In the past, gluten-free was thought of as a niche market for the less than one percent of the world population that suffers from celiac disease. But in the last 5-10 years, there has been a surge in awareness of this autoimmune disorder and diagnoses within the entire spectrum of gluten sensitivities.
In increasing numbers, consumers have chosen to cut back on wheat or remove the wheat protein known as gluten from their diet entirely. As food companies get more skilled at delivering gluten-free products, these diets will be more sustainable for consumers that choose them and many food companies are betting that this shift in dietary patterns is here to stay.
Nothing highlights the functionality of gluten like a traditional French baguette. The protein complex known as gluten has a unique ability to transform under the forces of mixing into a fine-stranded large molecular network.
A developed gluten network has the ideal balance of strength and elasticity to support expanding bubbles of gas and steam during baking. In skilled hands, a baguette can leaven and bake into an open porous structure full of aroma and tender to chew.
When bakeries remove the gluten-containing wheat flour from their formula and substitute with another starch source, they are left with several important properties they still have to meet. Whey protein isolate (WPI) is a particularly good option to meet all these challenges, with clean flavour, an attractive nutrient profile and a clean label. • Dough hydrationWhen gluten doughs are mixed, they hydrate and hold on to the water within the large protein matrix. A gluten-free dough with only a starchy ingredient replacing the flour will be sticky, hard to handle, and the baked product will be dry and crumbly.
Kurt Nordstrom, Maryland, US
Ella, Tel Aviv, Israel
Gums such as xanthan and egg whites have often been incorporated in some gluten-free formulas to serve this hydration purpose. Whey proteins can also manage moisture during mixing, forming and baking to get just the right performance.
• Dough strength and elasticity
In order to work with dough to shape it, hold pizza toppings or simply to hold gas during baking, the gluten-free baker needs a replacement for gluten’s unique strength and elasticity profile.
As in the French baguette, dough needs to be able to stretch and deform without losing its cohesiveness. This is the most challenging property of gluten to match. Gum and protein systems are sometimes used to replicate these properties.
Whey protein isolate is another good option. Once hydrated, whey protein can provide strength to the dough to aid in handling without sacrificing elasticity. During baking, the gas cells expand, and as the dough heats, whey proteins will denature and form inter-molecular bonds. Along with the starch, this protein network will stabilise the bubbles and support the baked volume.
• Baked texture
After baking, many gluten-free products are known to have a dry and crumbly texture. A gluten-replacer must be able to hold on to water as a plasticiser while also contributing to strength. Whey protein’s disulphide-stabilised networks provide strength to the crumb structure.
Whey proteins are able to provide the functionality of protein in a clean-flavoured package. Some whey protein isolates can be used at 10 percent in foods and beverages with negligible flavour impact.
The colour of baked goods is not only a cue for palatability for the consumer, but is also the visual cue for adequate baking. Dough that does not brown the same in a commercial oven will be a challenge for a baker to optimise.
It is well known that the right protein, sugar and pH can optimise the Maillard browning reaction. What is often overlooked is how inter-related oven performance is with colour development. A gluten-free dough that does not rise in the oven and lose moisture at the same rate as wheat dough would not have the same heat transfer properties at the surface.
Holding on to too much water will extend baking times and result in a more pale colour. Releasing water too quickly, will result in a darker colour as well as a dryer, more crumbly texture.
The best way to match the baking profile of wheat dough is to find a gluten-replacer that hydrates and holds water in a similar way as gluten. This is one advantage that whey proteins have over gum systems, which have very high water-holding capacities.
A protein-based gluten-replacer can replicate both the hydration as well as dehydration kinetics of baking to optimise oven performance and yield the right texture, colour and finished product moisture.
Consumers who choose gluten-free diets are inherently a health-conscious population. Perhaps the greatest advantage a whey protein-enhanced gluten-free formula can provide is an opportunity for consumers to get the protein levels they need throughout the day.
Research has demonstrated the importance of getting the right amount of protein at every eating occasion for the body to metabolise nutrients in the optimal way.
As summarised by the Dr RL Walzem of Texas A&M University for the US Dairy Export Council, whey proteins are well-known to be among the highest quality protein sources available, with a complete amino acid profile, high in branched chain amino acids, and high digestibility (WPI has a PDCAAS >1, while gluten is only 0.4).
Most notably, whey proteins are among the highest sources of the amino acid leucine, the molecular trigger for muscle protein synthesis. Consuming adequate leucine levels is the best way to ensure the protein you consume at any meal is put to use in the body to maintain muscle mass.
At any stage of life or on any diet, maintaining muscle mass is important for health. For child development, adult weight management, sports nutrition and slowing the loss of muscle with ageing known as sarcopenia, optimising muscle protein synthesis is a key part of a healthy diet.
As an example, four of the gluten-free cookies below made with 10 percent whey protein isolate provides 10 g of protein and about 1.1 g of the 2.5-3.0 g of leucine recommended per eating occasion.
The world of gluten-free baking presents some exciting business opportunities and technical challenges. A little bit of knowledge of the principles of hydration, protein network formation and oven performance allows us to pick the right ingredients and conditions to make the best gluten-free baked goods we can.
High protein whey protein isolates are able to meet these challenges without sacrificing flavour, and can give a nutritional boost in return. Best of all, whey proteins are accepted on food labels as a natural and wholesome source of protein.