Unlike dough made from wheat flour, gluten-free dough does not easily form into a smooth ball because it lacks this important binder. That poses a challenge for dough and can also pose a challenge before final baking.
For frozen or chilled dough products such as cookies, pizzas and breadsticks, the result after baking tends to be softer or chewier than most people might expect. For soft cookies that might be acceptable. But crispy, thin-crust pizza, for example, is much more difficult to achieve with a sticky dough.
During processing, dough that sticks to mixer blades and the sides of mixing/blending equipment can increase cycle times. Thorough mixing can become more difficult with gluten-free products, yet overmixing can impact dough quality and the texture of the finished baked product. At the same time, stickiness can contribute to yield losses per batch. Losses of just 2-3 percent can add up. Equally important, stickier dough can put a drag on downstream forming or processing operations — increasing process variability and contributing to unnecessary downtime, waste, and inefficiency.
Chilling with ice at the mixer, especially bagged ice, is inherently prone to batch variation and increased labor, and that is a special challenge for bakeries scaling up. Tight temperature control before or during mixing can help alleviate these issues for faster cycle times, more repeatable operations, better dough handling characteristics, and more consistent quality of the finished product. With the proper know-how and engineering, processors can usually achieve such results cost-effectively with cryogenic chilling technology.
A new, in-line cryogenic injection system can chill flour and other dry ingredients to within +/- 1 degree F of a setpoint as they travel from the silo to the mixer/blender. For dough processing, chilling dry ingredients as they are pneumatically conveyed is almost always preferred over batch chilling with ice at the mixer. New dry-ingredient chilling systems can provide an important upgrade over older chilling methods, or can be easily retrofitted to replace an older cryogenic system.
Leading technology suppliers can customize dry ingredient chilling systems to meet plant-specific requirements. Prior to system installation, operating parameters for any new ingredient can be validated at a test laboratory. Dough and baking operations should always consider an engineered flour-chilling system when facing a major upshift in demand or planning an expansion, or whenever specifying a new silo or dry-ingredient pneumatic conveyor system.
Bottom-Up Chilling Approach
Another alternative to any top-chilling method at the mixer is to inject liquid nitrogen or carbon dioxide (CO2) from the bottom. Cryogenic bottom-injection (BI) systems are designed to use the cryogen more efficiently than chilling with dry ice pellets or even CO2 snow from the top. The liquid cryogen is injected into food as it is mixing, and the cryogen captures additional BTUs in the phase change from liquid to gas, or liquid to solid to gas with CO2.
Bottom injection systems have proven widely successful in the meat and poultry industry for chilling ground protein and fat during blending. If not properly chilled, fat can smear. Just as in the baking industry, more consistent temperature control in batch mixing can mean more consistent forming and handling downstream — and better finished product quality.
Advanced BI chilling systems can be installed when purchasing a new mixer/blender, or retrofitted to existing mixer/blenders. Design is key. Advanced systems are always customized to maximize processing efficiency, and these usually start with an in-plant assessment.
In the baking industry, gluten flour doughs can also be sticky, and mixing operations can benefit from the same cryogenic chilling advantages. Mixing is the first and most important stage of dough processing. During ingredient mixing, both the development of the dough and the dough temperature are established. If either are not tightly controlled, product quality will suffer.
Developing the gluten network through the dough requires adding energy and thorough mixing with the water and flour. The art is to develop the proper consistency so the dough will have excellent machinability as well as gas retention properties.
When wheat flour is removed for a gluten-free recipe, other binders or combinations are added instead, though trying to match the overall performance of gluten can always pose a challenge.
Gluten-Free Health Trend
Many consumers perceive “gluten-free” as healthy; improving digestive health and eliminating toxins from the body. So it is not surprising that gluten-free claims are extending to other food industry segments beyond bakeries and makers of dough products(1). Picking up on the gluten-free trend, Smashburger started using gluten-free buns(2), and Oscar Mayer now adds the claim to labels of qualifying products(3).
Gluten also finds its way into processed meat products in marinades and batter, as well as many binders, fillers and extenders. Hidden sources of gluten can include: spices and flavorings, caramel color, modified food starch, hydrolyzed vegetable protein, soy sauce, malt and maltodextrin. There are many gluten-free starches available. Starches bind moisture, provide heat and sheer stability, improve freeze/thaw stability and can enhance texture(1).
While Celiac disease only effects an estimated 1 in 100 people worldwide, 2.5 million Americans are undiagnosed and at risk for long-term health complications. The autoimmune disorder can occur in genetically predisposed people where ingestion of gluten leads to damage in the small intestine. Gluten-free diets are not just for those with Celiac disease, but also those with gluten sensitivity, according to the Celiac Disease Foundation. However, the Foundation advises screening and diagnostic testing before starting a totally gluten-free diet(4).
Obviously, if a family member is diagnosed with Celiac disease, especially if it’s the person doing most of the cooking, others in the family are likely getting more gluten-free flour products in their diet. According to a Mayo Clinic study, about 1.8 million Americans have been diagnosed with Celiac disease, while another 1.6 million follow a gluten-free diet even though they haven't been diagnosed(5). A survey by the NPD Group amplifies that point: About 11 percent of U.S. households include at least one person following a gluten-free diet, yet only about a quarter of those households identify Celiac disease or gluten sensitivity as the reason.
(1) Jeff Gelski, “Report finds people view gluten-free items as healthy,” FoodBusinessNews.com, May 30, 2013.
(2) Monica Watrous, “Smashburger goes gluten-free,” FoodBusinessNews.com. May 8, 2014.
(3) Donna Berry, “Gluten-free meat,” FoodBusinessNews.com. Oct. 19, 2013.
(4) The Celiac Disease Foundation.
(5) “Gluten-free diet fad: Are celiac disease rates actually rising?” CBSNews.com. July 31, 2012.