Cristian Hernández-Hernández 1, Cristóbal Noé Aguilar 1 , Adriana Carolina Flores-Gallegos 1 , Leonardo Sepúlveda 1 , Raúl Rodríguez-Herrera 1 , Jesús Morlett-Chávez 2, Mayela Govea-Salas 3 and Juan Ascacio-Valdés 1,*
1 Bioprocesses and Bioproducts Research Group, Food Research Department, School of Chemistry, Autonomous University of Coahuila, Saltillo 25280, Mexico;
2 Laboratory of Molecular Biology, School of Chemistry, Autonomous University of Coahuila, Saltillo 25280, Mexico;
3 Laboratory of Nanobiosciences, School of Chemistry, Autonomous University of Coahuila, Saltillo 25280, Mexico;
The rambutan peel (RP) is a relevant source of bioactive molecules, which could be used for application in cosmetics, food, and pharmaceutical areas. Total soluble polyphenol content was extracted from Mexican variety rambutan peels using an emergent ultrasound/microwave-assisted extraction (U/M-AE) technology. Five extractions were performed using dierent mass/volume and ethanol/water ratios; 1:16-0; 1:16-70; 1:8-0; 1:8-70; 1:12-30. Condition 1:16-0 was defined as the best extraction condition with 0% ethanol percentage (only water). The content of total soluble polyphenols was 307.57 mg/g. The total bound polyphenol content was 26.53 mg/g. Besides, two separation processes were made with the soluble fraction; the first one was performed using Amberlite XAD-16 (Sigma-Aldrich, Saint Louis, MO, USA), and seven polyphenolic compounds were obtained. The second one was performed using a preparative HPLC (Varian, Palo Alto, CA, USA) equipment obtained fraction where three compounds were obtained: geraniin (main compound), ellagic acid, and ellagic acid pentoside. The major compound isolated in the two separations was geraniin, according to HPLC/ESI/MS (High Performance Liquid Chromatography/ElectroSpray Ionization/Mass) analysis.