Keywords

6.1 Background

Beer and wine have concealed a fascinating part of history and our social life. Although the discovery and development of brewing and wine processing signify a cornerstone achievement of humankind, its origin is still mysterious. In ancient civilization, people used to preserve fruits and grains in wooden containers for an extended period to produce beer and wine. The entire process of production is termed as fermentation, which came from theLatin word ‘fervere’, meaning ‘to boil’. The crushed fruits and grains in the wooden container produced bubbles due to microbial action or activities as if they were boiling. During that period, people didn’t fully understand that a tiny, eukaryotic fungus was making the entire recipe work (Alba-Lois & Segal-Kischinevzky, 2010). Researchers took ten decades to find out how a diminutive microbe makes the entire fermentation successful and resulted in a potation that became a status symbol in the modern era. Nevertheless, the concept of brewing and wine processing was established prior to thousands of years, which was found in the graves and settlements of early civilizations. Ancient Egyptians made wine 8000 years ago from fruits and labelled it as such by pouring it in fruit-shaped flasks, while beer came to the limelight 7000 years ago from China. Initially, Germany, the United Kingdom, the United States, Belgium, Spain and Italy were the leading countries for beer and wine production. However, in the last five decades, beer and wine production has confronted significant changes as per the demand. Global beer production reached 1940 mhl in 2018, with China being the largest producer as well as a consumer (https://www.statista.com/statistics/270275/worldwide-beer-production). In contrast, as per the data of the International Organization of Vine and Wine 2018, the global wine production has reached 292.3 mhl, with 246 mhl consumption, where, Italy, France and Spain are the highest producers.

Enzymes are the bio-macromolecules that act as catalysts in specific reactions and play a vital role in food science and fermentation technology. Since 6000 BC, enzymes have been recognized as a biochemical substance to be utilized in the processing of various foods, such as cheese preparation, brewing, wine preparation and meat tenderizing to enhance the nutritional, sensorial and functional values of the finished products (Gomaa, 2018; Gurung et al., 2013). Amongst all, enzymes offer a heroic performance in brewing and winery by accelerating the release of digestive sugars and other nutrients used by the yeasts during fermentation (Spier et al., 2016). Brewing refers to the oldest fermentation process where complex starch is bio-transformed to ethanol by the action of yeasts. This traditional process involves a series of complex endogenous and exogenous enzymes that regulate the malting of grains, the mashing of grist and rate of fermentation to produce low-calorie beer with admirable flavour, aroma and texture (Oliver, 2011; Bamforth, 2009). While grapes bio-transformed to wine by yeasts under fermentation. This process is catalysed by a wide array of enzymes that not only convert complex sugar to ethanol but also release several volatile and non-volatile substances to enhance the quality and stability of the wine (Ottone et al., 2020). Traditionally, these enzymes of brewing and winery were produced naturally by yeast or present in the grains or grapes. However, recent trends in fermentation technology pave the way for commercial production of enzymes to enhance the quality and productivity of wine and beer (Claus & Mojsov, 2018). Hence, this chapter offers a comprehensive summary on the sequential processing of brewing and winery using different enzymes as well as their mechanism of action. Moreover, the effect of enzymes on the quality and quantity of the final product and pros and cons have been enlightened.

6.2 Enzymes Used in Breweries

The process of brewing evolved centuries ago as a result of the resourcefulness and artistry of the brewers. Traditionally, lager type is the most common method of brewing, comprising low-temperature fermentation of barley and pure water with an extended maturation period. However, variations have developed in the young beer style, where brewing is not possible without the application of enzymes that hydrolyse complex starch to simple fermentable sugar and then convert it to ethanol and CO2 by yeast or bacteria. In brewing, the keystones, malted grains and barley are the sources of enzymes, including α- and β-amylase, exo-peptidase, carboxy-peptidase, proteases glucanases and cellulases (Sammartino, 2015). The detailed key role or mode of action of these enzymes is discussed below.

6.2.1 Enzymes Used in Different Stages of Brewing

The competitive brewing industry is repetitively sounding forward to improving the process in terms of quality and manufacturing costs. Brewing that refers to conversion of cereal to ethanol involves two steps: enzymatic hydrolysis of starch to fermentable sugars and conversion of fermentable sugar to ethanol and CO2. Depending on the brewing process, raw materials and technical preferences, different steps such as malting, mashing, pitching and aging are directly affected by the enzymes, while others are indirectly affected. The detailed process of beer preparation is presented in Fig. 6.1. The extent and achievement of each step depends on the development and stability of native enzymes that ultimately affect the quality and quantity of the final product.

