Improving extraction of lycopene from tomato waste by-products using ultrasonication and freeze drying

Waste food by-products represent a major disposal problem for the food industry, and they are often used as animal feed or fertilizers. This study examined the possible utilization of tomato waste as good sources of lycopene. Results revealed that lab-prepared tomato waste (LPTW) contains significantly (p<0.05) a larger amount of lycopene (57.87±5.30 µg/g fresh wt.) than industrial tomato waste by-products (ITWBP) (27.11±0.83 µg/g fresh wt.). The average amounts of extracted lycopene obtained from ultrasonication, freeze drying, and their combination were 45.51±1.84, 104.10±1.23 and 138.82±6.64 µg/g fresh wt., respectively. Subjecting ITWBP to freeze drying and to ultrasonication separately increased their lycopene contents by 2.8 and 0.68 folds, respectively. However, applying the combined treatment of freeze drying and ultrasonication (45 min at 50 Hz) increased the yield of extracted lycopene from industrial tomato waste by 4.12 folds.  Antioxidants scavenging capacity of FDITW calculated as % reduction in the DPPH and ABTS free radicals using1.5mg freeze dried industry tomato waste were 49.64±0.44 and 12.3±0.11, respectively.