Effects of olive leaf extract nanoliposomes on physicochemical, microbiological and sensory properties of butter

Olive leaf extract as a rich source of phenolic compounds has significant anatioxidant and antimicrobial properties, but its direct addition to foods has disadvantages due to bitter taste. Encapsulation by nanoliposomes is one of the useful methods to carry bioactive compounds such as phenols. Therefore, aim of this study was to evaluate addition of nanoliposomes carrying olive leaf extract to butter stability.

First nanoliposomes of olive leaf extract was prepared and at 0 (control sample), 50, 100, 200 and 400 ppm spiked to butter samples, then stored in refrigerator for 80 days, and their physicochemical properties (moisture and fat content, fatty acid profile, acidity and peroxide value), microbial properties (total sycrotroph content) and organoleptic properties (bitter taste, rancidity and general acceptance) evaluated.

Obtained results showed that addition of olive leaf extract nanoliposomes had no effect on butter composition, however, it could prevent from increasing of acidity and peroxides. Microbial analysis also showed that nanoliposomes spiking could prevent from microbial deterioration of butter samples. Organoleptic tests also showed nanoliposomes effect on prevention of olive leaf bitter taste exposure and also rancid taste development of butter samples.

Encapsulation as nanoliposomes is a advanced and useful methods to fortify butter with phenolic compounds of olive leaf and prevention from chemical and microbial spoilage and enhancement of its shelf life.