Enzyme preparations are widely used in food, and this article will detail the roles of different enzyme preparations in food.
α-Amylases:
α-Amylases (EC 3.2.1.1) are enzymes that break down starch by hydrolyzing α-1,4 glycosidic bonds of polysaccharides, resulting in the production of short-chain dextrins. They are widely distributed in all living organisms, with most being metalloenzymes that require calcium ions for activity, stability, and integrity. α-Amylases are used in the food industry for baking, brewing, starch liquefaction, and as a digestive aid. In baking, they improve bread quality as a flavor enhancer and antistaling agent by converting starch into smaller dextrins that yeast can ferment, enhancing the taste, crust color, and toasting qualities of bread. They are also used in the production of high-molecular-mass branched dextrins, as a glazing agent for rice cakes and powdery foods, and for starch liquefaction, which converts starch into glucose and fructose syrups. α-Amylases are used in the production of ethanol by converting starch into fermentable sugars, which are then fermented to alcohol by Saccharomyces cerevisiae. They are also used for the clarification of fruit juices to improve yield and cost-effectiveness.
Glucoamylases:
Glucoamylases (EC 3.2.1.3) are enzymes that catalyze the hydrolysis of polysaccharide starch from the non-reducing end, releasing β-glucose. They are also called saccharifying enzymes and are widely distributed in all living organisms. Glucoamylases are stable at low temperature, but at higher temperatures, they lose activity due to conformational change. They are used in the food industry for the production of high-glucose syrups and high-fructose syrups, as well as to improve flour quality, reduce dough staling, improve bread crust color, and improve the quality of high fiber baked products. Glucoamylases convert starch in flour to maltose and fermentable sugars, leading to dough rise when fermented by yeast. They are also used for the production of glucose, which upon fermentation with Saccharomyces cerevisiae yields ethanol. Glucoamylases play an important role in the production of sake and soya sauce, as well as in the production of light beer by metabolizing dextrins and converting them to fermentable sugars with reduced calorific value and alcohol content.
Proteases：
Proteases are enzymes that break down peptide bonds in proteins and polypeptides. They are widely used in detergent, pharmaceutical, and food industries and represent 60% of industrial enzymes on the market. The global demand for protease enzymes has grown at a compound annual growth rate of 5.3% from 2014-2019 and is expected to increase further as they find applications in leather processing and bioremediation processes. Proteases can be classified based on their origin, catalytic activity, and the nature of the reactive group in the catalytic site. The major sources of protease enzymes are animals, plants, and microorganisms. Proteases are divided into two groups: exopeptidases and endopeptidases, based on the site of action on polypeptide chains. The exopeptidases act on the ends of polypeptide chains and endopeptidases act randomly in the inner regions of polypeptide chains. Plant proteases such as bromelain, ficin, and papain are widely used in the food industry for various applications such as brewing, meat tenderization, milk coagulation, and as a digestive aid. Proteases are also used to improve the flavor, nutritional value, solubility, and digestibility of food proteins, as well as to modify their functional properties including coagulation and emulsification. Proteases are widely used in baking for the production of bread, baked goods, crackers, and waffles. These enzymes are used to reduce mixing time, decrease dough consistency and uniformity, regulate gluten strength in bread, and improve texture and flavor. Acidic fungal proteases are used in improving the fermentation of beer by balancing the amino acid profile of beer. Another major application of proteases is associated with the dairy industry. Naturally occurring proteases contribute significantly to the flavor characteristics of cheese. They are used for the acceleration of cheese ripening, to modify the functional properties, and reduce the allergenic properties of milk products. Proteases are also used in cheese making to hydrolyze specific peptide bonds to generate paracasein and macropeptides.
Lactase：
Lactase (β-Galactosidase) is an enzyme that catalyzes the hydrolysis of lactose, a crucial biotechnological process in the food industry. β-Galactosidase belongs to the family of hydrolases and can be obtained from various biological systems, including plants, animals, and microorganisms. However, the production of β-galactosidase from microorganisms such as bacteria, fungi, and yeast is preferred due to higher yields and relatively low cost.
The selection of β-galactosidase source depends on the enzyme’s final application or industry.
In industrial applications, two major classes of β-galactosidase are of prime importance: cold-active and thermostable β-galactosidase. On a commercial scale, microorganisms with GRAS status are used for β-galactosidase production in milk and dairy products. Lactase is used with milk and milk-based products to reduce lactose intolerance. The hydrolysis of lactose with lactase improves the scoopability and creaminess of ice creams and reduces the need for sweeteners, which can enhance product sweetness. Additionally, lactase is used for lactose hydrolysis in whey, a byproduct of cheese production, which causes environmental issues due to lactose’s high biological oxygen demand (BOD) and chemical oxygen demand (COD). Lactase can also form galactooligosaccharides (GOS) from lactose hydrolysis due to β-galactosidase’s transglycosylation activity, which can be used as prebiotic food ingredients.
Lipase：
Lipases are enzymes that catalyze the hydrolysis of long-chain triglycerides. They are naturally present in the stomach and pancreas of humans and other animal species for digesting fats and lipids. Microbial lipases are produced by bacteria, fungi, and yeast, which contribute to approximately 90% of the global lipase market. Lipases have diverse applications in various industries, including food, biofuel, detergents, animal feed, leather, textile, and paper processing.
In the food and beverage industry, lipases find major application in dairy, baking, fruit juice, beer, and wine industries. Commercial lipases are mainly used for flavor development in dairy products and processing of other foods containing fat. Different types of cheese can be made using lipases from various sources, improving their characteristic flavor and texture. Lipases are also used as flavor development agents in butter and margarine and to prolong the shelf life of various baking products. In alcoholic beverages such as wine, lipases can modify the aroma. Lipases are also used to improve the quality of cocoa butter by replacing palmitic with stearic acid.
Lipases find application as a biosensor in the food industry, with immobilized lipase being used for the determination of organophosphorous pesticides and triglycerides and blood cholesterol. Lipases could also be used in the processing of different waste streams released from food industries. Despite finding many applications, lipase’s market share is less than 10% of the global industrial enzyme market.
Phospholipases：
Phospholipases are enzymes that selectively break down phospholipids into fatty acids and other lipophilic substances. They are classified into four major classes (A, B, C, and D) based on their mechanism of action. Phospholipase A1 (PLA1), phospholipase A2 (PLA2), and phospholipase B act on the carboxylic ester bonds of phospholipids, thereby displacing and replacing the acyl group chain through various chemical reactions such as hydrolysis, esterification, and transesterification. Phospholipases C (PLC) and D (PLD), which modify the polar head group, are also known as phosphodiesterases, and they recognize the phosphodiester linkage. Phospholipases are widely used in the food industry, particularly in the production of oils, dairy products, and bakery items. They are also used in the degumming of various vegetable oils, cheese manufacturing, and bread manufacturing. Phospholipases are also used in various dairy products to enhance the stability of fat or maximize the yield of cheese, milk, butter, and ice cream. Lipases have important applications in enhancing cheese flavor, producing lipolyzed milk fat for use in butter as flavor, and more.