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 PROCESS4 main stages: MALTING MASHING & WORT PREPERATION YEAST FERMENTATION (prepared

but not ready to use) POST-FERMENTATION*

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*

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 consumption1. CASK AND BOTTLE CONDITIONONG OF

ALES2. KRAUENING3. LAGERING4. STORAGE AGEING5. 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 grapecultivation3 Grape maturity and condition at harvest4 The methods of grape pressing and processing

FACTORS THAT INFLUENCE THE PROPERTIES OF A WINE.

5 The primary fermentation, which generates variablequantities of ethanol, CO2, higher alcohols, esters,aldehydes and ketones

6 Any secondary fermentation to produce winecarbonation, or for acidity reduction via a malo-lacticfermentation, whereby malic acid is converted to lacticAcid

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 thatmake up the natural microflora;2 temperature;3 pH;4 initial sugar concentration; and5 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

STEPS

Milk Cream Legal pasteurization Aging Ripening Churning Draining buttermilk Washing

Working Pakaging Storage Butter

YOUGERT PRODUCTION

VIDIO http://www.youtube.com/watch?v=cvxT

aCNP66w

FERMENTED PLANTS

PRODUCTS

ALI RAZA ANSER

Fruits Cereals Leaf and root vegitable Legumes OilseedsThese are all used for the

production of fermented foods.

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

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

Coffee 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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