A Green Extraction Process to Recover Polyphenols from Byproducts of Hemp Oil Processing

Abstract

The valorization of solid waste hemp (Cannabis sativa L.) by a non-conventional method is presented in this article. Hemp polyphenols were extracted using aqueous solutions of 2-hydroxypropyl-β-cyclodextrin as an eco-friendly extraction solvent. Cyclodextrins (CD’s) are known to enhance the extraction of polyphenols in water by forming water soluble inclusion complexes. The process was optimized by implementing a response surface methodology (RSM) that took into consideration the following independent variables: CD concentration (CCD), solid-to-liquid ratio (S/L), and temperature (T). The assessment of the extraction model was based on two responses: the total polyphenol yield (YTP) and the antiradical activity (AAR). The optimum operating conditions were found to be: CD concentration, 32.1% (w/v); solid/solvent ratio, 1/15.2 g/mL; and extraction temperature, 28 °C. Different kinetic models were employed to fit with experimental data and the Peleg’s model was successfully developed for describing the mechanism of extraction under different processing parameters.

Keywords

• antioxidants
• hydroxypropyl-β-cyclodextrin
• glycerol
• Cannabis sativa
• kinetic models