Sequential extraction of mucilage and pectin from banana peels using natural deep eutectic solvents

Banana peels, a common agricultural waste, have significant valorization potential, but the sequential extraction of mucilage and pectin is not yet explored. This study explores the integrated use of microwave-based dry-blanching for mucilage extraction. Further, ultrasound coupled with microwave-assisted natural deep eutectic solvents (NADES) was used for the sequential extraction of pectin from banana peels. The mucilage exhibited an excellent swelling capacity (50 ± 0.62%). The zeta potential of mucilage (−43.5 mV) indicates it is suitable for stable colloidal formulations. The NADES, composed of choline chloride and tartaric acid as hydrogen bond donors and acceptors, respectively, produced a high pectin yield. The Box–Behnken design was employed to optimize processing parameters such as sonication duration (30 min), microwave intensity (28 W/g), and microwave duration (1.25 min). The combined effect of ultrasound and microwave-assisted NADES under optimized conditions significantly enhanced the pectin yield (31.2 ± 0.01%) compared to the acid-extracted pectin (11.2 ± 0.15%). The moisture content and ash content of NADES-based extracted pectin were within the range recommended by the International Pectin Producers Association. The FTIR of NADES-based pectin is functional as it has a similar fingerprint region for carbohydrates (800–1,300 cm −1 ). The acid-extracted pectin had a higher degree of esterification (85.52 ± 0.54%). The NADES-based pectin had a lower degree of esterification (9.52 ± 0.07%) with a greater anhydrouronic acid content (66.52 ± 0.18%), and a smaller particle size (184.9 nm) with improved solubility. This highlights the advantages of NADES-based pectin for use in dairy-based and low-sugar food applications.