Optimization of extraction of high purity all-trans-lycopene from tomato pulp waste.

The aim of this work was to optimize the extraction of pure all- trans -lycopene from the pulp fractions of tomato processing waste. A full factorial design (FFD) consisting of four independent variables including extraction temperature (30–50 °C), time (1–60 min), percentage of acetone in n-hexane (25–75%, v/v) and solvent volume (10–30 ml) was used to investigate the effects of process variables on the extraction. The absolute amount of lycopene present in the pulp waste was found to be 0.038 mg/g. The optimal conditions for extraction were as follows: extraction temperature 20 °C, time 40 min, a solvent composition of 25% acetone in n-hexane (v/v) and solvent volume 40 ml. Under these conditions, the maximal recovery of lycopene was 94.7%. The HPLC–DAD analysis demonstrated that, lycopene was obtained in the all- trans -configuration at a very high purity grade of 98.3% while the amount of cis -isomers and other carotenoids were limited. [ABSTRACT FROM AUTHOR]