APPLICATIONS OF ENZYMES IN FOOD TECHNOLOGY

The use of enzymes and microorganisms in food processing has a long history. With technological advancements, new types of enzymes with diverse applications and specific properties continue to be developed, and new areas of application are continuously researched. Microorganisms such as bacteria, molds, yeast, and their enzymes are widely used in food processing to enhance flavor, structure, and provide significant economic benefits to various industries. Enzymes derived from microorganisms are more commonly applied than those from plants and animals due to advantages such as easier and more uniform production, as well as higher economic efficiency. Below is a discussion of current technological advancements in enzyme technology in the food industry.

Microorganisms have been used in food fermentation since ancient times, and fermentation processes are still applied in the early stages of many food products. Microbial enzymes play a central role in the food industry because they are more stable than plant and animal enzymes. They can be produced through cost-effective fermentation techniques that require less time and space. Due to their high consistency, adjusting and optimizing processes can be easily accomplished. Most of these enzymes have various applications in different industrial sectors. For example, amylolytic enzymes are used in food, detergents, paper, and textile industries. They are used to produce glucose syrup, crystalline glucose, high-fructose corn syrup, maltose syrup, etc. In the detergent industry, they are used as additives to remove starch-based stains. In the paper industry, they are used to reduce the viscosity of starch for paper coating. In the textile industry, amylase is used for desizing cotton fabrics. Similarly, enzymes such as protease, lipase, or xylanase have widespread applications in the food sector.

α-Amylase

α-Amylases are enzymes that hydrolyze starch, breaking glycoside bonds in polysaccharides and producing shorter dextrin chains. They are present widely in all living organisms. Most α-amylases are metalloenzymes that require calcium ions for activation, providing stability and integrity.

The extensive applications of α-amylases in the food industry include baking, beer production, starch hydrolysis, and digestive aids. They are widely used in the baking industry as flavor enhancers and anti-staling agents to improve the quality of bread. In the baking process, α-amylase is added to convert starch into smaller dextrins, which are then fermented by yeast. This improves flavor, crust color, and the quality of the bread. α-Amylases are also used in the production of high-concentration glucose syrup, crystalline glucose, high-fructose corn syrup, and maltose syrup. In the brewing industry, they play a crucial role in converting starch into fermentable sugars. The enzyme contributes to the flavor development, color, and quality of beer.

α-Amylases find applications beyond the food industry, such as in fruit juice extraction, where they enhance the yield and economic efficiency when used in combination with cellulase and pectinase. They are also used in the textile industry for fabric desizing and play a role in the production of bioethanol by converting starch into fermentable sugars.

Glucoamylase

Glucoamylase (EC 3.2.1.3) is an enzyme that catalyzes the hydrolysis of polysaccharide starch into β-glucose. It is also known as an amyloglucosidase. Glucoamylase is primarily produced by Aspergillus niger and Aspergillus awamori, and strains from Rhizopus oryzae are widely used for industrial applications. Most glucoamylases are stable at low temperatures, and their activity diminishes at higher temperatures due to changes in conformation.

Glucoamylase has diverse applications in the food industry, particularly in the production of high-glucose and high-fructose syrups. It is utilized in the baking industry to improve flour quality, reduce the toughness of dough, and enhance the color and quality of baked products. Glucoamylase converts starch in flour into maltose and fermentable sugars, influencing the texture and taste of bakery products.

In the production of alcoholic beverages, glucoamylase is crucial for converting starch into fermentable sugars, facilitating the subsequent fermentation process by yeast (e.g., Saccharomyces cerevisiae) to produce ethanol. It plays a significant role in the production of sake, soy sauce, and low-alcohol beer. Glucoamylase is also used in the dairy industry to convert lactose into glucose and galactose, improving the sweetness of dairy products.

Protease

Proteases are enzymes that catalyze the hydrolysis of peptide bonds in proteins and polypeptides. They are extensively used in detergents, pharmaceuticals, and, predominantly, in the food industry. Proteases account for 60% of the industrial enzyme market, and their global market demand has been growing at a Compound Annual Growth Rate (CAGR) of 5.3% during the period 2014-2019. Their demand is expected to further increase as new applications are discovered in leather processing and various biological treatment processes.

