A Novel Approach to Protect Brazil Nuts from Lipid Oxidation: Efficacy of Nanocellulose–Tocopherol Edible Coatings

Abstract

High levels of unsaturated fatty acids in Brazil nuts compromise their sensory quality through lipid oxidation. To mitigate this reaction, it is crucial to package nuts under a vacuum and in aluminate packaging. An alternative method is the application of an edible coating with antioxidant properties. This study aimed to develop an edible coating composed of carboxymethylcellulose and sorbitol, physically reinforced with nanocellulose, and chemically fortified with tocopherol. The edible coating was characterized based on its physical properties, mechanical strength, biodegradability, optical light transmission properties, color parameters, and water vapor permeability. Formulations CC5 (Carboxymethyl cellulose (CMC) + sorbitol + 5% nanocellulose) and CCT5 (CMC + sorbitol + tocopherol + soy lecithin + 5% nanocellulose) showed enhanced mechanical strength. The combination of nanocellulose with tocopherol in formulations CCT3 (CMC + sorbitol + tocopherol + soy lecithin + 3% nanocellulose) and CCT5 developed superior barriers to visible and ultraviolet light, a desired characteristic for coatings intended to increase the shelf life of Brazil nuts. The nuts coated with CC5 and CCT3 showed the lowest PV values at the end of the accelerated oxidation test conducted at 60 °C.