Commercial edible grade soybean oil was obtained from market and was refined again to reduce free fatty acid and water content further. The fatty acid consisted of: palmitic acid
12.3%, stearic acid 5.8%, oleic acid 26.5%, linoleic acid 49.4% and linolenic acid 5.9%, according to GC (Shimadzu DC-9A) analysis [18]. The acid value was less than 0.1 mgKOH/g, and the average molecular weight of 874 g/mol was calculated from the saponification value (Sv = 193 mgKOH/g).