Encapsulation of Spirulina protein hydrolysates in liposomes: Impact on antioxidant activity and gastrointestinal behavior

A Spirulina hydrolysate was encapsulated within anionic liposomes composed of soybean lecithin and γ-oryzanol at an encapsulation efficiency of 90 %. A combination of 10 mg/mL hydrolysate and 1.3 mg/mL γ-oryzanol exhibited a significant synergism in inhibition of the formation of thiobarbituric acid-reactive substances (TBARS) and provided good protection of the liposomes against oxidation. The particle size of the liposomes increased significantly in the presence of the hydrolysate. Chitosomes were formed by coating the anionic liposomes with cationic chitosan. The antioxidant activity of the hydrolysate-loaded liposomes and chitosomes and free hydrolysate decreased under the highly acidic conditions in the stomach with the reduction in activity being greatest for the free hydrolysate. However, after exposure to small intestine conditions, the antioxidant activity of all formulations increased significantly (p < 0.05). This study highlights the potential of non-coated and coated liposomes to increase the stability and bioactivity of bioactive protein hydrolysates.