Storage stability of milled flaxseed
- 357 Downloads
Two samples of flaxseed, Linott and a mixture of several varieties, were milled and stored at 23±2°C for 128 d in paper bags with plastic liners. Samples were evaluated at 0, 33, 66, 96, and 128 d for chemical, sensory, and volatile indicators of quality. Neither the mixed variety nor Linott samples showed a significant increase in peroxide values or conjugated double bonds throughout the 128-d storage period. Only the Linott sample showed a significant increase in free fatty acids, which was likely due to the presence of immature seed in the sample. Total volatiles increased with storage in the mixed variety sample but showed minimal change in the Linott sample. Overall, the levels of total volatiles in the milled flaxseed samples were much lower than levels reported in stored vegetable oils containing significantly lower levels of linolenic acid. Dienals, formed during polyunsaturated fatty acid oxidation, and hexanal, a compound used as an indicator of oxidative deterioration, were found at very low levels in both samples and did not reach high levels throughout the 128-d storage period. A trained sensory panel could not detect any differences in the odor properties of fresh or stored milled samples. No differences in flavor could be detected between bread made with 0- and 128-d milled flaxseed. This study showed that milled flaxseed can be stored up to 4 mon at ambient temperatures without noticeable changes in quality. The presence of endogenous antioxidants in the milled flaxseed may account for the stability observed.
Key WordsBread ground flaxseed milled flaxseed storage stability
Unable to display preview. Download preview PDF.
- 1.Chen, Z.-Y., Ratnayake, W.M.N., and S.C. Cunnane, Oxidative Stability of Flaxseed Lipids During Baking, J. Am. Oil Chem. Soc. 71:629–632 (1994).Google Scholar
- 2.Hettiarachchy, N.S., and J. Barr, Effect of Additives on the Shelf-Life Stability of Lipids in Ground Flax, in Program and Exhibit Directory, 52nd Annual Meeting of the Institute of Food Technologists, Chicago (1991).Google Scholar
- 3.Official Methods and Recommended Practices of the American Oil Chemists' Society, 4th edn., edited by D. Firestone, American Oil Chemists' Society, Champaign, 1990.Google Scholar
- 6.International Organization for Standardization, 3656 Animal and Vegetable Fats and Oils—Determination of Ultraviolet Absorbance, 1989.Google Scholar
- 7.Przybylski, R. 1991. Efficient Trapping System for Volatile Components Evaluation in Oils and Fats, in Eighth International Rapeseed Congress Proceedings, edited by D.I. McGregor, Saskatoon, Canada, July 9–11, 1991, Vol. 3, pp. 861–866.Google Scholar
- 8.Meilgaard, M., G.V. Civille, and B.T. Carr, Sensory Evaluation Techniques, 2nd edn., CRC Press Inc., Boca Raton, 1991.Google Scholar
- 9.SAS, Release 6.04 Edition, SAS Institute Inc., Cary, 1992.Google Scholar
- 10.Daun, J.K., Oilseeds—Processing, in Grains and Oilseeds Handling, Marketing and Processing, Canadian International Grains Institute, Winnipeg, Canada, 1993, pp. 833–935.Google Scholar
- 11.Rui, R.C., The Role of Endogenous Lipid Components in Vegetable Oil Stability, Ph.D. Thesis, University of Manitoba, Winnipeg, 1997.Google Scholar