Bakery products are a dietary mainstay of a large proportion of the population. Whilst some bakery products have to contain a certain proportion of protein (such as gluten in bread), there are a number of bakery products and snacks where protein levels can be low and could benefit from protein fortification.
Proteins are complex and diverse molecules made of linked chains of twenty-one types of amino acid. Once eaten, the proteins are broken down into individual amino acids, which are used by the body to make new proteins. Proteins are vital to growth and development as they are key mechanical and structural components of our bodies. They can also be broken down further to produce energy in times of hunger.
Not all amino acids are equal in the diet. Only three are truly dispensable as we are able to make them ourselves. Nine are absolutely essential as they cannot be made by the body, and therefore must be present in the diet to avoid deficiency.
The popularity of protein as a positive nutrient has seen its audience and consumer base grow to become a mainstream trend. Much attention has been paid to replacing dietary energy from carbohydrates and fats with that derived from protein due to evidence for weight loss. This is postulated to be due to the satiating properties of proteins.
Protein fortification uses isolated protein from single sources. Traditionally the majority of proteins that have been used to fortify products have been from animal sources, such as whey and casein from cow’s milk, but these are now being replaced by plant sources. Over the past few years there has been a proliferation of lesser known proteins, including from algae, hemp, cranberry and pea, as well as isolated animal proteins from beef, chicken and salmon.
Choosing the right source of protein
When it comes to fortifying bakery and snack products, there are a number of areas to consider when choosing the most suitable protein source for your application. These range from fundamental questions around source, such as whether to choose an animal or plant based protein based on consumer acceptance, dietary requirements and allergen control, to more technical aspects, such as flavour, colour and textural concerns.
The identification of the most appropriate source of protein depends not only on the properties required in the final product but also the interactions with other ingredients. Each source of protein can have a different effect on a product, some desirable, and some less so. Protein fortification at the correct level can act as an emulsifier, and its effect on water binding properties can help slow down staling.
Table 1 Functional properties of protein from different sources with examples of product applications.
Whey, either in an isolate or concentrate, can provide a high level of protein, along with functional benefits such as emulsification activity, as well as potential improvements to structure. However, as both an allergen, and an animal by-product, it may not be suitable for some applications
Soy, (a complete protein), as with whey, is another commonly used source of protein in bakery applications, which can deliver functional benefits, along with a high level of protein. Allergen concerns remain.
Other, non allergenic protein sources, such as pea, rice and hemp can be harder to incorporate due to potential flavour impacts that these ingredients can have, as well as them being incomplete proteins.
Pseudocereals and Ancient Grains
Ancient grains and pseudocereals, such as quinoa, amaranth, buckwheat and sorghum are a growing area of interest due to the high quality and quantity of protein they possess. As well as having essential amino acids, many are also suitable for gluten-free applications due to the different composition of storage proteins they have. In some cases the lack of gluten does however cause a trade off when looking to fully incorporate these grains into a product as, although they have good all round nutritional profiles, gluten is paramount to quality and performance in some processes. As a result this has led to a growing interest around the use of composite flours in baked and extruded products, keeping the functionality of wheat proteins but looking to build on the nutritional profile through the addition of wheat alternatives.
Protein fortification of bread and other yeast leavened bakery products is not straightforward, as many important aspects of a dough could be impacted by the addition of protein, such as dough handling, mixing times, crumb structure and other attributes. Protein fortification could also lead to an increase in acrylamide.
There is no perfect protein for use as a fortification agent in bakery products - it very much depends on the needs and demands of your consumers, paired with the recipe and process that you have within your bakery.
Mike Adams - Bakery Science Section Manager
Dr. Jenni Bradbeer – Research Scientist
Dr. Fraser Courts – Nutrition Specialist
Joe McGurk - Senior Scientist - Cereals and Ingredients Processing