Incorporation of ultrasound-assisted olive leaf extract into mozzarella cheese: effects on physicochemical, functional, and textural properties

Mozzarella cheese is one of the most commonly consumed and popular dairy products globally. Its characteristics and internal matrix structure make it ideal for containing bioactives like polyphenols, plant extracts, and functional lipids. Olive leaves are the byproduct of olive cultivation and processing, and these are rich in phenolic compounds like oleuropein. The objective of the current study was to formulate and characterize mozzarella cheese encapsulated with olive leaf powder extract (OLE). Mozzarella cheese was prepared through ultrasonication of milk at different levels of OLE. The different treatments of mozzarella cheese were then subjected to antioxidant, physiochemical, textural, and sensory analysis. The inclusion of OLE significantly enhanced (p < 0.05) the antioxidant capacity of the treated mozzarella cheese when compared to the control. The influence of OLE inclusion on the moisture, fat, and ash content (p < 0.05) and on pH was significant. In colorimetric analysis, the a* and b* values increased, while there was a significant (p < 0.05) decrease in L* value with increasing OLE concentration in treatments. The microencapsulation of OLE led to a significant (p < 0.05) reduction in the stretchability and an increase in the meltability of the mozzarella cheese treatments. Moreover, the OLE treatment had a significant effect on the textural properties of the cheese, such as cohesiveness, springiness, chewiness, and gumminess. However, the parameter of hardness remained the same. Sensory evaluation did not show any significant difference (p > 0.05) among the treatments. It was concluded that the incorporation of encapsulated OLE into the mozzarella cheese resulted in an improved antioxidant capacity, with a negligible influence on the cheese’s textural and sensory properties. The addition of OLE increased the antioxidant capacity of mozzarella cheese. Ultrasound-assisted microencapsulation effectively delivered OLE to cheese. Color significantly darkened with increased OLE concentration. No significant change in the hardness of cheese across treatments.