Mango (Mangifera indica) seeds and peel-derived hydrocolloids: Gelling ability and emulsion stabilization

Abstract

Mango is a tropical fruit that is consumed worldwide and is distinguished by its sweet and juicy flesh. Unfortunately, the peels and seeds of mango fruit are often discarded despite the fact that they contain compounds that can be valorized for certain applications. In this study, a physicochemical and hydrodynamic characterization of hydrocolloids extracted from the peel and seeds of mango fruit was performed and the impact on the microstructure and rheological behavior of derived gels, as well as the ability to form emulsions, were analyzed. The physicochemical parameters and proximate compositions of the different samples showed that the hydrocolloids extracted from the seeds are rich in proteins whereas those from the peel are rich in carbohydrates. The molecular weights calculated from the hydrodynamic characterization (M_v) are 101515 g/mol and 102,580 g/mol for hydrocolloids extracted from the peel and seeds, respectively. Dispersions of these hydrocolloids in water produced hydrogels upon heating, which exhibited a shear thinning response that can be described by the Williamson model. The ability of these hydrocolloids to form thermally-induced strong gels was monitored and analyzed by means of curing tests. Throughout thermal treatments, the storage modulus showed a significant increase, especially at concentrations greater than 2.5 wt%. Mango seeds and peel-derived hydrocolloids are also able to stabilize o/w emulsions. Derived emulsions showed D₅₀ mean diameters and zeta potential values (ζ) in the ranges from 10.04 to 82.52 μm and from -17.63 to -11.12 mV, respectively. On the basis of the observed rheological behavior of hydrogels and emulsion-forming ability, the hydrocolloids derived from mango seeds and peels possess suitable characteristics to be potentially implemented in diverse food matrices, offering functional and nutritional benefits to final consumer products.