TRADITIONAL AFRICAN CEREAL FOODS AND BEVERAGES

Transcription

1 TRADITIONAL AFRICAN CEREAL FOODS AND BEVERAGES HOW THEY CAN HELP US DEVELOP BETTER GLUTEN-FREE PRODUCTS John Taylor Institute for Food, Nutrition and Well-being and Department of Food Science University of Pretoria

2 WHY GLUTEN-FREE FOOD AND BEVERAGE PRODUCTS? Where are all these new apartment buildings China?

3 No In fact Addis Ababa Ethiopia

4 Until the Age of Discovery starting in the 15 th Century Most People in the World did not know Wheat and Barley People in the Americas, Asia and Africa Developed Sophisticated Technologies to Optimise the Processing of their Local Grains

5 Phylogenetic relationship between the cereal species

6 ` Phylogenetic relationship between the cereal species `

7 Beers and Non-alcoholic Cereal Beverages

8 Uji Motoho Mageu Kenya Lesotho South Africa African Soured Non-alcoholic Cereal Beverages

9 Bacteria from a traditional African soured beverage (strain of Lactobacillus plantarum) Lactic acid bacteria on starch granules in sorghum fermentation

10 Traditional Opaque-type Sorghum Beer Southern Africa

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12 Sorghum Lager Beer Brewery next to Lake Victoria - Uganda

13 Temperature (oc) Sorghum Malt or Thermostable Alpha-amylase Proteases Cellulases + Raw Sorghum COOKING Fungal alpha-amylase MASH IN MASHING Brewing time (min) Simplified General Process for Brewing Sorghum Lager/Stout using Raw Sorghum, Sorghum Malt and Commercial Enzymes

14 Traditional Cloudy-type Pito (Dolo) Beer - Ghana (Burkina Faso)

15 Dolo/Pito Beer Making in Burkina Faso and Ghana Sorghum floor malting for Pito Beer- Ghana

16 Mashing

17 Mashing Adding Grewia bark (contains a hydrocolloid) to sorghum malt mash

18 Starchy adjunct cooking Adding the starchy adjunct to the mash cooker

19 Starchy adjunct Cooking and Mashing processes After cooking The adjunct it is returned back to the mash vessel (foreground) Mashing is then carried out overnight

20 Flocculation of wort insoluble solids

21 Wort clarification

22 Sorghum malt What Were The Ladies Doing In the Mashing Process? Warm Water Step 1: Add sorghum malt to warm water with stirring

23 Step 2: Add Hydrocolloid Allow starchy solids to settle out

24 Step 3: Remove starchy solids Enzyme extract Starchy Solids `

25 Step 4: Cook starchy solids to gelatinise the starch Enzyme extract Starchy Solids ` COOK

26 Cooked Starchy Solids Step 5: Allow to cool somewhat Add cooked starchy solids back to enzyme extract Enzyme Extract

27 Step 6: Mash Malt amylases hydrolyse cooked starch into sugars

28 From: G.H. Palmer et al MIRCEN J Appl. Micro. Biotech 5: 265 Recently, a decantation mashing procedure was devised to convert sorghum malt more efficiently 1. The mash is carried out at 45 o C for 30 min 2. The active enzymic wort (amylase enzyme rich solution) is decanted 3. The starchy-grist residue is heated to 80 o C or 100 o C to gelatinize the starch 4. The mash is then cooled and the decanted enzymic wort is readded to achieve a conversion (starch hydrolysis) temperature of 65 o C

29 Decoction (from β-amylase) (from α-amylase) Effect of Different Mashing Conditions with Sorghum Malt Taylor, JRN J. Amer. Soc. Brew. Chem. 50:13

30 Breads and Baked Goods

31 OLD? DOUGH-MAKING TECHNOLOGY LACTIC ACID FERMENTATION Sourdough Technology Traditional in Africa For Making Breads with Non-wheat Cereals - Sorghum, Maize, Millets, Rice, Teff Traditional KISRA flatbread from Sorghum - Sudan

32 INJERA flatbread - Ethiopia

33 INJERA FLOWCHART KEY INJERA TECHNOLOGIES Mixed yeast LAB sourdough fermentation Pre-gelatinise part of the dough Yetneberk S. et al. Cereal Chem

34 Sourdough Fermentation Increases Maize Bread Loaf Volume - Much larger gas cells and open crumb structure Falade A T et al. J. Cereal Sci

