CHARACTERIZATION AND STABILITY OF SPRAY DRIED TUCUMÃ OIL (Astrocaryum vulgare Mart)

Carotenoids are lipophilic pigments with provitamin A and antioxidant activities, which are present in high amounts in the oil extracted from the pulp of tucumã fruit (Astrocaryum vulgare Mart). Unsaturated fatty acids and carotenoids that constitute this oil are susceptible to oxidation, resulting in losses of their properties and biological activities. This could be avoided by encapsulating the oil through techniques such as spray drying. Hence, the aim of this work was to produce, characterize and evaluate the stability during storage of tucumã oil microparticles obtained by spray drying. Emulsions composed of tucumã oil and arabic gum in two different proportions (20%:80% and 30%:70%), in terms of total solids content (30%), were spray dried at 120°C (inlet air temperature). Oxidative stability of the oil and microparticles was evaluated by Rancimat at 120°C, while stability of carotenoids during storage was determined after 25 days of storage at 25°C and 32.8% relative humidity. Moisture content, water activity, particle mean diameter, process yield, encapsulation efficiency and carotenoids retention (after the drying process) of the treatments 20% and 30% were, respectively: 5.1 and 3.8%; 0.25 and 0.20; 19.0 and 10.5 μm; 87.3 and 87.3%; 74.2 and 44.4%; 101.0 and 102.7%. Color parameters L*, a* and b* were, respectively, 80.0, 3.6 and 37.9 (20% treatment), and 77.8, 5.3 and 46.8 (30% treatment), showing that the increase in oil concentration resulted in a powder with intensified yellow color. Oxidative stability of tucumã oil was greatly improved by encapsulation, since Rancimat induction times increased from 0.3 h (pure oil) to 4.5 h (20% treatment) and 4.7 h (30% treatment). Carotenoids retention after 25 days storage were 97.7% (pure oil), 97.0% (20% treatment) and 97.1% (30% treatment). One may conclude that tucumã oil microparticles have potential to be incorporated into processed foods as a functional ingredient.