Fermentation and its impact on nutrition
In food production, fermentation is described as the process by which carbohydrates are broken down to produce alcohol or organic acids using microorganisms. Fermentation has been used for many years for the purpose of stabilisation of perishable food products in the case of pickling, and is very well known for its role in alcohol production. However, fermentation can also be used to create certain organoleptic, functional and nutritional attributes.
Reduced sugar content
In accordance with its definition, fermentation uses carbohydrates (and specifically, sugars) as substrates for driving the fermentation reaction. Therefore, this needs to be considered for its potential effect on the nutritional values of the end product. Fermented products cannot be assumed to contain the same amount of sugar as calculated for the raw materials. It is for this reason that theoretical calculation is not a suitable method for predicting the nutritional content of fermented foods. To begin with, the raw product contains intrinsic and/or added sugars; but following the fermentation process, nutritional analysis shows there is less sugar – or in some cases, no sugar – present in the final product. Examples of where this occurs are bread and fermented drinks such as kombucha.
Alcohol production
As mentioned above, sugar is used in as a substrate in driving fermentation, which in some cases leads to alcohol production. This is the primary goal of fermentation processes used in the alcohol production industry. However, what about products that are fermented but for which alcohol production is not the primary goal of the fermentation process? Examples of these products include kombucha and soya sauce. Fermentation is an essential step in their production process; however, alcohol may be produced as an undesired by-product. While the type of fermentation and the agent used will affect this, it is something that manufacturers who aim to produce products by fermentation should consider. If the final product does contain alcohol, it will affect the energy content, and the alcohol content would be required to be included on the label.
Production of alternative protein sources
Fermentation, although an ancient process in food manufacturing, is emerging as a way of creating alternative protein sources. There are three types of fermentation used in the production of alternative proteins:
- Traditional methods of fermentation use intact live microorganisms to modulate and process plant-derived ingredients to produce the protein source. An example is tempeh, which is soybeans fermented using Rhizopus mould. It is high in protein, fibre and nutrients such as riboflavin, niacin and calcium.
- Biomass fermentation is where microorganisms are grown in large fermentation vats, and then processed and textured to produce meat-like alternatives. The fermented micro-organisms themselves are the protein, and are thought to have a similar protein content and quality to that of plant-based meat analogues. They are also a source of polyunsaturated fatty acids, and are cholesterol free. Examples of this type of fermented protein include mycoproteins.
- Precision fermentation uses microorganisms to produce specific functional ingredients which enable alternative protein producers to efficiently make specific proteins, enzymes, flavour molecules, pigments and fats that can be used in vegan meat or dairy alternatives. It is commonly used in the production of amino acids, ‘egg white’ proteins, casein and whey in imitation milk products, heme proteins, growth factors and collagen proteins.
Fermentation and allergies
While fermentation can have some effects on certain organoleptic, functional and nutritional components, it does not make allergens such as gluten disappear. This is a common misconception, especially in the case of sourdough bread. Although the process of fermentation can potentially make products such as bread more tolerable for those with mild sensitivities, it is important to note that it does not remove gluten or other allergens.
Given the current growth in food innovation, understanding the possibilities (as well as any potential drawbacks) of processes such as fermentation is vital to the product development process. FACTS has a team of dietitians, food scientists and food technologists with a unique understanding of food regulations, food processing and nutritional outcomes, ready to assist at any stage of the new product development process.
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