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