Encapsulation of a citrus by-product extract: Development, characterization and stability studies of a nutraceutical with antioxidant and metalloproteinases inhibitory activity

- ExO showed Hesperidin and Cyanidine 3-glucoside as major polyphenols compounds.
- The spray-dried aqueous citrus by-product possesses a good antioxidant activity.
- ExO showed high inhibitory effect on MMPs 2 and -9 also microencapsulated with CAP.
- Antioxidant activity and MMPs inhibition are due to a synergic polyphenols effects.
- Spray-drying technology and CAP improve ExO shelf life and antioxidant efficiency.

Spray-dried aqueous extract from citrus by-product (“pastazzo”, ExO) was studied to evaluate the polyphenols content, the antioxidant properties and the inhibition of metalloproteinases over-expressed in dysmetabolic disease. During shelf life studies, ExO changes polyphenols content and decreases the antioxidant properties. Furthermore, Citrus flavonoids are unstable in gastric environment and ExO showed an incomplete in vitro dissolution rate in simulated biological fluids, probably due to their low solubility. For these reasons, formulation studies have been performed to develop spray-dried gastroresistant microsystems for oral administration. Our studies revealed that all the prepared gastroresistant microsystems preserved the polyphenols content, prolonged the shelf-life and the antioxidant efficiency of ExO and maintaining its inhibitory effects on metalloproteinases.