Food industry chemometrics

NIR is increasingly used in process and environmental analysis, the food industry, agriculture, the pharmaceutical industry and polymer analysis. In-line measurement with fiber optics and rapid multi-component quantification are the most important advantages of NIR spectroscopy. In comparison to mid-infrared, NIR analysis is much faster and more versatile. Most samples are analysed in one minute or less. Often chemometric methods must be applied to determine the parameter of interest... 

In the 50 years since its introduction, the use of GC by the petroleum industry has helped foster many breakthroughs in GC instrumentation. Open-tubular GC columns and the theory that describes them were first introduced by Golay and Ettre in the mid-1950s. The further development of open-tubular capillary columns was done by Desty of British Petroleum, and, with subsequent refinement, this technique is now the standard method for most GC applications. The use of GC for sample analysis was also quickly adopted by the pharmaceutical and food industries and is used for fundamental studies of reaction kinetics and physiochemical measurements. Today the use of GC for the analysis of complex samples such as serum proteins, natural products, essential oils, and environmental samples has become a routine with multidimensional separation techniques and multivariate chemometric analysis providing identificatimi and quantification of trace analytes from complex samples in the sub-ppb range. A GC system usually consists of the following elements (Fig. 1) ... 

Near-infrared (NIR) spectroscopy is widely used in the food industry as a fast routine analytical method for the quantitative measurement of water, proteins, fats and carbohydrates [13]. Although the near-infrared bands are less useful for qualitative analysis of foods because of their broad overlapped appearance, these bands are suitable for quantitative analysis when using chemometric techniques. Figure 8.12 illustrates the appearance of the major food components in the near-infrared, showing the spectrum of a sample of dehydrated tomato soup. 

Prediction of the sensory texture properties of cooked potatoes, based on raw potato analysis, is of major importance to the food industry. The sensory texture quality of potatoes has been predicted using T2 LR NMR. Correlation of the T2 LR NMR data with the chemical composition of potatoes has also been performed using chemometrics. Differentiation between potato varieties and determination of dry matter content has also been done using Ti and T2 LR NMR. 

Martinez-Mayorga K, Peppard TL, Yongye AB, Santos R, Giulianotti M, Medina-Franco JL (2011) Characterization of a comprehensive flavor database. J Chemometr 25 550-560 Sprous DG, Salemme FR (2007) A comparison of the chemical properties of drugs and FEMA/FDA notified GRAS chemical compounds used in the food industry. Food Chem Toxicol 45 1419-1427... 

NMR spectroscopy is one of the most widely used analytical tools for the study of molecular structure and dynamics. Spin relaxation and diffusion have been used to characterize protein dynamics [1, 2], polymer systems[3, 4], porous media [5-8], and heterogeneous fluids such as crude oils [9-12]. There has been a growing body of work to extend NMR to other areas of applications, such as material science [13] and the petroleum industry [11, 14—16]. NMR and MRI have been used extensively for research in food science and in production quality control [17-20]. For example, NMR is used to determine moisture content and solid fat fraction [20]. Multi-component analysis techniques, such as chemometrics as used by Brown et al. [21], are often employed to distinguish the components, e.g., oil and water. 

There is probably more experience of NIR spectroscopy in continuous process monitoring than any other spectroscopic technique [ 100]. The technique has been used for qualitative and quantitative measurements in the agricultural, food, chemical and pharmaceutical industries for several decades [101]. Because of the complexity of correlations within the spectra, the technique has almost driven the specialism of chemometrics, which is essential for extracting useful information. In this section, we shall explore how NIR spectroscopy has achieved this dominant position and how it measures up against alternative techniques as a process-monitoring technique for continuous processes. 

The application of chemometrics in near-infrared spectroscopy is finding widespread use in many different industries for monitoring the identity and quality of raw materials and finished products in the food and agricultural industry [46], polymer, pharmaceutical, and organic chemical manufacturing industries [18, 47],... 

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