Ultrasound assisted extraction of lycopene from tomato processing wastes

Tomato paste processing wastes, an important by-product of the paste industry, is rich in potentially health-promoting compounds such as lycopene. In this study, extraction yield of lycopene from tomato paste processing wastes by application of ultrasound assisted extraction (UAE) was compared with conventional organic solvent extraction (COSE) method. BHT (butylated hydroxytoluene) 0.05 % (w/v) added hexane:acetone:ethanol (2:1:1) mixture was used as solvent. Three different solvent solid ratios; 50:1, 35:1 and 20:1, (v/w) were used in both COSE and UAE. COSE experiments were performed at 20 °C, 40 °C and 60 °C for 10, 20, 30 and 40 min. 50, 65 and 90 W of ultrasonic power were applied in UAE for 1, 2, 5, 10, 15, 20 and 30 min. Lycopene contents of the samples were determined by spectrophotometric method. The effects of different factors, including the temperature, solvent solid ratio and ultrasonic power on lycopene yield were investigated. It was determined that the most efficient application for COSE was extracting samples by 50:1 solvent solid ratio at 60 °C for 40 min run, for UAE, 35:1 (v/w) solvent solid ratio, 90 W ultrasonic power for 30 min run. It was showed that UAE of lycopene requires less time, lower temperature and lower solvent than COSE.