A hydrocolloid based biorefinery approach to the valorisation of mango peel waste

An environment-friendly hydrothermal process was developed to extract pectin from a horticultural waste, namely mango peels, at a reasonable temperature and pressure. High average yields of pectin (15.7%, 27.2%) were obtained from the two mango cultivars namely, Calypso (Australian) and Totapuri (Indian). The physico-chemical characteristics were determined in terms of the degree of esterification (77-89%), molecular weights (Mw) (49,742-49,862 Da), FTIR and gelling tests. The spent liquor was hydrolysed to recover the specific polyphenols and sugars. The polyphenols in the hydrolysed liquid were quantified as gallic acid (525.1-1405.6 mg/l), mangiferin (7.8-162.2 mg/l), quercetin (40.6-49.2 mg/l) and ellagic acid (38.8-69.3 mg/l). The solid residue obtained as a solid co-product after pectin extraction was found to be rich in cellulose (38%) and lignin (16%). In this paper, an attempt has been made to address the challenges of the extraction of pectin from mango peels, in a conventional process. It was demonstrated that mango peels may be a promising unconventional source for recovery of food-grade quality pectin. Considerable efforts, which were earlier expended in the processing, were reduced when recovery of other food-grade co-products was integrated with the process of hydrocolloid extraction. (C) 2017 Elsevier Ltd. All rights reserved.