Table of Contents

By Dr. René Floris, NIZO’s Chief Innovation Officer and Dr. Els de Hoog, NIZO’s Principal Scientist for Taste & Texture.

Part 1: The best of both worlds: Plant and dairy ‘hybrid’ foods

Hybrid, blended, mixed or enriched. Whatever you call them, foods that incorporate animal-free components into traditional animal-based products look set to have a major impact on the food market. But you can’t just add a new ingredient into an established process and hope to get a saleable product. So how do you create blended food products that will find success in the marketplace?

What’s driving the blend?

The growth in plant-based alternatives to animal-based foods has stalled recently. These products target people who have been regular meat eaters but now want to cut down – whether for health, environmental or animal welfare reasons. They want to make the change, but still want taste, texture and “cookability” that they can recognize from their animal-based favourites. And they aren’t yet finding that in 100% plant-based products.

At the same time, in response to cost concerns and regulation, many food retailers and manufacturers have set themselves ambitious targets to sell more alternative proteins and less animal protein. These two factors are driving growing interest across the food industry in foods that use alternative food components within traditional products: blended or enriched foods. Retailers have been at the forefront of this, with Aldi and Lidl both launching blended mince featuring 40% plant-based ingredients. Dutch supermarket Albert Heijn is going even further, announcing a blended range that includes semi-skimmed milk, sausages, salami and deli meats.

“Blended foods give flexitarian consumers the health and sustainability benefits they are looking for, without compromising on taste and texture. But only if you get them right,” says Dr. Els de Hoog, Principal Scientist Taste & Texture at NIZO.

Why is blending so challenging?

Creating a successful blended product isn’t straightforward. Plant proteins, for instance, often bring off-flavours that could be noticeable in a blended product. Moreover, adding any additional ingredient to a well-known foodstuff is likely to affect the matrix and microstructures of that food, potentially changing the mouthfeel. Sometimes the effect only becomes apparent after further processing: for example, adding some plant-based proteins to cow’s milk can prevent the milk coagulating when you add rennet, so you end up with sloppy cheese.

Plant-based products also have a very different set of likely microbial contaminants, with more heat-resistant and spore-forming microbes present. If you use the same process with the same heat profile as for your animal-based product, you could end up with a serious food safety issue. However, if you just increase the heat load in the process, you risk denaturing the animal proteins and ruining the taste and texture you are trying to deliver.

“If you are only adding small amounts of plant-based ingredients, this probably won’t be a major problem” Els points out. “But if you want to make blended products that will have a real impact on sustainability, you need to have a significant proportion of alternative components. And the higher that proportion, the greater the risk of noticeable problems arising.”

The art of the blend – is science

You can, of course, try to tackle these issues through trial and error. But that can take a lot of time, effort and resources. For faster results, you need to think about what happens in blended products on a molecular level. And over the last couple of years, the food industry has put a great deal of effort into understanding how different ingredients interact at the molecular level and the impact this has on the taste, texture and stability of the final product.

“This is a topic NIZO is perfectly placed to explore, being born from the dairy world and having decades of experience in plant-based ingredients. We can apply our understanding of ingredient functionality and product-process interactions to the individual ingredients and to the blended product. In 2024, we set up an international research consortium to investigate taste and texture in blended dairy products,” Els explains.

This industry-wide effort is paying off. For instance, in the sloppy cheese example above, we now know that some plant proteins interact with casein micelles in milk more strongly than others. This stops the casein from forming the complex structures that give a cheese its specific texture.

Similarly, NIZO has been using a combination of gas-chromatography-olfactometry and mass spectrometry to explore which volatile compounds cause the off-flavours associated with certain plant proteins. Crucially, we also understand how many of these compounds interact with different product matrices and so are better able to predict whether the off-flavour will be perceived in a given product.

Applying the knowledge

Once you understand how and why things go wrong, you also have a starting direction for putting them right. Unfortunately, there is no one-size-fits-all approach. Every case has its own solution – but that solution will usually be based on some common tactics.

First is the careful selection of ingredients based on the knowledge accrued in the industry in recent years. That could mean choosing plant proteins whose off-flavours will be least noticeable or more easily masked in your chosen product format (drink, yoghurt, cheese, meat etc). Or alternative ingredients that interact minimally with the microstructures in your product matrix.

Second is to optimize your production process to suit the combination of ingredients. For example, adjusting the parameters of heat treatment stages to ensure food safety without denaturing proteins. Meanwhile, processes such as drying and fermentation can reduce off-flavours further. However, any fermentation stages will need to be carefully reviewed as the presence of alternative ingredients could impact the fermentation process, potentially changing the flavour profile and the growth of unexpected bacteria.

“You have to consider these two steps holistically,” Els explains. “You want to be sure that the desired properties of your chosen ingredients will survive under the heat, pH shifts and mechanical stresses of your optimized process. So, understanding product-process interactions is critical,” says Els.

The bigger the proportion of alternative ingredients, the bigger the changes needed to properly optimize the production process. And the investigations carried out in recent years suggests above a certain level, you can’t tweak existing processes enough to avoid problems in blended foods.

“Where that level is varies greatly with each specific product,” Els adds. “To go beyond that level, the industry will need to develop new process technologies. But for now, a proper molecular-level understanding of your specific case can tell you how far you can go in creating great-tasting blended products.”