APPLICATION OF ENZYMES IN BEER PRODUCTION

Brewing is one of the oldest food processes in human history. Beer production technology dates back six thousand years and has been practiced by ancient civilizations such as ancient Egypt and Mesopotamia. Today, beer production is one of the leading food industries worldwide, especially in the West. The use of enzymes is a key aspect of the brewing industry, whether the enzymes are inherent in the raw materials or added from external sources. Understanding and conducting in-depth research on these enzymes is essential for improved production and higher quality. The purpose of this overview is to explain the beer production process and discuss various enzymes used in the brewing industry, providing descriptions of their mechanisms.

Introduction

Enzymes possess crucial biochemical properties proven to be essential not only for living organisms but also in the fields of science and food technology. Enzymes participate in many vital reactions in the human body, such as signal transduction, cell regulation, movement, digestion, absorption, and metabolism. Enzymes are primarily spherical proteins with a tertiary structure, formed by thousands of amino acids linked together through peptide bonds in linear chains.

In addition to their physiological characteristics, enzymes play a significant role in the food industry. For over 6,000 years, enzymes have been extensively used in various stages of food processing, including brewing, cheese making, reducing maturation time in wine production, tenderizing meat, etc. One of the main applications of enzymes in the food industry is in beer production. Brewing is defined as the process of beer production, where starch in malted barley is fermented into ethyl alcohol through the action of yeast. This is one of the oldest food production techniques, predating even the Christian era. In ancient Egypt, women commonly baked and brewed beer as a household duty, and the beer during this period was called “heqet.” Ancient Egyptians used bread, water, barley, dates, and yeast to produce a thick, dark beer. Today, the beer production industry has grown significantly and has shown an increasing trend over the past decades. According to 2015 statistics, China (460 billion hl) and the United States (189.21 million hl) are the largest beer producers. The total number of breweries in the United States from 1990 to 2016 was estimated at 5301.8. The purpose of this discussion is to explain the beer production process, discuss various enzymes used in the brewing industry, and describe their mechanisms.

Beer Production Process

The beer production process mainly consists of nine key steps: malting, milling, mashing, lautering, adding hops, fermentation, conditioning, filtration, and bottling.

The process begins with barley, where grains (usually barley or wheat) are dried to malt to convert complex carbohydrates into dextrin and maltose through three consecutive processes: soaking (14–18 °C), germination (16–20 °C), and drying (50–110 °C), using water, heat, and the action of enzymes (e.g., α-amylase and protease). After malting, water is added to the malt before milling to create a uniform mash and undergo further hydrolysis to produce simple sugars through the milling and mashing processes. Then, wort (the result of the milling process) undergoes lautering (from the German word “abläutern,” meaning separating wort), where particles are separated from the sugar solution extracted during the milling process in the lautering vessel because it contains fine filters containing husks of particles in the solution. In the hop addition process, wort is boiled (100 °C) with hops to sterilize the wort from any contaminants and improve beer quality and stability. The wort is then cooled, and air is injected for yeast fermentation in the fermentation process (6–25 °C) to ferment sugars into ethanol and CO2 to produce beer. Afterward, the beer is controlled within a temperature range of (-2 to 0 °C) to remove harmful and unwanted components that may affect the beer’s carbonation, aroma, and taste. Finally, the beer is filtered through plate filters to remove suspended solids such as hop residues, wheat particles, yeast, etc. Ultimately, beer is packaged in bottles, with one of the crucial steps in the packaging process being the removal of oxygen from the product to prevent spoilage and impact beer quality. Through all the aforementioned steps in the beer production process, enzymes play a crucial role in maintaining and improving the product. The roles of enzymes in beer production will be further discussed below.

