Efficiency of ethanol and hexane extraction of sunflower oil from seeds of plants inoculated with Azospirillum brasilense and fertilized with sewage sludge

Abstract

Helianthus annuuss L. is an annual oilseed crop that grows well in various types of soil. Sunflower oil can be used for several purposes, including human consumption, biodiesel production, and as an ingredient in cosmetics, pharmaceuticals, and veterinary products. Sewage sludge application can provide essential nutrients for plant development. This study aimed to determine the efficiency of ethanol and hexane in extracting sunflower oil and assess the effects of sewage sludge application and inoculation with Azospirillum brasilense on sunflower oil yield. Sunflower oil was obtained from dried ground seeds by Soxhlet extraction. Thrity-eigth samples were used and the experiment was carried out in a completely randomized block design. Each treatment had four repetitions. The following doses were applied: 0 (control); 5,000; 10,000; 20,000; and 40,000 kg/ha sewage sludge. Seeds were either inoculated (150 mL per 50 kg of seed) or not. Hexane and ethanol did not differ in extraction efficiency. The seeds inoculated with the bacteria and the presence of sewage sludge showed a higher yield, being 42% with higher doses of sewage sludge. The results show that ethanol, an environmentally friendly and sustainable solvent, is as efficient in extracting sunflower oil as hexane. Sludge fertilization and inoculation of sunflower with A. brasilense improve oil yield, probably by enhancing nitrogen fixation and uptake. The results show that ethanol, an environmentally friendly and sustainable solvent, is as efficient in extracting sunflower oil as hexane. Sludge fertilization and inoculation of sunflower with A. brasilense improve oil yield, probably by enhancing nitrogen fixation and uptake.