Relationship between antioxidant components and oxidative stability of peanut oils from roasting temperatures

Abstract

The study sought to investigate the effect of roasting temperatures on antioxidant components and oxidative stability of peanut oils. The total phenolic content, total flavonoid content, α-tocopherol content, and phytosterol content in peanut oils was influenced by roasting at temperatures of 120, 140, and 160, while those roasting temperatures had no effect on the fatty acid profile and γ-tocopherol content of peanut oils. Roasting promotes the quality of peanut oil aroma via the Maillard reaction, particularly those derived from N-heterocyclic compounds (such as pyrazine and pyrrole). The oxidative stability of peanut oils was investigated using the Rancimat method, and the result shows that in relation to temperature, the natural logarithms of the induction period is linearly varied (R2: 0.959˜0.998). This was determined based on the Arrhenius equation, which indicated the activation energies (Ea) were 82.08˜108.61 KJ/mol. In PCA analysis, the antioxidant stability of the increasing levels of phenols released in the peanut oils was found to be rise with increment of roasting temperatures. The data obtained in this study should be helpful to peanut oil producers in terms of producing peanut oils that will be most appealing to consumers.