Pro Tip: The four different resistant starches can help in formulating keto-friendly baked goods.
In recent years, a growing trend in the baking industry has been the development, launch and promotion of keto-friendly breads. There is a strong appetite from consumers for low-carbohydrate or zero-net carbohydrate keto options, but do we truly understand what makes a product Keto?
The origin of “keto” stems from the ketogenic diet, which is a high-fat, low-carbohydrate diet, much like the popular Atkins diet. By drastically reducing carbohydrates and replacing with fats, the keto diet forces the body to burn fat, which puts the body into a metabolic state known as “ketosis.”
Therefore, bakers are challenged to re-formulate everyday bakery products such as breads to reduce carbohydrates. When consuming a slice of white bread, starches turn into sugar when combined with digestive enzymes. However, resistant starches (RS) are a type of starch that bypasses the small intestine and is not digested in the stomach or small intestine.
What are these resistant starches and in what forms are they available? Let’s look at four types of resistant starches that can be used to create keto formulations.
Resistant starch type 1 (RS1): This type of starch is physically trapped within a food matrix, which slows down enzyme digestion. RS1 is abundant in whole grain foods, seeds and legumes. Starchy foods coated with seeds or germ (e.g., unprocessed whole grains, legumes such as soybean seeds, beans, lentils and dried peas) are other examples.
Resistant starch type 2 (RS2): RS2 is a granular or crystalline starch that resists digestion. Because of its tightly packed structure, digestive enzymes can’t break it down easily and resists digestion and absorption. You can find this type of starch in raw potatoes, green banana flour and high-amylose corn flour.
Resistant starch type 3 (RS3): RS3 starch is a retrograded starch that is created by cooking and cooling; for example, cooked and cooled breads, rice, pasta or even cornflakes. A good example is when a cooked potato is left in the refrigerator overnight. Due to the cold exposure, a portion of the starch is converted to resistant starch, which is similar to parboiled rice.
Resistant starch type 4 (RS4): RS4 is a synthetic form of resistant starch that is chemically modified to make it slow or resistant to digestive enzymes. High-maize resistant is a classic example.
Remember that formulating with new ingredients like RS will require testing and validation to ensure the process (water absorption) and shelf life are not affected.
Richard Charpentier is a classically trained French baker, CMB, holds a degree in baking science from Kansas State University, and is owner and chief executive officer of Baking Innovation. Connect with him on LinkedIn.