Heat Treatment and Thirty-Day Storage Period Do Not Affect the Stability of Omega-3 Fatty Acid in Brown Flaxseed ( Linum Usitatissimum) Whole Flour

Abstract

This study was conducted to verify if the processing and storage of brown flaxseed whole flour result in loss of func- tional properties, such as reduced linolenic acid content, increased lipid peroxidation and sensory changes. The flours were obtained from seeds dried by heat treatment in oven at 150˚C, for 15 minutes and subsequent grinding to obtain flour with a particle size of 20 mesh. Meal samples, with and without synthetic antioxidants (BHA and BHT combined, at 100 ppm each), were stored for a thirty-day period, under similar conditions to those used commercially. The lino- lenic acid content was quantified by gas chromatography. Lipid peroxidation was analyzed by thiobarbituric acid reac- tive substance assay. Color and flavor were evaluated by sensory tests. The linolenic acid content and lipid peroxida- tion did not significantly change after processing or during storage. Fluctuations in color and flavor occurred during storage, but at the end of 30 days, only the heat treatment presented negative effect (p < 0.05) on the parameter color. Heat treatment and thirty-day storage period do not change the stability of n-3 fatty acid in brown flaxseed whole flour.