Wheat and Flour Testing Methods - WHEATFLOURBOOK.ORG
Wheat and Flour Testing Methods - WHEATFLOURBOOK.ORG
Wheat and Flour Testing Methods - WHEATFLOURBOOK.ORG
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Solvent Retention Capacity (SRC)<br />
Method<br />
1. Prepare four solvents: deionized water, 50 percent<br />
sucrose, 5 percent sodium carbonate, <strong>and</strong> 5 percent lactic<br />
acid.<br />
2. Weigh 5 grams of flour in a 50 milliliter conical bottom<br />
polypropylene centrifuge tube for mixing with each<br />
solvent.<br />
3. Add 25 grams of a solvent <strong>and</strong> cap tube.<br />
4. Shake vigorously for 5 seconds to suspend flour.<br />
5. Shake for 5 seconds at 5, 10, 15, <strong>and</strong> 20 minutes.<br />
6. Centrifuge for 15 minutes without braking.<br />
7. Invert tube <strong>and</strong> drain for 10 minutes.<br />
8. Weigh tube with residue.<br />
9. Repeat steps 2 through 8 for each solvent.<br />
Results<br />
• Solvent retention capacity (SRC) is the weight of solvent<br />
held by flour after centrifuging<br />
• SRC is expressed as percent of flour weight, on a<br />
14 percent moisture basis.<br />
• Four solvents are independently used to produce values<br />
for each solvent: water SRC, 50 percent sucrose SRC,<br />
5 percent sodium carbonate SRC, <strong>and</strong> 5 percent lactic<br />
acid SRC.<br />
Why is this important?<br />
Generally, lactic acid SRC is associated with gluten protein<br />
characteristics. Sodium carbonate SRC is related to levels of<br />
damaged starch <strong>and</strong> sucrose SRC with pentosan components.<br />
Water SRC is influenced by all water adsorbing components<br />
in flour. The combined pattern of these flour SRC results<br />
establishes a practical flour quality <strong>and</strong> functionality profile<br />
that is useful in predicting baking performance.<br />
<strong>Wheat</strong> <strong>and</strong> <strong>Flour</strong> <strong>Testing</strong> <strong>Methods</strong>: A Guide to Underst<strong>and</strong>ing <strong>Wheat</strong> <strong>and</strong> <strong>Flour</strong> Quality: Version 2