INFLUENCE OF BLEACHING TEMPERATURE ON MACAUBA OIL (Acrocomia aculeata): QUALITY PARAMETERS AND BIOACTIVE COMPOUNDS

Macauba (Acrocomia aculeata) is an American palm from the tropical zones that presents oil productivity and quality similar to that of oil palm. Macauba oil pulp presents different minor compounds in its composition, such as tocopherols, tocotrienols, and β-carotene. The oil pulp is light yellow to dark orange due to the presence of carotenoids, and the great majority (> 80%) is represented by β-carotene, which is a precursor of vitamin A. As macauba oil is derived from the oil pulp it has low phosphorus content (<50 mg/kg) and high acidity (4 – 20 %) expressed as oleic acid. Refining conditions are very important to obtain high quality macauba oil. Therefore, this study aimed to evaluate the effect of bleaching temperature on the quality parameters (free fatty acid-FFA and phosphorus content) and bioactive compounds (carotenoids, tocopherols, and tocotrienols). The oils were bleached at 90, 105, 110 oC using 1% (w/w) of activated bleaching earth. The crude macauba oil presented a FFA content of 4.5%, phosphorus content of 32 mg/kg, and a carotenoids content of 60 mg/kg. The processing results revealed that the FFA presented an increase of 10%, what can be due to the inherent acidity of the activated bleaching earth or due to a catalytic affect forming FFA. The phosphorus removal was increased with the increase of the temperature reaching values of 77, 73, and 81%, respectively for 90, 105, 110 oC. The carotenoids and tocols were better preserved by the use of the mildest temperature (90 oC) with a retention of 68% for the carotenoids total, 87% for alfa-tocopherol, 73% for alfa-tocotrienol, and 93% for β/γ-tocotrienol. Thus, the bleaching processing parameters are of great importance for the content of bioactive compounds and quality of macauba refined oil.