Food and Nutrition Sciences, 2011, 2, 281-286 doi:10.4236/fns.2011.24040 Published Online June 2011 (http://www.scirp.org/journal/fns) Copyright © 2011 SciRes. FNS Heat Treatment and Thirty-Day Storage Period Do Not Affect the Stability of Omega-3 Fatty Acid in Brown Flaxseed (Linum Usitatissimum) Whole Flour Dayane de C. Morais 1 , Érica A. Moraes 1 , Maria Inês de S. Dantas 1 , Júlia C. C. Carraro 1 , Cassiano O. da Silva 1 , Paulo R. Cecon 2 , Hércia S. Duarte Martino, Sônia M. Rocha Ribeiro 1* 1 Department of Nutrition and Health, Federal University of Viçosa, Viçosa, Brazil; 2 Department of Computer Science, Federal University of Viçosa, Viçosa, Brazil. Email: sribeiro@ufv.br Received February 1 st , 2011; revised March 3 rd , 2011; accepted March 8 th , 2011. 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. Keywords: Flaxseed, Flour, Omega-3, Lipid Peroxidation, Heat Treatment 1. Introduction The increasing interest of consumers in disease preven- tion and the scientific evidence about the benefits of functional foods have stimulated the food industry to invest in the development of healthier products. The in- creased intake of alpha linolenic acid (omega-3) has been associated with prevention of chronic noncommunicable diseases [1-4] and nutritional benefits[5]. Thus, it is sug- gested that the highest intake of omega-3 is important to correct the high ratio of omega-6/omega-3 in Western diets [6], which have been associated with the installation of inflammatory processes related to the pathogenesis of several diseases [7]. Flaxseed (Linum usitatissimum L.) has approximately 40% of total lipids, out of which about 50 to 55% is composed of α-linolenic acid (omega-3), and 15 to 18%, of α-linoleic acid (omega-6), with a favorable balance of polyunsaturated, monounsaturated and saturated fatty acids [8,9]. Flax seed is considered the highest vegetable source of essential fatty acid for human diet [10,11], due to its high concentration of α-linolenic acid. It also pro- vides other bioactive compounds, such as phenolic com- pounds, including lignans, vitamin E and dietary fiber [11]. Flaxseed has generally been used as raw whole seeds in food. However, the seeds are not completely digested in the digestive tract, and the bioavailability of its bioac- tive compounds, including linolenic acid, can be impaired. It is assumed that the milling of flaxseed is an excel- lent strategy to increase the bioavailability of the bioac- tive compounds [12]. The seed heat treatment may in- crease product life by reducing humidity and improving the physical properties of food, making it more suitable to partially replace starch and eliminating cyanogenic compounds, which have toxic potential [13]. Therefore, the mechanical and heat processing of flaxseed is the