Sustainable extraction of carotenoids and polyphenols from carrots (Daucus carota L.) using pH-responsive Switchable Deep Eutectic Solvents

Abstract

This study investigated the extraction of carotenoids and polyphenols from Daucus carota. L using pH-responsive phase-Switchable Deep Eutectic Solvents (SDESs). After screening several SDESs, DL-menthol: Octanoic acid (1:1 molar ratio, SDES A) and Octanioc acid: Decanoic acid (1:1 molar ratio, SDES B), were selected for extraction studies. Optimization using Response Surface Methodology paired with Box-Behnken design was performed on the extraction yield (Total Carotenoids Content (TCC) and Total Polyphenol Content (TPC)). After the optimization, 1.33 ± 0.05 mg/g of TCC and 1.50 ± 0.07 mg/g were obtained using the hydrophobic SDES A and SDES B, respectively. TPC obtained using the hydrophilic phase of SDES B under optimal conditions (0.39 ± 0.01 mg/g) was significantly higher than with SDES A (0.31 ± 0.01 mg/g). Both hydrophobic and hydrophilic bioactives were more stable in SDES B, compared to SDES A. Similar antioxidant activity was detected in polyphenol extracts obtained with both SDESs.