Extraction, Optimization, and Characterization of Neem Seed Oil via Box-Behnken Design Approach

This study was aimed at extracting, optimizing, and characterizing the neem seed oil through Box-Behnken design. The effects of extraction parameters such as temperature (50-80°C), particle size (0.15–0.3 mm), and time (60-180 min) were considered. The extraction of oil was studied using the soxhlet extraction process, applying n-hexane as a solvent. The quadratic model was suggested to demonstrate optimal extraction parameters of 132.677 min, 64.416°C of temperature, and 0.212 mm of particle size using numerical optimization. The experimental yield of oil at optimum conditions 44.141%, which was close to the model-anticipated value. The physicochemical properties suggested that neem oil had an ash content of 2.1%, moisture content 4.61%, density 0.875 g/cm3, viscosity 33.5 mm2/s, specific gravity 0.88, saponification value 206.7 mg KOH/, iodine value 122.5 g I2/100 g, acid value 1.81 mg KOH/g, and cetane number of 75. The extraction parameters had a significant effect on the yield of neem seed oil. However, the temperature and particle size had a higher effect compared to the extraction time. The most important unsaturated fatty acid is oleic acid (60.924 %). The properties of the oil revealed that the neem seed oil can be used as a potential source of material for industrial applications. It can be concluded that neem seeds have the potential to be used as industrial feedstocks in the future.