Has the nutritional value of wheat changed? Ravindra Chibbar Professor & Canada Research Chair Crop Quality (Molecular Biology & Genetics) ravi.chibbar@usask.ca Conflict: Member Science Advisory Committee, Healthy Grains Institute, Toronto, Ontario, Canada Department of Plant Sciences October 11, 2016
Presentation Outline Wheat a global crop Wheat a nutritionally rich grain Proteins Carbohydrates Minerals Conclusions Department of Plant Sciences
Wheat a Global Crop
Wheat production in the world 2013-2014
Harvest time for Wheat around the World Month January February March April May June July August September October November December Region Argentina, Southern Australia, Chile, Uruguay Upper Egypt, Southern India Egypt, India, Libya Southern Egypt, India, Iran, Iraq, Mexico, Syria Algeria, Morocco, Central and Southern Asia, Tunisia, Southern USA Central China, Southern Europe, Central USA Austria, Central Europe (Northern), Central Russia, Northern USA Britain, Central Europe (Southern) Southern Russia, Central USA Canada, Scandinavia, Northern Russia, Northern USA Northern Canada, Northern Russia, Northern Scandinavia Northern Argentina, Brazil South Africa, Argentina, Central Australia Wrigley, C..W. 2009, Wheat: A Unique Grain, In Wheat eds. Khan, K. and Shewry, P.R, AACCI, pp7
Cereal grains a major component of human diet Lobell & Gourdji, 2012, Plant Physiology 160:1686-1697
Wheat is consumed as diverse regional and ethnic products
Increase in global population
Wheat grain Bran Aleurone layer Endosperm Germ / Embryo
Research Question Is modern wheat nutritionally different from its predecessor wheat cultivars released in Canada?? Analyzed Protein, Carbohydrates, and Minerals in historical and modern day wheat varieties in Canada
Varieties used in Historical Wheat Trials (1989 2007) Year of registration Number of Varieties 1860 1900 4 1901 1950 12 1951 1975 8 1976 2001 12 Total 36
Photo by Gloria Gingera
Wheat varieties - 2014
Modern and heritage wheats - 2014
Modern wheat varieties - 2014
Genetic gains and rate of change in selected traits over a century of wheat improvement in Canada Trait units Mean rate units / year P value Grain yield Kg / ha 15 0.000 Kernel weight mg 0.02 0.019 Plant height cm - 0.09 0.000 Days to spike emergence days - 0.02 0.000 Grain Protein % 0.01 0.001 Flour Yield % 0.006 0.110
Experimental Study Plan A B A B C D C D 2013 2014
Gluten Osborne classification (1924) Glutenins and Gliadins Proteins that form the gluten complex are major determinants for wheat grain end use Gluten impart unique viscoelastic properties of the dough
Grain Proteins SOY Slightly hydrophobic High ionic strength WHEAT GLUTEN More hydrophobic than soy Low ionic strengths CORN GLUTEN Too hydrophobic Gliadin, Midwest Grain Products, Kansas, U.S.A., p.21
Function and Structure of Gliadins Hsieh, F-H., Use of Gliadin and Wheat Glutenin in Pasta and Noodles, Food Science & Engineering Unit, University of Missouri- Columbia.
Glutenin structure and characteristics Gliadin, Midwest Grain Products, Kansas, U.S.A., pp.13, 15
Protein determination methods Wheat grain Wheat meal Extract 250 mg of wheat flour with 50% isopropanol LECO Analysis for protein concentration Pellet (Polymeric proteins) Freeze dried Bean et al 1998, Cereal Chem., 75 : 374-379 Dupont et al 2005, J. Agri. Food. Chem., 53 : 1575-1584
Concentration (%) 16 Protein concentration in wheat lines 15 14 13 12 11 10 9 1860-1900 1901-1950 Canadian Wheat Varieties 1950-2000 2001-2007
Percent total grain protein Wheat grain polymeric protein fraction 65 60 55 50 45 40 35 30 Canadian Wheat Varieties 1860-1900 1901-1950 1950-2000 2001-2007
Percent Total Protein Monomeric protein fraction 65 60 55 50 45 40 35 30 25 20 Canadian Wheat Varieties 1860-1900 1901-1950 1950-2000 2001-2007
Mean protein content of Canada Western Red Spring wheat (1927 2011) Years Edwards, N.M., Hatcher, D.W., Fu, B.X. (2012, Quality of Western Canadian wheat 2011, Canadian Grain Commission, Winnipeg, ISSN 498-9654, pp12.
