Study of alcoholic and aqueous extraction of pequi (Caryocar brasiliense Camb.) natural antioxidants and extracts concentration by nanofiltration

Pequi (Caryocar brasilense Camb.) is a typical Brazilian fruit, rich in polyphenols and carotenoids. The present work studied aqueous and alcoholic pequi extraction, in bench scale, evaluating time and temperature variation influence on polyphenols and carotenoids recovery. For the extraction best conditions (25 °C within 1 h for aqueous extract and 40 °C within 24 h for alcoholic extract), a residue reextraction was carried out, which has increased compounds recovery from fruit material. The final extract (a mixture of the first and second extract) was submitted to a concentration step by nanofiltration (in a stirred cell with a temperature of 25 °C and a pressure of 800 kPa). For alcoholic extract, the rejection towards bioactive compounds was small (around 10% for carotenoids and 15% for polyphenols). For aqueous extract, nanofiltration showed a high efficiency to concentrate the polyphenols and carotenoids (with retention coefficient around 100% and 97%, respectively).