Paper No.: 03 Paper Title: FOOD MICROBIOLOGY. Module 19: Fermented beverages. (e-text and Learn More)

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1 Paper No.: 03 Paper Title: FOOD MICROBIOLOGY Module 19: (e-text and Learn More)

2 Component-I (A) - Personal Details: Role Name Affiliation National Coordinator Professor R.C. Kuhad University of Delhi South Campus New Delhi Subject Coordinator Professor Vijayakhader Former Dean, Acharya N.G. Ranga Agricultural University, Hyderabad Paper Coordinator Professor A. K. Puniya National Dairy Research Institute (NDRI), Karnal Content Writer/Author Dr. Tejpal Dhewa Bhaskarcharya College of Applied Sciences (University of Delhi), Sector-2, Phase-1, Dwarka, New Delhi Content Reviewer Language Editor (LE) Technical Conversion

3 Component-I (A) - Module Structure: Structure of Module/Syllabus of a module (Define Topic of module and its subtopic) Introduction, Alcoholic beverages (Beer and Wine), Non-alcholic beverages (Kombucha and Kefir). Component-II - Description of Module Description of Module Subject Name Technology Paper Name Module Name Module Id Pre-requisites Objectives Keywords FT/FM/19 Microbial fermentation, Beverages. To study about types of fermented beverages and their properties as health benefits. Beverages, Alcohol, Beer, Wine, Kombucha, Ale.

4 TABLE OF CONTENTS 1. Introduction 2. Alcoholic beverages 2.1 Beer 2.2 Wine 3. Non-alcoholic beverages 3.1 Kombucha 3.2 Kefir 4. Summary 5. Glossary 6. Did you know 7. Web links / references

5 1. Introduction In general, a drink is a liquid substance which is mainly made for human consumption (drinking purposes) and it is often called a beverage (any one of various liquids for drinking, usually excluding water). Beverages can be divided into several categories: Hard or alcoholic beverages Soft or non-alcoholic beverages Fruit or vegetable juices and Hot drinks such as coffee and hot chocolate. Beside to fulfilling a basic biological need, beverages form part of human culture as well. Beverages are prepared by fermentation of carbohydrates sources using specific strains of microorganism (i.e. yeast in beer production). An alcoholic beverage is a drink that contains ethanol. For example, beer has been a part of human culture for 8,000 years. Moreover, in several countries, drinking alcoholic beverages in a local bar or pub is a cultural tradition. A non-alcoholic drink is one that contains little or no alcohol. Such includes low-alcohol wine and non-alcoholic beer if they contain less than 0.5% alcohol by volume (Table 1.1). Table 1.1: Strength of different alcoholic beverages Alcoholic beverages Examples Alcohol % (Alcohol by volume) Beer Pilsner 3 6% Lager Porter 4-5% IPA (India Pale Ale) 6-7% Stout 5-10% Wines Sparkling Wine 8 12% Table Wine 9 14% Barley Wine 11 15% Fortified Wines Sherry 17 22% Bum Wine 15-20% Vodka/Whiskey/Rum 40%

6 Other Drinks 2. Alcoholic beverages Rectified Spirits Fruit Juice Wine Breezers/Coolers Cider Alcopops Source: 96% < 0.1% 4-7% 4 8% 3-7% An alcoholic beverage is a drink that contains ethanol and legally consumed in most countries around the world. Alcoholic beverages have been consumed by humans since the Neolithic era; the earliest evidence of alcohol was discovered in Jiahu, dating from BC. Alcoholic beverages are a source of food energy. Each gram of alcohol provides 7.1 kcal and each milliliter provides 5.6 kcal. In general, alcohol (ethanol, ethyl alcohol) is usually prepared from sugar, starch and other carbohydrates by fermentation with yeast and sometimes, synthetically from ethylene or acetylene. It is colorless, clear, very mobile, flammable liquid, a pleasant odor and miscible with water and with many organic liquids. Ethanol has a slightly sweet taste and a characteristic aroma. Alcoholic beverages are commonly called by one of several names based on the source of the sugar. The most common sources are fruit, grain and sugar but some other sources of fermentable sugars like vegetables may be used as well. Following are most popular alcoholic fermented beverages: 2.1 Beer It is the world's most commonly consumed alcoholic beverage and is the third-most popular drink overall, after water and tea and it is believed by some to be the oldest fermented beverage. In general, beer is an alcoholic beverage (usually around 4% to 6% alcohol by volume (abv), however, it may vary between 0.5% and 20%) produced by the saccharification of starch and fermentation of the sugar. The carbohydrate source (i.e. starch) and saccharification enzymes are often derived from malted cereal grains. Generally, malted barley and malted wheat and most beer are also flavored with hops (which add bitterness and act as a natural preservative). Some other flavorings such as herbs or fruit may sometimes be incorporated.