Mean protein content of Canada Western Amber Durum wheat (1963 2011) Years Edwards, N.M., Hatcher, D.W., Fu, B.X. (2012, Quality of Western Canadian wheat 2011, Canadian Grain Commission, Winnipeg, ISSN 498-9654, pp34
Extraction of Glutenins and Gliadins Flour Precipitate with NH 4 AC/MeOH Extract with 7% propanol,0.3 N NaI Precipitate with Acetone Gliadin Pellet 1 Extract with SDS and DTT Albumin - Globulin Dupont et al 2005, J. Agric. Food. Chem.,Vol.53(5), 1575-1584 Starch Glutenin Precipitate with NH 4 AC/MeOH
Glutenins 198 98 HMW Glutenins 62 49 LMW Glutenins 38 28 17 14 6 3
HMW Glutenins - Analysis 5 8 10? 2 7 9 12? 1? 2*? 6
Starch BRAN ENDOSPERM Amylose GERM Grain Wheat kernel Starch granules Amylopectin Starch digestibility
Experimental Plan Total starch Starch Amylose (HPSECmethod) Amylose (Iodine method) Starch Granule Size Distribution Dietary fibre Mineral analysis
Starch % Starch concentration 80 70 60 50 40 30 20 10 0 1860 Cultivars 2007
Amylose % 35 Amylose concentration 30 25 20 15 10 5 0 Cultivars 1860 2007
Amylose % Apparent Amylose concentration 35 30 25 20 15 10 5 0 1860 Cultivars 2007
Redfife Preston Stanley Huron Marquis Early Red Ruby Garnet Red Bobs Ceres Thatcher Apex Regent Rescue Redman Saunders Selkirk Lake Canthatch Pembina Manitou Neepawa Napayo Sinton Chester Columbus Katepwa Roblin Laura CDC Teal AC Barrie AC Intrepid Mckenzie Superb Harvest Lillian Unity VB volume % C-type starch granules (<5µm) 12 10 8 6 4 2 0 1860 Cultivars 2007
volume % B-type starch granules (5-15µm) 45 40 35 30 25 20 15 10 5 0 1860 Cultivars 2007
volume % A-type starch granules (>15µm) 80 70 60 50 40 30 20 10 0 1860 Cultivars 2007
Regression analysis of starch characteristics No significant trend observed for starch characteristics
Resistant Starches Escape digestion in the small intestine but are fermented in the large intestine by bacterial microflora Potential health benefits and functional properties Digestive activities in the gastrointestinal tract include the chewing and mixing of food, the release of nutrients from food, the absorption of nutrients into the cells, and the excretion of wastes in the feces. Hegarty, V. Nutrition: Food and the Environment. 1995, Eagan Press, p.18. Cereal Foods World, American Association of Cereal Chemists, September 1998, Vol. 43, No. 9, pp.690-691.
Soluble starch (%) Starch digestibility parameters 100 80 RS RDS Readily Digestible Starch 60 40 20 0 SDS RDS 0 30 60 90 120 240 SDS Slow Digestible Starch RS - Resistant Starch Time (min)
Wheat Variety In vitro enzymatic hydrolysis of wheat grain meal to assess its digestibility Year of release Readily Digestible Slow Digestible Resistant Starch Red Fife ~1860 25.4 64.0 10.6 Preston 1892 21.0 63.2 15.7 Stanley 1895 21.2 70.6 8.2 Huron 1900 20.1 57.9 21.9 Marquis 1909 19.0 51.6 29.4 Thatcher 1935 24.2 68.1 7.6 Saunders 1947 24.9 69.1 6.1 Neepawa 1969 21.9 70.7 7.4 CDC Teal 1991 22.3 73.5 4.1 Unity VB 2007 25.8 69.9 4.4
Mineral Analysis Canadian Light Source (Synchrotron) VESPERS beam line
Synchrotron X-ray fluorescence spectra used for mineral determination in wheat grain meal a. Control starch b. Starch spiked with mineral cocktail c. Wheat AC Vista d. Chickpea Jaiswal et al. (2016) Microchemical J. 126: 509-514
mgkg -1 mgkg -1 Regression analysis of mean concentration of Selenium (Se) and Zinc (Zn) for two years (2013-2014) Se Zn 1 40 0.95 35 0.9 30 0.85 25 0.8 0.75 0.7 0.65 20 15 10 0.6 0 50 100 150 Years 5 0 50 100 150 Years Year 0 = 1860; Year 150 = 2010
mgkg -1 mgkg -1 Regression analysis of mean concentration of Iron (Fe) and Nickel (Ni) for two years (2013-2014) 90 80 70 Fe 0.45 0.4 0.35 Ni 60 0.3 50 0.25 40 0.2 30 0.15 20 0 50 100 150 Years 0.1 0 50 100 150 Years Year 0 = 1860; Year 150 = 2010
Regression analysis of mean concentration of Calcium (Ca) and Manganese (Mn) for 2 years (2013-2014) Year 0 = 1860; Year 150 = 2010
Grains - Great Metabolic Regulators Wheat is a very nutritious grain. Blood sugar Blood cholesterol Intestinal function Nutritional composition of wheat grain of today is similar to that grown more than a century ago.
Acknowledgements Plant Sciences / Crop Development Centre, U of S Professor Pierre Hucl Dr. Monica Båga Dr. Sarita Jaiswal Dr. Udhaya Kannan Dr. Manu Gangola Dr. Bharathi Ramadoss Ms. Connie Briggs Ms. Swarna Ranasinghe Mr. Craig Irvine Saskatchewan Structural Sciences Centre Dr. Ramaswami Sammynaiken Mr. Robert Bauer Canadian Light Source (Synchrotron) - Saskatoon Dr. Renfei Wang