Sugarcane straw extracts: production and purification by amberlite XAD-2

Sugarcane straw is a byproduct and possible source of phenolic compounds that can be used as a value-added ingredient. Hence, the intent of this study was to extract phenolic compounds from sugarcane straw and purify them to improve their potential biological capacity (e.g. antioxidant capacity). The amberlite microporous resin XAD-2 was used to evaluate the enrichment of polyphenols via adsorption and desorption mechanisms. The purified extract was analyzed by LC-ESI-QqTOF-HRMS resulting in the identification of 54 secondary metabolites, mainly belonging to three major classes namely hydroxybenzoic acids, hydroxycinnamic acids, and flavones. The main compounds were chlorogenic acid, neochlorogenic acid and 3-O-feruloylquinic acid. A small number of monosaccharides were detected in the extract such as glucose, cellobiose, and xylose + arabinose. The purified extract also exhibited a higher antioxidant capacity, measured by ABTS and DPPH methods, when compared with the non-purified one. The purification of the sugarcane straw extract allowed us to obtain an extract rich in phenolic compounds that display improved antioxidant capacity, showing promising potential for food and cosmetic applications.