This document discusses various fermentation processes used in food production. It describes how pickles are produced through the fermentation of cucumbers in brine by lactic acid bacteria. Sauerkraut production is also discussed, involving the fermentation of cabbage by Leuconostoc mesenteroides and Lactobacillus plantarum in a salt solution. Yeast fermentation is described for producing leavened breads. Vinegar production through the fermentation of ethanol by acetic acid bacteria is summarized. Fermentation processes for idli, single cell protein, milk and yogurt are briefly outlined.

2. Fermentation of pickle
 Pickling is the process of preserving food by anaerobicfermentation
in brine or vinegar. The resulting food is called a pickle. This
procedure gives the food asaltyorsourtaste.
 The fermentationof cucumbers isvery similar to the sauerkraut
fermentation; only brine (salt solution) is used instead of dry
salt. The washed cucumbers are placed in large tanks and
chlorinated brinewith 15 to 20% sodium chloride isadded.
 Thecucumbers aresubmerged in brineensuring that none

3. float on thesurface, preventspoilageof pickle.
 Another distinguishing characteristic is a pH less than 4.6, which is
sufficient to kill most bacteria. Pickling can preserve perishable foods
for months. Antimicrobial herbs and spices, such as mustard seed,
garlic, cinnamonorcloves, areoften added.
 If the food contains sufficient moisture, a pickling brine may be
produced simply by adding drysalt.
 Natural fermentation at room temperature, by lactic acid
bacteria, produces the required acidity. Other pickles are made
by placing vegetables in vinegar. Unlike the canning process,
pickling (which includes fermentation) does not requirethat the
food becompletelysterile before it is sealed.

4.  The acidity or salinity of the solution, the temperature of fermentation,
and the exclusion of oxygen determine which microorganisms
dominate, and determine the flavor of the end product.
 When both salt concentration and temperatureare low,
Leuconostoc mesenteroides dominates, producing a mix of acids,
alcohol, and aroma compounds. At higher temperatures
Lactobacillus plantarum dominates, which produces primarily
lactic acid. Many pickles startwith
Leuconostoc, and change toLactobacillus
with higheracidity.

5. • Sauerkraut:
• The words sauerkrautaregermen terms forsourcabbage. Sauerkraut is
a product of natural lactic acid fermentation of fresh cabbage in the
prescence of a small amount of salt involving lactic acid bacteria,
leuconostoc mesenteroides and lactobacillusplantarum.
• Sauerkraut is rich in vitaminc and hasa mild laxativeaction due to
dextran content of theproduct.
Nutritional value per (100 g)(3.5oZ)
- 78KJ (19 Kcal)
- 4.3g
Energy
carbohydrate
sugar
dietaryfibre
- 1.8 g
- 2.9g

6. Fat
Water
Vitamin B
Vitamin C
Iron
Sodium
- 0.14 g
- 92 g
- 0.13 mg (10%)
- 15 mg (18%)
- 1.5 mg (12%)
- 661 mg (44%)
 It has a long shelf-life and a distinctive sour flavor, both of which result
from the lactic acid that forms when the bacteria ferment the sugars in
thecabbage. Sauerkraut is also used asacondiment upon various foods,
such as meatdishes and hotdogs.

7. Bread:
• Leavened breads are made by adding baker’s yeast to dough made
from flour, waterand salts. Yeast fermentsugar in dough toalcohol
and carbondioxide.
• A pre-fermentand a longerfermentation in the bread-making process
have several benefits: there is more time for yeast, enzyme and, if
sourdough, bacterial actions on the starch and proteins in the dough;
this in turn improves the keeping time of the baked bread, and it
creates greater complexities offlavor.
• Though pre-ferments havedeclined in popularityas direct additionsof
yeast in bread recipes have streamlined the process on a commercial
level, pre-ferments of various forms are widely used in artisanal bread
recipes and formulas.

8. • Most of the bakery foods consumed throughout the world are bread
.
and rolls made from yeast-leaveneddoughs.
Bread making:

9.  Vinegar:
 Vinegar is a liquid consisting mainly of acetic acid (CH3COOH) and
water. The acetic acid is produced by the fermentation of ethanol by
acetic acid bacteria.
 Vinegar is now mainly used asacooking ingredient, but historically, as
the most easily available mild acid, it had a great variety of industrial,
medical, and domestic uses, some of which (such as a general
household cleanser) are still promotedtoday.
 Commercial vinegar is produced either by fast or slow fermentation
processes. . In general, slow methods are used with traditional
vinegars, and fermentation proceeds slowly over the course of
months or ayear.

