IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Preservation of walnut oil using walnuts? polyphenols as antioxidants
Autor/es:
GROSSO A. L.; NEPOTE V.; ASENSIO C.M.; GROSSO N. R.
Lugar:
Baltimore
Reunión:
Congreso; Conference on Food Chemistry and Technology, FCT-2017; 2017
Institución organizadora:
United Scientific Group
Resumen:
The walnut kernels are appreciated for their flavor and health benefits. Walnuts are susceptible to lipid oxidation because they exhibit high amount of PUFAs. Antioxidants are known to reduce lipid oxidation. The objective of this study was to evaluate the preserving effect of walnut polyphenols on walnut oil. Walnut oil was extracted by cold pressing from the kernels and walnut polyphenols were extracted using alcohol 70%, and separated in to fractions: ethyl acetate (PA) and water (PHO). The treatments consisted in walnut oil control (ANC), walnut oil with PHO (ANPHO), walnut oil with PA (ANPA), and walnut oil with BHT (ANBHT). An oven test (60 °C) was performed on the samples for 11 days. Lipid oxidation indicators were measured on the samples: peroxide value (IP), conjugated dienes (DC) and trienes (TC), carotenoid content (C), and volatile compounds by GC-MS. The results were statistically analyzed (ANOVA y Test LSD-Fisher). Lipid oxidation indicators increased in all the treatments, mainly in the control sample (ANC). On the last storage day, ANPA exhibited the lowest IP (23.49 meqO2/kg), DC (4.99), TC (0.39), while ANC showed the highest values of these indicators (33.48, 5.13, 0.44, respectively). ANPA presented the highest carotenoids content through all the test, while ANC and ANBHT the lowest. Volatile compounds related to lipid oxidation (Hexanal, 2-Heptenal(E)-, Nonanal) exhibited lower content in ANPAC (362221.58, 95048.14, 14864.70 electronic counts, respectively) than in ANC (258032.55, 120080.76, 77584.43, respectively). Walnuts polyphenols are good antioxidant and show protection against lipid oxidation in this product during storage.