FOOD & BEVERAGE FERMENTATIONS

GROUP MEMBERS BEENISH GILANI SHARMEEN RAFIQUE MARIA IQBAL ALI RAZA

FOOD & DAIRY PRODUCTS Important for living organisms. Provide energy Can be obtain from plants, animals and microorganisms

TRADITIONALN FERMENTED FOODSTUFFS ALCOHOLIC BEVERAGES: beers, wines, distilled spirits derived from sugars and starches. DAIRY PRODCTS: cheese, yoghurt, sour cream and kefir. FAT & MEAT PRODUCTS: fish sauce and fermented sausages. PLANT PRODUCTS: cereal based breads, fermented rice products, fermented fruits, vegetables, legumes, olives, soya sauce, coffee beans.

Products orignally evolved as means of food presevations. Stabilize microbial activity Microbial biomass as noval food e.g mashrooms Microbial enzymes use as food processing aids.

ALCOHOLIC BEVERAGES Produced throughout recorded human history Manufacture worldwide by sugars derived from fruit juices, plat sap, honey. Drunk freshly Aged to modify their flavour Distilled to increase alcoholic strength

Bacteria involved in production Zymomonas species ?????? Saccharomyces cerevsiae

Beer brewing Non-distilled alcoholic beverges Partially germinated cereal grains Includes ales, lagers, stouts, 3-8% ethanol Hops for flavour and aroma Water yeast

Brewing process 4 main stages: MALTING MASHING & WORT PREPERATION YEAST FERMENTATION (prepared but not ready to use) POST-FERMENTATION* *After translation protein is not functional, it goes into post translational changes cleavage, folding etc for proper funtion

MALTING Partial germination of barley grains Modify hard vitreous grains into friable with more degradable starch & hydrolytic enzymes Sock barley in water for 2 days at 10-16°C Increase moisture 45% Water drained out Aeration* *to prevent anaerobic conditions which may affect embryo n embryo is best source of starch.

After steeping barley partially germinated for 3-5 days at 16-19°C Spread grains on malting floor Airated with moist cool air

WORT PREPERATION Production of aqueous fermentation media. Extraction of fermentable sugars, amino acids, vitamins from malt. Aducants are also added. Roller-milled prior

MASHING Starch hydrolysis Malt & adjunct starch to fermentable sugars. Malt enzymes degrades starch: β-Glucan hydrolysis, Protein hydrolysis. Mashing system: 1. infusion mashing 2. decoction mashing 3. temperature programmed mashing (modern)

YEAST FERMENTATION S. cerevisiae as starter culture Selected on the basis of performance in brewery enviornment. Polypoid and more stable Undergoes alcoholic fermentation Ethanol, CO2, minor metobolites. Last for 2-7 days.

POST FERMENTATION Maturation of beer Condition for consumption CASK AND BOTTLE CONDITIONONG OF ALES KRAUENING LAGERING STORAGE AGEING PREVENTION OF OXIDATION

Wine production Plant extract or fruit juice that contains sufficient levels of fermentable sugars. Berries of the grape vine, primarily cultivars of Vitis vinifera, which can be grown in most temperate regions of the world. Total world production is now approximately 1010L/annum

Grape juice wine production because it contains high levels of fermentable sugars (mainly glucose and fructose; 160–240 g/L), The natural acidity (pH 2.8–3.8) inhibits potential spoilage organisms Grapes also have very pleasant flavour and aroma components. Most wines are table wines that normally contain up to 14% (v/v) ethanol. However, some regions produce wines fortified with ethanol,

Factors that influence the properties of a wine. 1 The specific grape variety or mixture used (e.g. Muscat grapes contain highly characteristic flavour and aroma components, the terpene alcohols linalool. 2 The soil, local climate and the mode of grape cultivation 3 Grape maturity and condition at harvest 4 The methods of grape pressing and processing

Factors that influence the properties of a wine. 5 The primary fermentation, which generates variable quantities of ethanol, CO2, higher alcohols, esters, aldehydes and ketones 6 Any secondary fermentation to produce wine carbonation, or for acidity reduction via a malo-lactic fermentation, whereby malic acid is converted to lactic Acid 7 post-fermentation and maturation treatments.

