Relationship between antioxidant components and oxidative stability of
peanut oils as affected by 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 results
show that there is a linear relationship between roasting and natural
logarithm of induction period (R2: 0.959~0.998). This
was determined based on the Arrhenius equation, which indicated the
activation energy (Ea) were 82.08~108.61 KJ/mol. In PCA
analysis, the antioxidant stability of the increase 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
confirmed to the nutritional benefits of peanut oils that will be most
appealing to consumers.