Spectroscopic Methods for Evaluating Nutraceuticals and Nano-Nutraceutical Formulations

Abstract

Nutraceuticals and functional foods are commonly referred to as products derived from food sources, whose impact goes beyond nutrition and includes therapeutic and medicinal value. While most nutraceutical products are readily available over the counter without prescription, there are regulations in some countries which require that specific constituents are displayed on the label of the package for each product. Analysis of nutraceuticals and functional foods is performed for a number of reasons, including quality control, identification and quantification of the chemical constituents, determination of degradation and adulteration, evaluation for safety, authentication of brand, region of origin, seasonality, and natural material source.

The wide range of spectroscopic methods used in the analysis of nutraceuticals and functional foods presented in this chapter include Fourier transform infrared, ultraviolet-visible, light scattering, nuclear magnetic resonance, atomic absorption and emission, photoacoustic, photoluminescence, impedance, circular dichroism, X-ray diffraction and scattering, electron spin resonance, Raman, and mass spectrometry. Due to the complex composition of most nutraceuticals and functional foods, the spectroscopic data collected is commonly used for multivariate analysis using a wide range of algorithms in the chemometric approach. These algorithms enable the determination of specific features in the composition of nutraceuticals and functional foods. Linear regressions for example are widely used to establish the multiplicity of component contributions to observed spectroscopic signals where there is likelihood of interference from multiple constituents. Although the use of multivariate algorithms as part of the chemometric approach has revolutionized the power of spectroscopic analytical tools, the mathematical description of these algorithms is beyond the scope of this chapter. Instead, the focus is on providing the description and examples of applications of each of these spectroscopic techniques in applied research on some nutraceuticals and functional foods. However, a general description of chemometrics has been provided with a few examples in research as applied to nutraceuticals and functional foods.

The chapter is divided into three sections: the background introduces the general applications of spectroscopic analysis of nutraceuticals and functional foods as the primary approach for data collection, the subsequent application of multivariate analytics, and the application of the outputs in imaging. The chapter goes into the description of each of the key spectroscopic methodologies and their applications in the analysis of nutraceuticals and functional foods. The last section describes some of the purposes and areas in which spectroscopic data collection on nutraceuticals and functional foods is most commonly applied. These include determination of nutritive and dietary impact, therapeutic and medicinal, toxicity including adulteration and pollution, skin health and cosmetics, elemental composition, proteomics, lipidomics, metabolomics, glycomics, native material prospecting, industrial quality control, formulation using nanostructured materials, bioavailability, and bioaccessibility. A descriptive reflection on each of the spectroscopic techniques and their use are summarized in Table 1 with the relevant references as cited in this chapter. Similarly, a descriptive reflection on each of the fields of nutraceuticals and functional foods in which the spectroscopic techniques discussed in this chapter are applied is summarized in Table 2 with references as cited.

Graphical Abstract

Spectroscopic analytical intervention in nutraceuticals and functional foods