Fig. 6.1
A chart illustrates barley, malting, mashing, pitching, aging, clarification, bottling, and finally producing beer. It indicates the steps in the preparation of beer.

Overview of brewing

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6.2.1.1 Malting

Malting is the initial and prime step of brewing, which stimulates complex carbohydrate and protein-reducing enzymes present in the barley grains. The most prominent endogenous enzymes of malt include α-glucosidase, α-amylase, β-amylase, carboxypeptidase, dextrinase, lipoxygenase, xylanase and glucanase. Besides these, peroxidase, acid or alkali phosphatases, catalase, polyphenol-oxidases and phytase enzymes are also responsible for malting reactions (Spier et al., 2016; Van Oort, 2010). The malting process comprises steeping, germination and drying. In steeping, barley grains are immersed in water for 48–60 h under oxic conditions that initiate germination and biosynthesis of amylase, glucanase, proteases and carboxypeptidase. Amylase acts on the modification of complex starch, whereas β-glucanase hydrolyses β-glucans for malting clarification and proteases act on the complex protein content of the grain (Van Oort, 2010). Then malt is subjected to drying with a temperature between 90 and 140 °C to enhance the flavour and colour of the finished product (Curtis, 2013). The challenge during this step is to maintain the quality of beer as the application of heat can adversely affect the functionality of enzymes.

6.2.1.2 Mashing

Mashing begins with boiling of malt with water, malt adjuncts and hops at different temperatures such as 50, 62, 72 and 78 °C for proteolysis, gelatinization, saccharification and inactivation of malting enzymes, respectively. Mashing embraces α- and β-amylases and protease, which degrade complex starch to maltose and dextrins, and the undesirable barley endosperm complex proteins to simple proteins, respectively (glutelin and hordein) (Dhillon et al., 2016; Spier et al., 2016). Additionally, exogenous enzymes, glucoamylases and pullulanases are added during mashing that break down the α-1,4 and α-1,6 linkages of starch to produce maltose, dextrin, maltotriose and glucose (Briess, 2013).

6.2.1.3 Pitching

Pitching refers to the addition of different strains of Saccharomyces such as S. cerevisiae, S. uvarum and S. carlsbergensis to the fermenter as inoculum. These strains own the MEL gene that synthesize α-galactosidases to cleave oligosaccharide melibiose to glucose and galactose. However, research is still on its way for genetically modified yeasts that can synthesize glucosidase, amylase and glucanase for metabolization of wort and soluble proteins (Stewart et al., 2013; Van Oort, 2010).

6.2.1.4 Aging

The beer obtained after completion of fermentation is called green beer due to its harsh taste and which can be removed by a process called aging. In aging, green beer is collected from a fermentation vat and stored in refrigerated conditions from a few weeks to several months. This process enhances the flavour of beer and precipitates yeasts, proteins and resins. During this period, diacetyl reductase is secreted by yeast, which reduces diacetyl to acetoin to develop an undesirable butterscotch flavour in beer. Thus, exogenous enzyme acetolactate decarboxylases is supplied that directly converts acetolactate to acetoin thereby reducing the undesirable flavour of beer during aging (Spier et al., 2016). In addition, several other enzymes actively involved in brewing are presented in Table 6.1.

Table 6.1 Sources and functions of enzymes involved in brewing
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6.2.2 Types of Enzymes in Brewing

The brewing process requires a prodigious knowledge of enzymology as it not only improves the quality of beer but also adds innovated attributes to the beer. Thus, enzymes with varied action and properties are used in the brewing industry. Enzymes involved in brewing can be either endogenous or exogenous. Endogenous enzymes are secreted naturally during the process of malting and mashing. Amongst all, the principal endogenous enzymes like amylase, protease, glucanase and peptidase are involved in brewing (Gomaa, 2018; Bamforth, 2009). On the other hand, at the pinnacle of enzyme technology, exogenous enzymes are applied to rectify the issues that evolved during brewing as well as to enhance the shelf life of beer by maintaining quality. Ficin, alpha-acetolactate decarboxylase (ALDC) and papain are commercially available enzymes typically used in brewing (Boulton, 2013). Details of all the enzymes are briefly discussed below.

