EXTRACTION AND QUANTIFICATION OF CAROTENOIDS FROM MACAUBA PULP AND PULP PRESS-CAKE BY ULTRASOUND USING GRAS SOLVENTS

Macauba (Acrocomia aculeata) pulp (MP) and its press-cake (PPC), co-product from oil extraction, contain carotenoids, which can be extracted by different solvents. However, nowadays there is a tendency to use GRAS solvents (Generally Recognized as Safe) and techniques to optimize extraction of different compounds for food applications. Thus, the objective of this work was to extract carotenoids from MP and PPC using GRAS solvents and ultrasound. Ethyl acetate, ethanol and isopropyl alcohol were used at different times and temperatures, in a shaking water bath, and in an ultrasonic bath set at a power of 400 W, varying the frequency at 25 and 45 kHz. The concentration of total carotenoids was determined by spectrophotometry (450 nm). The solvent with the best performance in extracting carotenoids from MP and PPC was ethyl acetate, followed by isopropyl alcohol and ethanol. When using ethyl acetate at 25°C for 5 minutes in the water bath, total carotenoid contents of 154.90 µg/g and 107.55 µg/g were obtained for MP and PPC, respectively. Using the same binomial and solvent in the ultrasonic bath at 25 kHz, higher values were obtained, 287.35 µg/g (MP) and 179.83 µg/g (PPC), whereas at frequency of 45 kHz, values of 236.44 µg/g (MP) and 189.85 µg/g (PPC) were observed. The highest carotenoid contents for isopropyl alcohol extracts were 204.12 µg/g (MP) at 60°C and 150.65 µg/g (PPC) at 50°C, both using ultrasound at 45 kHz for 30 min. For ethanol extracts, the highest values obtained were 201.40 µg/g (MP) at 45 kHz, 50°C/30 min, and 130.23 µg/g (PPC) at 25 kHz, 25°C/5 min. Therefore, it was possible to extract high concentrations of carotenoids from both MP and PPC using ultrasound and GRAS solvents, demonstrating macauba’s potential as a raw material for large-scale production of carotenoids.