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.