6.2.2.1 Amylase

During brewing, both α- and β-amylases are involved in the biotransformation of complex starch to simple sugars such as dextrin, maltose, glucose and oligosaccharide (Bamforth, 2017). Endogenous α- and β-amylases are released from the barley, when the outer membrane of the granules is hydrolysed by xylanases and glucanases. During malting and mashing, amylase degrades complex starch, thereby increasing the availability of fermentable sugar. Amylase (α) strikes the internal α-(1–4) glycosidic linkage of α-glucose amylose and amylopectin to produce dextrin, whereas β-amylase cleaves the external α-(1–4) glycosidic bonds of amylose and amylopectin to release maltose. Both the amylases function optimally at pH 5.2–5.5 and temperatures about 62–74 °C (Sammartino, 2015). Moreover, α-amylase is only used endogenously during brewing, while β-amylase is used endo as well as exogenously due to its vital role in saccharification.

6.2.2.2 Protease

Proteases have many reimbursements in brewing like digestion of peptide bonds of proteins to enhance clarification of malting, augmentation of protein solubility, lowering of beer viscosity and favour rapid yeast growth. Temperature labile protease has a key role in the malthouse, functions optimally at 52 °C and can be deactivated at 70–75 °C, however, it can function at a wide range of pH. Though protease is endogenous, it is advisable to use exogenous protease to maintain the quality of beer. Brewers are acclaimed to use 0.3–1 kg of protease per ton of barley as an overdose of protease can cause foam instability leading to degradation of beer quality (Gomaa, 2018).

6.2.2.3 β-Glucanases

It is the key enzyme of malting and mashing involved in the digestion of the outer membrane of starch that allows other hydrolysing enzymes to act on starch granules. This enzyme not only lowers the viscosity of beer but also helps protease activity in the hydrolysis of a matrix of starch granules to make the kernel soften during germination. Though, β-glucanase are present naturally in barley, in the case of light beer it is supplied externally (0.3–1 kg per ton of wort) for improvement of light quality and texture of the beer (Bamforth, 2017; Lyven, 2016). β-Glucanase hydrolyses the cell wall at an optimum pH of 6 and temperature of 45–50 °C, however, this extremely heat-sensitive enzyme denatures at 60 °C (Bamforth, 2017). Thus, heat-stable microbial β-glucanases of Bacillus subtilis, Aspergillus, Penicillium and Trichoderma are used exogenously in the mashing stage of brewing.

6.2.2.4 Exogenous Enzymes

When the enzyme technology is at its zenith, other than endogenous many exogenous enzymes are also supplied to maximize the fine ability of beer during processing, storage and transportation. Some of the prime exogenous enzymes, bromelain, ficin and papain, belong to protease and alpha-acetolactate decarboxylase (ALDC) from lyases is involved in brewing (Boulton, 2013). Ficin, bromelain and papain are the chill-proof enzymes extracted from Pawpaw latex and fig plants and they are responsible for chilling haze by removing polyphenols and polypeptides leading to hydrolyzation of proteins as well as improvement of colloidal stability of beer. This chill-proof enzyme functions in a wide range of pH with temperatures ranging from 60 to 65 °C and supplies directly to the storing vessels at a concentration of 1–2 g/hl of beer (Gomaa, 2018; Boulton, 2013). Besides, ALDC is added to the beer during pilot-scale production for increasing the product yield at less fermentation time, without affecting the quality. ALDC attacks the C–C bond in the α-acetolactate for catalyzing the bioconversion of α-acetolactic acid to acetoin (Hans, 2008; Dulieu et al., 2000). It remains active at 25–40 °C temperature, 5–7 pH and is added directly during the initial period of fermentation at a concentration of 1–5 g/hl of wort and 0.4–1 g/hl of wort in post-fermentation period. Apart from these, many other exogenous enzymes such as pullulanases, phytase and diastase is also used efficiently during malting, mashing and post-fermentation period to enhance the quality of beer.

