Gluten Index TesterIt is a specialized instrument for dehydration and gluten index determination of wheat flour wet gluten. Its principle is to make dough from flour samples using sodium chloride buffer solution, wash and separate starch, sugar, cellulose, soluble protein, etc. in the dough using sodium chloride buffer solution, and then remove excess washing solution. The remaining gelatinous material is wet gluten. Under the action of centrifugal force, the wheat gluten is centrifuged to remove the water adhered to the surface and allow some wet gluten to pass through the sieve box orifice plate. After weighing and calculating, the wet gluten content and gluten index in flour or whole wheat flour can be obtained. After drying the wet gluten with a dryer, the dry gluten content and gluten water holding capacity can be obtained by weighing and calculating.

　　Gluten Index TesterThe general operation steps are as follows:

1. Sample preparation: Take a certain amount of wheat flour, granular flour, or whole wheat flour, usually around 10g, accurately weigh it with a balance, and pour it into a washing cup.

2. Noodles: Add an appropriate amount of sodium chloride buffer solution, usually a 2% -5% concentration sodium chloride solution, to the flour in the washing cup. The solution temperature should be controlled between 20 ℃ -24 ℃. Start the mixer and stir at a speed of 120r/min ± 2r/min for 1-2 minutes to fully mix the flour with the sodium chloride solution to form a dough.

3. Washing: Wash the dough repeatedly with sodium chloride buffer solution, and the washing time can be set within the range of 1-15 minutes, usually 5-7 minutes. During the washing process, the solution flow rate is usually 50mL/min-56mL/min to remove water-soluble substances such as starch from the dough until the washing solution is clear. At this point, the remaining gelatinous material is wet gluten.

4. Centrifuge: Place the wet gluten into a centrifuge box, being careful not to separate the gluten balls. If only a single gluten ball needs to be centrifuged, about 3g of rubber block should be weighed on another centrifuge box instead of the sample as a weight to balance the centrifuge. Close and flatten the centrifuge cover plate, set the centrifuge speed to 3000r/min or 6000r/min ± 5r/min, and centrifuge for 1 minute. Start the centrifuge, wait for a moment after centrifugation is complete, and then open the centrifuge cover plate.

5. Weighing calculation: Carefully scrape off the gluten passing through the sieve plate with a stainless steel scraper, weigh it on a 0.01g sensory balance, and then remove the gluten that has not passed through the sieve plate with tweezers and weigh it together with the gluten passing through the sieve plate on the balance to obtain the total weight of the gluten. According to the formula, calculate the content of wet gluten and gluten index. Gluten index=weight of wet gluten remaining on the sieve plate/total weight of wet gluten x 100%.

6. Drying (optional): If you need to measure the dry gluten content and gluten water holding capacity, you can turn on the power of the dryer, preheat for about 10 minutes, open the lid, place the wet gluten on the drying plate, close the lid, and dry at a temperature of 150 ℃ -200 ℃ for about 6 minutes. Weigh immediately after removal and calculate the dry gluten content and gluten water holding capacity.