白砂糖色值与pH关系模型的研究测定

Study on the Relationship Model between the Color Value of White Granulated Sugar and pH

论文研究测定不同等级的、一定p H范围的糖液的白砂糖样品的色值,发现除精制糖外,其色值均随糖液的p H值增大而升高,均呈现明显的指数关系,其中二级白砂糖为y=5.996e0.4955 x,一级白砂糖为y=1.154e0.6528 x,相关性好;精制糖和优级糖的糖液在紫外区有较高的吸收值,对其色值与它们的40%(w/w)浓度的糖液在220、240、260、280、300 nm这5个波长处的吸光值进行一元线性回归模拟分析,发现色值与糖液在220 nm处的吸光值线性关系较好,模型相关系数较大,预测的标准偏差较小。采用多元线性回归的方法处理5个波长处糖液的吸光度,得到相关系数R2=0.965的白砂糖色值的多元线性回归测算模型C=60.334A220+16.657A240-69.062A260-20.220A280+47.662A300-50.207,其预测精度比一元线性回归的更好,模型的鲁棒性更高。

Measuring of the color value of different-class white granulated sugar was studied at a certain range ofpH, results showed that： ＂the color values＂ of second-class, first-class and superior granulated sugar increased with the increase of pH, and significant and good exponential relationships were shown in the first two： y = 5.996e^0.4955 x and y = 1.154e^0.6528 x. used in measuring of the color value without buffer system. Linear regression simulation analysis was made between the color value of superior and refined granulated sugar and absorbance of their 40% （w/w） concentration of sugar solution in the 220, 240, 260, 280, 300 nm wavelength, the mathematical model with best correlation was： C=60.334A220＋16.657A240-69.062A260-20.220A280＋47.662A300 -50.207, R=0.965, of which the prediction accuracy and robustness were good.