Effect of ultrasound waves on amount and antioxidant capacity of extracted lycopene from tomato residue

Nowadays request for extraction of phytochemicals by using ultrasound method has been increased. In this research, the effect of ultrasound waves as pretreatment and the effect of solvent combined with ultrasound waves in lycopene extraction from tomato residue was studied and the super chef variety of tomato was chosen for treatment. Samples of tomato residue in triplicate under effect of ultrasound waves with 205 W power, constant 35 KHz frequency in four times of 0 (without ultrasound), 10, 20 and 30 min and at temperature levels of 15, 35 and 45 ºC and using hexane and ethyl acetate as solvents, were employed. Then, the extract from each sample was evaluated considering the amount of lycopene and antioxidant capacity. According to the results, it was observed that, there was a significant difference (P<0.01) between samples in the case of lycopene amount and antioxidant capacity. Maximum amount (P<0.01) of lycopene was related to ultra-sounded samples with hexane solvent at 45 ºC and 10 min time of ultrasound treatment.Treatment of samples with ethyl acetate solvent during 10 min of ultrasound treatment at 35 ºC increased (P<0.01) the antioxidant capacity of extracted lycopene compared to samples which were not treated with ultrasound. Results showed that using ultrasound pretreatment for tomato residue before extraction of lycopene increases the amount of lycopene and antioxidant capacity.