0-200 mg/kg potassium sorbate solution did not change with the frequencies,and which were positively correlated with the excitation voltages.When the mass fraction of potassium sorbate solution increased,the potential differences of potassium sorbate solution in the secondary coil increased under different frequencies and excitation voltages.There was a linear correlation among the mass fraction of potassium sorbate solution,excitation voltage,frequency and system potential difference,and the correlation coefficient R² was 0.916.Five kinds of bread samples were detected by the in-phase equal difference induction voltage method and chemical method,and the relative errors of detection results were within 4%.In this study,the pretreated food liquid was used as the secondary coil,and its electrical parameters were measured by the in-phase equal difference induction voltage method to quantify the content of potassium sorbate.These results provided a new method for the detection of potassium sorbate in food.