Chia seed oil microencapsulated by spray-drying: optimization and microcapsules characteristics

A current trend in food research is the development of beneficial health products that could help to decrease certain risks of diseases. The chia seed (Salvia hispanica L.) oil is a proven source of essential fatty acids (omega-3), which can help to prevent cardiovascular diseases. In this study, chia seed oil was characterized and fatty acids were identified before and after the spray-drying process. A 32 factorial design with response surface methodology was utilized for chia seed oil spray drying experiments. Statistic design factors and levels were as follows: gum arabic: maltodextrin mixture (GA:MD) (1:1, 1:2 and 1:3 w/w) and drying temperatures (DT) (140, 160, and 180°C). A total of 67.9% of unsaturated fatty acids were found in raw chia seed oil and 65.7% in microencapsulated oil. The optimal parameters for the spray drying process were as follows: GA:MD 51:1 and DT, 180°C; powder yield rate, 49.5% (w/w), mean size of particles 129 µm, and sphericity coefficient of 0.11. Microcapsules tended to demean over time, changing their color, and producing agglomerate, which decreased their flowing capacity. On the other hand, the product was easier to handle, the oil was protected from heat and moisture conditions, and the microencapsulation process provided stability to the oil's active substances, such as omega-type fatty acids.