6.2.3 Effect of Enzymes on Quality of Beer

One of the most momentous advancements in brewing is to study the use and effect of different enzymes for beer production in order to fulfil the demand of consumers for a beer with an appealing taste and flavour. Therefore, it is the need of the hour to know the effect of enzymes on the quality of beer. Malting is the sole source of endogenous enzymes like α- and β-amylases that are actively involved in the conversion of complex starch to simple fermentable sugar. These enzymes are also responsible for increasing the fermentability by boosting the saccharification, higher product yield and enhancing of thermal stability of mash during brewing, which ultimately removes the bitter taste from beer. The poor activity of β-glucanases can lead to deprived runoff, recovery, spent-grain drainage, filter performance and sedimentation in beer. However, surpassing β-glucanases activity makes the mash thermostable and boosts the fine ability and filterability of beer (Aehle, 2007). Malthouse enzyme protease provides foam stability in brewing. Moreover, the shelf life improvement, maturation and flavour of beer are also greatly affected by enzymatic activity. These enzymes ensure protein solubilization during mashing, together with sugar availability to yeast during fermentation. Enzymes like amylase also decrease the fermentation period during pilot-scale brewing. Furthermore, enzymes in combination with substrate and temperature affect the carbonation, aroma and flavour of the beer. Many commercial enzymes are also cast-off to boost the quality attributes (clarification, texture, colour and flavour) of beer. The enzymes utilized in brewing are assorted in their action and properties and are key factors for the improvement of each step of brewing. Hence, intensive research is highly essential regarding the mode of action and properties of these brewing enzymes.

6.3 Enzymes Used in Wineries

Biotechnological advances facilitate the combined use of fruit juice, yeasts and enzymes to make a surface for wine preparation. Wine is the partial or complete alcoholic fermentation of grape juice by yeasts where sugars are bio-transformed to ethanol and other metabolites. These metabolites, including volatile and non-volatile composites add significant flavour, colour, odour, taste and aroma to wine. Enzymes are either naturally present in the grapes or supplied exogenously to catalyse fermentation process as well as enhance the sensory properties of the wine. In this high-tech era of biotech, endogenous and exogenous enzymes are involved at different stages of wine preparation for smooth management of pre and post-fermentation conditions. Several enzymes such as pectinases, glucanases, glycosidases, xylanases, glucose oxidases, proteases, ureases, peroxidases and proteases are actively involved in the catalyzation of different reactions occurring during wine preparation. The role of these enzymes at various stages are momentarily discussed below.

6.3.1 Enzymes Used in Different Stages of Wine Preparation

Wine production begins with the collection of matured grapes followed by crushing for extraction of juice. Then, the juice is subjected to maceration for must formation, where enzymes start functioning as a part of pre-treatment. The must undergo fermentation by yeasts to obtain raw wine with a precise aroma due to the involvement of specific enzymes. In clarification, pectic enzymes are implied to reduce the viscosity and turbidity of the wine. Finally, suitable enzymes are used in the ageing process to get good quality wine, where pertinent physicochemical properties are incorporated into the wine. The implementation of various enzymes in different steps of wine preparation is presented in Fig. 6.2.

Fig. 6.2
A chart illustrates grapes, crushing, maceration, fermentation, clarification, stabilization, aging, filtration, and finally bottling the wine.It indicates the steps in the preparation of wine.

Overview of wine preparation

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6.3.1.1 Maceration

Desired enzymes of maceration not only expedite extraction of colour, aroma and antioxidant activity but also regulate ethanol concentration of the wine (Ottone et al., 2020). The endogenous cellulases and hemicellulases catalyse the lysis of grape cells, whereas pectinases lead to the degradation of polysaccharide to accelerate the extraction of juice. These enzymes cause activation, release and solubilization of derivatives of antioxidant activity and colour and fragrance precursors (Garg et al., 2016). Besides this, the addition of glucose oxidase to the must regulate the ethanol concentration of the wine, as it maintains the concentration of glucose in the must by using it as an electron acceptor. However, the by-product H2O2 released during maceration oxidized the phenolic components of the wine, resulting in reduced antioxidant activity. Thus, exogenous catalase enzyme is added to the must for conversion of toxic H2O2 to non-toxic H2O.

