Obtaining and characterization of natural extracts from mango (Mangifera Indica) peel and its effect on the rheological behavior in new mango kernel starch hydrogels
David Ramírez-Brewer, Somaris E. Quintana, Luis A. García‐Zapateiro
Abstract
Hydrogels based on natural polymers have aroused interest from the scientific community. The aim of this investigation was to obtain natural extracts from mango peels and to evaluate their addition (1, 3, and 5%) on the rheological behavior of mango starch hydrogels. The total phenolic content, antioxidant activities, and phenolic acid profile of the natural extracts were evaluated. The viscoelastic and thixotropic behavior of hydrogels with the addition of natural extracts was evaluated. The total phenol content and antioxidant activity of the extracts increased significantly ( p < 0.05 ) with the variation of the ethanol-water ratio; the phenolic acid profile showed the contain of p -coumaric, ellagic, ferulic, chlorogenic acids, epicatechein, catechin, querecetin, and mangiferin. The viscoelastic behavior of the hydrogels showed that the storage modulus G ′ is larger than the loss modulus G ′ ′ indicating a viscoelastic solid behavior. The addition of extract improved the thermal stability of the hydrogels. 1% of the extracts increase viscoelastic and thixotropic properties, while concentrations of 3 to 5% decreased. The recovery percentage (%Re) decreases at concentrations from 0% to 1% of natural extracts, however, at concentrations from 3% to 5% increased. • Natural extracts of mango peel are a good source of phenolic compounds with antioxidant activity. • An increase in ethanol concentration significantly increases the TPC and TEAC of natural mango peel extracts. • The addition of natural extracts influences the viscoelastic and thixotropic behavior of the mango kernel starch hydrogels. • Mango kernel starch hydrogels with the addition of natural extracts from mango peel presented a viscoelastic solid behavior.