PRODUCTION OF GRAPE MUST Mechanical destemming, crushing and pressing to form the must Red wine must consists of the macerated fruit, whereas for white wines it is only the clarified juice that is fermented. Carbonic maceration, White wine earlier removal of skin and seeds

WINE FERMENTATION Alcoholic fermentation of wine is carried out by indigenous yeast or added starter yeast. The fermentation rate is influenced by: 1 the starter yeast strain used or yeast strains that make up the natural microflora; 2 temperature; 3 pH; 4 initial sugar concentration; and 5 nutritional components of the batch of grape or supplement.

Traditional spontaneous wine fermentations Once the juice is released from the grapes it will ferment spontaneously as it is immediately exposed to the natural indigenous microflora. Traditional fermentations are comparatively slow They can also be prone to some flavour and aroma defects due to the overactivity of certain yeasts. To ensure complete fermentation, and avoid production of unwanted flavour and aroma compounds, winemakers encourage the growth and dominance of S. cerevisiae. This may be achieved by adding SO2 to the grape must at a concentration of 30–50 mg/L, which inhibits non- Saccharomyces yeast and spoilage bacteria.

Use of starter cultures Newer wine-producing regions have less well developed natural microflora. Therefore, added starter cultures are normally used. Use of starter cultures provides several advantages: it ensures completion of the fermentation and allows the fermentation rate to be controlled, to give a shorter lag period, and more even and rapid fermentation rates. Also, there is less opportunity for the production of off-flavours by wild yeasts and bacteria, giving more consistent flavour characteristics and quality.

Secondary wine fermentation Such secondary fermentations include a yeast alcoholic fermentation in bottles or cask to create naturally carbonated sparkling wines. Malo-Lactic acid fermentation takes place, It reduces the acidity through the decarboxylation

Post Fermentation treatment A small amount of SO2 is added to prevent microbial activity. Some wine is stored for a period of a few weeks to several years in wooden casks, where it acquires additional flavour characters. wine is filtered, pasteurized or sterile filtered, and filled into bottles or other packages

Vinegar when a natural solution of fermentable sugars is exposed to indigenous microbial activities is an alcoholic fermentation by yeasts, followed by bacterial oxidation of the ethanol to acetic acid (acetification). If sufficient acetic acid is produced it may be classified as vinegar. It is produced from fermentable substrates and alcoholic beverages and fruit juices and sugar syrups, molasses and honey, root starch.

Vinegar Fermentation Alcoholic fermentation: This is an anaerobic process performed by specific vinegar-making strains of yeast, usually S. cerevisiae var. ellipsoideus, Fermentation products are ethanol, CO2, and small amounts of glycerol, acetic acid and some higher alcohols. Acetic acid fermentation: The acetic acid fermentation is a highly aerobic process, essentially a biotransformation by acetic acid bacteria, involving incomplete oxidation of ethanol to acetic acid

Methods of acetification in vinegar manufacture Conversion of alcohol to acetic acid is largely a problem of aeration technology, There are three main techniques that can be used to achieve this 1 Traditional surface method: These traditional batch methods are generally slow and unpredictable

Methods of acetification in vinegar manufacture TRICKLING GENERATORS: These methods involve the movement of alcoholic liquid over surfaces on which films of acetic acid bacteria have become attached (a supported film system), and a good air supply is provided to facilitate ethanol oxidation.

SUBMERGED METHODS Submerged methods are five times faster than the trickling methods and require less capital investment. Since their introduction Improved aeration efficiency, based on Frings acetators, consists of a highly aerated stainless steel stirred tank reactor. This vessel is continuously stirred at 1450–1750 r.p.m. Submerged processes are usually operated automatically on a semicontinuous basis.

