Objective To study the effect of volume fraction of viscosity of a suspension To study the effect of shear rate on the pasting behavior of rice flours. Rotational Rheometer with Cone Plate Fixtures Precise control of shear stress or shear rate Small sample size (100 mg) Viscosity in fundamental units TA Instruments Rotational Rheometer Cone Plate Fixtures Peliter Plate for temperature control 1
1 Objective To study the effect of volume fraction of viscosity of a suspension To study the effect of shear rate on the pasting behavior of rice flours. Rotational Rheometer with Cone & Plate Fixtures • Precise control of shear stress or shear rate • Small sample size (100 mg) • Viscosity in fundamental units TA Instruments Rotational Rheometer Peliter Plate for temperature control Cone & Plate Fixtures
Cone was fabricated from Polysulfone Plastic to provide for better temperature control. Cone was machined with an angle of 4 and a diameter of 4 cm. 2 Y= Cone and plate geometry provides for a constant shear rate throughout the gap. Types of Rice Grains Long Medium Short Waxy 00 0 L-204 M-202 Koshihikari Calmochi-101 Increasing Amylose Content 2
2 Cone was fabricated from Polysulfone Plastic to provide for better temperature control. Cone was machined with an angle of 4° and a diameter of 4 cm. γ = Ω α Cone and plate geometry provides for a constant shear rate throughout the gap. L-204 M-202 Koshihikari Calmochi-101 Long Medium Short Waxy
Materials Rice:Short grain S-102 (18%amylose) Medium grain M-202(17%amylose) M-401(19%amylose) Long grain L-202 (25%amylose) L-204 (23%amylose) Waxy grain CM-101(1%amylose) Rice Grain 6mm Starch Granules .Granules of Glucose Polymers amylopectin and amylose Size-5μmto50um .Crystalline and Amorphous regions 3
3 Materials Rice: Short grain S-102 (18% amylose) Medium grain M-202 (17% amylose) M-401 (19% amylose) Long grain L-202 (25% amylose) L-204 (23% amylose) Waxy grain CM-101 (1% amylose) 6 mm •Granules of Glucose Polymers amylopectin and amylose •Size - 5µm to 50µm •Crystalline and Amorphous regions R ci e 5 µm
Amylopectin .Highly Branched Glucose Polymer .Main Component of Starch MW-107to109 Fig.4.37.Arrangement of amylopectin molecules in a starch granule
4 •Highly Branched Glucose Polymer •Main Component of Starch •MW - 107 to 109
Amylose .Linear Glucose Polymer .Smaller Component of Starch .MW 105 to 106 Amylose content (% Short Grain 14.8 (Koshihikari) Medium Grain 16.8 (M-202) Medium Grain 17.5 (M-401) dwld logM Differential M.W.Distribution 20 MoI M4401 M202 61 Calmochi 174 5 01.0e+7 1.0e+8 1.0e+9 M(g/mol) 5
5 •Linear Glucose Polymer •Smaller Component of Starch •MW - 105 to 106 Amylose content (%) Short Grain (Koshihikari) Medium Grain (M-202) Medium Grain (M-401) 14.8 16.8 17.5 1.0e+7 1.0e+8 1.0e+9 M (g/mol) 0 5 10 15 20 dW/d logM Differential M.W. Distribution Rice Mw 106 M401 72 M202 61 Koshihikari 84 Calmochi 174
Sample preparation Ground rice to 0.5 mm flour particle size Make 8%rice flour slurry with distilled and degassed water Stir and degas the slurry for 15 min Aqueous Suspension of Starch Granules 0° 0 8 00 80 0 0 00 0 0 a 00 0 8 0 0 0 0 59. o P 0 。3 0 64C 66'C 6
