Response surface analysis of extract yield and flavour intensity of Brazilian cherry (Eugenia uniflora L.) obtained by supercritical carbon dioxide extraction

This work evaluated the effect of pressure and temperature on yield and characteristic flavour intensity of Brazilian cherry (Eugenia uniflora L.) extracts obtained by supercritical CO2 using response surface analysis, which is a simple and efficient method for first inquiries. A complete central composite 22 factorial experimental design was applied using temperature (ranging from 40 to 60 °C) and pressure (from 150 to 250 bar) as independent variables. A second order model proved to be predictive (p ≤ 0.05) for the extract yield as affected by pressure and temperature, with better results being achieved at the central point (200 bar and 50 °C). For the flavour intensity, a first order model proved to be predictive (p ≤ 0.05) showing the influence of temperature. Greater characteristic flavour intensity in extracts was obtained for relatively high temperature (> 50 °C). Therefore, as far as Brazilian cherry is concerned, optimum conditions for achieving higher extract yield do not necessarily coincide to those for obtaining richer flavour intensity.Industrial relevanceSupercritical fluid extraction (SFE) is an emerging clean technology through which one may obtain extracts free from organic solvents. Extract yields from natural products for applications in food, pharmaceutical and cosmetic industries have been widely disseminated in the literature. Accordingly, two lines of research have industrial relevance, namely, (i) operational optimization studies for high SFE yields and (ii) investigation on important properties extracts are expected to present (so as to define their prospective industrial application). Specifically, this work studied the optimization of SFE process to obtain extracts from a tropical fruit showing high intensity of its characteristic flavour, aiming at promoting its application in natural aroma enrichment of processed foods.