10.  The longerfermentation period allows fortheaccumulation of a
nontoxic slime composed of aceticacid bacteria.
 Fast methods add mother of vinegar (i.e., bacterial culture) to the
source liquid before adding air using a venturi pump system or a
turbine to promoteoxygenation toobtain the fastest fermentation.
 In fastproduction processes, vinegar may be produced in a period
ranging from 20 hours to threedays.

11.  Vinegar productionprocess:

12. Uses
• Vinegar is commonlyused in food preparation, in particularin pickling
processes, vinaigrettes, and other saladdressings
Blood glucose control and diabetic management
• Prior to hypoglycemic agents, diabetics used vinegar teas to control
their symptoms. Small amounts of vinegar (approximately 25g of
domesticvinegar) added to food, or takenalong with a meal, have been
shown by a number of medical trials to reduce the glycemic index of
carbohydrate food forpeoplewith and withoutdiabetes.
• This also has been expressed as lowerglycemic index ratings in the
region of 30%.

13. Diet control
• Multiple trials indicate that taking vinegarwith food increases satiety
(the feeling of fullness) and, so, reduces theamountof food consumed.
Daily intakeof 15 mL of vinegar (750 mg aceticacid) might be useful in
the preventionof metabolicsyndrome by reducing obesity.
Idli:
• Idly, is a traditional breakfast in south Indian households. Idli is savory
cakeof South India that is most popular throughout the southern partof
India including Karnataka, Tamil Nadu, Pondicherry, Kerala, Andhra
Pradesh and neighbouring countries like SriLanka.
• Thecakes are usually two to three inches in diameterand are
made by steaming a batter consisting of fermented blacklentils
(de-husked) and rice.

14.  The fermentation process breaks down the starches so that they are
more readily metabolized by thebody.
Idli fermentation process:

15.  Bacteria identified as part of microflora responsible for the
production of good idli include, leuconostoc mesenteroides,
lactobacillus fermentum, lactobacillus delbrueckii, lactobacillus
lactis.
Single cell protein:
 The dried cells of microorganisms used as food or feed are
collectively known as “singlecell protein” since the ancient times
numberof microorganisms have been used asa partof diet.
 The protein stroage, microorganismsoffermany possibilities for
protein production. they can be use used as to totally or
partially thevaluableamountof conventional vegetable

16. and animal proteinfeed.
 Since the spirullina is a rich source of protein (60-70%),
vitamins, aminoacids, minerals, crudefibresetc.. it is used asa
supplented food in developingcountries.
 Mass multiplication of spirullinaoffersseveral advantagesover
other single cellprotein.
 Beingsa filamentousalage, spirullinacan be harvested by simple
and less expensivemethod.
 Filamentof spiullina float on watersurfacedue to the prescence
of gas vacuoles, hence harvesting iseasy.
 There is a leastchanceof contamination in growth tanksof
spirullina as itgrows at high pH 8-11.

17.  Heatdrying is sufficient forspirullinaas it has thin cell wall.
 Spirullina is highly digestive (85-95%)due to thin wall and low
nucleic acid content (4%). It contains high percentage of
proteins (62-72%) vitamins,aminoacids.
Single-cell protein (SCP) typically refers to sources of mixed
protein extracted from pure or mixed cultures of algae, yeasts,
fungi or bacteria (grown on agricultural wastes) used as a
substitute forprotein-rich foods, in humanand animal feeds.
Production Process
 Single-cell proteinsdevelopwhen microbes fermentwaste
materials (including wood, straw, cannery,and

18. food-processing wastes, residues from alcoholproduction,
hydrocarbons, or human and animalexcreta).
 The problem with extracting single-cell proteins from thewastes is the
dilution and cost. They are found in very low concentrations, usually
less than 5%. Engineers have developed ways to increase the
concentrations including centrifugation, flotation, precipitation,
coagulation, and filtration, or the useof semi-permeable membranes.
 The single-cell protein must be dehydrated to approximately 10%
moisture content and/or acidified to aid in storage and prevent
spoilage. The methods to increase the concentrations to adequate
levelsand thede-watering process requireequipment that is expensive
and notalways suitable forsmall-scaleoperations.