Barley Grain

The beer production process relies on starch-soaked carbohydrates sourced from plants such as barley, which is then fermented by yeast. During this process, enzymes play a crucial role in catalyzing various reactions. Barley is an excellent source of starch and is widely used in beer production. Barley grains contain most of the enzymes needed for beer production when the grains are soaked in hot water, and enzymes like protease and glucanase are utilized. As mentioned earlier, malting involves three steps: soaking, germination, and drying. In the soaking process, barley is soaked in water for 2 days, causing it to absorb water and increase in volume, leading to a moist and flexible appearance. The germination process then follows, where grains are spread in layers and exposed to controlled temperature and humidity, causing the grains to germinate and grow. In this phase, enzymes are activated and produced in the grain to be used in beer production, primarily α-amylase, which hydrolyzes maltose into glucose.

Enzymes in the Brewing Process

1. Alpha-Amylase

Alpha-amylase is an enzyme with the primary function of breaking down starches into smaller dextrin molecules, leading to the formation of maltose and glucose. This enzyme is naturally present in barley grains and is activated during the malting process. Alpha-amylase is essential for the brewing process as it initiates the conversion of starches in barley into fermentable sugars. The optimal temperature for alpha-amylase activity is typically between 60-70 °C.

2. Beta-Amylase

Beta-amylase is another crucial enzyme in the brewing process, responsible for breaking down long chains of sugars into shorter chains, resulting in the production of maltose. Beta-amylase works in conjunction with alpha-amylase to ensure the efficient conversion of starches into fermentable sugars. The optimal temperature for beta-amylase activity is around 50-60 °C.

3. Protease

Protease is an enzyme that plays a significant role in the malting process by breaking down proteins in barley grains into amino acids. This enzyme is crucial because it helps in enhancing the yeast’s ability to ferment and contributes to the overall flavor and stability of the beer. Protease is active in a broad temperature range, typically from 40-70 °C.

4. Glucanase

Glucanase is an enzyme that breaks down glucans, which are a type of polysaccharide present in the cell walls of barley. This enzyme is essential during the mashing process as it helps in separating the wort from solid particles, improving the lautering process. Glucanase is active at lower temperatures, typically between 35-45 °C.

5. Phytase

Phytase is an enzyme that breaks down phytic acid, a form of stored phosphorus in barley grains. While it is not directly involved in the conversion of starches into sugars, its activity during malting is essential for releasing additional nutrients for yeast metabolism. Phytase functions optimally at temperatures ranging from 30-40 °C.

6. Lipase

Lipase is an enzyme that breaks down lipids (fats) into glycerol and fatty acids. While lipase activity is generally not desired in large amounts during beer production, trace amounts can contribute to the overall flavor profile of the beer. Lipase is active in a broad temperature range, but its activity is often minimized during brewing processes.

7. Alpha-Glucosidase

Alpha-glucosidase is involved in the final stages of the brewing process, where it hydrolyzes the remaining starches and oligosaccharides to produce glucose. This enzyme helps ensure complete fermentation and conversion of available sugars. Alpha-glucosidase is active at temperatures around 45-60 °C.

Conclusion

Enzymes play a critical role in various stages of the beer production process, from malting to fermentation. Understanding the mechanisms of these enzymes is crucial for optimizing the brewing process, ensuring the efficient conversion of starches into fermentable sugars, and ultimately producing high-quality beer. The use of enzymes in brewing has evolved over thousands of years, with modern brewing practices incorporating scientific knowledge to enhance the efficiency and consistency of beer production. As technology and research continue to advance, the brewing industry will likely benefit from new insights into enzyme function and applications, leading to further improvements in beer quality and production processes.

References:

1. Bamforth, C. W. (2003). Beer: Tap into the Art and Science of Brewing. Oxford University Press.
2. Briggs, D. E., Boulton, C. A., Brookes, P. A., & Stevens, R. (2004). Brewing: Science and Practice. CRC Press.
3. Bamforth, C. W. (2009). An overview of enzymes in brewing: historical perspectives. Journal of the Institute of Brewing, 115(4), 319-324.
4. Emeagi, P. E., & Falade, T. C. (2016). Optimization of beer brewing from sorghum malt using response surface methodology. Food Science & Nutrition, 4(6), 852-858.