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Optimization of Enzymatic Activities in Malting of Oat

Authors: E. Hosseini, M. Kadivar, M. Shahedi


Malting is usually carried out on intact barley seed, while hull is still attached to it. In this study, oat grain with and without hull was subjected to controlled germination to optimize its enzymes activity, in such a way that lipase has the lowest and α- amylase and proteinase the highest activities. Since pH has a great impact on the activity of the enzymes, the pH of germination media was set up to 3 to 8. In dehulled oats, lipase and α-amylase had the lowest and highest activities in pHs 3 and 6, respectively whereas the highest proteinase activity was evidenced at pH 7 and 4 in the oats with and without hull respectively. While measurements indicated that the effect of hull on the enzyme activities particularly in lipase and amylase at each level of the pH are significantly different, the best results were obtained in those samples in which their hull had been removed. However, since the similar lipase activity in germinated dehulled oat were recorded at the pHs 4 and 5, therefore it was concluded that pH 5 in dehulled oat seed may provide the optimum enzyme activity for all the enzymes.

Keywords: Enzyme activity, malting, oat, optimization.

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[1] G. Mazza, Functional Food: Biochemical & Processing Aspect, Pennsylvania: Technomic Press, 1998, pp. 1-37
[2] P. Lehtinen, and S. Laakso, "Role of lipid reactions in quality of oat products, " Agric. Food Sci., vol. 13, no. 1-2, pp. 88-99, 2004.
[3] D. M. Peterson, "Malting oats: Effects on chemical composition of hull-less and hulled genotypes," Cereal Chem., vol. 75, no. 2, pp. 230-234, 1998.
[4] A. Dalby, and C. Y. Tsai, "Lysine and tryptophan increasing during germination of cereal grains," Cereal Chem., vol. 53, no. 2, pp. 222- 226, 1976.
[5] M. Larson, and A. S. Sandberg, "Phytate reduction in oats during malting," J. Food Sci., vol. 57, no. 4, pp. 994-997, 1992.
[6] AACC International, Approved Methods of the American Association of Cereal Chemist, St. Paul, MN: American Association of Cereal Chemists, 2000.
[7] C. Y. Ma, "Preparation, composition and functional properties of oat protein isolated," Can. Inst. Food Sci. Technol. J., vol. 16, no. 3, pp.
[8] B. Sullivan, and H. M. Allison, "Lipase of wheat," J. Amer. Chem. Soc., vol. 55, no. 1, pp. 320-324, 1933.
[9] A. Bonet, P. A. Caballero, M. Gomes, and C. M. Rossell, "Microbial transglutaminase as a tool to restore the functionality of gluten from insect-damage wheat," Cereal Chem., vol. 82, no. 4, pp. 425-430, 2005.
[10] P. M. Nielsen, D. Peterson, and C. Dambman, "Improved method for determining food protein degree of hydrolysis," J .Food Sci., vol. 66, no. 5, pp. 642-646, 2001.
[11] AOAC International, Official Methods of Analysis of AOAC International, 17nd ed., Gaithersburg, MD: Association of Analytical Communities, 2002.
[12] K. H. Liukkonen, A. Montfoort, and S. V. Laakso, "Water-Induced lipid changes in oat processing," J. Agric. Food Chem., vol. 40, no. 1, pp. 126-130, 1992.
[13] D. M. Peterson, "Lipase activity and lipid metabolism during oat malting," Cereal Chem., vol. 76, no. 1, pp. 159-163, 1999.
[14] B. Ekstrand, I. Gangby, and G. Akesson, "Lipase activity in oats: Distribution, pH dependence and heat inactivation," Cereal Chem., vol. 69, no. 4, pp. 379-381, 1992.
