There are many challenges to improving the nutritional profile of our diets, including a reduction in the fat, salt and sugar content of food products together with the enhancement of fiber and micronutrients.
by Gary Tucker and Mike Adams, Department of Baking and Cereal Processing, Campden BRI
This is highly relevant to the bakery sector because of the functionality of each of these materials within bakery products, as well as the fact that in many countries, bakery and cereal-based products are staple foods.
Government initiatives to reduce the total fat content of foods are based on both calorie reduction, since fat is a calorie-dense nutrient, and on the removal of certain fat fractions from our diet, notably trans and saturated fatty acids. Hard fats have been used in bakery products for centuries. Traditionally these have been animal-based fats, such as suet and butter, but are now more commonly sourced from tropical seeds, such as palm, shea, and coconut. They have many functional properties of benefit to product quality. In recent years, the bakery sector has worked hard to achieve reductions in fat, particularly hard fat, both for health reasons, and in the case of palm, sustainability, and ethical reasons.
Fat not only contributes to the eating qualities of biscuits and cakes, but it also plays a functional role in dough handling and baking. Since fat has a range of technical roles, it is important to ensure that these roles are still met in reduced-fat products or in those containing a replacement material. Table 1 outlines some of the functional properties of fats in biscuits that will need to be addressed to avoid a loss in quality.
Table 1: Main functional properties of fats in bakery products
|Aeration and stability||Gases released from the leavening agents are retained better. Fats prevent gas loss and allow bread, cakes, and biscuits to expand better. The creaming operation used with some cakes traps air within a fat and sugar matrix.|
|Dough handling||Fats are nature’s lubricants. Higher fat levels improve dough handling by preventing dough sticking to contact surfaces. This is particularly important for molded biscuits.|
|Emulsification||Retention of gas is improved if protein-fat and starch-fat links are made in the material surrounding the gas cell walls.|
|Enriching||Some, but not all, fats are highly flavored ingredients that contribute to the flavor of biscuits and cakes.|
|Texture||Fat gives a short and crumbly texture to baked products such as biscuits and cakes. It interferes with the undesirable gluten development during mixing of recipes with flour and water.|
|Colour||Butter contributes to the yellow coloration of biscuits. Other fats can be selected to have a more neutral color.|
|Shelf-life||Fats prevent moisture from entering the crumb of biscuits or leaving the crumb of bread, cakes, and cookies. Higher fat products tend to retain their softness or crispness for longer.|
|Mouthfeel||Distinct from texture, mouthfeel can be described as the eating quality of the product during mastication. The melting of hard fats provides a unique eating experience.|
Sugar has received negative publicity recently because of its impacts on our health.
Sugar is a key ingredient affecting many properties of baked products (Table 2). When replacing sugar, some of these technical functions must be mimicked to make a product that is palatable, functional and appealing. This usually requires more than one ingredient to be added, which increases costs. Sugar is one of the least expensive and readily available ingredients compared with other bakery ingredients such as flour, egg, and fat. Sugar replacement usually comes at a cost and more ingredients must be declared on the label.
Table 2: Main functional properties of sugar in bakery products
|Flavor||Sugars are highly flavored and sweeten products. Different sugars such as glucose, fructose, lactose, etc. confer different flavors.|
|Bulking agent||Sugar in its solid-state occupies volume. This has to be replaced if the reformulated baked product will have a similar volume.|
|Viscosity control||Sugar solutions contribute to increased viscosity of batters and creams. This helps to trap air that can expand during baking to lighten the texture of cakes and biscuits.|
|Humectant (preservative)||Sugars bind with water, slowing down the growth of microorganisms such as mold and bacteria. This is measured with water activity (aw). Cakes rely heavily on sugar to extend their shelf-life.|
|Softens the texture||The water-binding capacity of all sugars allows water to remain in the structure. Water softens the texture of baked products.|
|Colour||Reactions such as caramelization and Maillard require sugars. Reducing sugar content also reduces the desired brown color of baked products.|
|Structure formation||The temperature at which starch and protein set depends on sugar content. High sugar cakes set later in the oven, which allows for more expansion.|
Recent research has shown that in the UK, a significant portion of the population is under consuming vital micronutrients, such as vitamin D, as well as iron, folate, and calcium (Farhat et al, 2019). While some bakery ingredients and products are fortified with micronutrients, evidence suggests that the bioavailability of these, such as elemental iron added to UK flour is poor (Hurrell 2002). While more bioavailable forms of nutrients are available for use, they often have very variable bioavailabilty, depending upon the matrix that they are added in. Careful consideration is required to ensure suitable fortificants are used.
Campden BRI is currently undertaking a three-year research program to improve the nutritional status of common bakery raw materials and their end products. Part of the study focuses on the potential to use natural processes, such as sprouting, to improve micronutrient content and bioavailability in staple foods. Hopefully this will assist the industry in helping tackle a global public health issue.
Evidence linking diets high in fat and sugar to a range of growing health issues such as obesity and diabetes has led health campaigners and governments to call for the level of fat and sugar to be reduced in common products. Bakery products are being targeted because they are high in both, particularly sugar.
Micronutrient deficiency is an issue across the globe. Staple bakery products are a suitable vehicle to try and increase the levels of important, under-consumed nutrients, such as iron.
You can read more in our print magazine European Baker & Biscuit (Sep/Oct 2019)!