Co-encapsulation of catechin and L-lysine in water-in-oil-in-water (W1/O/W2) double emulsion using membrane emulsification process: application in carrot based infant-purée

Abstract

This present study is aimed to encapsulate L-lysine and catechin in a double emulsion using a membrane process. Therefore, the obtained data revealed that the encapsulation efficiency, mean average droplet, globule sizes, and polydispersity index ranged from 67.3 to 93.12%, 260 to 149.40 nm, 10.20 to 12.80 µm, and 0.13 to 0.164, respectively. Moreover, the pasteurization exhibits an insignificant decrease in encapsulation efficiency (EE), and a low increase in the mean diameter of globules, and polydispersity index (PDI) (p > 0.05). In addition, pea protein isolate and chitosan in the external water phase notably exhibits the lowest degradation rate constant (k). Also, the results demonstrated that an increase of the volume fraction of the globules (Φ_g), from 10 to 70 wt%, decreases the released L-lysine and catechin contents. Likewise, the effect of added catechin-lysine double emulsion, ranging from 0 to 10% (w/w), assisted with pasteurization on quality attributes of carrot purée samples was also investigated. Lys-Cat-double emulsion preserved the color of carrot purée samples and exhibited microbiological counts below the limit level during 90 days of refrigerated storage (4 °C). Furthermore, the rheological properties of the carrot purée samples showed that they are non-Newtonian liquids with pseudoplastic or shear-thinning behavior with a predominance of viscous modulus (G″) through the frequency range. Finally, these findings revealed a possible use of Lys-Cat-double emulsion, to promote the inhibition of microbial proliferation and enzymatic activities, improve the nutritional and functional properties, and preserve the quality attributes of carrot purée.