Use of yeast: major developments
People instinctively link yeast to bread and baking tradition.
But tradition does not mean that techniques do not change! Whether in traditional or innovative fields of application, yeast is constantly being updated.
Evidently, knowledge and tools change, but so does society: bread consumption has become more international. For example, the Indian chapati or Italian ciabatta are now found everywhere and eaten worldwide. Current research focuses on the adaptation of yeasts to these different types of bread-making and modern processes (resistance to freezing for example).
With the development of sourdough bread, attention is also turned on finding the best yeasts compatible with the acidic conditions of leavened recipes. Yeasts also play a decisive role in the taste of bread. Researchers thus work on strains that develop the most attractive aromatic ranges. And with current progress made in nutrition, research strives to improve the bioavailability of vitamins and minerals naturally present in bread through yeasts.
As the different players in the wine trade have various requirements for the quality of their finished products, there is even more ongoing research on the role of yeasts in wine-making than in bread-making. The aim is to isolate strains involved in the aromatic characteristics of wine, particularly those responsible for its specific local character.
The biochemical composition of yeast reveals a product containing several elements which, when ingested by a living being, contribute to the smooth operation of its organism. This living being can be human, animal and even plant.
The latter is the subject of a recent research field. Yeast can therefore not only act as a food supplement, but as a natural fertiliser. Some yeasts thus improve plants’ capacity to take nutritive elements from the soil which they use for their growth. They thus act as a totally inoffensive natural fertiliser for humans and animals. Researchers also work on the use of yeast to control plant disease or act against mould in fruit: an organic alternative to chemicals.
Yeast is already commonly used as a food supplement by humans and as an additive in pet food. In particular for its high vitamin B, D2 or protein content. Research actively strives to improve production of these beneficial nutriments.
The application of yeasts as probiotics is another very dynamic area of diversification in terms of scientific publications. The results are very promising and outline a wide range of new applications.
Not only does yeast interact beneficially with intestinal microflora by favouring healthy bacterial groups, it also interacts with certain pathogens by occupying the space they could invade (barrier effect) and acting directly on some of the toxins they give off that have a negative impact on human or animal health.
Only recently, researchers discovered the “dialogue” between yeast, the intestinal microflora and the host – human, animal or plant – in cases of inflammation or immunity reactions. This field, which is currently being decoded, is a genuine scientific revolution In animal health, it opens new vistas including the improvement of milk production in ruminants or the use of probiotics as growth factors to replace antibiotics in pigs.
To date, yeast is the best micro-organism to produce alcoholic fermentation from simple sugars.
Humans, with centuries of experience in this field in baking, wine-making or brewing, have very effective strains available to them. They are now used to make biofuels from renewable agricultural products – beet, sugar cane, molasses and other amylased products. Research is currently focusing on the transformation of new raw materials into biofuels.