Impact of fractionation on fatty acids composition, phenolic compounds, antioxidant characteristics of olein and super olein fractions of flaxseed oil

Abstract

Flaxseed oil was fractionated at −40°C, filtrate was designated as olein fraction (31% yield), which was further fractionated at −60°C, and filtrate was named as super olein fraction (17% yield). Flaxseed oil, olein, and super olein fractions were stored at 25°C–30°C for the duration of 90 days. Alpha linolenic acid in flaxseed oil, olein, and stearin fraction was 55.26%, 63.47%, and 71.61%. High-performance liquid chromatography (HPLC) characterization showed that phenolic compound was concentrated in olein and super olein fractions. In super olein fraction of flaxseed oil, concentration of gallic acid, protocatechuic acid, 4-hydroxybenzoic acid, syringic acid, p-coumaric acid, and ferulic acid was 8.14, 40.59, 75.38, 7.95, and 9.27 mg/100 g. Total phenolic contents of flaxseed oil, olein, and super olein were 145, 185, and 247 mg GAE/100 g. Peroxide value of 90 days stored flaxseed oil, olein, and super olein was 0.59, 0.75, and 0.96 (MeqO2/kg) with no difference in color and flavor scores. Practical applications Several fractions of palm oil and milk fat are commercially produced for large number of industrial applications. However, fractionation of flaxseed oil is not previously performed, and chemical characteristics of olein and super olein fractions of flaxseed oil are not reported in literature. In this study, olein and super olein fractions of flaxseed oil were produced by dry fractionation. Super olein fraction revealed more than 70% alpha linolenic, higher magnitude of phenolic compounds than parent flaxseed oil, with reasonable oxidative stability and acceptable sensory attributes. Olein and super olein fraction of flaxseed oil may be conveniently used for the supplementation of large number of food products.