“Anytime you change a formula, obviously, there are moving parts,” says Kyle Marinkovich, marketing manager, bakery category & Horizon Milling, Cargill Health & Food Technologies, Minneapolis.
From a processing standpoint, the bran and its fiber throw a wrench into things. Fiber is notoriously thirsty, with a nearlimitless capacity to suck up formulation water. “When you put whole grains and whole-grain flours in doughs, the doughs tend to get what we call ‘bucky,’ because the fiber continues to absorb water,” says Witwer. “And so you mix and mix and you think you’re doing OK, and then 10 minutes later, the fibers are still absorbing water and you end up with dry dough.” The solution is to increase the dough’s moisture content and plan for longer hydration and bake times, to absorb all that extra water and drive it off in the oven. Whole grains can also hamper a baked good’s rise, making lower-profile snacks like crackers, chips and sheeted bars better candidates for inclusion than lofty cakes and breads. Some attribute the volume deficit to insufficient gluten in the whole-grain flour and, indeed, some alternative grains, like rice, quinoa and corn, are virtually gluten-free. But the real culprit, at least in the case of wholewheat flour (which is actually fairly high in gluten), is the knife-like action of the bran.
Bran’s rough edges “cut through the gluten strands and make it difficult for something with high whole-grain content to rise,” Harriman explains. Helpful counterstrategies include gentler and shorter mix times—not always an option when you have to mix in all that added water to accommodate the fiber in the dough. There, adding ingredients like vital wheat gluten, dough conditioners and dough strengtheners can help set dough structure and bolster finished-product volume.
Similar volume issues plague whole-grain expanded and extruded snacks—and for similar reasons. Products puff best when their formulas are maximized for starch; fiber, fat and protein, by contrast, merely weigh down expansion. The presence of the fibrous bran, the germ’s lipids, and high levels of protein in whole-grain flours, crowd out starch and yield a compact, densely textured expanded piece.
As a solution, Bonner suggests using whole-grain brown rice flour, which, because of its chemical composition, “is a practical base in these types of products.” Without as much fat, fiber or protein as other whole-grain flours, it permits a more vigorous puff. “It is often the primary ingredient, followed by lower levels of other whole grains,” in expanded whole-grain snacks. Another trick for boosting expansion is to add starches from wheat, tapioca or rice “at some lower level—20% to 30%—and balancing the final consumer product to above 51% whole grains,” he says.
Whole grains get stealthy
Assuming you overcome the technical difficulties, there remains the question of how well your snack’s new whole-grain sensory profile will fly. Whole grains’ darker color, coarser texture and more-pronounced flavor don’t always jibe with consumers’ expectations for light and fluffy buns, cookies, crisps and other goodies.
Within the past decade, that’s begun to change as white whole-wheat flours that look, taste and feel like refined flour, but have all the nutrition of whole grain, have entered the market.