Proteases can be classified based on their source, catalytic activity, and the nature of the reaction group at the catalytic site. The main sources of proteases are animals, plants, and microorganisms (bacteria and fungi). Proteases can be divided into two groups: exopeptidases and endopeptidases, depending on their activity at the ends or within the polypeptide chain. Endopeptidases are further categorized into six groups based on the catalytic residue present at the active site: serine, aspartic, cysteine, metallic, glutamic acid, and threonine proteases.

Plant proteases, such as bromelain, ficin, and papain, are widely used in the food industry for various applications, including brewing, meat tenderization, milk coagulation, and digestive aids. Proteases are crucial in the baking industry for producing bread, pastries, biscuits, and cinnamon rolls. These enzymes reduce mixing time, decrease dough viscosity, regulate gluten strength in bread, and improve the texture and flavor of bakery products. Specific proteases, such as those from Aspergillus usamii, have been successfully used to enhance the functional properties of wheat gluten.

In the brewing industry, proteases play a significant role in beer production. They can accelerate the breakdown of proteins into peptides and amino acids, promoting suitable fermentation. Fungal proteases with acid properties are used to enhance the beer fermentation process even at low pH levels by balancing the amino acid profile. Another major application of protease is related to the dairy industry. Proteases significantly contribute to the flavor characteristics of cheese. They are used to accelerate cheese maturation, modify functional properties, and reduce allergenic properties in dairy products.

Lipase

Lipase is an enzyme that catalyzes the hydrolysis of long-chain fats. It naturally occurs in the stomach and pancreas of humans and other animals to digest fats and lipids. Microbial lipases are produced by bacteria, fungi, and yeast. Enzymes from microorganisms constitute about 90% of the global lipase market. Lipases find applications in various industries, including food, biofuel, detergents, animal feed, leather, textiles, and paper. In the food and beverage industry, lipase is primarily used in dairy processing, baking, fruit juice production, beer brewing, and wine making.

Commercial lipases are mainly used to enhance the flavor of dairy products and process foods containing fats. They can improve the characteristic flavor of cheese by acting on milk fats to produce free fatty acids after hydrolysis. Different types of cheese can be produced by using lipases from various sources, such as lipases from the stomach pre-gland of sheep for Romano cheese, lipases from Penicillium camemberti for Camembert cheese, and lipases from Aspergillus niger or A. oryzae for cheddar cheese. Lipase catalysis can enhance the structure and softness of cheese. Lipase is also used as an improver in the flavor of butter and vegetable butter, extending the shelf life of various baked products. In alcoholic beverages like wine, the aroma can be adjusted by using lipase. Lipase is used to improve the quality of cocoa butter, which has a melting temperature of 37°C, making it easily melt at body temperature. Lipase can be immobilized for various applications, including the synthesis of lipophilic antioxidants applied in sunflower oil. It is also used as a biosensor in the food industry. Immobilized lipase has been successfully used to determine organophosphorus pesticides using a surface acoustic wave sensor through lipase hydrolysis. It can also be used to determine triglycerides and cholesterol in blood when immobilized on pH/oxygen electrodes combined with glucose oxidase.

Pectinase

Pectinase is an enzyme that catalyzes the hydrolysis of glycoside bonds in pectic polymer chains. Pectic substances are found in tomatoes, pineapples, oranges, apples, lemon zest, and various other fruits, serving as natural substrates for this enzyme. Pectinases can be classified into polygalacturonase (hydrolyzing glycosidic α-(1-4) hydrolysis bonds), pectin esterase (removing acetyl and methoxyl groups from pectin), pectin lyase, and pectate lyase. Pectinase can be produced from natural bacteria as well as recombinant strains, with efforts made to improve their thermal stability and productivity. Pectinase can also act on fine or hairy pectin regions.

Pectinase has numerous industrial applications, such as paper bleaching, food industry, and various processing operations. The addition of pectinase to fruit juices enhances clarity compared to juices without enzymes. In addition to reducing turbidity and smoke for naturally sourced fruit juices like apple and banana, pectinase improves the color and flavor of beverages. Supplementing gelatin and pectin significantly increases the viscosity and turbidity of fruit juices, and removing haze is the most expensive part of juice production. Using biological enzymes like pectinase in fruit juice appears to be more effective than mechanical methods for better results.

Source: Food Technol Biotechnol. 2018 Mar.