Effect of spray drying on the bioactive content and antioxidant capacity of encapsulated sea buckthorn oil powders

Sea buckthorn (Hippophaë rhamnoides L.) oil (SBO) as the most valuable part of berries receives increasing attention worldwide due to health effects. It is rich source of bioactive compounds like tocopherols, carotenoids, flavonoids, essential and polyunsaturated fatty acids and essential amino acids. These compounds are relatively unstable and susceptible to degradation and it is important to improve their stability during handling, processing and storage. Spray drying method is the most commonly used microencapsulation method in the food industry for oil protection. Therefore, the objective of this study was to evaluate the influence of the spray drying conditions at different temperatures (120 to 180 °C) and wall to core ratio (2 to 4) on the total carotenoid (TC) and tocopherol (TT) content and antioxidant capacity (AC) of sea buckthorn oil microencapsulated using gum Arabic as wall material. The TC and TT was determined using HPLC methods and AC by the ORAC method, respectively. The carotenoid retention in powders compared to SBO was in range from 8.19 to 47.13 % and tocopherol retention from 34.75 to 45.33 %, respectively. The results showed that increase in a wall to core ratio favors carotenoid and tocopherol retention, while carotenoids were more susceptible on increase of drying temperature than tocopherols. Temperature and wall to core ratio significantly affected the AC. The highest retention of carotenoids (88.36 mg/100 g dm) and tocopherols (50.79 mg/100 g dm) showed sea buckthorn powder obtained at 120 °C and wall to core ratio of 2 while the highest ORAC value (305.8 μmol TE/L) was determined in powder obtained at same drying temperature but wall to core ratio of 4. The sea buckthorn oil powders obtained by spray drying showed carotenoid and tocopherol stability with antioxidant properties and potential to be used for the development of functional products.