Morphology and Stability of Edible Lycopene-Containing Micro- and Nanocapsules Produced Through Electrospraying and Spray Drying

In this work, lycopene was encapsulated through electrospraying and spray drying (using a microporous membrane cap) within different edible biopolymeric matrices. Specifically, dextran, a whey protein concentrate (WPC) and chitosan were used as matrix materials. As a strategy to incorporate the hydrophobic bioactive within the hydrophilic matrices, emulsion electrospraying and spray drying from emulsion were carried out. Moreover and for comparison purposes, coaxial electrospraying was also performed. The electrospraying solutions properties were studied, since they do not only affect the success of the electrohydrodynamic process but also influence the morphology of the capsules. Apart from characterizing the morphology and molecular organization of the developed capsules, the encapsulation efficiency and the lycopene stability under moisture and heating conditions were also evaluated. Results showed that even though encapsulation structures were obtained from all the matrices assayed through both processing technologies, spray drying, as a consequence of the high temperatures needed in this process, affected lycopene stability and very poor encapsulation efficiencies were found in this case. It was also seen that WPC presented the greatest encapsulation efficiency (around 75 %), probably ascribed to the interactions between the biopolymer and the lycopene. Furthermore, WPC capsules were able to better protect lycopene against moisture and thermal degradation.