Exploring green extraction methods to obtain polyphenols from partially defatted chia (Salvia hispanica L.) flour

Abstract

Aim: The extraction of polyphenols is commonly accomplished using conventional techniques such as solid-liquid and liquid-liquid extraction, which are associated with the use of high quantities of organic solvents, long extraction times, and low selectivity and reproducibility. These limitations have led to the development of innovative extraction technologies. The purpose of this study was to investigate the ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) of polyphenols from partially defatted chia flour (PDCF). Methods: The effect of four factors on the extraction of polyphenols (percentage in relation to the initial weight of PDCF) and on the antioxidant activity [quantified by 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) methods] was investigated and the UAE and MAE processes were optimized using the response surface methodology (RSM). Results: It was found that MAE improved the extraction yield (polyphenol content and antioxidant activity) in shorter extraction times when compared to UAE. Conclusions: The application of these alternative green technologies improved the performance of the polyphenol extraction process from PDCF. Overall, both techniques could be used as efficient green alternatives.

Keywords

• chia flour
• ultrasound-assisted extraction
• microwave-assisted extraction
• phenolic compounds
• antioxidant capacity
• response surface methodology