The process of making beer is called brewing, which includes breaking the starch in the grains into sugary liquid, so-called wort and fermenting the sugars in the wort into alcohol and CO 2 by

7 The process of making beer is called brewing, which includes breaking the starch in the grains into sugary liquid, so-called wort and fermenting the sugars in the wort into alcohol and CO 2 by microbes (yeasts). In this fermentation process, two main species are used: 1. Saccharomyces cerevisiae (top-fermenting), as it forms foam on top of the wort and used to produce lagers. 2. Saccharomyces uvarum (bottom-fermenting) used to produce ale. The temperature used for top-fermenting (15-24ºC) induces the production of a lot of esters and flavor products that give beer a fruity taste. Hops are added during boiling as a source of bitterness, flavor and aroma. Though, hops may be added at more than one point throughout the boil. The lengthier the hops are boiled, the more bitterness they add, but the less hop flavor and aroma leftovers in the beer. Brewer's yeasts are very rich in essential minerals and B vitamins, with the exception of vitamin B12. Nowadays, beer brewing is performed by added pure cultures of the desired yeast species to the wort. After the fermentation is over, the beer is cleared of the yeasts by precipitation or with the use of clearing additives and it is packaged either into casks for kegs, aluminum cans or bottles for other kinds of beer (Fig 2.1). Figure 2.1: Beer Production Process Source: industrial_brewing_flow_chart.jpg

8 2.2 Wine It is an alcoholic beverage can be made from fermented grapes or other fruits. Several varieties of grapes and strains of yeasts produce different styles of wine. Wines made from produce besides grapes are usually named after the product from which they are produced (i.e. pomegranate wine, rice wine, elderberry wine and apple wine) and are generically called fruit wine. In general, the term wine can also refer to starchfermented or fortified beverages having higher alcohol content, like barley wine, huangjiu or sake etc. Steps of wine making process (Fig 2.2): 1. Crusher: The grapes are first cleaned of leaves and stems and the fruit is crushed into must that is ready for fermentation. Therefore, grapes are conveyed to a de-stemmer/crusher where grape leaves and stems are removed and grapes are crushed. 2. Fermentation: Most red grapes go to the fermenter for primary fermentation while most white grapes are pressed prior to fermentation. Yeast (Saccharomyces cerevisiae) is added to start the fermentation. However, there are hundreds of commercially available yeast strains for wine fermentation and it is significant to keep the temperature in the fermentation vessel lower than 40ºC to keep the yeasts alive. Furthermore, to improve yeast growth, some extra nutrients, like diammonium phosphate, are may be added in this step. 3. Press: After completion of fermentation, the red wines go to press to separate the wine from the grape skins. 4. Tank: Most wines are settled in large stainless steel or upright oak tanks. 5. Barrel: After settling, red wines and fuller-bodied white wines are put into small oak barrels for aging. 6. Filter: After barrel aging and earlier to bottling, certain wines are filtered to help stabilize and clarify them. 7. Bottle: Finished wines are bottled. 8. Aging: Wines may be aged further in a bottle if desired. Wine also has proven following health benefits: 1. Red wine is rich in flavonoids and it may protect your heart by reducing LDL (bad) cholesterol, increasing HDL (good cholesterol) and reducing blood clotting. 2. White wine can help to improve lung function.

