基于感应方法的咸蛋清盐分分析

Assess the Salt Content in Albumen Based on Inductive Methodology

为了探索交变磁通对含有大量自由离子的液态食品的电学特性影响,采用降压变压器体系(Np/Ns=20),以咸蛋清作为次级线圈导体,在开路状态下检测其终端电压和降压系数——λ值。测试环境为室温22℃,采用极低频50~400 Hz及1~20 V作为初级线圈的激励条件,结果表明:咸蛋清的终端电压和λ值不随频率变化而变化,而随着盐分含量的变化而变化;终端电压随着盐分含量的提高而增大,λ值随盐分含量的提高而减小。基于变压器技术的电学参数与咸蛋清盐分含量呈现较显著的相关性(a<0.01),数学模型的决定系数最高为R^2=0.954(终端电压-盐分含量)和0.911(λ值-盐分含量)。检测条件为频率400 Hz,激励电压5 V。采用回归方程模型对30个验证样本进行预测,表明盐分含量与终端电压的相关系数为r=0.970,预测标准差为0.773%,偏差为0.028%。将不同理化性质的样品作为螺旋导体,在其中通入变化的磁通,进而引发其电学参数的变化,该检测系统可为农产品的品质评估提供一条途径。

In order to explore electrical properties of the liquid food which contains a certain amount of free ions under the action of alternating magnetic flux, a detecting system based on the transformer with step-down characteristics（Np/Ns=20）has been established to determine electrical parameters（terminal voltage and λ-value） in salted albumen. All the measurements were conducted at the room temperature 22 ℃, and the test conditions as follows： the applied voltage on the primary coil 1~20 V; operating frequency range 50~400 Hz. Findings showed terminal voltage increased and λ-value decreased with salt content increasing in salted albumen, irrespectively of frequencies. Meanwhile, the correlation analysis of these electrical parameters of salted albumen in the function of salt content was also significant（a≤0.01） with highest determination coefficient of the regression models R^2=0.954 for terminal voltage and R^2=0.911 for λ-value（at 400 Hz, 5 V）. The model used to predict salt content in albumen for the samples in the validation set which indicating that the highest correlation coefficient between salt content and terminal voltage was r = 0. 970, and with a bias of0. 028%, as well as, SEP of 0.773%. Food materials with different physicochemical properties as a spiral conductor will lead to changes in electrical parameters under the influence of magnetic flux. The detection system can provide a potential method to assess the quality of agriculture products.