An investigation on the effect of ultrasound waves and pretreatment methods on the extraction of oil from pomegranate seeds

Pomegranate seed oil is rich in functionally and nutritionally important compounds and hence has a wide application in food، pharmaceutical and cosmetic industries. In this study the effect of high power ultrasonic waves and pretreatment method on the extraction efficiency of oil from pomegranate seeds was investigated at a frequency of 20 kHz. Variables in question were extraction procedure at 2 levels (solvent extraction with and without ultrasound)، extraction time at 3 levels (30، 45 and 60 minutes) and pretreatment of seeds and sample preparation at 6 levels (grinding، soaking and grinding، sonication and grinding، soaking، sonication and grinding، grinding، sonication and dehydration، and soaking، grinding، sonication and dehydration). The results showed that ultrasound significantly increased the extraction efficiency with no effect on the composition of fatty acids and their quantitative values. It was also found that pretreatment of whole seeds by sonicating them in hot water led to highest extraction efficiency. Moreover، the extraction time decreased to 30 min in the presence of ultrasound waves.