二组分食用混合油的线性混合模型研究与应用

发布时间：2019-01-23 10:35

【摘要】：基于二组分混和食用油的吸收系数是各自组分吸收系数按照掺杂比例的线性组合的假设以及朗伯-比尔吸收机理,提出并推导了二组分食用混合油的线性混合数学模型。该数学模型可根据相同厚度的两种原料油和其二组分混合油对相同光源的吸收光强变化计算出混合油的组分比例。根据误差理论,利用全微分公式分析了组分比例计算值的误差,表明通过选择使两种原料油的透射光强和吸光度差值的乘积较大的波长位置,可以优选出检测波长。搭建了可见-近红外光谱检测系统,利用花生油掺杂玉米油、花生油掺杂大豆油和玉米油掺杂大豆油三种混合油对模型进行了验证。结果表明,该模型对掺杂10%以上的混合油的成分比例计算值和实际值的相对误差在5%以内,相关系数分别达到0.999 4,0.999 7和0.999 3,标准误差分别为0.006 9,0.005 1和0.007 6,并证实本研究的波长选取方法是合理的。此外,对3种按同样比例组合的、未混合的分立油样本进行了检测,计算组合比的相对误差也可控制在10%以内,同时揭示入射光源的平行度和待测装置的垂直度对检测精度有一定影响。试验证明,不同于传统的光谱结合化学计量学的检测方法,本方法可以仅通过检测原料油和混合油在选定波长上的吸收光强即可准确计算得到掺杂比例。
[Abstract]:Based on the assumption that the absorption coefficient of two-component mixed edible oil is a linear combination of their absorption coefficients according to the doping ratio and the Lamber-Beer absorption mechanism, a linear mixed mathematical model of two-component edible oil is proposed and deduced. This mathematical model can calculate the composition ratio of the mixed oil according to the light intensity variation of two kinds of feedstock and its mixed oil of the same thickness to the same light source. According to the error theory, the error of the component proportion calculation value is analyzed by using the total differential formula. It is shown that the detection wavelength can be selected by selecting the wavelength position where the transmission intensity of the two feedstock oils and the product of the absorbance difference are larger. The model was verified by peanut oil doped corn oil, peanut oil doped soybean oil and corn oil doped soybean oil. The results show that the relative error between the calculated value and the actual value is less than 5%, and the correlation coefficient is 0.999 and 0.999 3, respectively. The standard error is 0.006 ~ 0.0051 and 0.007 ~ 6, respectively, and it is proved that the method of wavelength selection in this study is reasonable. In addition, the relative error of the calculation of the combination ratio can also be controlled within 10% of the three unmixed oil samples combined in the same proportion. It is also revealed that the parallelism of the incident light source and the perpendicularity of the device to be tested have a certain influence on the detection accuracy. It is proved by experiments that the doping ratio can be accurately calculated by only detecting the absorption intensity of feedstock and mixed oil at selected wavelengths, which is different from the traditional spectroscopic combined chemometrics method.
【作者单位】：天津大学精密仪器与光电子工程学院;中国医学科学院生物医学工程研究所;
【基金】：国家(863)计划项目(2015AA021105)资助
【分类号】：O657.3;TS227

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