RESUMEN
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.
Asunto(s)
Antioxidantes , Hidrogeles , Mangifera , Extractos Vegetales , Reología , Almidón , Mangifera/química , Hidrogeles/química , Extractos Vegetales/química , Almidón/química , Antioxidantes/química , Viscosidad , Frutas/química , Fenoles/químicaRESUMEN
Mango (Mangifera indica) is a fruit highly consumed for its flavor and nutrient content. The mango peel is rich in compounds with biological functionality, such as antioxidant activity among others. The influence of microwave-assisted extraction variables on total phenol compounds (TPC) and antioxidant activity (TEAC) of natural extracts obtained from mango peel var. Tommy and Sugar were studied using a response surface methodology (RSM) and Artificial Neural Networks (ANN). TPC of mango peel extract var. Tommy was significantly influenced by time extraction (X1), solvent/plant ratio (X2) and concentration of ethanol (X3) and while mango peel extract var. Sugar was influenced by X2. TEAC by ABTS was significantly influenced by X3. Maximum of TPC (121.3 mg GAE / g of extract) and TEAC (1185.9 µmol Trolox/g extract) for mango peel extract var. Tommy were obtained at X1=23.9s, X2=12.6mL/gand X3=63.2%, and for mango peel extract var. Sugar, the maximum content of TPC (224.86 mg GAE/g extract) and TEAC (2117.7 µmol Trolox/g extract) were obtained at X1=40s, X2=10mL/g and X3=74.9%. The ANN model presented a higher predictive capacity than the RSM (RANN2>RRSM2,RMSEANN