Volatiles and Tendency of Radical Formation of Cold‐Pressed Brazil Nut Oil During Ambient Storage

Abstract

AbstractCold‐pressed Brazil nut oil (BNO) is a value‐added nontimber forest coproduct of market interest, despite the lack of knowledge about its ambient storage stability. The objective of the present study was to investigate oxidative changes in BNO stored in clear and brown glass bottles under retail conditions with a focus on monitoring for the first time the formation of volatile aroma compounds (VAC), the depletion of tocopherol analogs, and the tendency of radical formation. VAC, whose formation continuously increased and correlated with storage time, were detected using headspace‐solid‐phase microextraction‐gas chromatography–mass spectrometry. Depletion of tocopherols was more pronounced for the oil stored in clear glass bottles and the content loss was higher for alpha‐tocopherol than for gamma‐tocopherol. Furthermore, the tendency of radical formation was detected using a spin‐trapping electron spin resonance spectroscopy method, which was demonstrated to be a simpler, faster, and less sample‐demanding tool to monitor the oxidative status of BNO stored under retail conditions and its results significantly correlated with those obtained using traditional methods for the determination of primary oxidation products. However, the simultaneous measurement of key off‐flavor volatiles is recommended for samples with unknown history.