Finishing process Some vinegars may be decolorized using potassium ferrocyanide pasteurized at 75–80°C for 30–40 s prior to bottling. Recovery of acetic acid can be achieved solvent extraction methods.

Dairy fermentations

Dairy fermentations

Dairy fermentations More recently popularized dairy products include fermented health drinks and foods,reffered to as probiotics. e.g Lactobacillus acidophilus

Use of pasteurized milk not only reduces the possibility of growth of potential pathogens . Also lowers the activity of certain milk enzymes that can affect some dairy fermentations. Fermentation generates lactic acid,which modifies milk proteins,and forms flavor.e.g diacetyl,which imparts a buttery flover.

Butter Production Milk Cream Legal pasteurization Aging Ripening steps Milk Cream Legal pasteurization Aging Ripening Churning Draining buttermilk Washing Butter Production

Working Pakaging Storage Butter

Yougert Production

vidio http://www.youtube.com/watch?v=cvxTaCNP66w

Fermented Plants Products

Ali Raza Anser

Fruits Cereals Leaf and root vegitable Legumes Oilseeds These are all used for the production of fermented foods.

Improve digestibility Nutritional value Texture Flavour Why fermentation? Improve digestibility Nutritional value Texture Flavour

Detailed Discussion Bread Sauerkraut Production Soya Bean Fermentation Coffee Cocoa Tea

Bread Production A History of 4000 Years Yeast Purpose: Generate Carbon dioxide Add flavor, alcohol, acid, chemical modified Gluten to promote the expansion of dough.

Wheat and several related cereal grains are used. Contain Gluten protein. Gluten Function Final flavor of the bread Dough making Elastic properties to the dough Dough trap CO2 and rise in volume Baking Bread protein is denatured and along with starch it forms the open crumb texture.

Bread dough contains more than 20% rye flour which must be acidified to produce acceptable bread. Amylase Activity stops (Acidification). Acidification can be done by adding citric acid or by sour dough fermentation.

Sauerkraut Production Wilted shredded Cabbage Mix with 2-3% salt to reduce the activity of water Inhibition of Gram negative bacteria. Starter culture of lactic cid bacteria are added (Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc mesenteroids). Fermentation occurs and lasts for 20-30 days at 18-20 C. Final lactic acid levels reach 1.5% v/v.

Moderen commercial fermentation Fiber glass or concrete tanks are used Capacity 100 tones. Traditional process Natural Micro flora is used. E.g. Sauerkraut

Soya Bean Fermentation Substituted for dairy fermented products in South east Asia. Different products like Miso Tempeh Soya sauces

soy sauce are used as colouring agents and flavouring as well. Involves the fermentation of cooked whole or dehulled soya beans by Rhizopus species. soy sauce are used as colouring agents and flavouring as well. Manufacturing involves three different stages. Koji it is solid substrate, aerobic fermentation of cooked soya beans. It is also made by steamed defatted soya flakes, with addition of rice and wheat flour.

The temperature is 25-30 Celsius and it is processed in 2-3 days. Moromi It involves the fermentation of the liquid slurry and it is anaerobic fermentation that results from the fermentation of brine to koji. The activity of microbe acidify and prevent spoilage.. Along with this they perform alcoholic fermentation and produce additional flavour compounds. The product is traditionally made in 6-9 months.

Coffee, Cocoa and tea fermentation Bean is either obtain by dry or wet process. Wet gives better beans. It involves better action of indigenous bacteria and filamentous fungi. The pulpy material that surrounds the bean is removed by the action of enzymes. Then it is subjected to lactic acid fermentation.

cocoa Has same microbial activity as coffee. But this is more important comparatively. At first we observe alcoholic fermentation. Followed by activity of lactic acid bacteria. Finally acetic acid bacteria does its duty and converts it into alcohol and acetic acid.

Tea No action of micro organisms is there. Action of enzymes are involved. Breaks the leaves and eliminate moisture content. To give a dry product that we refer to as tea.

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