Application of the central composite design and response surface methodology for investigation of induction time, conjugated diene, conjugated triene and trans fatty acid content of corn oil enriched with carotenoids

Abstract

The central composite design technique was used to investigation of induction time, conjugated diene, conjugated triene and trans fatty acid content of corn oil enriched with lutein, β-carotene and lycopene in this study. The levels of lutein and β-carotene and were between 0 and 94 mg/kg, while lycopene levels was 0–49.56 mg/kg. Oil samples with and without lutein, β-carotene and lycopene were prepared according to central composite design. The influence of these three independent variables on the four dependent variables such as time, conjugated diene and conjugated triene and trans fatty acid content was evaluated using a reduced cubic model. The each independent variable was effective on the induction time, conjugated diene, conjugated triene and trans fatty acid content of corn oil. The positive effect on the induction time was observed high concentrations of lutein and lycopene concentrations. Lutein, β-carotene and lycopene had a significant effect on conjugated diene, conjugated triene and trans fatty acid content. The desirability function and the 3D plots suggested that optimum parameters were lutein concentration of 19 mg/kg, β-carotene concentration of 19 mg/kg and lycopene concentration of 12.5 mg/kg as optimum parameters for maximum induction time and the minimum formation of conjugated diene, conjugated triene and trans fatty acid species.