Encapsulation of olive leaf extract (Olea europaea L.) in gelatin/tragacanth gum by complex coacervation for application in sheep meat hamburger

The aim of the study was to encapsulate the phenolic extract of the olive leaf by using gelatin and tragacanth gum as wall materials, followed by complex coacervation or lyophilization. The extract was applied in sheep meat hamburger, in order to reduce oxidative degradation. The gelatin and gelatin/tragacanth matrices showed higher values of encapsulation efficiency and antioxidant activity than the matrix with only tragacanth, independent of the encapsulation technique used. The encapsulation was confirmed through DSC and FTIR analyses, and the particles obtained presented an irregular shape. The application of the particles in hamburger demonstrated that the particles of gelatin and gelatin/tragacanth showed greater capacity to reduce oxidative reactions than those of tragacanth, they provided the highest percentages of phenolic compounds release in the first two months of storage. These particles proved to have higher antioxidant efficiency than sodium erythorbate; however, vitamin C showed the highest antioxidant capacity.

Automated summary

The study showed that encapsulating olive leaf extract using gelatin and tragacanth gum can enhance encapsulation efficiency and antioxidant activity, contributing to reducing oxidative reactions.