Microencapsulation of fish oil by spray-drying using two different wall materials: a comparison

Oils and fats have a wide range of health benefits, especially those that have a high concentration of polyunsaturated fatty acids, like fish oils. Unfortunately, oils are highly susceptible to heat, light, and oxygen degradation, causing them to lose the qualities that would make them interesting for the public. With this in mind, this study compared two methods of spray-drying, a technique that helps preserve the stability of oils in storage for longer periods of time. Emulsions made with skimmed milk powder and with maltodextrin and whey protein hydrolysate were spray-dried, resulting in 2 different microencapsulated fish oils. They were compared regarding encapsulation efficiency, water activity, moisture content, and peroxide index. The skimmed milk showed better results, with a 28.17% lower peroxide index than the non-encapsulated oil and lower water activity and moisture content compared to the emulsion using maltodextrin (2.690±0.19% vs 6.747±0.29% moisture content and 0.376±0.013 vs 0.554±0.006 water activity). Since skimmed milk powder is rather cheap, it is ideal for spray-drying, a simple and fast technique. In this way, fish oil can be safely microencapsulated in powder form, lasting longer than the oil capsules currently available, since the oil is protected from light, temperature, moisture, and oxidation. In addition, the oily odor is masked, making it more appealing to the consumer, and it may be combined with other powders, like vitamins and minerals, which opens up new possibilities for the production of supplements.