The Wonderful World of Fermentation

Can we positively impact the future of our global food supply by further leveraging fermentation processes? Let’s explore this question by first looking at what history tells us about fermented foods and beverages. Today, there are more than 3,500 types of traditionally fermented foods and beverages eaten around the world, the result of experimentation over millennia. Among the earliest examples are bread (30,000 years ago), beer and wine (7000 BC/5400 BC), and yogurt and cheese (6000 BC/5000 BC). Our ancient ancestors also used traditional fermentation processes to produce pickles, jiang, a precursor to soy sauce and miso, and kimchi (2400 BC, 1000 BC, and 700, respectively), as well as chocolate (1900 BC) and coffee (1500) (Kim 2013).

While many of the fermentation processes for these products are industrialized today, we often forget that fermentation processes that occur in the field are the key to making coffee and chocolate, and these processes are not yet fully industrialized. We know fermentation, which uses microorganisms and enzymatic action to convert or change food properties and components, is an excellent way to preserve foods in terms of safety and quality. So, how can we develop and advance these traditional processes to achieve greater levels of food preservation, unique sensory experiences, food security, and human health benefits?

Culture: Many Layers of Meaning

The Art of Fermentation is a comprehensive source of information for making just about every type of fermented food at home (Katz 2012). The book describes the impact and importance of fermented foods in a new way. While the opinions the author expresses on the industrialization of food are likely not in alignment with the science of food, the book is captivating, nonetheless, particularly with regard to defining the term culture.

Katz writes that our human culture exists only as communities, as do microbial cultures. Food is one of the greatest community builders. People gather as families, friends, and neighbors around food, and fermented food and beverages play a significant role in this community building. Many feasts, rituals, and celebrations are organized around fermented foods such as bread, cheese, and wine. Katz also recognizes that as one explores the history and recipes about food fermentation, one word comes to mind repeatedly: culture. It is an important word with many layers of meaning, both within the science of food microbiology as well as through its broadest connotations:

• The starter added to milk to make yogurt or cheese—or for making other fermented foods—is called “culture.”
• “Culture” also means the totality of everything we as humans seek to pass on from generation to generation—our language, music, art, and scientific knowledge.
• The cultivation of the land and its creatures, including microorganisms, is essential to “culture.”

It is fascinating to think about how fermentation and culture, with its many interconnected meanings, has evolved to enrich peoples’ lives around the globe in so many ways.  Fermentation, and its extension into biotechnology, has benefited humanity in powerful ways in our past and present—and it will continue to provide innovative solutions for the challenges facing the food system well into the future.

Foundation for the Future

We know that fermented foods and beverages are some of the oldest and most important sources of sustenance that add both value and stability to raw agricultural products. They have been, and continue to be, essential to the foundation of all communities as part of both human and economic development. Since fermentation is a relatively efficient, low-energy preservation process that increases shelf life and decreases the need for refrigeration or other forms of preservation, it can be an appropriate and valuable technique for use in developing countries and remote areas. Certainly, fermented foods are universally popular in their various forms, and in some regions, they make a significant contribution to the diet of millions of people every day. They play an important role in ensuring the food security of millions of people (Battcock and Azam-Ali 2009).

Traditional food fermentation processes can be broadly classified into lactic acid fermentation, fungal fermentation, and alkaline fermentation. During food and beverage fermentation, metabolites such as lactic acid, acetic acid, carbon dioxide, ethanol, hydrogen peroxide, bacteriocins, and antimicrobial peptides, produced by the fermenting microorganisms, and acting alone or in combination, inhibit the growth of spoilage and pathogenic organisms, achieving an extension in the shelf life and ensuring safety of susceptible products (Voidarou et al. 2021). Traditionally, foods have been preserved through naturally occurring fermentation; however, modern large-scale production generally now uses defined starter culture systems to ensure consistency and quality in the final product.