6.3.1.2 Fermentation

The overall flavour and aroma of the wine are determined by the concentration of volatile components synthesized during bioprocess technology. Wine can be prepared with four types of aromas such as varietal, pre-fermentative, fermentative and post-fermentative. Production of varietal aroma is due to the partial metabolism of grapes depending on the variety, ripening percentage, soil and climate, while pre and post-fermentative aromas are developed during maceration and ageing (Samoticha et al., 2017). Moreover, the fermentative aroma is generated by acids, esters, alcohols and sulfur and carbonylated substrates produced by yeasts during fermentation. Oenology is incomplete without the involvement of yeasts like Saccharomyces cerevisiae and Saccharomyces carlsbergensis. These yeasts release certain enzymes that enhance the rate of fermentation and product yield and add flavour and aroma to the wine. Invertase is one of the most vital enzymes that causes hydrolysis of saccharose to fructose and glucose (Ribéreau-Gayon et al., 2006), whereas β-1,3-glucanases catalyses the synthesis of mannoprotein in fermentation medium and cell wall hydrolysis. Pectinases and β-glucosidase also found in yeasts catalyse the degradation of pectic components and improve the aroma of the wine respectively (Merín et al., 2014; Villena et al., 2007). Except for these endogenous enzymes, exogenous β-glucanases are also implemented during fermentation for better stability and structure of the wine (Spagna et al., 2002).

6.3.1.3 Clarification and Stabilization

In wine preparation, clarification steps make the way for bottling. The chemical reactions that occur during maceration and fermentation release many insoluble, floating materials that develop a cloudy appearance in the wine. Thus, in clarification and stabilization all the suspended materials are removed by processes like flotation, centrifugation, filtration, pasteurization, refrigeration, maturation and racking to improve the quality of the wine. Pectinase enzymes are added in the initial period of clarification to increase the juice yield, colour and flavour of the wine and to reduce the viscosity and turbidity of must (Martín & Morata de Ambrosini, 2014). It also significantly reduces the filtration time of wine preparation. Though pectinase is highly indispensable for clarification, they are not synthesized naturally during wine preparation. Thus, commercially synthesized pectinase from microbes and plants is employed during bioprocess technology. On the other hand, protease is added to the medium to circumvent haze formation. Sometimes the reaction medium gets contaminated by Lactobacillus sp. and Pediococcus sp. causing acidity, mousy taint and buttery flavour in the wine (Bartowsky, 2009; Liburdi et al., 2014). Thus, lysozyme is supplemented, which not only inhibits the growth of these contaminants but also enhances malolactic fermentation (Ottone et al., 2020).

6.3.1.4 Ageing

Ageing potentially improves the quality of the wine, where it is aged for a significant time period till the availability of oxygen for the development of premium flavour, aroma and taste. However, throughout ageing the naturally occurring urea and ethanol react to form ethyl carbamate, which has carcinogenic activity. Therefore, acid urease is added in this period for removal of urea that effectively minimizes ethyl carbamate formation to reduce the toxicity in the wine.

6.3.2 Types of Enzymes in the Winery

Over the past decades enzymes have been established as a processing aid in oenology. The enzymes offer several advantageous bids during pre-fermentation, fermentation, clarification, stabilization and ageing steps that ultimately enhance the juice yield and add colour, odour and flavour to the wine, leading to the generation of extremely fine-quality wine. Pectinase, lipase, lysozyme, glucanases, glycosidases, ester hydrolases and synthetases, phenol oxidases and urease are the potential enzymes widely used in wine preparation (Table 6.2). The above-said enzymes are naturally synthesized during oenological practice; however, in some cases, they are also supplied externally.

Table 6.2 Enzymes of the winery and their functions
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6.3.2.1 Pectinase

The grape cell comprises cellulose, hemicellulose, mannan, pectin and xyloglucan linked with proteins. During wine processing, the highly viscous pectin impedes juice extraction, filtration, clarification and diffusion of aromatic components into the must (Claus & Mojsov, 2018). The enzyme pectinase hydrolyses pectin to enhance the juice yield and ease clarification and filtration. Pectinase treatment boosts the absorbance of phenols and anthocyanins by the must, as well as intensifies the colour and clarity of the wine (Mojsov et al., 2011). Polygalacturonase, pectin lyase, pectinesterase and acetylesterase are the pectinase enzymes actively involved in wine preparation. However, pectinase is neither present naturally in grapes nor secreted by the yeasts. Therefore, commercial pectinase solutions composed of 2–5% of active enzymes and additives (preservatives, sugar and salt) are used in wine preparation (Mojsov, 2013). The pectinase available in the market is generally of fungal origin or produced by Rhodotorula mucilaginosa and Cystofilobasidium capitatum. Nevertheless, high amounts of tannin, alcohol (above 17%) and SO2 (above 500 mg/l) render the pectinase activity (Van Rensburg & Pretorius, 2000).