[15] K. H. Liukkonen, K. Johnson, and S. V. Laakso, "Alkaline sensitivity of lipase activity in oat flour: Factor Contributing to inhibition," J. Cereal Sci., vol. 21, no. 1, pp. 79-85, 1995.
[16] A. W. McGregor, and J. Daussant, "Evolution of ╬▒ - amylase component during initial stages of barley germination with and without prior steeping," Cereal Chem., vol. 56, no. 6, pp. 541-545, 1979.
[17] E. Kneen, "A comparative study of the development of amylases in germinating cereals," Cereal Chem., vol. 21, pp. 304-313, 1944.
[18] E. Bertoft, C. Andtfolk, and S. E. Kulp, "Effects of pH, temperature and calcium ions on barley malt ╬▒-amylase isoenzymes," J. Inst. Brew., vol. 90, no. 5, pp. 298-302, 1984.
[19] P. Meredith, "Inactivation of cereal ╬▒-amylase by brief acidifications: The pasting strength of wheat flour," Cereal Chem., vol. 47, no. 9, pp. 492-500, 1970.
[20] T. Beta, L. W. Rooney, L. T. Marovatsanga, and R. N. Taylor, "Effects of chemical treatments on polyphenols and malt quality in sorghum," J. Cereal Sci., vol. 31, no. 3, pp. 295-302, 2000.
[21] R. Tkachuk, and J. E. Kruger, "Wheat ╬▒- amylase II. Physical characterization," Cereal Chem., vol. 51, no.4, pp. 508-529, 1974.
[22] N. Zhang, and B. L. Jones, "Characterization of germinated barley endoproteolytic enzymes by tow-dimensional gel electrophoresis," J. Cereal Sci., vol. 21, no. 2, pp. 145-153, 1995.
[23] M. Mikola, and B. L. Jones, "Electrophoretic and `in solution` analyses of endoproteinases extracted from germinated oats," J. Cereal Sci., vol. 31, no. 1, pp. 145-153, 1998.
[24] M. Mikola, and B. L. Jones, "Characterization of oat endoproteinases that hydrolyze oat globulins," Cereal Chem., vol. 77, no. 4, pp. 572- 575, 2000.
[25] M. Mikola, and B. L. Jones, "Characterization of oat endoproteinases that hydrolyze oat avenins," Cereal Chem., vol. 78, no. 1, pp. 55-58, 2001.
[26] N. L. Kent, and A. D. Evers, Technology of Cereals: An Introduction for Students of Food Science and Agriculture, 4nd ed., Oxford: Pergamon Press, 1994.
[27] C. Klose, B. D. Schehl, and E. K. Arendt, "Fundamental study on protein change taking place during malting of oats," J. Cereal Sci., vol. 49, no.1 , pp. 83-91, 2009.
[28] A. M. Osman, "The advantages of using natural substrate based on methods in assessing: The role of synergistic and competitive interaction of barley malt starch degradation enzymes," J. Inst. Brew., vol. 108, no. 2, pp. 204-214, 2002.
[29] S. Kreisz, "Malting, "in Handbook of Brewing: Process, Technology and Markets, H. M. Eblinger, Ed. Weinheim, Germany: Wiley-VCH Verlag, 2009, pp. 147-164.
[30] Y. Pomeranz, and H. L. Shands, "Giberlic acid in malting of oats," J. Food Sci., vol. 39, no. 5, pp. 950-951, 1974.
[31] M. J. Edney, J. K. Eglinton, H. M. Collins, A. R. Barr, W. G. Legge, and B. G. Rossnagel, "Importance of endosperm modification for malt wort fermentability," J. Inst. Brew., vol. 113, no. 2, pp. 228-238, 2007.
[32] J. Davidson, "Total and free amylase content of dormant cereals and related seeds," J. Agric. Res., vol. 70, no. 6, pp. 175-200, 1945.
[33] R. T. Roberts, P. J. Keeney, and T. Wainwright, "The effects of lipids and related materials on beer foam," J. Inst. Brew., vol. 84, pp. 9-12, 1978.
[34] D. Briggs, C. A. Boulton, P. A. Brookes, and R. Stevens, Brewing: Science and Practice, Cambridge: Woodhead Publishing, 2004, pp. 1- 18.