The present study aimed to evaluate the impact of industrial processing (neutralization/degumming, bleaching, and deodorization) on physicochemical characteristics of soybean oil and soybean oil deodorizer distillate (SBO-DD) collected from two different industries. The substantial impact of processing was observed on all physicochemical parameters except the iodine value (IV) and saponification value (SV). Gas chromatography-flame ionization detector (GC-FID) and Gas chromatography-mass spectrometry (GC-MS) analytical techniques were used for the quantification of individual fatty acids, sterols, and 3-monochloropropane diol (3-MCPD) ester. Among the fatty acids, palmitic and linoleic acids were present at higher concentrations in all processing stages. Among sterols, β-sitosterol was found to be higher (25.65 µg/g) in crude soybean oil and reduced to 16.44 µg/g after processing till the final deodorization stage. 3-MCPD ester was developed during the neutralization/degumming process and further increased during bleaching and deodorization up to 315 µg/kg, respectively. SBO-DD was found to be a rich source of total and individual sterols as compared to crude or processed soybean oil. High free fatty acid (FFA) level in deodorizer distillate indicated that SBO-DD is a potential source of biodiesel production.

Zahid Hussain Laghari, Sarfaraz Ahmed Mahesar, Hamide Filiz Ayyildiz, Huseyin Kara Mustafa Topkafa, Syed Tufail Hussain Sherazi and Abdul Hameed Kori