A response surface methodology study on the efects of some phenolics and storage period length on vegetable oil quality: change in oxidation stability parameters

Abstract

In the present study, response surface methodology was conducted for the determination of efects of some phenolics (gallic acid, ellagic acid, and quercetin) on some stability parameters of mixed oil prepared with sunfower and hazelnut oils (50:50, v/v). In this respect, peroxide value (PV), free fatty acids (FFAs), p-anisidine value, induction period, and refractive index of mixed oil were investigated. Predictive regression equations were constructed for the estimation of each studied parameter (R2 > 0.861). Te storage period caused a signifcant increase in the peroxide value, FFAs, p-anisidine, and refractive index values of the mixed oil, while it decreased the induction period value of oil (P < 0.01). Te addition of gallic acid signifcantly retarded oxidation (P < 0.05), and in general gallic acid and quercetin were found to be efective for preserving oil against oxidation.