35 Sorghum ferm Wheat-(standard) Sorghum unferm B Fonio 2 ferm B Fonio 1 ferm B Fonio 2 unferm B Fonio 1 unferm Effect of Sourdough fermentation on Mixolab dough profile Sorghum and Fonio Compared to Wheat W Fonio 1 ferm W Fonio 2 ferm W Fonio 1 unferm W Fonio 2 unferm Edema, M.O. et al Starch/Stärke

36 Sourdough fermentation produces a more cohesive maize dough - Larger more uniform gas bubbles/cells in the dough and bread Dough Bread Straight dough With yeast Chemically acidified dough With yeast L. plantarum fermented dough With yeast Sourdough fermented dough With yeast L. plantarum fermented dough No yeast Sourdough fermented dough No yeast Falade A T et al. J. Cereal Sci

37 Anton Paar GmbH Anton Paar GmbH Anton Paar GmbH Anton Paar GmbH Anton Paar GmbH Anton Paar GmbH A 10 6 Pa G' 10 3 d c CSD a b spontaneously fermented maize dough without yeast 1c G' Storage Modulus l.plantarum fermented maize dough without yeast1b 1 G' Storage Modulus myny2b 1 G'' G' Storage Modulus chny3a G' Storage Modulus b c d CSD a Pa 10 3 spontaneously fermented maize dough without yeast 1c 1 G'' Loss Modulus l.plantarum fermented maize dough without yeast1b 1 G'' Loss Modulus 10 2 myny2b 1 G'' Loss Modulus chny3a 1 G'' Loss Modulus 10 1 CSD c a b d spontaneously fermented maize dough without yeast 1 Shear Stress l.plantarum fermented maize dough without yeast1b 1 Shear Stress myny2b 1 Shear Stress chny3a 1 Shear Stress 10 2 Elastic modulus Loss modulus Shear stress B G' 10 6 Pa % Strain Elastic modulus G', G'' c a b d d C 160 Temperature T b a c d b c a * % % 10 2 Strain Strain 10 5 Pa s msscny4a lpny1 1 G' Storage Modulus G' myny2b 1 Storage Modulus G' chny3b 1 Storage Modulus a c 10 3 G' Storage Modulus Complex viscosity b d C C 160 Temperature T Temperature T Effects of L. plantarum fermentation or multiple 1 strains starter culture G', G'' b a c a: Maize dough. b: Chemically acidified maize dough. c: L. plantarum fermented maize dough. d: Multiple strains starter culture fermented maize dough d d a c b tan( ) msscny4a lpny1 1 * Complex Viscosity myny2b * Complex Viscosity chny3b 1 * Complex Viscosity d * Complex Viscosity Tan delta fermentation - Rrheological properties of maize dough A: strain sweep analysis parameters B. Temperature sweep analysis parameters b a c d c G', G'' a b b d a c msscny4a 1 lpny1 1 tan( ) Damping Factor myny2b 1 tan( ) Damping Factor chny3b 1 tan( ) Damping Factor tan( ) Damping Factor Falade AT et al. J Cereal Sci. 2014

38 b c d 10µm 10µm e f 10µm 10µm b Effect of Sourdough Unfermented Fermentation on Fonio Starch Granules Edema MO et al Starch/Staerke Fermented 10µm 10µm 10µm 10µm

39 MODIFY MAIZE ZEIN WITH LACTIC/ACETIC ACID A = Unmodified Zein + Starch flour after mixing B = Modified Zein + Starch flour after mixing; C = Dough properties D = Alveograph dough bubble of Modified Zein + Starch dough Sly AC et al J Cereal Sci

40 Wheat flour Maize flour Maize flour +Zein - only

41 FUTURE OF GLUTEN FREE PRODUCTS IN AFRICA Combine Traditional and Modern Technologies Beers and non-alcoholic cereal beverages Reduce gelatinization temperature of tropical cereal starches Optimise tropical cereal malt beta-amylase activity Improve tropical cereal protein and cell wall digestibility Lactic acid fermentation Breads and Baked Goods Application of flour improvers Enzymes etc Use of Hydrocolloids and Gums Develop novel dough-making technologies To handle batters Co-proteins Legume proteins + Cereal proteins Sourdough fermentation See Forthcoming Special Issue of the Journal of Cereal Science Functionality of Cereal Based Non-gluten Dough Systems Edited by John Taylor and Cristina Rossell

42 DEDICATION Dr Mojisola Edema Federal University of Technology, Nigeria