Enzyme-assisted extraction of lycopene from tomato processing waste

A central composite design was used to optimize the enzyme-assisted extraction of lycopene from the peel fraction of tomato processing waste. Tomato skins were pretreated by a food-grade enzyme preparation with pectinolytic and cellulolytic activities and then subjected to hexane extraction. The factors investigated included extraction temperature (10–50 °C), pretreatment time (0.5–6.5 h), extraction time (0.5–4.5 h), enzyme solution-to-solid ratio (10–50 dm3/kg) and enzyme load (0–0.2 kg/kg). Overall, an 8- to 18-fold increase in lycopene recovery was observed compared to the untreated plant material. From a response surface analysis of the data, a second-degree polynomial equation was developed which provided the following optimal extraction conditions: T = 30 °C, extraction time = 3.18 h and enzyme load = 0.16 kg/kg. The obtained results strongly support the idea of using cell-wall degrading enzymes as an effective means for recovering lycopene from tomato waste.