Ultrasound assisted extraction of polyphenols from Punica granatum (Grenada) fruit

Introduction: extraction of bioactive compounds from vegetable materials is a classical operation applied in many industrial processes. Few studies have made reference to processes to obtain extracts from Punica granatum. This fruit is generally consumed as such or as fermented juices. In Cuba, it is known as grenade and numerous studies have shown antiviral, antioxidant and antimicrobial properties. Maceration process is the main used technology in the preparation of extracts from Punica granatum fruit, being this a long and expensive process. Ultrasound-assisted extractions have been proven to significantly decreased extraction time and increased extraction yields in many vegetable materials. However, few papers report the use of this methodology in the extraction processes of Punica granatum. Objective: to evaluate an ultrasound-assisted extraction process to extract polyphenols from Punica granatum fruit. Methods: an experimental surface, response 3², randomized and replicate design was made to identify the effect of the extraction time and the alcoholic concentration of the menstruum as well as an extraction study in the course of time, keeping the best extraction conditions set in the design. Results: the studied parameters did not show significant influence over the process (p= 0.0981 and p= 0.8504 for time of extraction and alcoholic content, respectively). The behaviour curve of the polyphenol extraction in time showed that top concentration values were reached at 60 minutes. Conclusions: according to results, the optimal conditions of polyphenol extraction were as follows: extraction time of 60 min, and 50 % alcoholic concentration (v/v) as menstruum.