19.  It is economically prudent to feed the product locally and soon
after it isproduced.
 Single Cell Protein thatcan be used in feed foranimals.
Examples
 Microbes employed include yeasts (Saccharomyces cerevisiae,
Pichia pastoris, Candida utilis=Torulopsis and Geotrichum
candidum (=Oidium lactis)), other fungi (Aspergillus oryzae,
Fusarium venenatum, Sclerotium rolfsii, Polyporus and
Trichoderma), bacteria (Rhodopseudomonas capsulata). and
algae (Chlorella and Spirulina). Typical yields of 43 to 56%,with
protein contents of 44% to60%.

20. • The fungus Scytalidium acidophilumgrows at below pH 1, offering
advantages of:
• low-cost asepticconditions
• avoiding over 100-fold dilution of theacidic hydrolysates to pH values
needed for othermicrobes
• afterthe biomass is harvested, theacids can be reused.
Product Safety andQuality
• Some contaminants can produce mycotoxins. Some bacterial SCPhave
amino acid profiles different from animal proteins. Yeast and fungal
proteins tend to be deficientin methionine.
• Microbial biomass hasa high nucleicacid content, and levels must be
limited in thedietsof monogastricanimals to <50 g perday. Ingestion

21.  of purine compounds arising from RNA breakdown leadsto
increased plasma levelsof uric acid, which can causegoutand
kidneystones.
 Uric acid can be converted to allantoin, which is excreted in
urine. Nucleic acid removal is not necessary fromanimal feeds
but is from humanfoods.
 A temperature hold at 64°C inactivates fungal proteases and
allows RNases to hydrolyse RNA with release of nucleotides
from cell to culturebroth.
Advantages of Production
 Large-scale production of microbial biomass hasmany
advantagesoverthe traditional methods forproducing proteins

22. for food orfeed.
 Microorganisms havea high rateof multiplication and, hence, rapid
succession of generations (algae: 2–6 hours, yeast: 1–3 hours,
bacteria: 0.5–2 hours)
 They can beeasily genetically modified forvarying theaminoacid
composition.
 A very high proteincontent 43–85% in thedry mass.
 They can utilize a broad spectrum of raw materials as carbon
sources, which includeeven waste products. Thus, they help in the
removal of pollutantsalso.
 Strainswith high yield and good composition can be selected or
produce relativelyeasily.

23.  Microbial biomass production occurs in continuous cultures and
the quality is consistent, since the growth is independent of
seasonal and climaticvariations.
 Land requirements is low and isecologically beneficial.
 A high solar-energy-conversionefficiency perunitarea.
 Solar energy conversion efficiency can be maximized and yield
can be enhanced by easy regulation of physical and nutritional
factors.
 Algal culturecan bedone in space that is normally unused and
so there is no need tocompete for land.

24. Nutritional value of spirullina for humanconsumption:
• Since spirullina is a rich source of protein (60-72%), vitamins,
aminoacids, minerals, crude fibre. Spirullina has a net protein
utilization of 56.6% spirullina contain 8 essentialaminoacids.
spirullina tablet
Spirullina as healthfood:
•Spirullina is a very popular health food. It
is the part of the diet of the US olymptic
team. jaggersbtakes spirullina tabletsfor
instant energy. Since it provides all the essential nutrients without
excess caloriesand fats, it is taken by thosewhowant tocontrol obesity.

25. Therapeutic and natural medicine:
Spirullina possesses many medicinal properties. It has been
recommended by medicinal experts for reducing bodyweight,
chloestrol and for betterhealth.
Cosmetics:
Spirullinacontains high qualityof proteinsand vitamins A and B.
thease play akey role in maintaining healthy hair. Phycocyanin
pigment has helped in formulating biolipstics and herbalface
cream in japan. spirullina

26. Single cell proteinprocess

27. Milk :
• Milk is an excellent medium for microbial growth and when stored
at ambient temperature bacteria and other pathogens soon
proliferate.
• The Centers for Disease Control (CDC) says improperlyhandled
raw milk is responsible for nearly three times more
hospitalizations than any other foodborne disease outbreak,
making itoneof theworld's mostdangerous food products.
• Diseases pasteurization can prevent include tuberculosis,
brucellosis, diphtheria, scarlet fever,and Q-fever; italso kills the
harmful bacteria Salmonella, Listeria, Yersinia, Campylobacter,
Staphylococcus aureus, and Escherichia coli amongothers.

