One of the toughest things about going on a calorie-controlled diet is cutting out some of the things we love. Weight control through hunger management shifts the focus. So treats like cakes and biscuits are no longer a no-go, providing they help limit the calories consumed later in the day.
As mentioned in our article on satiety science, foods supplemented with dietary fiber and protein can slow the onset of hunger and reduce later energy intake. We set ourselves the task of developing concepts for sweet muffins and breakfast biscuits that are every bit as delicious as we expect, but with added fiber and protein to make them even more filling.
Working in the DuPont Nutrition & Health bakery lab, our first priority has been to balance the recipe.
More water needed
When protein is added to the dry ingredients, the equivalent amount of flour has to be taken out. That calls for a protein with similar characteristics to the flour, specifically in relation to hydration.
For our trials, we used a mild-tasting soy protein isolate. But, regardless of which protein you choose, the high water absorption properties will require the addition of extra water, so the biscuit dough or muffin batter has the right viscosity.
A standard biscuit dough normally requires 7-8% water addition. On replacing 8% of the flour with soy protein, we increased water addition to 13% to facilitate mixing and shaping. In turn, this requires a slightly longer baking time to ensure the final biscuit contains just 2-3% water.
Avoiding a fragile crumb
For our muffin recipe, we adopted a different approach. Here, we tested a batter where we replaced only 4% of the flour with a powder soy protein, as a higher addition can cause the crumb structure to become fragile. At this level of protein, the water content only needs slight adjustment. The baking time is then unchanged, and the extra water content a benefit for muffin softness.
But this did not qualify our concept for a ‘source of protein’ claim. To do that, we had to overcome the crumb fragility issue. Our solution was to add 4% cocoa-flavored soy protein nuggets, half of them to the batter and half as a sprinkle on the top. The result is a muffin with a soft, rich texture and added crunch from the crispy nuggets.
Softness and crunch with neutral fiber
So far so good with the protein. But what about the dietary fiber?
As in many of our concepts for the bakery industry, we drew on polydextrose – an unproblematic addition in cake recipes due to its neutral impact on taste and texture and crumb-softening effect.
In our biscuit concept, on the other hand, we limited polydextrose addition to below 4%. A higher level could cause the dough to become too ‘cookie-like’, so any pattern on top of the biscuit disappears during baking. In the final biscuit, however, the polydextrose acts as a crisping agent, enhancing snap.
Both our sweet muffin and breakfast biscuit concepts meet EU requirements for source of protein and fiber claims. Contact us for more formulation advice.
For our trials, we used SUPRO® isolated soy protein, SUPRO® NUGGETS and Litesse® Two polydextrose from the DuPont™ Danisco® range.