Natural deep eutectic solvent-assisted pectin extraction from pomelo peel using sonoreactor: experimental optimization approach

• Main Authors: Elgharbawy, Amal A.M., Hayyan, Adeeb, Hayyan, Maan, Mirghani, Mohamed Elwathig Saeed, Mohd. Salleh, Hamzah, Rashid, Shahidah Nusailah, Ngoh, Gek Cheng, Liew, Shan Qin, Mohd Nor, Mohd Roslan, Zulkifli, Mohd Zamani, Alias, Yatimah
• Format: Article
• Language: English; English; English
• Published: MDPI 2019
• Subjects: TP Chemical technology; TP248.13 Biotechnology
• Online Access: http://irep.iium.edu.my/73049/9/73049%20Natural%20Deep%20Eutectic.pdf; http://irep.iium.edu.my/73049/15/73049_Natural%20deep%20eutectic%20solvent-assisted%20pectin_SCOPUS.pdf; http://irep.iium.edu.my/73049/21/73049_Natural%20Deep%20Eutectic%20Solvent-Assisted%20Pectin_wos.pdf; http://irep.iium.edu.my/73049/; https://www.mdpi.com/2227-9717/7/7/416/htm

Background: Natural deep eutectic solvents (NADESs) can be used for extracting a wide range of biomaterials, such as pectin. This study introduces a new generation of natural solvents for pectin extraction which could replace the conventional solvents in the food industry. Methods: In this study, NADESs were used for pectin extraction from pomelo (Citrus grandis (L.) Osbeck) peels using a sonoreactor. Definitive screening design (DSD) was used to screen the influence of time, temperature, solid/liquid ratio, and NADES/water ratio on the pectin yield and degree of esterification (DE). Results: The primary screening revealed that the best choices for the extraction were choline chloride–malonic acid (ChCl-Mal) and choline chloride–glucose–water (ChCl:Glc:W). Both co-solvents yielded 94% pectin and 52% DE after optimization at 80 ◦C, with 60 min of sonication, pH < 3.0, and a NADES-to-water ratio of 1:4.5 (v/v). Morphological screening showed a smooth and compact surface of the pectin from ChCl-Mal where glucose-based pectin had a rough surface and lower DE. Conclusions: NADESs proved to be promising co-solvents for pectin extraction with a high degree of esterification (>55%).