PROCESS EXPO | Expert in Residence
Into the Thick of Things
Dave Krishock | Kansas State University
Last month in this space, I talked about hydrocolloids and modified or specialty starches in a very broad sense. Let’s get into the thick of it with how hydrocolloids (a.k.a. gums) can solve some “sticky situations.”
Hydrocolloids’ main effects result from their ability to bind water and/or form networks. They are used to influence texture and mouthfeel, as well as water-binding and the stabilization of crystallization properties of confectionary products and ice cream. From the consumer acceptance/marketing side, most gums used in the baking industry are non-GMO, all-natural trans-fat free, and are excellent sources of dietary fiber.
Let’s look at one specific example of hydrocolloid possibilities for a donut glaze formulation. To control crystal formulation, reduce syneresis without excessive chipping and cracking while still reducing adherence to packaging materials, commonly used hydrocolloids would be locust bean gum, (LBG), guar gum, carrageenan, alginate, gum Arabic, and agar. Each has their specific attributes, processing requirements, and cost considerations.
Agar, produced from seaweed, forms firm gels, imparts neither flavor nor color, and is very heat stable (important for a donut glaze). However, it must be boiled to be activated. In bakeries that don’t “cook up” donut glazes, agar would not be very functional. Agar also tends to have a higher cost then other gums even if it is used at only a 0.4% formula basis.
A much better choice would be carrageenan, the kappa variety, produced from red kelp. It has good water-binding abilities, provides increased viscosity, is thermally reversible while it remains clear when combined with sugar, and imparts no flavor notes. Kappa would need to be used at a higher level, 1.0–1.5% formula basis, but that would be offset by its lower cost. To provide even better interactive synergies for the needed donut glaze, carrageenan could be combined with locust bean gum for a stronger, smoother, and more heat-stable application.
The proper selection of hydrocolloids in fillings, icings, and sweet goods applications require a much more extensive understanding than this space will allow as the specific properties of each hydrocolloid are very unique to the required baked/fried product attributes and various processing parameters. While hydrocolloids are used extensively in the food and beverage industry, they play a major role in the stabilization of icings, glazes and filling in the baking industry.
Dave Krishock [email protected]
Bakers National Education Professor
Dept. of Grain Science and Industry
Kansas State University