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.