Table of Contents
INTRODUCTION
- When it comes to milling or grinding cereals, the formation of gluten is truly a marvel. This cohesive and elastic protein product is nothing short of magical, derived from the perfect combination of gliadin and glutenin.
- It’s amazing how it forms the water-insoluble part of wheat atta, obtained only after removing the starch and bran from the dough, beneficial in food technology principles.
- The gluten content is the key to unlocking the true strength of flour, making it an indispensable ingredient for any baker. Hard wheat is a powerhouse, packing in 11-13% gluten, making it the perfect choice for baking bread that’s hearty, chewy, and oh-so-delicious.
- On the other hand, soft wheat’s lower gluten content of 7-8% makes it ideal for crafting delicate biscuits and crispy crackers.
The Empowering Core Principle of Unleashing the Magic of Gluten
- The isolation of gluten involves preparing a dough from flour in a buffered sodium chloride solution. This dough is then washed with a buffered sodium chloride solution, followed by the removal of excess washing solution.
- The resulting wet gluten is dried, and a ball of gluten is weighed to determine its quantity.
REQUIREMENTS
Reagents
- Sodium chloride, 20 g/l solution, buffered to pH 6.2: Dissolve 200 g of NaCl in water and add 7.54 g of potassium dihydrogen phosphate (KH2 PO4 ) and 2.46 g of disodium hydrogen phosphate dihydrate (Na2 HP04 .2H2 O). Dilute to 10 liters with water. Prepare a fresh solution daily.
- Iodine-approx. 0.001 N solution.
PROCEDURE
- Grind approximately 100 g of the material using a pestle and mortar or a suitable food grinder.
- Sieve the ground material through a fine treble extra silk with a 150-micron IS Sieve aperture, collecting the material that passes through.
- Weigh about 25 g of the material accurately into a dish.
- Add approximately 15 ml of water to the material and create a dough, ensuring all the material is incorporated.
- Place the dough gently in a beaker filled with water and let it stand for 1 hour.
- Remove the dough and transfer it to a piece of bolting silk cloth with a 150-micron IS Sieve aperture. Wash the dough with a gentle stream of tap water until the water passing through the silk no longer turns blue when a drop of iodine solution is added.
- Spread the silk tightly on a porcelain plate for easier scraping.
- Using a spatula, transfer the residue from the silk to a tared porcelain dish.
- Spread the wet gluten into a thin layer and cut it into small pieces.
- Transfer any residue remaining on the spatula into the porcelain dish.
- Place the porcelain dish in an air oven maintained at 133 ± 2°C and dry for two hours.
- After drying, allow the dish to cool in a desiccator and then weigh the gluten.
CALCULATION
Where,
W2= weight, in g, of the dish with dry gluten,
W1= weight, in g, of the empty dish,
W = weight, in g, of the material taken, and
M = moisture, % in the sample
RESULTS AND INFERENCE
During the determination of dry gluten, it is important to note that the difference between the results of two determinations carried out simultaneously or in rapid succession by the same analyst should not exceed 0.5% of the dry gluten. This ensures consistency and accuracy in the measurements.
As mentioned earlier, the gluten content varies between different types of wheat. The strong and hard wheat typically contains 11-13% gluten, while the soft wheat has a lower gluten content of 7-8%.
This disparity in gluten content makes the hard wheat more suitable for bread making, as the higher gluten provides the necessary structure and elasticity for bread dough.
On the other hand, the lower gluten content in soft wheat makes it more appropriate for making biscuits and crackers, where a more delicate texture is desired.
PRECAUTIONS
To ensure accurate results during the determination process, it is important to follow certain precautions:
- Check the washings with iodine solution: It is essential to continue checking the washings until the gluten is free from starch. The addition of iodine solution helps detect any remaining starch, ensuring that only the gluten is measured.
- Use a 150-micron sieve: During the washing process, it is recommended to utilize a 150-micron sieve. This allows for the collection of small particles of gluten, ensuring that the measurement is accurate and representative of the gluten content.
By adhering to these precautions, one can obtain reliable and precise results when determining the gluten content of wheat flour. These measures help eliminate potential sources of error and ensure the accuracy of the analysis.
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