3. Non-alcoholic beverages Figure 2.2: Wine making process Source: http://www.davidstuff.com/wine/winemaking.gif A non-alcoholic beverage also known as a virgin drink.

In general, non-alcoholic versions of some alcoholic beverages like non-alcoholic beer (near beer) and cocktails (mock tails), are most widely accessible where alcoholic beverages are retailed.

9 3. Non-alcoholic beverages Figure 2.2: Wine making process Source: A non-alcoholic beverage also known as a virgin drink. It is defined in the United States as a beverage that contains less than 0.5% alcohol by volume (abv). In general, non-alcoholic versions of some alcoholic beverages like non-alcoholic beer (near beer) and cocktails (mock tails), are most widely accessible where alcoholic beverages are retailed. Sodas, juices and sparkling cider comprise little or no alcohol. Following are most popular traditional non-alcoholic drinks: 3.1 Kombucha Kombucha is a raw, fermented, probiotic and naturally carbonated drink and the ancient Chinese called the Immortal Health Remedy? It s been about for more than 2,000 years and has a rich anecdotal antiquity of several health benefits. It is made by inoculating a sweetened tea with fermenting SCOBY (Symbiotic

10 Culture of Bacteria and Yeast). After steeping tea in boiling water and allowing it to cool, a SCOBY is added to tea and allowed to ferment in a warm room (25-28 C) for 1-2 weeks. The fermented drink is sour from the acetic acid produced by the culture and can be drunk still or carbonated. Health benefits of kombucha are as follows: Detoxification: It is rich in many of the enzymes and bacterial acids your body produces and/or uses to detox our system, thus reducing our pancreatic load and easing the burden on our liver. Joint Care: Kombucha contains glucosamines (a strong preventive and treatment all types of arthritis. Aids Digestion and Gut Health: Due to it s naturally fermented with a living colony of bacteria and yeast. Immune Boosting: It is strangely anti-oxidant rich and boosting immune system and energy levels. 3.2 Kefir Kefir is a fermented milk drink that originated in the Caucasus region and known for its nutritional and probiotic benefits. It was traditionally fermented in leather sacks placed by a door and people were expected to kick or shake the sack as they entered the household. Kefir is produced by microbial activity of kefir grains (starter culture) consisting of lactic acid bacteria and lactose fermenting yeast. Such, microbes produce organic acids like lactic acid, acetic acid and alcohol, which give kefir its characteristic properties and flavor. In addition, the production of organic acid (acidic nature) gives an antimicrobial property to the mixture that inhibits the growth of most undesirable (spoilage causing) microbes. Kefir has become an important functional dairy food and therefore, research on kefir has increased in the past decade. The claimed health benefits of kefir are as follows: 1. Reduction of lactose intolerance symptoms 2. Stimulation of the immune system 3. Lowering cholesterol 4. Antimutagenic and anticarcinogenic properties. 4. Summary Nowadays, all around the world, fermented beverages are part of the human culture. Using native knowledge of nearby available raw materials from animal or plant sources, people globally produce this type of food and drink either naturally or by fermentation (adding starter cultures that contain microorganisms i.e. Yeast or bacteria). Microorganisms convert such raw materials/substrates both biochemically and organoleptically

11 in terms of the taste, texture and flavor into eatable products that are culturally acceptable to the consumer. Fermented drinks can be either alcoholic (like beer and wine) or non-alcoholic (i.e. kefir). Furthermore, such fermented beverages have health-promoting benefits.

Dr.Nibras Nazar. Microbial Biomass Production: Bakers yeast

Dr.Nibras Nazar. Microbial Biomass Production: Bakers yeast Microbial biomass In a few instances the cells i.e. biomass of microbes, has industrial application as listed in Table 3. The prime example is the production of single cell proteins (SCP) which are in