6 Sample preparation • Ground rice to 0.5 mm flour particle size • Make 8% rice flour slurry with distilled and degassed water • Stir and degas the slurry for 15 min Aqueous Suspension of Starch Granules
Amylograph or Pasting Curve of Starch Granules during Heating 0.5 100 0.4 (s.ed) 02 , 60 o 200 400 600 Time(sec) 0.600 100.0 6.0 Temperature(Deg C) 10i.0 300.0500.0 Global time(s) M202 Rice Flour Viscosity Profile Analysis Rice Flour Concentration(%) Temperature (C) 100 Time(s) 7
7 60 80 100 Temperature °C 0 0.1 0.2 0.3 0.4 0.5 Viscosity (Pa .s) 0 200 400 600 800 Time (sec) Amylograph or Pasting Curve of Starch Granules during Heating M202 Rice Flour Viscosity Profile Analysis Rice Flour Concentration (%) Global time (s) Temperature (Deg C) 0 100.0 300.0 500.0 800.0 0.6000 0 0.1000 0.2000 0.3000 0.4000 0.5000 Viscosity (Pa.s) 100.0 40.0 50.0 60.0 70.0 80.0 90.0 6% 7% 8% 9% 60 80 100 Temperature (°C) 0.0 0.2 0.4 0.6 Viscoisty (Pa .s) 200 400 600 800 1000 Time (s) Non-waxy Waxy
0.8 95 100sl (s Ed)uso3stA 04 175s 75 200*-1 55 250 500 750 1000 Time(s) Viscosity(Pa·s) 0.10 CL-101 M-202 M-401 0.5 S-102 L-204 L-202 0.0 70 80 90 TemperatureC Other Polysaacharides 8
8 55 75 95 0.2 Temperature (°C) 0.4 0.6 0.8 Viscosity (Pa s) . 0 250 500 750 1000 Time (s) 175 s -1 200 s -1 300 s -1 400 s -1 600 s -1 100 s -1 0.00 0.05 0.10 Viscosity (Pa .s) 50 60 70 80 90 Temperature °C M-202 L-202 CM-101 M-401 L-204 S-102 ONSET TEMPERATURE Other Polysaacharides
Polysaccharides ·Seaweed ·Plant Exudates ·Seed gums Plant structural material ·Microbial gums ·Starch Seaweed ·Agar ·Alginate ·Carrageenans ·Furcellaran Problem:Alginates are heteroglycans made from B-D-marmuronic and a-Lguluronic acids join by 4 linkages. The polysccharide is linear and consists of periods of three Distinct repeating regions as defined below 【+4)-go-ManpA(t+4外eo-ManpA0+l. 【→)-gt-GupA→4at-GpA→L 【+4)-3-p-ManpA(t-+4e-t:GupA1-+l。 A solution ofalginate will gel with calcium.Draw The structures of the three regions and predict which region forms The gel with calcium cross linking. Plant Exudates ·Gum Arabic ·Gum Ghatti ·Gum Tragacanth ·Karaya Gum 9
9 Polysaccharides • Seaweed • Plant Exudates • Seed gums • Plant structural material • Microbial gums • Starch Seaweed • Agar • Alginate • Carrageenans • Furcellaran Problem: Alginates are heteroglycans made from β-D-mannuronic and α-L-guluronic acids join by 1--> 4 linkages. The polysaccharide is linear and consists of periods of three Distinct repeating regions as defined below A solution of alginate will gel with calcium. Draw The structures of the three regions and predict which region forms The gel with calcium cross linking. Plant Exudates • Gum Arabic • Gum Ghatti • Gum Tragacanth • Karaya Gum
Plant Seed Gums ·Locust Bean Gum ·Guaran Gum ·Tamarind Flour ·Arabinogalactan Plant Structure ·Cellulose ·Hemicellulose ·Pectin Microbial Gums Xanthan gum 10
10 Plant Seed Gums • Locust Bean Gum • Guaran Gum • Tamarind Flour • Arabinogalactan Plant Structure • Cellulose • Hemicellulose • Pectin Microbial Gums • Xanthan gum
