Filmes e revestimentos comestíveis ativos para controle de oxidação lipídica em castanhas-do-Brasil (Bertholletia excelsa Bonpl.).

Abstract

Brazil nuts (Bertholletia excelsa Bonpl.) have a high content of unsaturated fatty acids, being susceptible to quality loss related to the triggering of lipid oxidative processes. The use of edible coatings such as oral disintegrating films (ODF) added with antioxidant compounds, in addition of protecting oilseeds from lipid oxidation, will also benefit human health due to the high contact surface area for antioxidant absorption in buccal cavity. Given the advantages that can be offered by the ODFs application as food coatings, the present study aimed to develop a technological solution to minimize lipid oxidation in Brazil nuts. Oral disintegration films based on carboxymethylcellulose were added with tocopherols, forming an emulsion. Physical, mechanical, antioxidant, barrier properties, surface microstructure and biodegradability of the films were determined. Initially, the films were evaluated as a model system, produced by casting method, to facilitate the understanding and comparison between the performances of filmogenic solutions and films. Later the films with better results for analyzed properties had their formulations used as edible coatings in the form of ODFs applied to Brazil nuts. The coated seeds were analyzed for mass loss, oxidation degree by peroxide index and conjugated diene content. Edible films with good technological properties, good appearance and mechanical, optical and barrier properties were obtained. The T4 coating, with 0.25% tocopherols (vitamin E) addition in the filmogenic solution, promoted greater stability to lipid oxidation in whole Brazil nuts, and did not change the mechanical properties (texture) and mass loss, thus considered the best treatment studied.