28. • Pasteurization is the main reason for milk'sextended shelf life. High-
temperature, short-time (HTST) pasteurized milk typically has a
refrigerated shelf life of two to three weeks, whereas ultra-
pasteurized milk can last much longer, sometimes two to three
months.
• When ultra-heat treatment (UHT) is combined with sterile handling
and container technology (such as aseptic packaging), it can even be
stored unrefrigerated for 6 to 9months.
Raw milk:
Raw milk is milk that has not been pasteurized or homogenized. While
proponents claim there are benefits to raw milk that is made without
pasteurization and homogenization, the medical community warns of
thedangersof unpasteurized milk. Availabilityand regulation of raw

29. vary from region toregion.
• Pasteurization is widely used to prevent infected milk fromentering
the food supply. The recognition of many potentially deadly
pathogens, such as E. coli , Listeria, and Salmonella, and their
presence in milk products has led to the continuation of
pasteurization.
• The Department of Health and Human Services, Center for Disease
Control and Prevention, and other health agencies of the United
States stronglyrecommend that the public do notconsume raw milk
or raw milkproducts.
• Young children, theelderly, peoplewith weakened immunesystems,
and pregnantwomenare particularly susceptible to infections

30. raw milk.
• Re-pasteurization occurs when pasteurized milk from theUS
mainland is transported by sea to Hawaii, and then pasteurized
again.
• Recent advances in the analysis of milk-borne diseases have enabled
scientists to track the DNA of the infectious bacteria to the cows on
the farms that supplied the rawmilk.
Spoilage inmilk:
• Spoilage is a term used to describe the deterioration of foods
texture, colour, odour or flavour to the unsustible for human
conssumption.
• Microbial spoilageof food aften involves thedegradation of protein,
carbohydrates and fats by the microbes or theirenzymes.

31. • Few specices of Bacillus, Clostridium, Corynebactrium, Arthrobacter,
Lactobacillus, Microbacterium, Micrococcus and Streptococcus can
survive pasterization and can grow at refrigeration temperatureswhich
can cause spoilageproblems
milk products:
• Important dairy product are yoghurt, cheese, kefir, kumiss,butter,
butter milketc..
Yoghurt:
• It is a fermented milk product, mostly available europe and north
america.
• The name is derived from furkish word “jaghurt” it’s obtainedfrom
cow’s milk, sheep’s milk.

32. • The two importantorganisms involved in production of yoghurtare
Strep. Thermophilus – faster and high acid
Lacto. Bulgaricans - adds flavour andaroma
• The final products of yoghurt has curd tastesand flavours due to
lactic acid and volatileproduct
• Worldwide, cow's milk, the protein of which mainly comprises
casein, is mostcommonly used to makeyogurt, but milk fromwater
buffalo, goats, ewes, mares, camels, and yaks is also used in various
parts of theworld.
• Alternatively, soy milk, nut milks such as almond milk, and coconut
milk can also beused.

33. • Dairyyogurt is produced using aculture of Lactobacillus delbrueckii
subsp. bulgaricus and Streptococcus thermophilus bacteria. In
• addition, other lactobacilli and bifidobacteriaarealsosometimes
added during orafterculturing yogurt.
• Somecountries requireyogurt tocontain acertain amountof colony-
forming units of microorganisms

34. Yoghurt productionprocess

35. Fermentation:
• Takes place about 4th day of addition of starter culture. Starterbacteria
ferment lactose to lacticacid.
• The lacticacid solubilises and denaturewhey protein and solubilise ca
and po4.
• Streptococcus inturn produce fermentation acid, pyruvate thatflavours
the growth of lactobacillus to produce purines init.
Yield:
• Yoghurtwith clean flavour 2-3 fat, slightly souracid in 0.9 % can goup
to1.1%.