6.3.2.2 Lysozyme

Traditionally, SO2 was added to the medium to prevent microbial contamination in the wine, but an allergic response caused by sulphites pushes the oenologist for an enzymatic solution (König & Fröhlich, 2017; Campos et al., 2016). Thus, lysozyme is used to prevent microbial contamination, which kills the bacteria by cell lysis. Lysozyme stabilizes the wine by preventing malolactic fermentation. As per the International Organization of Vine and Wine, hen’s egg lysozyme at a concentration of 250–500 mg/l can be used in wine preparation. Moreover, after completion of bioprocess technology, this enzyme can be removed from the wine by the implementation of fining agents.

6.3.2.3 Glycosidase

Almost 90% of aroma precursors such as phenolic compounds, nerol, terpenes linalool and geraniol are present in grapes’ skin in conjugated form as odourless compounds. Glycosidase hydrolyses these precursors to liberate volatile, aromatic terpenes that ultimately activate the organoleptic properties of the wine. These enzymes are naturally found in grapes and promote the liberation of aromatic compounds under optimized condition. However, these grape glycosidases are inactivated at high alcohol and glucose concentrations and at pH 5. Therefore, commercially available glycosidases extracted from the species of Saccharomyces, Pichia, Candida and Rhodotorula are also employed in wine preparation (Claus & Mojsov, 2018; Ugliano, 2009).

6.3.2.4 Glucanase

Lactic acid bacteria and some fungus associated with the skin of grapes release viscous polysaccharides, which hamper the wine filtration. Neither flocculants nor filtration can remove these polysaccharides; thus, glucanase is used for reduction of wine viscosity. Both endo andexo-glucanase release mannoproteins to enhance the varietal flavour in the wine. Endo-glucanase is naturally synthesized by Saccharomyces species during fermentation, while exo-glucanase is supplemented to the fermentation medium. Moreover, the commercially available exo-glucanase is extracted from fungus like Taleromyces versatilis and Trichoderma sp., different species of yeast like Kloeckera, Zygosaccharomyces and Pichia and lactic acid bacteria (Claus & Mojsov, 2018).

6.3.2.5 Protease

Proteins present in must or synthesized by starter culture cause allergic reactions in the consumer (Van Sluyter et al., 2015; Rizzi et al., 2016). Though proteins are precipitated after fermentation, the presence of acid, proteolytic and heat-resistant pathogenesis-related (PR) proteins causes undesirable turbidity in the wine. Generally, bentonite is used for the removal of PR proteins, but it can adversely affect the quality and quantity of the wine (Jaeckels et al., 2015). Thus, researchers are now focusing on protease as an attractive enzymatic solution for the removal of these undesirable proteins. Protease can not only enhance the quality and quantity of the wine but also reduce the haziness in the wine. Saccharomyces species doesn’t show any protease activity; however, some fungus and non-Saccharomyces species depict the same. So, nowadays researchers are shifting their attention to selecting or developing protease positive starter culture for wine production.

6.3.2.6 Urease

In wine, fermentation yeast generates urea that is chemically converted to carcinogenic ethyl carbamate (Lonvaud-Funel, 2016). In 1997, urease was established as an enzymatic solution that cleaves urea into CO2 and NH3 and prevents ethyl carbamate synthesis. Generally, urease of Lactobacillus origin is used at a concentration of 25–50 mg/l in the fermentation medium (Pozo-Bayón et al., 2012).

6.3.2.7 Lipase

Lipids are released during wine fermentation as a result of the autolysis of yeast or grape cells, which cause significant changes in fermentation as well as in the finished product. Hence, lipase is employed in wine preparation to decompose the lipids present in the cell membrane for the improvement of the colour and texture of the wine. It is found in a few wild strains of Lactobacillus and yeasts.

