Physico-Chemical Analysis and Fatty Acid Profiling of Fenugreek (Trigonella foenum-graecum) Seed Oil Using Different Solvents

Abstract

Fenugreek (Trigonella foenum-graecum) a native to Southern Europe, Mediterranean region and Western Asia has been used as a spice all over the world to increase the sensory quality to the food. It is also known for its medicinal properties such as anti-diabetic, anti-carcinogenic, hypocholesterolemic and immunological activities and can also be used as a food stabilizer and emulsifying agent. The ash, protein, moisture and fiber content of defatted fenugreek seed powder obtained were 9%, 23.04%, 3.8%, 25.47% respectively. So, this study is systematically intended to determine the fatty acid composition, to be best among the different solvents used are the ethanol, petroleum ether, acetone and hexane for the extraction of the fenugreek seed oil and to analyze its susceptibility to oxidation. This study was carried out to investigate and examine the results such as acid value, peroxide value, saponification value, iodine value and the physical properties such as the color value and the refractive index of the seed oil. The results stipulate that the oil extracted using the solvent hexane had better quality and yield. Linoleic acid (41.97%) followed by alpha-linolenic acid (29.33%) and cis-9 oleic acid (12.95%) was found as the primary fatty acids present in the oil extracted using hexane. Along with these fatty acids, the PUFA content of hexane oil (71.30%) was also observed to be in a good range. So, on comparing these results with codex standards, it revealed that it can be considered as edible oil with further purifications.

Keywords: Trigonella foenum-graecum; fatty acid; fenugreek seed oil; physicochemical properties; solvent extraction.