Value is added to foods through fermentation because it contributes to their preservation; actively participates in the development of their texture, flavor, and aroma; helps to eliminate pathogens and toxic substances; improves digestibility; creates new products for new markets; and increases dietary value. Fermentation plays a vital role in health and human nutrition (Battcock and Azam-Ali 2009). Fermentation can remove or detoxify naturally occurring toxins and antinutritional compounds, for example, removing cyanide from cassava, improving safety. It can result in increased levels of vitamins within the final fermented product. Fermentation can improve the digestibility of many foods; for example, decreasing the lactose content in milk when cheese or yogurt is made or via cellulase or pectinase production, which makes fermented foods more digestible than the unfermented raw material. Fermentation can salvage waste food that otherwise would not be usable as food by changing the consistency of the product and making it digestible. This increases the range of raw materials available as food. For example, tempe-bongrek is a protein-rich food made in Indonesia by using Rhizopus species to ferment peanut and coconut press cakes, which are the waste materials remaining after oil extraction from the peanuts or coconuts. The product is similar to traditional tempeh produced from the fermentation of soya beans. There is a wealth of information published in the scientific literature about the health benefits of fermented foods, including the consumption of microorganisms, such as lactic acid bacteria.

There is an increasing body of evidence that prebiotics and postbiotics are also beneficial to human health. The human body is host to an elaborate indigenous microbiota. In and on our bodies, bacteria outnumber the cells that contain our unique DNA by more than 10 to 1, with the vast majority inhabiting our intestinal tract. We are just beginning to understand the significant role bacteria, like lactic acid bacteria we consume in fermented foods, play in the regulation of energy balance, production of certain key nutrients, immune modulation, and many other important health benefits for humans. Our scientific knowledge of this topic unfolds each year, as molecular methods, genomic techniques, and bioinformatics evolve. Additionally, as new tools are developed and computational power continues to expand exponentially via digital transformation, they will be used to study the extraordinarily complex relationship and dynamic interaction between microbes, human digestive systems, and human health.

Certainly, there are many reasons why fermented foods and beverages have been a ubiquitous part of the human diet, culture, and economy for many thousands of years. It is quite interesting to see that over the past several years, fermented foods and beverages are the rising stars in the “foodies” scene throughout traditional and social media. There is a renewed interest and excitement in producing an entire range of fermented food and beverage products by professional chefs in restaurants and by the food industry for retail sale, as well as by those who enjoy preparing food at home. This interest is spurred by the desire to obtain the health benefits that fermented products confer when consumed. Equally, these products are rising stars because of the broad range of cultural and sensory experiences fermented foods and beverages have to offer.

Untapped Potential

There is tremendous untapped potential for innovation via fermentation and industrial biotechnology. The possibilities are endless, from fermentation‐derived ingredients, novel protein sources, and fermented foods using unconventional feedstock, to improved accessibility and affordability of food, to improved sustainability of food production. Utilizing the ability of microorganisms to produce specific molecules through precision fermentation allows the inexpensive and large‐scale production of virtually any food ingredient (e.g., enzymes and other proteins, natural pigments, and fats) (Teng et al. 2021). Biomass fermentation for protein production is based on microorganisms’ abilities to rapidly multiply and produce high protein content of more than 50% dry weight. The resulting whole‐cell biomass can be served directly or blended with other food ingredients, including, for example, Vegemite, made from yeast extract; mycoprotein from filamentous fungi as alternative proteins (e.g., Quorn’s meatless burgers); and rice and pea protein fermented by Shiitake mycelia (e.g., MycoTechnology’s FermentIQ).

Utilizing novel feedstock sources for fermentation can also help to meet increasing consumer preference for plant‐based diets. Companies already are developing and commercializing alternatives to traditionally fermented dairy products such as cheese and yogurt using soy, nuts, and cereals. There are also positive environmental effects in using fermentation to produce alternative proteins, by ultimately reducing the demand for livestock, which helps to decrease greenhouse gas emissions and pollution while saving land, water, and animal feed.

Let us go back to the question posed at the beginning of this article. Can we, as professionals in the science of food, as members of our families, our communities, and our culture, harness the power of fermentation to have a positive impact on the global population and planet today and as we move into the future? My answer is a resounding yes!ft