Study On Determination Of Iron Content In Brown Sugar Products And Color Value Properties Of White Granulated Sugar

In order to provide a theoretical basis for the actual production of sugar factory,this paper attempted to establish a method for determining the content of iron in brown sugar by triple-wavelength spectrophotometry and the establishment and comparison of four different triple-wavelength spectral methods for data were in progress.Secondly,the determination of pH value and color value of 20 batches of three brands of white granulated sugar and absorbance of white granulated sugar solution in UV-visible wave band,and mathematical models between pH value and the color value of white granulated sugar were researched.The content and results of the research were as follows:1.Determination of total iron and ferrous content in brown sugar by triple-wavelength spectrophotometry was studied,results showed that:(1).The three wavelength method of the left 1/2,which was lower than the maximum absorption wavelength of 510 nm,was better than that of the left side of the 3/4;It was not feasible to establish the right 1/2 or 3/4 three wavelength method,which was higher than the maximum absorption wavelength of 510 nm.(2).According to the appearance of sugar products and the appropriate concentration of the sugar solution to build the three wavelength method to make the resultant error smaller;The total iron content by the left side of 1/2 or 3/4 three wavelength method in 80% rock sugar were respectively 2.08mg/kg and 2.06mg/kg,which had only 0.96% relative error;The content of total iron in two different brown sugar samples were respectively 17.59±0.37 and 13.65±0.29 mg/kg,and the content of ferrous iron were respectively 17.35±0.15 and 13.29±0.18 mg/kg.The valence state of iron in brown sugar was mainly in the form of ferrous,which was more easily absorbed by the body.(3).The recovery rate of the total iron content is about 103%.2.Determination of pH value and color value of 20 batches of three brands of white granulated sugar and absorbance of white granulated sugar solution in UV-visible wave band,and mathematical models between pH value and the color value of white granulated sugar were studied,results showed that:(1).Three brands of white sugar in different batches of the averages of p H value were respectively7.11±0.39(Lotus brand),6.75±0.15(Yinmao brand)and 6.54±0.06(Yongquan brand).And the variances of pH value were respectively 0.055,0.015 and 0.003.The volatility of color value index of three brands of white sugar was: Lotus brand>Yinmao brand>Yongquan brand.(2)Three brands of white sugar in different batches of the averages of color value were respectively 105.03±5.03 IU(Lotus brand),100.20±7.60 IU(Yongquan brand)and 96.93±2.87 IU(Yinmao brand).The volatility of pH index of three brands of white sugar was: Lotus brand>Yongquan brand>Yinmao brand.Under overall consideration,Yinmao brand white sugar was the best choice among the three brands of white granulated sugar.(3)Measuring of the color value of white granulated sugar was studied,results showed that: “the color values” of three different brands of granulated sugar increased with the increase of pH.When the pH 6 to 7,“the color values” of Lotus brand white sugar increased by 3.7 with pH increasing by 0.1.This value was 11.6 when the pH 7 to 8.This value was 16.7 when the pH 8 to 9.The relationships between “color value” and pH value of Lotus brand white sugar were: y = 1.9461e0.5867 x R2 = 0.9893(pH6.0~9.0),y=36.80*x-153.31 R2 = 0.986(pH6.0~7.0),y = 1.0081e0.667 x R2 = 0.9918(pH7.0~9.0);When the pH 6 to 7,“the color values” of Yinmao brand white sugar increased by 3.3 with pH increasing by 0.1.This value was 10.6 when the pH 7 to 8.This value was 16.1 when the pH 8 to 9.The relationships between “color value” and pH value of Yinmao brand white sugar were: y = 1.7322e0.592 x R2 = 0.9888(pH6.0~9.0),y=33.04*x-134.75 R2 = 0.997(pH6.0~7.0),y = 0.9078e0.6702 x R2 = 0.9935(pH7.0~9.0);When the pH 6 to 7,“the color values” of Yongquan brand white sugar increased by 3.0 with pH increasing by 0.1.This value was 12.9 when the pH 7 to 8.This value was 16.4 when the pH 8 to 9.The relationships between “color value” and pH value of Yongquan brand white sugar were: y = 1.5754e0.611 x R2 = 0.9763(pH6.0~9.0),y=33.30*x-133.05 R2 = 0.958(pH6.0~7.0),y = 0.7836e0.6978 x R2 = 0.9902(pH7.0~9.0)?Under overall consideration,Yinmao brand white sugar was the best choice among the three brands of white granulated sugar.(4)Through the absorption spectrum curve of three brands of white granulated sugar,it was found that the absorption spectra change trend of sample solution was basically the same,but the size and distribution of different range of absorbance were different.In terms of the fluctuation of the absorption spectrum curve of the sample solution,it was obviously that volatility of the Yinmao brand white granulated sugar was minimal.Therefore,Yinmao brand white sugar was the best choice among the three brands of white granulated sugar.