Correlation between sensory and chemical markers in the evaluation of Brazil nut oxidative shelf-life

摘要

Sensory analysis is one of the most suitable processes for measuring oxidative damage and determining the shelf-life of nuts, but it is an expensive and time-consuming methodology. Thus, our objective was to correlate sensory data and chemical markers obtained during the accelerated oxidation of Brazil nuts and to determine the chemical parameters values associated with the sensory shelf-life of the nuts as established by the consumers. Brazil nuts were kept at 80 °C for 21 days. At intervals of 2 days, the oxidized odor of the samples was analyzed by nine trained panelists using a discriminative scale, and the oil was extracted to quantify the chemical parameters. A high (r 0.95) and significant correlation (p 0.05) was observed between the sensory data and the hydroperoxide concentration (PV), para-anisidine value (pAV), hexanal content, and α- and γ-tocopherol concentrations. When compared with fresh samples, sensory identification of oxidized odor occurred on the 4th day, noticeably earlier than changes in chemical markers (12th day). Consumers rejected the nuts after 12 days of storage, which corresponded to PV = 18.8 meq kg−1 oil, pAV = 7.68, hexanal = 48.95 μmol 100 g−1 oil, α-tocopherol = 15.01 mg kg−1 oil, and γ + β-tocopherol = 73.88 mg kg−1 oil. Our study suggests that simple spectrometric methods, such as PV and pAV, can be used to estimate the oxidative shelf-life of nuts based on sensory analysis.