Dry, flat, crumbly, sticky, stale — terminology people don’t want to describe their bread. And these words were commonly used by consumers who had grown accustomed to the inadequate textures and, therefore, had acclimated to the bad taste of gluten-free bread.
“An enjoyable eating experience is a balance of taste and texture,” said Chris Thomas, principal technical service technologist, Ingredion, Inc. “If a gluten-free bread has a soft crumb but an off flavor, the eating experience will not be optimal. If a gluten-free bread has a great flavor but is dry and crumbly, the eating experience will not be very pleasurable.”
Finding this balance is the ultimate challenge with gluten-free products. However, according to the study “Going Gluten-Free By Choice” from Ingredion, roughly 20% of U.S. consumers now consistently purchase gluten-free products voluntarily in addition to the approximate 1% of U.S. consumers diagnosed with celiac disease. Insufficient mouthfeel associated with many gluten-free bread varieties is affecting a larger population than in previous years.
The increasing focus on gluten-free over the past 10 years has not only improved products’ quality, but it has also raised consumer expectations.
“Consumers who previously were forgiving of a poor texture or flavor just to have a bread they can eat are now much more discerning,” Mr. Thomas said. “They want great flavor and texture at an affordable cost.”
Creating the same soft, chewy deliciousness of traditional bread in the absence of gluten isn’t easy. In fact, it requires more time, ingredients and process sensitivity.
“Gluten is an amazing combination of proteins that provide the proper balance of elasticity and extensibility, which in turn defines the characteristics of traditional bread,” said Jesse Weilert, vice-president of technical services, Canyon Bakehouse, Johnstown, Colo. “No other single ingredient in nature can function as it does, which makes the art of recreating the texture and taste a balancing act utilizing numerous other ingredients.”
Among the list of ingredients, gums are at the forefront. These hydrocolloids act as water-control agents to provide stabilization, moisture, elasticity and staling protection, all of which are essential for a tasty experience.
Each particular gluten-free application determines the type and amount of gum that should be used.
“Gluten-free bread needs to have the gas entrapment capability that wheat gluten provides to get the desired volume and eating quality, but gluten-free brownies do not need that type of functionality,” Mr. Thomas explained.
The most common gums used in gluten-free bread are hydroxypropyl methylcellulose (HPMC), xanthan, guar, carboxymethyl cellulose (CMC), pectin and locust bean.
Every gum is different in its function and management. Some hydrocolloids require heat to be soluble; others are soluble at room temperature. Some provide binding in gluten products; others hold moisture to reduce graininess and still others emulsify liquids. For example, xanthan, HPMC and CMC create gel structures during formulation while guar gum is typically used to help thicken dough, according to Lirong Zhou, senior scientist, TIC Gums, owned by Ingredion, Inc.
Due to the unique function of each type of hydrocolloid, bakeries can mix and match them to trigger synergistic effects.
“Formulators of gluten-free products often take advantage of gum blends,” said Tina Tang, food scientist, TIC Gums. “These blends can help leverage the characteristics of multiple ingredients while maintaining the convenience of a single ingredient.”
Asim Syed, director of food applications, Brenntag North America, said gluten-free bread bakers often combine CMC and HPMC. CMC is used as a thickener, stabilizer, film former and suspending agent while HPMC provides a good viscosity and forms a mushy gel when heated and liquefies as it cools. Together, these gums can also protect against staling through consistent moisturization to improve shelf life.
One of the issues that can sneak up on bakers when using gums is their property of thickening in water when activated, which can result in un-hydrated material surrounded by hydrated material, also known as a fish eye.
“Fish eyes can cause clogging during production or incomplete hydration, which inhibits functionality,” said Davis Luna, beverage technologist, TIC Gums. “This challenge can be easily avoided if formulators ensure that enough water is present in the product to activate full hydration. Formulators can also disperse the hydrocolloids in other dry ingredients, such as sugar, to help accelerate the hydration during manufacturing.”
Part of the whole
Gums can’t act on their own to create the desired mouthfeel and taste in gluten-free bread, so they are typically paired with starches and proteins.
“The right combination of starches, proteins and gums can match gluten systems in terms of cold dough, or batter, viscosity during mixing and proofing, as well as the right texture, color and nutritional profile of the final products,” Ms. Zhou said.
Starches act as bulk flour replacements, or the base of gluten-free bread, as well as improve elasticity and manage moisture for freezing and thawing stability. Mr. Syed advised bakeries to incorporate starches from multiple crops such as rice, tapioca, potatoes, corn garbanzo, chia flaxseed and fava — at least three — in a formulation.
“This will create a more robust and interesting texture,” he explained.
Proteins are used in varying amounts, depending on the formulation, but ultimately have a major impact on the finished product, Mr. Weilert noted. Eggs are the most popular proteins used in gluten-free breads. According to “Gluten-Free Solutions Begin with Real Eggs” by the American Egg Board, when egg protein strands are exposed to acid or heat, they break apart and, as the structure sets, they aggregate back together and entrap air for volume and moisture.
By maintaining the structure of the bread through air entrapment, Caroline Simon, customer application specialist, Dow Chemical, said eggs provide the resistance needed during the slicing stage. In addition to boosting the binding, emulsification, air cell development and color in bread formulations, eggs are important for flavor, along with vinegar, sugar and salt, Mr. Syed said.
Plant-based proteins — TIC Gums recommends pea protein — are also highly functional ingredients and can be coupled with hydrocolloids to enhance texture and add nutritional qualities. Ingredion has noticed that bread has a crispier surface crust and less dense cell structure when plant-based proteins are used.
The numerous ingredients combined to replace gluten cause the development process to be one of trial and error.
“Too much gum yields gummy mouthfeel, short texture and low volume, irregular cell structure, collapsed structure, and large air pockets,” Mr. Syed said. “Too little gum will yield a crumbly, dry and irregular bread with a short shelf life.”
It might also take multiple tries to get the right taste, even after a bakery has managed the texture. Because gluten-free products don’t have a wheat taste and require additional starches, protein and fibers easily lead to an off-taste, Ms. Simon said.
“The good news is that there are ingredient suppliers who are happy to help bakers overcome these challenges,” Mr. Thomas noted. “If a gluten-free flour is functioning well in a bread but is contributing to an undesirable flavor, we can provide guidance on other starches and gluten-free flours that can provide the same functionality and have less flavor impact like tapioca flours and potato flours.”
Once the ingredients have been chosen and the right recipe has been created, production precision and process conditions are key.
“Never forget to optimize water absorption; control process parameters like temperature, mixing time and speed, and proofing conditions; and use high quality ingredients,” Ms. Simon said.
Without gluten, it takes an ingredient system approach to obtain optimal bread textures and taste. However, the ideal hydrocolloid quantity and counterpart ingredients take bakeries one step closer to closing the gap between the quality of gluten-free and traditional bread.