Producing foods and drinks with reduced sugar and salt continues to be a major challenge for manufacturers, especially as they aim for clean label solutions. 

Herwig Bachmann, Group Leader of Fermentation at Foodvalley Member NIZO, says fermentation could meet consumer demand for products that are naturally lower in sugar and salt, without compromising on taste, texture or product image.

What are the benefits to using fermentation as a tool to cut salt or sugar?

“There are a number of benefits. From the consumer side, the important thing is that it is natural and clean label.

Once you have implemented it into a product it is relatively simple. Let’s take yoghurt as an example. If you have a fermentation that allows to reduce sugar no more additional steps are needed because it’s a fermented product anyway. In fermented plant-based products, flavour profiles and textures can be improved, such as removing off-flavours and creating a smoother mouthfeel. By removing off-flavours you can get by with using less sugar.”

How does it work?

“Every customer need is unique, the power is in working together on tailored solutions. Every approach will need to be adjusted for the specific need and situation, leading to a number of options and custom solutions. One could be to produce sweet compounds through fermentation and another is to use strains that split lactose into galactose and glucose, which leads to enhanced sweetness.

With salt, often used as taste booster and preservative, we also see plenty of opportunities to reduce it through fermentation. Take the example of the addition of specific starter cultures, which produce a lot of volatile compounds. This introduces much more flavour that compensates for a reduction in salt. Besides our fermentation know-how, at NIZO we have in-depth knowledge on application, flavour and texture, so we can monitor and characterise the impacts of fermentation.”

In which products is it possible to cut salt using fermentation?

“If you are talking about salt, the main example we have is cheese. There we have been able to reduce salt by up to 40% just by adding different cultures. Although cheese is the main product where we have examples, other products that use fermentation would also be suitable. You could use it in condiments, for example.”

How is flavour retained when using this method?

“Fermentation can be used to add flavour through the production of flavour volatiles, or to remove off-flavour by enzymatic degradation. Either of these can be used to compensate for the omission of sugar or salt in specific products.”

What are the main challenges in producing salt-reduced foods?

“The main challenge in such products is to retain good sensory properties. Besides that, safety might be something that starts playing up as well, because salt and to a lesser extent sugar are important in preservation. Together, sensory changes and food safety are the two biggest challenges. At NIZO we can monitor safety issues that arise from reducing salt, and once we have mapped the potential issues we can work efficiently together with costumers on possible effective solutions.”

How can companies cut sugar using fermentation, and in which applications?

“There are examples with dairy and plant-based applications. Besides sweetness, sugar is often used to mask bitterness, for instance. A number of companies are looking at production of sweeteners, such as erythritol production from yeast. It produces a very high potency sweetener while also consuming carbohydrates. However, during fermentation undesired molecules such organic acids might be produced. This limits the use of fermentation to some extent.

Undesired flavour molecules might be avoided by fermenting a side stream and, after evaporating undesired volatiles, bringing it back into the product.”

Apart from taste, how does fermentation help improve texture in reduced sugar products?

yoghurt raspberries - pixabay

“This is something where there is a lot of experience and again, much of it is captured in our rich dairy history, which we are applying more and more to other food applications. What people do to increase the viscosity of yoghurt, for example, is to use strains that produce exopolysaccharides, which hold water and can have a big effect on texture and mouthfeel. It’s a very nice, elegant and clean label way to change the texture of yoghurt. There are studies of using EPS-producing strains in cheeses too, and I think you should be able to use a similar concept in other products.

Very recently, I supervised a PhD student who looked at a new concept, using Lactococci to increase the hardness of a gel. We found that the expression of bacterial pili make the gel structure of fermented milk harder and more viscous, most likely through direct interaction with milk proteins. This is a totally new and different approach that I think could be very interesting.”

Currently, what are the main limitations to using fermentation as a tool for salt and sugar reduction?

“Limitations could be either technological or regulatory. From a technological aspect, when you produce certain molecules through fermentation you may end up with some unwanted flavours. Certain sweeteners have an intrinsic flavour that you don’t want to have, which would then need to be masked or produced differently. On the regulatory side, if one would be allowed to use GMOs, there would be more options to consider.”

Why would a company choose fermentation to cut sugar or salt over the use of sweeteners or salt replacers?

The nice thing about it is that it is clean label and natural, but you could also ask the question, are there other benefits of fermentation that you can bring along? This depends on the product, but you could consider using strains that overproduce a vitamin. With Lactobacillus for example, we have strains that can produce vitamin B12.  A lot of companies are looking at probiotics too, so why not bring along some of those extra benefits if you are fermenting a product anyway?

Think also about the increasing consumer demand for more transparency. Fermentation is an ancient method (bread, wine, tempeh, etc.) that is seen as natural. Using fermentation can support the transparent stories of food products as they are presented to consumers.