ULTRASOUND-ASSISTED EXTRACTION OF CAROTENOIDS FROM MACAUBA PULP AND PULP PRESS-CAKE USING ETHYL ACETATE

Introduction: The macauba (Acrocomia aculeata) is a palm native to Brazil. The pulp (MP) of the fruit is notable for its high content of oil, dietary fiber, and carotenoids. After oil extraction, the pulp press-cake (PPC) is obtained, which can be used in animal feed due to its nutritional value and absence of anti-nutritional factors. Both the MP and PPC contain carotenoids, which are bioactive compounds that can be extracted. Conventional extraction methods use toxic solvents such as hexane, acetone, and petroleum ether, which are harmful to the environment and human health. This study aimed to optimize the extraction of carotenoids, promoting sustainability by using ethyl acetate, a Generally Recognized as Safe (GRAS) solvent, combined with the use of ultrasound. Methods: The extraction of total carotenoids from the MP and PPC was carried out with ethyl acetate and an ultrasonic bath, varying parameters of temperature (25°C, 42.5°C, and 60°C), time (5, 17.5, and 30 minutes), and frequency (25 and 45 kHz), maintaining a power of 400 W. Total carotenoid content was determined using a spectrophotometer (450 nm). Results: The optimization models generated equations and response surfaces. For the MP, the total carotenoid content ranged from 200.69 to 247.22 µg/g, while for the PPC, the values ranged from 92.48 to 123.84 µg/g. Temperature was significant (p < 0.05) for carotenoid extraction. The temperature/frequency interaction was significant only for the PPC, resulting in higher extraction levels with increased temperatures and frequencies. In the MP, there was a difference in extraction content when employing different frequencies; however, the variation was marginally significant. Temperature was a significant variable in the model. Conclusion: Macauba is a promising source of carotenoids for the industry. The use of GRAS solvents and non-conventional technology, such as ultrasound, can enable the sustainable extraction of these compounds, which have potential uses as antioxidants and natural colorants in food.