Effects of microwave and steaming pre-treatments on oil yield and quality of Neem seed

Abstract

Neem, scientifically known as Azadirachta indica, belongs to the family Meliaceae. It is famous worldwide for its many uses and bioactive compounds present in neem seed oil, which contain many triterpenes, such as azadirachtin. This study explored the impact of microwave and steaming pretreatment techniques on neem seed oil extraction, focusing on oil yield and quality analysis. Microwave treatments were applied at different power levels (300, 450, and 600 W) for 120 and 180 s, whereas steaming treatments were conducted at a constant pressure of 1.5 kg/cm² and a temperature of 121 °C for various times (5, 10, and 15 min). The results showed that higher microwave power levels and longer treatment times significantly increased the oil yield, with the highest yield of 42.18% being achieved at 450 W for 180 s. In terms of quality parameters, increased acid value, free fatty acid content, and peroxide value were observed. Steaming pretreatment resulted in a 4.42% increase in oil yield in comparison with the untreated sample (31.51%), with the highest yield of 35.97% observed after 15 min. Steaming slightly reduced the acid and free fatty acid content, although it increased the peroxide value.