Pretreatment and extraction of oil from seeds of tomato pomace using ultrasound

Abstract

Tomato pomace is a waste product of tomato paste processing that is consumed mainly as livestock and poultry feed. Tomato pomace seeds are a good source of vegetable oils and have high nutritional value and are rich in polyunsaturated fatty acids and therefore can be widely used in food, pharmaceutical and health industries. The effect of ultrasound on the extraction efficiency, and the fatty acids amount was investigated at a frequency of 37 kHz and power of 550 watts. Investigated treatments consist of two levels of oil extraction methods (Extraction through immersion in hexane and ultrasound-assisted solvent extraction), process time (at three levels of 30, 60 and 90 min) and pretreatment of seeds (at two levels of hot water and mill , hot water and ultrasonic treatment) at 3 different times and mill. The test results have confirmed an increase in extraction efficiency in the use of ultrasonic waves in both pretreatment and extraction processes and showed that these waves had no oxidation effect on the soluble oil. The use of ultrasound-assisted solvent extraction procedure in this study leads to reduction of time and temperature of process to 30 minutes and 40 ° C respectively and a dramatic reduction of 92 percent for the used solvent compared to conventional method of Soxhlet