Comparative evaluation of sesame oil obtained with microwave-assisted enzymatic extraction and conventional solvent extraction

Abstract

This research investigates the impact of extraction methods on sesame seed oil, specifically comparing traditional Soxhlet extraction (SE) with the relatively newer Microwave-Assisted Enzymatic Extraction (MAEE). While SE exhibited a higher oil yield (46.13%) compared to MAEE (45.20%), the difference was not statistically significant, suggesting MAEE as a viable alternative to conventional methods. These findings align with prior research, emphasizing SE's efficiency in oil extraction. SE, involving solvent circulation, yielded a darker oil due to increased pigment extraction. Specific gravity values showed a slight decrease in MAEE (0.915) compared to SE (0.917), yet the difference was not significant. The refractive index (RI) of MAEE-extracted oil (1.463) was significantly higher, indicating potential advantages in oil quality. MAEE's transparency to monochromatic light suggests a preference for obtaining high-quality oil from sesame seeds. Free Fatty Acid (FFA) values were higher in MAEE (1.33%) than SE (1.19%), signifying potential benefits in oil quality and stability. The use of enzymes in MAEE may mitigate oxidation and degradation during extraction, contributing to lower FFA values. Saponification values were significantly higher in SE (197.34) compared to MAEE (192 mg KOH/g), attributed to solvents extracting a wider range of fatty acids. The degree of saturation, determined by iodine value, was significantly higher in MAEE (111.19) than SE (107.6), possibly due to enzymatic hydrolysis resulting in a higher yield of unsaturated fatty acids. Peroxide values were non-significantly different between MAEE (1.79 meqO2/kg) and SE (1.72 meqO2/kg), suggesting oxidation in sesame oil is influenced more by intrinsic factors than extraction technique. MAEE's potential advantage lies in improved shelf-life and stability, attributed to its higher antioxidant content. MAEE presented as a promising alternative with potential benefits in terms of oil quality, transparency, and stability.