Production of Wheat Flour/PBAT Active Films Incorporated with Oregano Oil Microparticles and Its Application in Fresh Pastry Conservation

Abstract

This study aimed to produce wheat flour and poly (butylene co-terephthalate adipate) films with the addition of free and microencapsulated oregano essential oil by blown extrusion and to evaluate its applicability as an active packaging in the preservation of the Brazilian fresh pastry, known as Pastel. The oregano essential oil microparticles were produced by spray drying and characterized in terms of morphology, encapsulation efficiency, and mean diameter. In the films, the physical, antioxidant, and diffusion kinetics of oregano essential oil were determined. Films with microencapsulated oregano essential oil showed lower tensile strength and Young’s modulus and higher elongation, solubility, antioxidant capacity, and diffusion coefficient when compared to the control and free oregano oil films. During 28 days of refrigerated storage, fresh pastry packaged with film with oregano essential oil microparticles presented a lower count of molds and yeasts, compared to pastries packed with control and free oregano oil films. The microencapsulation protected oregano essential oil from extrusion condition shearing and temperature damages during film production, allowing the development of biodegradable active films for application in foods where contamination by molds and yeasts is predominant.