The so-called “keto” diet trend has become widely popular as a weight-loss approach. High in fat, with adequate levels of protein and low levels of carbohydrates, the keto diet forces the body to burn fats rather than carbohydrates, a state called “ketosis.” Doctors initially created this diet to prevent seizures in children with epilepsy, and it may be used by people with metabolic disorders including diabetes.
People following a keto plan or the similar Atkins diet may look to keto or high-protein/lower-net carb breads to support their weight-loss goals. In fact, Mintel reports (September 2021) that 64% of U.S. adults were eating less bread than a year ago to cut down on carbs, and nearly one- in - five bread shoppers say they look for low- or reduced-carb options. “This can be attributed to the popularity of low-carb diets like keto and publicity about the negative health effects of refined carbohydrates.”
Low-carb bread launches in North America rose in the year to July 2021, although they “remain niche,” Mintel says. One reason for this may be consumer perception that low-carb or diet-friendly breads are lacking in taste and satisfying texture.
But commercial bakers can create keto bread comparable to classic white bread with the use of alternative processing methods and ingredients.
Keto Bread Baking Processing Suggestions
- Mixing: The high amount of wheat proteins in keto bread baking require proper hydration and longer mix time to fully develop the gluten.
- Fermentation: The baker needs to plan for additional time during the fermentation process because of the lack of sugar or other nutrients required by the yeast to leaven the dough.
- Baking: Monitoring the correlation between oven conditions (timing/temperature) and microbial inactivation, crumb set, and color formation using thermal profiling can help manufacture a more consistent and desirable product.
In general, keto baking replaces wheat flour with low-carbohydrate sources and other functional ingredients. A label for a commercially available keto-friendly bread, for example, contains no flour, sugar or artificial sweetener, and no emulsifiers. It does contain significant amounts of wheat protein isolate/wheat gluten and modified wheat starch/fiber. As a result, the bread is higher in protein, higher in fiber, contains lower net carbs and lower caloric counts.
The label for a commercial classic white bread includes bread flour, malted barley flour, High Fructose Corn Syrup, and ingredients to improve texture quality and shelf life, along with improving mix tolerance during processing. This bread contains 28 grams of net carbohydrates and has 150 calories per serving size of 56 grams.
With the use of alternative ingredients, baking low-carb or keto bread creates common challenges including:
- Lower loaf volumes
- More open crumb grain
- Tunneling (presence of holes)
- Gummy mouthfeel
An analog flour solution
However, partial or complete replacement of the flour can help in successfully developing a formulation for low-carb products, with protein and dietary fiber as the crucial ingredients.
Neutral flavors such as wheat protein concentrates and isolates, dairy proteins, and soy protein are used widely. Wheat proteins can be used in keto bread applications to provide the “bread and dough” properties such as gas retention, texture, flavor, and crumb and crust characteristics. Other proteins can provide properties such as water solubility, water holding capacity, emulsification properties, gelation, and whipping properties. Additionally, low carbohydrate goods often contain ingredients like nuts, flaxseed, and coconut flour.
Increasing the amount of fiber can compensate for the bulking properties of easily digestible carbohydrates while reducing the net digestible carbohydrates. It is crucial to evaluate for heavy taste and texture while using dietary fibers. Examples of dietary fibers include resistant starch, inulin, gums, flaxseed, (delete soy), oat, barley, and wheat fibers.
Baking application tests found that an analog flour of Fibersym® RW RS4-type Resistant Wheat Starch, combined with Arise® wheat protein isolate and vital wheat gluten, can be used to replace all the wheat flour in low net-carb or keto formulations while providing the texture, structure, and mouthfeel of a conventional wheat-based product.
Each ingredient has a significant attribute that is important in reducing carbohydrates: Fibersym contains 90% total dietary fiber, while Arise has a protein level of 85% to 90%, compared with 75% protein in vital wheat gluten.
Resistant wheat starch plays a unique role in low-carb breads, acting as more than a filler. It provides a surface suitable for a strong union with the gluten and dilutes gluten to a consistency desirable for dough processing.
Fiber-rich Fibersym RW starch blends easily and doesn’t require processing changes, as do other fiber ingredients such as cellulose, which binds excessive water, resulting in a longer bake, dilution of ingredients and a weaker proofed dough; or inulin, which doesn’t hold water and causes production loss through lower yield and significantly longer proof time.
Yeast-leavened bakery products such as white pan bread, lower-carb or keto bread are prime candidates for application of Arise wheat protein isolate because of its ability to improve dough handling and the quality of the finished product. Arise increases dough extensibility and elasticity and results in bread with higher loaf volume.
Wheat-based keto bakery applications require large amount of wheat proteins. Wheat protein isolate is often used in combination with vital wheat gluten to provide extensibility property, and help with dough handling. Wheat protein isolate when added at a 2-3% level reduces the microwave heating-induced toughening of breads, or the tough and rubbery texture after breads are microwaved. Also in bread applications, wheat protein isolate can match the loaf volume performance of chemically-sounding additives like SSL or DATEM at 0.5% level.
The functional attributes of Fibersym and Arise together in keto bread formulations are important. But achieving a low-carb label acceptable for the keto diet is critical. Here, the analog flour of Fibersym and Arise contributes to superior nutritional qualities. An American Institute of Baking (AIB) study on a high-protein and high-fiber bread formula was revised to create a high-protein, low net carbohydrate bread formula where wheat flour was replaced with Fibersym, Arise and oat or soy fiber. The nutrition facts listed 3 grams of net carbohydrates and 12 grams of protein per serving size of 75 grams. If calculated using a serving size of 28 grams, the amount of net carbohydrates is 1 gram and that of the proteins is 5 grams. (Learn more here.)
The demand for keto bread is growing as weight-conscious consumers seek healthy, nutritious alternatives to bread. Selecting the right ingredients will help bakers overcome functional challenges and create highly nutritional keto breads as appealing as classic white bread.