Krill oil microencapsulation: Antioxidant activity, astaxanthin retention, encapsulation efficiency, fatty acids profile, in vitro bioaccessibility and storage stability

Krill oil (KO) emulsions with a ratio of KO/arabic gum of 1:4 (w/w) were prepared and then spray dried. The effect of drying temperatures on antioxidant activity, astaxanthin retention, and microencapsulation efficiency was evaluated and microcapsules with better results were employed for further analysis. The encapsulation of KO in arabic gum was confirmed by using Fourier transform infrared spectroscopy. KO microcapsules showed eicosapentaenoic and docosahexaenoic content of 21% of the total fatty acids, low ω-6/ω-3 and SF/unsaturated FA ratios, and a bioaccessibility of 53.8% after 2 h of in vitro digestion. The effect of aw on color change and degradation of astaxanthin contained in KO microcapsules was evaluated during storage at 35 °C. Monolayer value was 3.7241 g H2O/100 g d.s. which corresponds to 0.4 of aw. The astaxanthin degradation rate increased considerably when the KO microcapsules were stored at an aw of 0.743, under these conditions the microcapsules showed drastic changes in the color parameters. •Microencapsulation by spray drying show be a suitable technique to overcome the instability of Krill oil.•Microcapsules of Krill oil had low ratios of ω-6/ω-3 PUFA and SFA/USFA.•Eicosapentaenoic and docosahexaenoic acids represent 21% of the total fatty acids contained in Krill oil microcapsules.•In-vitro bioaccessibility of Krill oil microcapsules in simulated gastrointestinal tract was 53.8%.•Degradation rate of Krill oil microcapsules stored at 35 °C is influenced by relative humidity.