Variations in quantity and quality of neemoil (Azadirachta indica A.juss) extracted by petroleum ether and ethanol in select areas of Guntur, Andhra Pradesh, India

Neem oil extracted from seeds of neem trees (Azadirachta indica A.juss) growing in three soil types has showed variations, using petroleum ether and ethanol. Effect of temperature and the influence of solvent on the extraction were studied. Results showed that the maximum oil yield was 42.60% with petroleum ether and 39.17% with ethanol at 50ºC. It was observed that the increase in temperature, decreased the iodine value, whereas increased acid, and peroxide values, envisaging that the higher extraction temperature, though gives higher oil yield, decreased the quality of oil. It was evident that petroleum ether (bp 60–80°C) can be effectively used as a good solvent for the extraction of oil in solvent extraction process. Further it was observed that some significant variations in Azadirachtin (980 – 2420 mg/kg), seed protein (27.2 -32.8%) and seed weight (16.8 – 18.9 g) were observed in trees growing in different soil types.