Pectin extracted from dragon fruit Peel: An exploration as a natural emulsifier

As a potential source of pectin, the peel of dragon fruit is a by-product of fruit processing and will bring considerable economic benefits. In this study, pectin (DFP) was extracted from dragon fruit peel by using a hot-acid method, and two commercial pectins were used as controls to correlate structural differences with physical and chemical properties through systematic evaluation. The galacturonic acid (GalA) content, degree of esterification (DM) and molecular weight (Mw) of DFP were 87.02 ± 0.89 %, 37.26 ± 1.37 % and 1181.75 ± 11.21 kDa, respectively. The FTIR and XRD analysis also confirmed that DFP is ultra-low methoxylated pectin and also contains characteristic functional groups naturally present in pectin. Compared to APA140 and LMP, DFP showed excellent emulsification at low concentrations. In particular, the extraordinary antioxidant activity of DFP may be attributed to polyphenols in free or bound form. Overall, DFP can be considered as a promising emulsifier and the results of the study provide an alternative to natural sources of emulsifiers in the food industry.