Fortification of queso blanco (QB) with flaxseed oil (FO) containing omega-3 polyunsaturated fatty acids may provide a functional food with health benefits such as improved cell, brain, and retina functionality, and protection against cardiovascular and immune-inflammatory diseases. However, QB experiences a short shelf life because of the early development of yeasts and molds and addition of FO may increase susceptibility to lipid oxidation. Oregano essential oil (OEO) is known for its antimicrobial and antioxidant properties, but due to its intense flavor compounds it may not be suitable for direct incorporation into QB. Thus, incorporation of OEO into an edible film prepared with whey protein isolate (WPI) may improve the shelf life of QB. Scanning electron microscopy (SEM) micrographs revealed that FO was successfully retained by the cheese after homogenization. The thiobarbituric-acid-reactive-substances (TBARS) and yeast and mold counts (YMC) of the wrapped cheeses were analyzed during 60 d of refrigerated storage. The oxidation rate increased significantly for nonwrapped QB containing FO (QBFO) during storage, however wrapping with WPI edible films containing OEO (WOF) significantly limited lipid oxidation and prevented growth of yeasts and molds. This study demonstrated the antioxidant and antimicrobial properties of WOF for preservation of QBFO during refrigerated storage.
Keywords: edible films; flaxseed oil; oregano essential oil; queso blanco; shelf life.
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