DDC Tech Day | Four Key Engineering Approaches of Biotechnology in Feed Flavorings

Enzymes are chemically proteins, and proteins are made up of 20 Composed of various amino acids, it acts as a biological catalyst, playing an invaluable role in numerous chemical reactions. Through enzymatic catalysis—especially that of immobilized enzymes—production processes can be streamlined, production costs reduced, and operational environments improved, leading to highly significant economic benefits. As people’s awareness of environmental protection and their quality of life continue to rise, the applications of enzymes in fields such as pharmaceuticals, food processing, and chemicals are expanding rapidly. Meanwhile, enzymes are increasingly being utilized as process auxiliaries in the production of flavoring ingredient raw materials. Acting as catalysts in biochemical reactions, they can selectively synthesize natural or semi-natural fragrance precursors, contributing to the manufacturing of feed-grade flavor enhancers—and even enabling the direct enzymatic production of natural complex fragrances like milky or meaty aromas.

Fragrance ingredients are substances that can be detected by the sense of smell as aromatic or by the sense of taste as flavorful—they serve as the raw materials for formulating fragrances and flavor enhancers. Following U.S. and European regulations stipulating that "natural" fragrances must be produced exclusively through physical processes (such as extraction from natural sources) or via enzyme engineering and microbial fermentation, technologies for producing fragrances using natural substances fermented or enzymatically treated have rapidly advanced. Moreover, the use of enzymes to synthesize chiral fragrances has also gained widespread application. For instance, most ester compounds exhibit floral, fruity, alcoholic, or honey-like aromas. As a result, esters and lactones occupy a crucial and indispensable position in the formulation of our feed flavoring products. Currently, the most common method for synthesizing esters on the market remains chemical synthesis; however, with growing global emphasis on safety and sustainability, natural-derived products are increasingly favored. Consequently, enzyme-based methods for producing natural esters have attracted significant attention. Typically, enzymatic synthesis of natural esters involves catalytic reactions such as enzyme-mediated hydrolysis of fats. Today, enzymatic processes for manufacturing aliphatic esters, ethyl lactate, and geranyl acetate—key fragrance ingredients—are already highly refined and widely adopted in industrial production. Beyond ester synthesis, enzyme engineering has also achieved remarkable maturity in the production of vanillin, leaf alcohol, menthol, lactones, and thiol-based fragrance ingredients, laying a solid foundation for enhancing the quality of milky and fruity notes in feed flavorings. Clearly, the role of enzyme engineering in the formulation of feed flavorings is becoming ever more critical, and its future potential for growth looks exceptionally promising.

So-called fermentation engineering is the process of utilizing microorganisms to produce specific products. Depending on the unique characteristics of different microorganisms, they can secrete particular enzymes or participate in specialized conversion reactions under certain conditions, ultimately yielding products that meet human needs. In fact, microbial fermentation engineering was one of the earliest biotechnologies applied in the field of flavoring agents—its origins can be traced back to our ancestors' ancient practices of brewing soy sauce, sauces, edible vinegar, and various types of alcoholic beverages. Meanwhile, modern microbial fermentation technology has emerged over the past millennium, built upon humanity's extensive practical experience accumulated over time. 19 Emerging in the mid-20th century, it has served as a platform for cutting-edge technologies such as genetic engineering, cell engineering, and enzyme engineering, playing a key role in large-scale production across industries like food, chemical, and pharmaceuticals.

Microbial fermentation is a series of biochemical reactions carried out by microorganisms, characterized by mild reaction conditions, abundant and renewable raw material sources, simple processes, and environmental friendliness. As a result, it has attracted significant attention in the flavoring agent industry. For instance, current natural ethyl maltol products are primarily produced via microbial fermentation by several biotechnology companies in the United States, Germany, and Japan. These products are widely used as key ingredients in flavoring formulations for tastes such as cream, dairy, yogurt, and vanilla. Recently, there have been reports highlighting groundbreaking advancements abroad, where fermentation techniques using papaya, soybeans, sunflower oil, and other materials have successfully yielded complex apple-like aromas.

Meanwhile, the microbial fermentation production of vanillin—the key ingredient responsible for milky flavors—is rapidly gaining momentum, largely due to limitations in the availability of vanilla bean resources. Several universities in China, including Shandong University, Northeast Agricultural University, and Shaanxi University of Science and Technology, are actively conducting research into this innovative process. Microbial fermentation for vanillin production primarily involves using ferulic acid—derived from the cell walls of wood, weeds, or cereal bran—as the fermentation substrate. Under the action of specific microorganisms, ferulic acid is converted into vanillic acid, which is then further transformed into vanillin by yet another type of microbe. Vanillin is the world's most widely used fragrance ingredient. With the maturation of its biotechnological production methods, we’ve finally overcome the constraints imposed by plant-based resources, significantly reducing both the cost of vanillin production and its final product price. This breakthrough now enables large-scale applications of vanillin in feed flavoring products, paving the way for the development of an extensive range of dairy-flavored offerings.

Cells are one of the smallest units essential for sustaining life and enabling the functions of living organisms. Preparing flavoring ingredients using cell engineering has become a hot topic of interest among biologists. Currently, the most widely applied method in this field involves tissue culture of animal and plant cells to produce specific feed-grade flavoring raw materials—such as vanillin, often hailed as the "king of spices." Through meticulous processes like selecting and treating healthy vanilla bean explants, as well as inducing and cultivating callus tissues, researchers have already successfully obtained natural vanillin in practical applications. As cell engineering technology continues to mature, scientists can now use tissue culture techniques to generate seedlings or highly aromatic somatic cells from nearly any common plant or animal species. This breakthrough not only alleviates the scarcity of rare plant and animal resources but also provides our flavoring industry with an abundant supply of diverse, high-quality, and cost-effective raw materials. Moreover, it greatly simplifies the extraction process, making it easier than ever to isolate and obtain valuable fragrance compounds.

20 Century 60 Over the decades, with the advancement and expansion of biochemistry and molecular biology, people have gained deeper insights into life's genetic material. --- We now have a relatively clear understanding of genes, and a series of advanced biotechnologies—centered around genetic engineering and encompassing fermentation engineering, cell engineering, and enzyme engineering—have gradually taken shape. In particular, the application of genetic engineering in the flavoring agent industry primarily involves genetically modifying microorganisms or plant and animal cells used for producing these agents. For instance, this includes breeding strains capable of efficiently producing various esters and lactones, as well as genetically modifying and enhancing yeast strains to boost their ability to produce phenylethyl alcohol. At its core, genetic engineering works by altering the genetic information within organisms, thereby improving the ability of microbes to synthesize specific compounds, streamlining metabolic pathways, or even partially eliminating feedback inhibition in metabolism—ultimately leading to increased yields of desired products.

In addition, genetic engineering can also enhance aroma and flavor by improving the quality of raw materials. For instance, by selectively breeding wine grapes, we can significantly boost and refine the distinctive flavors of wine. This demonstrates that genetic engineering—a sophisticated yet accessible technology—is actually much closer to us than we might think, and it’s far from being an unattainable feat. Indeed, its widespread application will undoubtedly usher in a revolutionary era, benefiting not only the production of aromatic ingredients but also countless other related industries.