Valorizing fruit by-products into functional pectin: A study on Burmese grape (Baccaurea ramiflora), hog plum (Spondias mangifera) and wild fig (Ficus racemosa)

Pectin is a complex plant polysaccharide widely used in food, pharmaceutical and cosmetic industries for its gelling, stabilizing and emulsifying properties. Meanwhile, agro-industrial fruit waste, particularly peels, represents a rich yet underexploited source of pectin. Hence, this study investigated the yield and quality attributes of pectin extracted from the peels of Burmese grape (BG), hog plum (HP) and wild fig (WF) harvested at green, mature and ripe stages. The pectin yield and quality varied significantly among fruit types and maturity stages where mature-stage peel produced functionally superior pectin in greater amounts over others, while HP outperformed BG and WF for quality pectin isolation. Significantly the highest yield (15.97%) was obtained from mature HP followed by BG (15.03%), while the lowest amount was extracted from WF (11.10%). Moreover, mature HP pectin possessed the highest equivalent weight (1316.30) with greater galacturonic acid (3.02%) and less impurities like ash (2.45%) and glucose (2.73%), whereas mature BG exhibited the highest methoxyl (11.87%) and anhydrouronic acid (90.83%) contents. Degree of esterification peaked in green HP (92.81%) and declined significantly as maturity progressed, particularly in ripe-stage BG (51.35%) and WF (52.01%). Further, correlation exhibited strong positive interrelationships among the yield and functional qualities against the impurity traits, while heatmap and PCA showed mature-stage HP and BG clustering in the favourable quadrant with key quality attributes. Thus, mature hog plum emerged as the most promising source of high-quality pectin, with Burmese grape as a viable alternative, supporting the valorization of indigenous fruit waste into value-added food products.