Analytical methods used for the characterisation of specific features of biological tissues related with obesity: A review

Obesity has become a global pandemic, leading to the development of many common disorders, such as type 2 diabetes, metabolic syndrome and cardiovascular diseases, and even increases the risk of several cancers. The adipose tissue of obese patients was characterised as a tissue microenvironment composed of adipose tissue macrophages, precursor and hypertrophic adipocytes, and other immune cells that predominantly produce pro-inflammatory cytokines for chronic, low-grade inflammation. In this study, several analytical techniques, such as gas and liquid chromatography, Fourier transform infrared (FTIR) and Raman spectroscopies, nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM) and elemental analysis, were discussed as the main tools used for the characterisation of adipose tissue samples. The emphasis was focused on the relation between the obtained results which provide information about the chemical and structural composition of adipose tissue layers in the human body, as well as main microstructural features and obesity. It was demonstrated that these methods are indispensable tools in order to investigate some special features of human adipose tissue, identifying chemical composition and structural features. Moreover, the summarised results let us to conclude that such characterisation of adipose tissue is an essential step for the possible prediction of the appearance of symptoms of different diseases.