Chemical and thermal analyses of golden and brown flaxseeds were carried out for raw and toasted seeds aiming at evaluating their nutritional and thermo-oxidative properties. Moisture, lipids, protein, soluble carbohydrates, and ash contents were quantified. Concerning lipids and proteins, in average, no meaningful differences were observed for the two varieties, being also equivalent to the literature data. The golden variety had a lower amount of fibers and a higher amount of soluble carbohydrates than the brown variety. The techniques of thermogravimetry and differential scanning calorimetry were applied for elucidating the thermal degradation process of the seeds. The toasted gold and brown seeds were more stable to thermal decomposition than the raw seeds, under oxidative conditions. Golden seeds seem to be more susceptible to oxidation than brown seeds, under toasting conditions. Finally, no meaningful advantages were observed for the golden seeds in comparison to the brown ones.
1. Adkins, Y, Kelley, D. Mechanisms underlying the cardioprotective effects of omega-3 polyunsaturated fatty acids. J Nutr Biochem. 2010;21:789–792. .
2. Cämmerer, B, Kroh, LW. Shelf life of linseeds and peanuts in relation to roasting. Food Sci Technol. 2009;42:545–549.
3. Cornish, SM, Chilibeck, PD, Paus-Jennsen, L, Biem, HJ, Khozani, T, Senanayake, V, Vatanparast, H, Little, JP, Whiting, SJ, Pahwa, P. A randomized controlled trial of the effects of flaxseed lignan complex on metabolic syndrome composite score and bone mineral in older adults. Appl Physiol Nutr Metab. 2009;34:89–98. .
4. Mason, JK, Chen, J, Thompson, LU. Flaxseed oil–trastuzumab interaction in breast cancer. Food Chem Toxicol. 2010;48:2223–2226. .
5. Ogawa, A, Suzuki, Y, Aoyama, T, Takeuchi, H. Dietary alpha-linolenic acid inhibits angiotensin-converting enzyme activity and mRNA expression levels in the aorta of spontaneously hypertensive rats. J Oleo Sci. 2009;58:355–360. .
6. Udenigwe, CC, Lin, Y, Hou, W, Aluko, RE. Kinetics of the inhibition of renin and angiotensin I-converting enzyme by flaxseed protein hydrolysate fractions. J Funct Food. 2009;1:199–207. .
7. Demark-Wahnefried, W, Price, DT, Polascik, TJ, Robertson, CN, Anderson, EE, Paulson, DF, Walther, PJ, Gannon, M, Vollmer, RT. Pilot study of dietary fat restriction and flaxseed supplementation in men with prostate cancer before surgery: exploring the effects on hormonal levels, prostate-specific antigen, and histopathologic features. Urology. 2001;58:47–52. .
8. Lazko, J, Dupré, B, Dheilly, RM, Quéneudec, M. Biocomposites based on flax short fibres and linseed oil. Ind Crop Prod. 2011;33:317–324. .
9. Bommareddy, A, Zhang, XY, Schrader, D, Kaushik, RS, Zeman, D, Matthees, DP, Dwivedi, C. Effects of dietary flaxseed on intestinal tumorigenesis in Apc (Min) mouse. Nutr Cancer. 2009;61:276–283. .
10. Mueller, K, Eisner, P, Yoshie-Stark, Y, Nakada, R, Kirchhoff, E. Functional properties and chemical composition of fractionated brown and yellow linseed meal (Linum usitatissimum L.). J Food Eng. 2010;98:453–460. .
11. Vick, BA, Zimemerman, DC, Weisleder, D. Thermal alteration of a cyclic fatty acid produced by a flaxseed extract. Lipids. 1979;14:734–740. .
12. Wu, M, Li, D, Wang, L, Zhou, Y, Brooks, MS, Chen, XD, Mao, Z. Extrusion detoxification technique on flaxseed by uniform design optimization. Sep Purif Technol. 2008;61:51–59. .
13. Antoniassi, R. Methods for the evaluation of the oxidative stability of oils and fats. Bol Cent Pesqui Process Alimen. 2001;19:353–380.
14. Association of Official Analytical Chemists. Official methods of analysis of the Association of Official Analytical Chemists, Arlington: AOAC; 1995.
15. Yemn, EW, Willis, AJ. The estimation of carbohydrate in plant extracts by anthrone. Biochem J. 1954;57:508–514.
16. Berglund, DR, Zollinger, RK. Flax production in North Dakota. Fargo: North Dakota State University, Extension Service (NDSU); 2007.
17. Coskuner, Y, Karababa, E. Some physical properties of flaxseed (Linum usitatissimum L.). J Food Eng. 2007;78:1067–1073. .
18. Selvi, KÇ, Pinar, Y, Yesiloglu, E. Some physical properties of linseed. Biosystems Eng. 2006;95:607–612. .
19. Muir, AD, Westcott, ND. Flax: the genus Linum. Boca Raton: CRC Press; 2003.
20. Oomah, BD, Mazza, G. Compositional changes during commercial processing of flaxseed. Ind Crop Prod. 1998;9:29–37. .
21. Oomah, BD, Mazza, G. Effect of dehulling on chemical composition and physical properties of flaxseed. Food Sci Technol. 1997;30:135–140.
22. Oomah, BD, Der, TJ, Godfrey, DV. Thermal characteristics of flaxseed (Linum usitatissimum L.) proteins. Food Chem. 2006;98:733–741. .
23. Li-Chan, ECY, Ma, CY. Thermal analysis of flaxseed (Linum usitatissimum) proteins by differential scanning calorimetry. Food Chem. 2002;77:495–502. .
24. Mothé, CG, Damico, A, Machado, MGS. Thermoanalytical study, HPLC and physical and chemical cracking from corn industry co-product. Cienc Technol Aliment. 2005;25:1–7. (in Portuguese).
25. Silva, SA, Conceição, MM, Souza, AG, Prasad, S, Silva, MCD, Fernandes Júnior, VJ, Araújo, AS, Sinfrônio, FSM. Thermal analysis of the powder and the bran of algaroba. J Therm Anal Calorim. 2004;75:411–417. .
26. Geneau-Sbartaï, C, Leyris, J, Silvestre, F, Rigal, L. Sunflower cake as a natural composite: composition and plastic properties. J Agric Food Chem. 2008;56:11198–11208. .
27. Rudnik, E, Szczucinska, A, Gwardiak, H, Szulc, A, Winiarska, A. Comparative studies of oxidative stability of linseed oil. Thermochim Acta. 2001;370:135–140. .
28. Silva, FAM, Borges, MFM, Ferreira, MA. Methods for the evaluation of the degree of lipid oxidation and the antioxidant activity. Quim Nova. 1999;22:94–103. (In Portuguese).
29. Jung, MY, Bock, JY, Back, SO, Lee, BTK, Kim, JH. Pyrazine contents and oxidative stabilities of roasted soybean oils. Food Chem. 1997;60:95–102. .
30. Rizzi, GP. Free radicals in the Maillard reaction. Food Rev Int. 2003;19:375–395. .