Roggo Yves, Duponchel Ludovic, Huvenne Jean-Pierre
Laboratoire de Spectrochimie Infrarouge et Raman, CNRS UMR 8516, Bâtiment C5, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France.
J Agric Food Chem. 2004 Mar 10;52(5):1055-61. doi: 10.1021/jf0347214.
The legal method (polarimetric measurement) for the determination of sucrose content and the wet chemical analysis for the quality control of sugar beet uses lead acetate. Because heavy metals are pollutants, the law could forbid their use in the future. Therefore, near-infrared spectroscopy (NIRS) was evaluated as a procedure to replace these methods. However, there are alternatives to lead clarification, such as the use of aluminum salts, which have been applied at many sugar companies. The real advantage of NIRS is in speed and ease of analysis. The aim of this study was to determine simultaneously the concentration of several components which define the industrial quality of beets. The first objective was the determination of sucrose content, which determines the sugar beet price. The standard error of prediction (SEP) was low: 0.11 g of sucrose/100 g of fresh beet. NIRS was also able to determine other beet quality parameters: brix, marc, glucose, nitrogen, sodium, potassium, sugar in molasses (i.e. sucrose in molasses), and juice purity. The results concerning brix, marc, sugar in molasses, and juice purity were satisfactory. NIRS accuracy was lower for the other parameters. Nevertheless, RPD (ratio standard deviation of concentration/SEP) and RER (ratio concentration range/SEP ratio) show that NIRS might be used for the sample screening on nitrogen, potassium, sodium, and glucose content.
用于测定蔗糖含量的法定方法（旋光测量法）以及用于甜菜质量控制的湿化学分析法使用醋酸铅。由于重金属是污染物，未来法律可能会禁止使用它们。因此，对近红外光谱法（NIRS）进行了评估，以作为替代这些方法的程序。然而，有替代铅澄清法的方法，例如使用铝盐，许多制糖公司都已采用。NIRS的真正优势在于分析速度快且操作简便。本研究的目的是同时测定定义甜菜工业品质的几种成分的浓度。首要目标是测定蔗糖含量，它决定了甜菜的价格。预测标准误差（SEP）较低：每100克新鲜甜菜中蔗糖含量为0.11克。NIRS还能够测定其他甜菜品质参数：糖度、废粕、葡萄糖、氮、钠、钾、糖蜜中的糖（即糖蜜中的蔗糖）以及汁液纯度。关于糖度、废粕、糖蜜中的糖和汁液纯度的结果令人满意。对于其他参数，NIRS的准确性较低。尽管如此，相对预测偏差（RPD，浓度标准偏差与SEP之比）和相对误差范围（RER，浓度范围与SEP比值之比）表明，NIRS可用于对氮、钾、钠和葡萄糖含量的样品筛选。
