Active edible coatings with Boldo extract added and their application on nut products: reducing the oxidative rancidity rate

Abstract

SummaryBrazil and Cashew nuts were coated with pure (gelatin, chitosan, sodium caseinate) or blended (gelatin:chitosan, gelatin:sodium caseinate) coating solutions, with and without Boldo‐of‐Chile extract. Brazil nuts exhibited lower moisture content (1.6%) and higher fat content (56.5%) when compared to Cashew nuts (4.7% and 45.5%, respectively). Similar content (≈37.0%) of oleic and linoleic fatty acids was displayed by Brazil nuts, in contrast to Cashew nuts, which showed 64.9% of oleic and 17.5% of linoleic fatty acids. Sodium caseinate solution displayed higher instability index, which was significantly reduced when using gelatin. Coating thickness (20 μm) of the nuts was evaluated by scanning electron microscopy analysis. A lower transmission rate of oxygen was observed in blended films with Boldo extract. Lastly, due to the oxygen barrier effect and the addition of Boldo extract, the coatings protected Brazil and Cashew nuts against oxidation, when compared with the unprotected samples, during 120 days of storage.