6.3.2.8 Esterhydrolases and Synthetases

Esters are either present in grapes or synthesized by yeasts during fermentation, which contributes a significant fruity flavour to the wine. Esterhydrolases and synthetases regulate the concentration of the ester during malolactic fermentation by promoting its synthesis as well as hydrolysis (Ugliano, 2009).

6.3.2.9 Phenoloxidases

Phenoloxidases affect not only the sensory attribute of the wine but also the final phenol concentration of the wine. However, these oxygen-sensitive enzymes on exposure to O2 cause enzymatic browning of wine. Phenoloxidases include tyrosinase, responsible for implementation of colour to the wine, and laccase, which causes phenol oxidation to enhance the organoleptic properties of the wine (Claus & Mojsov, 2018).

6.3.3 Effect of Enzymes on Quality of the Wine

Enzymes have a very controversial effect on wine preparation as they are highly selective. Several studies have been directed to know the effect of different enzymes on the organoleptic as well as quantitative properties of the wine. The colour extraction of the wine is greatly influenced by xylanase and glycosidase activities. During maceration, the enzymatic treatment enhances the extraction of phenolic compounds while depicting undesirable anthocyanin content and colour parameters. Similarly, glycosidase helps in aroma extraction in the wine; however, an abundance of glucose inhibits its action. Lysozyme causes total inhibition of lactic acid bacteria from wine, but the presence of the residual amount of lysozyme can cause an allergic reaction in the consumer (Liburdi et al., 2014). Furthermore, protease is essential to remove PR proteins from wine, but it is only functional under restricted alcohol concentration, pH and temperature (Espejo, 2020). It can’t be ignored that enzymes are highly essential for wine preparation, but the sensitivity of these enzymes influences industry and academia to analyse the pros and cons before further application.

6.4 Pros and Cons of Enzymes Used in Brewing and Winery

Before taking any step forward towards the enzymology of brewing and wine preparation, it is highly recommended to study their pros and cons. The application of enzymes in brewing enhances the maturation of beer, catalyses low-calorie beer production, stabilizes the beer by improving mashing and clarification and reduces the viscosity, leading to fine-quality beer production (Gomaa, 2018). Nevertheless, the cost is the prime barrier in the enzymatic treatment of beer. Besides, the sensitivity of enzymes towards temperature, pH, alcohol and glucose concentration also significantly affects the use of enzymes in brewing. Like in brewing, enzymes also have a significant effect towards the enhancement of the flavour, aroma and taste of the wine. Some enzymes are used to prevent contamination of the wine by toxic microbes and compounds. Enzymes also ease the wine processing for higher yield and lower production cost, leading to a booming profit. On the other hand, it is always advisable to consider the drawbacks of these enzymes for a better future. Sometimes specific activity and side effects of a few enzymes have a detrimental effect on wine quality. Also, the use of commercial enzymes requires a lot of pre-treatment, which is time-consuming as well as expensive. Intermittently, enzymes undergo unwanted chemical reactions with the components of the fermentation medium and cause an allergic response to the consumer. Hence, a detailed study of individual enzymes is highly essential before their use.

6.5 Conclusion

In the present scenario, breweries and wineries have established themselves as extremely lucrative businesses in the agriculture and alcohol industries. Earlier these two were produced by traditional methods, but in the modern era, the establishment of brewery and winery is not possible without the involvement of enzymes. On account of this, brewers and oenologists amalgamate traditional and advanced enzymological techniques for the development of modern methods for beer and wine production. Amylases, glucanases, proteases and cellulases are the foremost important enzymes being used in beer industries. Though the implementation of enzymes ensures faster and higher beer production, the brewer should screen the appropriate enzyme with eyes open because a slight modification in enzymatic treatment can cause devastating effects on the finished product. On the other hand, enzymes have a flourishing future in the wine industry and a wide array of enzymes are being used for the furtherance of different stages of wine preparation. Pectinases, protease, glucanases, lysozyme and lipase are the enzymes used during the different stages of wine processing for the production of superior-quality wine. These enzymes accomplish every goal to provide chemical, mechanical and thermal stability to wine. Moreover, recent advances in biotechnology pave the way for researchers to articulate a stringent plan of work or phenomenon to overcome various drawbacks of brewery and winery. This chapter intensely discussed several aspects of enzymes used in brewery and winery; however, further study is highly essential in this regard.