36. Cheese
• Cheese is a food derived from milk that is produced in awide rangeof
flavors, textures, and forms by coagulation of the milk proteincasein. It
comprises proteinsand fat from milk, usually the milk of cows, buffalo,
goats, orsheep.
• During production, the milk is usually acidified, and adding theenzyme
rennet causescoagulation.
• The solidsareseparated and pressed into final form. Somecheeses have
molds on the rind or throughout. Most cheeses melt at cooking
temperature.
• Hundredsof types of cheese fromvarious countries are produced. Their
styles, texturesand flavors depend on theorigin of the milk (including
the animal's diet), whetherthey have been pasteurized,

37. the butterfatcontent, the bacteriaand mold, the processing, and aging.
Herbs, spices, orwood smoke may be used as flavoring agents.
• Theyellow to red colorof manycheeses, such as Red Leicester, is
produced by addingannatto.
• Other ingredients may beadded to somecheeses, such as black
peppers, garlic, chives orcranberries.
• Fora fewcheeses, the milk is curdled by adding acids such asvinegar
or lemonjuice.
• Most cheeses are acidified to a lesser degree by bacteria, which turn
milk sugars into lacticacid, then theaddition of rennetcompletes the
curdling. Vegetarian alternatives to rennet are available; most are
produced by fermentation of the fungus Mucor miehei, but others
have beenextracted fromvarious speciesof the Cynara thistle family.

38. Cheese productionprocess

39. classification of cheeses
• Cheesesare normallyclassified according to firmness, which varies
with the degree ofmoisture.
• The moisturecontentof firm cheeses may beas low as 30%, while that
of soft or fresh cheeses may be as high as 80%. The most common
designations include fresh (or unripened) cheeses, soft ripened
cheeses, firm orsemi-firm cheeses, blue-veined, processed and goat’s-
milkcheeses.
Freshcheeses
• Fresh orunripened cheeses arecoagulated under theaction of lactic
acid fermentation in the milk instead of adding rennet. While they
aredrained afterformationof thecurd, theyare neitherripened nor
fermented.

40. • This category includes cottage cheese, ricotta, mascarpone,cream
cheese and quark. Fresh cheeses are mainly used in baking and
desserts, plainor flavored with vegetables, fruits, herbs orspices.
Softcheeses
• Softcheeses are ripened fora relatively short period of time before
being drained and turned into molds without being pressed or
cooked.
• They havea moisturecontentof 50% to 60% and their fatcontent
represents 20% to 26% of the cheese’sweight.
• They developa soft rind thatcan be moreor less satinyand are usually
eaten with bread, since they tend to losea lotof flavorwhen heated.

41. Firm and semi-firmcheeses
• Semi-firm cheeses are uncooked pressed cheeses thataredenseand
usually pale yellow in color. They include Cheddar, Cantal,
Reblochon, Edam, Gouda and MontereyJack.
• Firm cheeses are cheeses that have been cooked and pressed. The
curd is heated for an hour in order to make it more concentrated,
which, upon pressing, produces a morecompactcheese.
• Their texture is usually firm, although some hard cheeses, like
Parmesanand Romano, may havea rathergranulartexture.
Blue-veined cheeses
Blue-veined (or blue) cheeses are neithercooked norpressed; thecurd is
inoculated with a species of blue-green mold, which is injected into the
cheese by means of long needles.

42. Cheese making
• Coagulation (“curdling”) is the curd-forming stage, when the casein
(the protein contained in the milk) coagulates in response to bacteria
orrennet.
• Drainage consists in removing thewater (thewhey or lactoserum)
from the curd and making itfirmer.
• The amountof whey retained in the curd afterdraining will determine
the firmnessand textureof thecheese.
• It is during thedraining stagethat thecurd is shaped in a mold.
• Salting acts as an antiseptic, slows down thedevelopment of
microorganisms, improves the storage lifeof thecheeseand
speeds up the drying process and the formationof a rind.

43. • Ripening (or maturing) is the period during which the insideof the
cheese is transformed through the biochemical action of the
bacterial flora contained in thecheese.
• This is thecrucial stage in which theconsistency, aroma, flavorand,
if desired, the rind of thecheese develop (fresh curd cheeses and
process cheeses are notripened).
• Ripening takes place undertemperatureand humidityconditions
thatvaryaccording to the typeof cheese.
• The longerthe ripening process, the less moisture the cheese retains,
and the firmerand stronger-tasting thecheese .

44. Butter
• Butter is adairy product thatconsists of butterfat, milk proteins, and
water. It's made by churning fresh or fermented cream or milk. It is
used as a spread and a condiment—and in cooking, such as baking,
sauce making, and panfrying.
• Commonly made from cows' milk, butter can also be manufactured
from the milk of other mammals, including sheep, goats, buffalo, and
yaks. Producers sometimes add Salt, flavorings, orpreservatives.
• Rendering butterproduces clarified butteror ghee, which is almost
entirely butterfat.

45. Butter productionprocess