Tip of the Week: A Look Into Our Labs

AIB International, located in America's heartland is home to eight unique labs that are the heartbeat of the company since the facility was built in 1978.

In the Science Training Lab, students begin to explore analytical tests that are used to determine characteristics of flour and other bakery ingredients. Like AIB’s Pilot Plant Labs, it was created to provide a safe place for baking students to learn first-hand how to run a variety of tests, and more importantly, how to interpret the results.

The lab is composed of two rooms: classroom and rheology lab. The classroom is designed to be extremely flexible, with a teaching island at the front, tables for students in the center, and additional benches around the sides. Equipment is brought out as needed.

One common question students ask in our science training lab is “What are pH and TTA used for in the baking process?”. pH is used to measure the power of the hydrogen ion – essentially how acidic the sample is. The greater the number of hydrogen ions in a given volume, the lower the pH will be (the pH scale typically runs from 0 to 14). Because the scale is logarithmic, for every drop of one whole unit in pH, the hydrogen ion concentration increases ten-times. The acids found in bakery ingredients and products generally ionize about 5% (ionize means to split apart, releasing that free hydrogen ion needed for pH). The pH impacts color, enzymes and yeast activities, gluten development, chemical leavening, mold growth, and the effectiveness of mold inhibitors.

Color changes and meters are used to measure pH. Using a strip of special pH paper coated with glucose syrup and comparing the reaction color to a standard chart is an easy, but less precise way to monitor the pH of the incoming ingredient.

PRO TIP: when using pH papers, place a drop of the sample onto the paper rather than emerging the pH paper into the sample, thereby contaminating your ingredient.

To measure the pH of a dough-sample or finished cake crumb, we usually disperse the sample in water and use a pH meter to provide a more accurate number, which is then compared to the desired pH range. Process control charts often require information on pH changes during processing, especially for fermented products.

TTA, or total titratable acidity, does just what the name states – it measures all of the acids present, not just the ions (that is pH). TTA provides the big picture approach to fermentation process control, monitoring 100 percent of the acids being produced (pH only measures about 5 percent). Meters are generally preferred for monitoring titration, although color indicators can be used. A known basic solution is run from a burette into the acidic sample that was diluted in water in a conical flask, swirling the flask as the base is added. When the end point is reached, the burette tap is closed, and the volume of base added is recorded. The more base needed the higher the total acid in the sample. During fermentation, you will see significant changes in TTA long before changes in pH will occur.

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