What are yeast extracts & how are they used in the food processing industry?

Yeast extracts are among the most useful ingredients for modern food manufacturers. They have a wide variety of uses, bringing out taste and mouthfeel in food, with the benefit of being natural, vegan and allergen-free – helping food producers appeal to wider consumer markets.

For many producers, they’re an integral part of their food production processes. Here we explain why.

What are yeast extracts?

First of all, let’s discuss what yeast is.

This single-celled microorganism belongs to the fungus family and first came into being hundreds of millions of years ago. Since then, yeast has evolved into around 1,500 different species.

One species that’s particularly interesting to people is Saccharomyces cerevisiae, which takes its name from the Greek for ‘sugar fungus’ or ‘sugar mould’. Also known as brewer's yeast or baker's yeast, people have been using it for fermenting beer and wine for centuries. Bakers would then use yeast-laden foam produced by fermentation to create leavened bread and other products.

Another species of yeast commonly used in foods is Torula yeast. It grows on wood and often forms on the liquid left over when wood pulp is used in paper production. This yeast can be collected and dried to use in powder form.

Yeast extract is a natural ingredient that can be extracted from fermented baker’s yeast or Torula yeast. The yeast cells are broken down and the cell wall is removed resulting in a yeast extract with all the natural components from the yeast cell. It is this combination of proteins and amino acids which provide yeast extracts with a unique taste. They often come in dry powder form, which is soluble in water, making them simple to transport, store and then incorporate into production.

How are yeast extracts produced?

There are three stages in yeast extract production :

• Fermentation
• Precision Extraction
• Drying

First of all, fermentation is the process of growing the yeast, using a source of sugar. To promote growth, temperatures and oxygen levels are finely balanced.

Precision Extraction involves breaking the cell walls, typically using a method called autolysis. But what is autolyzed yeast extract exactly?

Invented in the 19th century, autolysis involves heating yeast cells until they rupture. After this, digestive enzymes in the cells produce amino acids and peptides.

Finally, separation uses a centrifuge to remove the insoluble cell walls. Following this, they’re filtered and – commonly – spray-dried to make them as convenient to use as possible.

So, that’s how yeast extracts are made, but what is yeast extract used for?

Applications of yeast extracts in the food processing industry?

Flavour balance and umami notes

Thanks to the unique combination of proteins, peptides and amino acids, yeast extracts can bring out the natural flavour and support the savoury character of foods. High nucleotide yeast extracts are particularly effective for this in applications such as soups, seasonings and sauces.

Yeast is also blessed with a natural umami taste, which brings complexity and longer-lasting flavours. This distinctive taste is down to the glutamic acid found naturally in yeast. This is the same amino acid that is also present in meat, cheese, mushrooms and tomatoes. So, whenever the umami notes of those foods are needed, yeast extract can help to enhance flavour perception.

Flavour delivery

With their incredible versatility, there are any number of ways you can use yeast to build or highlight flavours.

Yeast extracts can impart a range of flavours, including roasted, meaty and even dairy notes.

This capability is put to full use in vegan or vegetarian foods, particularly where alternative proteins are involved. Yeast extracts can help to deliver a convincing, savoury taste, as well as masking off-notes that often come with plant-based proteins.

Mouthfeel enhancer

Of course, when we eat it’s not just about flavour. The mouthfeel is often the thing that keeps us coming back for more. For the food processing industry, achieving a distinctive, desirable texture is a key goal.

And that can be particularly challenging when you’re trying to make a meat substitute feel like real meat. Authentic texture and mouthfeel are the key to success.

But through skilful use of yeast extracts, it’s possible to provide the juicy, fatty mouthfeel that people associate with real meat.

Salt reduction

Excess levels of salt in human diets have been linked to high blood pressure and a greater risk of heart disease and stroke. It’s only natural, therefore, that salt reduction is a concern for both food manufacturers and consumers.

Thanks to their natural umami taste, yeast extracts can help disguise a reduction in a recipe’s salt level by bringing out saltiness in other ingredients and increasing our overall perception of savoury flavours. Simply put, including yeast extracts in certain foods means manufacturers have the opportunity to reduce salt content by up to 50%. And they can do this without compromising on taste and flavour, so making their dishes healthier as a result.

Yeast extracts are incredibly useful, versatile ingredients, which have greatly improved the food we eat.

They offer a surprisingly impressive range of taste improvement options. Plus, they can deliver convincing textures, notably in vegan solutions that use plant-based proteins, which might otherwise be less palatable.

All in all, yeast extracts are vital ingredients in the food processing industry.