Chapter 7 - Advances in the green extraction methods and pharmaceutical applications of bioactive pectins from unconventional sources: a review

Abstract

This review aims to discuss the current advances in green methods for the isolation and characterization of pectic polysaccharides with a focus on unconventional extraction sources and their bioactive applications in the pharmaceutical industry as new biopolymers or drug delivery systems. The physicochemical, structural, and functional properties of crude pectins, fractions (pectin oligosaccharides), and their domains (homogalacturonan, rhamnogalacturonan-I, rhamnogalacturonan-II, and xylogalacturonan) isolated from underutilized raw and agro-waste materials are compared using novel analytical techniques, such as Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), 1H-13C heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, high-performance size exclusion chromatography (HPSEC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and rheology. The advantages and drawbacks of green and innovative methods are analyzed to indicate the best ecofriendly techniques for extracting bioactive pectins from unconventional sources and their structural effects. Chemical modifications and potential pharmaceutical applications of bioactive pectins are considered to assess the effects of their biological activity in cancer and cardiovascular diseases. Finally, trends and future opportunities related to bioactive pectins and their fragments isolated from unconventional pectin sources are critically analyzed to provide guidelines for research in innovative technological developments and their possible applications in emerging public health problems such as the COVID-19 pandemic.