Extraction of mangiferin and pectin from mango peels using process intensified tactic: A step towards waste valorization

Simultaneous extraction of mangiferin and pectin from the waste mango peels was at-tempted with the aim of reducing the number of processing steps, minimizing the op-eration time and avoiding the requirement of harsh acids. Microwave-assisted extraction has been employed along with different hydrotropes (sodium cumene sulfonate, sodium salicylate, and sodium p-toluene sulfonate) and methanol with varying concentrations. The highest yield of mangiferin (10.43 mg/g) was attained using sodium cumene sulfonate at 80 W microwave power, 10 min time, 0.5 M concentration, 80 degrees C temperature and 1:50 g/ mL solid-liquid ratio. The mangiferin recovery was 20 % higher using hydrotropic solution in comparison to methanol (50 %, v/v). The hydrotropes have concurrently extracted pectin (25.38 %, w/w), which was not possible using methanol. Thus, the incorporation of hydrotropes has led to the avoidance of acidic solution for the recovery of pectin. Pectin has a higher methoxy content (similar to 74 % degree of esterification) and a higher percentage of D-galacturonic acid. The extraction time was further reduced in the range of 50-70 % by embedding sonication with microwave-assisted extraction. Moreover, the extract has exhibited good antioxidant activities (> 70 % DPPH and > 90 % ABTS). A symbiotic effect of hydrotrope, microwave and sonication has resulted in the simultaneous extraction of mangiferin and pectin along-with better processing conditions thereby providing a sus-tainable option which can be explored at a higher scale. In addition, the present study has presented a judicious utilization of mango waste.(c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.