Physicochemical characterization of microcapsules containing cold pressed black cumin seed oils (Nigella sativa L.) as an alternative nutrient source in a functional diet

Black cumin seed oil has high nutritional value. However, due to its peppery taste, strong odor, and rapid oxidative deterioration, its application in food formulations has been limited. Encapsulation techniques with hydrocolloids combined with other nutritive wall materials may overcome these problems and provide more health benefits for consumers. For these reasons, cold-pressed black cumin seed oil was microencapsulated by spray drying in four different microcapsule models, including gum arabic alone (GA) and in combination at a 50:50 ratio with maltodextrin (GM), inulin (GI), or whey protein (GW). The microencapsulation efficiency of GA presented the highest yield of up to 88%. Replacing 50% of the gum arabic with whey protein (GW) reduced the microencapsulation efficiency from 88 to 75% while GI and GM were 86.12 and 83.51, respectively. The wettability and solubility of the microencapsulated powders prepared (GI, GM, and GW) were superior to those of the microcapsules prepared by gum arabic alone. Under SEM, the GA and GM powders collapsed at the surface, while the GI and GW powders were spherical and smooth. The highest thymoquinone content was found in the GI powder. There were no differences (P˃0.05) in the thymoquinone content observed among all powders.