Evaluación de dos métodos de extracción de compuestos fenólicos en hibiscus sabdariffa l., para la formulación de una bebida antioxidante.

Abstract

Jamaica's calyxes are widely used in the traditional elaboration of soft drinks, becoming a rich source of bioactive compounds with potential favorable effects on health. Currently, in the food industry there is great interest in the extracts obtained from its calyxes, due to the compounds and properties they possess. By virtue of this, the extraction assisted by ultrasound, arises as a fast technique with certain advantages for the recovery of bioactive compounds. In this context, the objective of the present research is to evaluate two methods of extraction of phenolic compounds in Hibiscus sabdariffa L., for the formulation of an antioxidant drink. Two extraction methods were tested from the dried and ground calyxes, using two levels of temperature and time, ultrasound assisted extraction (UAE) (30°C for 30 and 60 minutes) and heat extraction (HE) (100°C for 15 and 30 minutes), considering 4 treatments. In the obtained extracts, it was quantified; total phenolic content by Folin Ciocalteu method, total monomeric anthocyanins by differential pH and trolox equivalent antioxidant capacity (TEAC), using DPPH and FRAP assays; besides, it was analyzed the kinetics of free radicals capture by DPPH. It was chosen the UAE to obtain the drink and there were proposed 4 formulations, considering as study variables the concentration of dry calyxes by volume of water (1.5 and 2 g/100 mL) and the percentage of stevia inclusion (0.4 and 0.5%). Afterwards, it was carried out a sensory evaluation with 29 semi-trained judges to assess the sensory acceptance of the formulated drinks.