Emerging Advances In Yeast Fermentation

Thursday, September 21st, 2017

Yeast, one of humankind’s oldest processing ingredients, has advanced in capabilities, traits and applications today. Used in both the food and beverage industry, what are some advances in yeast fermentation? By Steve Campbell, president, Campbell & Company Strategies Incorporated

Buoyed by their perceived naturalness and healthiness, fermented beverages and foods are enjoying a surge of consumer popularity around the world. New and emerging categories are joining established fermented products such as beer, wine, kimchi, yogurt and bread; among them are lightly fermented chocolate, and teas such as kombucha, that can be used as healthy and flavourful additions to other drinks, sauces, desserts, etc.

The booming interest in fermented products is being helped along by emerging innovative advances in yeast’s capabilities, both for specialty applications in beverages such as wine, beer and cider, and for larger markets such as bread and baked goods. These evolving yeasts (and other fermentation agents such as food-grade bacteria) are about to drive the next wave of innovation in fermented foods and beverages.

Aside from fire, yeast is the oldest food processing agent known to man, and has been used for millennia to ferment foods and beverages. Yeast’s essential role in the production of these staple foods underlies its important role in the foundation of human civilisation—a position that continues to strengthen every day through an ever-widening range of applications for this most trusted of microorganisms.

Given yeast’s long-term and widespread use across the food and beverage industries, it is easy to take the microbe for granted and assume it is a simple ingredient. In fact, it is anything but simple. The impact yeast has on the end product is truly transformative—just think about the difference between leavened and unleavened bread, grape juice and wine, wort and beer, etc. Yeast has the power to fundamentally improve the physical, chemical and even biological characteristics of a vast range of products.

However, when it comes to the value-added capability of yeast, we are currently realising only a fraction of its intrinsic potential. It is only in the last century and a half that we have begun to truly understand yeast’s importance and commercially harness its power. During this time, however, we have selected yeast strains with easy-to-quantify and industrially advantageous traits: maximum gassing power, temperature tolerance, neutral flavour profiles, and the like.

What we have failed to capitalise on to date is the huge range of natural biodiversity inherent in the wider yeast family. That is about to change, however, as yeast undergoes a major revolution in its use in foods and beverages.

Traditionally viewed as a workhorse ingredient, yeast is applied principally in large, commodity-type applications for major products in the baking and beverage markets. Therefore, it is hardly surprising that less than one percent of commercially viable yeast strains are currently in production. While this might be desirable from an industrial efficiency standpoint, it works to limit the functionality of the yeast, and thus the variety of the end products. That need not be the case.

Non-GMO Classical Breeding Advances Yeast

Recent improvements in yeast technology, particularly in the areas of classical breeding and strain evolution techniques, have led to some truly remarkable advances in strain development. Importantly, these are all non-genetically modified organism (GMO) methods and products—a significant advantage given that GMO yeasts, and the foods and beverages made with them, may not be widely accepted by consumers for many years to come.

Enhancing a desirable but otherwise repressed trait through adaptive evolution is one such valuable advance in yeast development. Another involves introducing a new trait into an existing strain through breeding, while maintaining the background strain’s functional performance. In fact, these classical techniques are the methods of choice when it comes to maintaining complex or multiple traits such as flavour and aroma. Advances in this area could be used to generate strains that (using baking as an example) leaven/gas as normal yet produce enhanced flavour profiles, all the while offering cleaner labelling.

These innovations have already led to new yeast products with exciting functionality and uses. For example, novel strains have many achievements to claim: they have enabled the prevention of the spoiling contaminant hydrogen sulfide in wine, cider and beer; helped to expand flavours and styles in beer; assisted in reducing the carcinogen acrylamide in certain cooked foods; added vitamin D and important minerals, such as selenium; and promoted gut health in the form of pre- and probiotics. Indeed, novel yeast strains—created by the confluence of an already impressive natural biodiversity and classical strain development—have the potential to be versatile, widely available and cost-effective clean-label solutions to a host of challenges facing the modern food and beverage industries.

Using Yeast To Prevent Hydrogen Sulfide Contamination In Wine And Beer

For millennia, hydrogen sulfide (H2S) contamination has been a natural and costly by-product of yeast fermentation in alcohol production, for instance in wine, beer, cider and distilled spirits. When H2S is produced in large amounts, the product is spoiled due to the characteristic rotten-egg smell of H2S and its more potent derivatives, mercaptans and disulfides.

Furthermore, even in trace amounts (at levels undetectable to the human nose), hydrogen sulfide affects quality by masking desirable sensory compounds, thereby preventing the full expression of the beverage’s flavour, aroma and personality.

A natural yeast trait was discovered by researchers at the University of California at Davis in wild yeast from a vineyard in Emilia-Romagna, Italy. It has the ability to prevent hydrogen sulfide from forming during fermentation. This trait, patented and protected by the university, has been classically bred into a suite of Renaissance yeasts suitable for the production of red, white and organic wines, as well as cider and even kombucha.

Using Yeast To Expand Flavours And Aromas In Beer-Making

Although the importance of yeast in brewing may be often overlooked, especially by consumers, yeast is actually one of the most important ingredients in terms of differentiating beer styles and creating flavour and aroma.

In fact, in any given fermentation, the majority of the final beer’s flavour and aroma compounds are created by yeast. In terms of opportunity for brewers and options for consumers, this is especially noteworthy as the rapid growth of the craft brewing segment means new styles and tastes are highly sought-after by brewers looking to be ‘first movers’ in an emerging beer category.

Today, classical development techniques enable conventional beer yeast strains to be redeveloped, enhanced and modernised, and even combined into tasty new hybrid strains that could lead to entirely new beer styles. Just as there has been expanded interest in forgotten varietals of fruits and vegetables over the last 20 years, the next few years will see a similar increase in the range of beer yeasts available—and a parallel expansion in available beer choices.

Big And Small Collaborations Accelerating Yeast Strain Development

Concomitant with these exciting advances occurring in fermentation and yeast, larger food companies are moving to expand their involvement in food technology innovations, mainly through working with small, research-focused companies working to develop new technologies.

Recently, as an example, Archer Daniels Midland and Naturex separately announced strategies to spur innovation by developing food technology incubators, and build closer linkages with small, innovative food tech companies.

Other firms, such as Campbell Soup and General Mills, are fostering and accessing technology innovation by establishing internal venture capital arms. Collaborations such as these are critical, as they have the potential to deliver results faster than large food companies working in isolation in their corporate labs.

However, in spite of the possibilities that abound for novel yeast strains, development in the manner described above is neither easy nor inexpensive. As a result, given what seems like ever-shrinking margins across all food and beverage sectors—and the consequent tightening of research budgets—strain development is an activity in which fewer and fewer players are engaging.

Moreover, today’s business realities have led to a fundamental mismatch of complementary assets needed to get new yeast strains to market. For example, small food technology research companies lack production, sales and distribution networks, while large manufacturing companies tend to be slow to develop new products needed to drive innovation thereby allowing them to maintain or grow market share and profit margins.

Ultimately, this collaboration between big and small firms needs to occur, as yeast holds vast intrinsic power and as-yet-unrealised capabilities to solve many industrial food quality and safety problems, all while providing a clean-label and natural avenue for enhancing flavours, aromas and tastes in many foods and beverages.

Yeast—humankind’s oldest food processing friend—will without a doubt remain at the forefront of the large-scale changes and improvements certain to take place in the area of fermented foods and beverages in the years ahead.