Fermented Foods Deepa

8/19/2019 Fermented Foods Deepa

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FERMENTATION

BYB.DEEPA



Campbell-Platt (1987) has defined fermented

foods as those foods which have been subjected to

the action of micro-oranisms or en!"mes so that desirable

biochemical chanes cause sinificant modification tothe food#

However, to the microbiologist, the term ”erme!t"tio!”#escribes " orm o e!erg$ $iel#i!g microbi"l met"bolism

i! which "! org"!ic s%bstr"te, %s%"ll$ " c"rboh$#r"te, isi!com&letel$ o'i#ise#, "!# "! org"!ic c"rboh$#r"te "cts"s the electro! "cce&tor.

INTROD()TION

FERMENTATION



Ferme!te# Foo#s

Micro-organisms cause changes in the foods which:

◦Help to preserve the food◦Extend shelf-life considerably over

that of the raw materials fromwhich they are made

◦ Improve aroma and avour

characteristics,◦ Increase its vitamin content or itsdigestibility compared to the rawmaterials.



*"ctic Aci# B"cteri"

Major group of Fermentative organisms.

This group is comprised of 11 genera of gram-positivebacteria: Carnobacterium, Oenococcus, Enterococcus,

Pediococcus, Lactococcus, Streptococcus, Lactobacillus,Vagococcus, Lactosphaera, Weissells and Lecconostoc

e!ated to this group are genera such as Aerococcus"Microbacterium" and Propionbacterium.



Lactic Acid Bacteria

#hi!e this is a !oose!$ defined group with no preciseboundaries a!! members share the propert$ ofproducing !actic acid from he%oses.

&s fermenting organisms" the$ l"c+ %!ctio!"lhemeli!+e# electro! tr"!s&ort s$stems orc$tochromes" the$ do not have a functiona! 'rebsc$c!e.

(nerg$ is obtained b$ substrate-!eve!phosphor$!ation whi!e o%idising carboh$drates.




The !actic acid bacteria can be divided into two groupsbased on the end products of g!ucose metabo!ism.

Those that produce !actic acid as the major or so!e product

of g!ucose fermentation are designatedhomoerme!t"tive.

Those that produce e)ua! amounts of !actic acid" ethano!and *+, are termed heteroerme!t"tive.

The homo!actics are ab!e to e%tract about twice as muchenerg$ from a given )uantit$ of g!ucose as thehetero!actics.



HOMOFERMENTATI-E FERMENTATION

HETEROFERMENTATI-E FERMENTATION




&!! members of Pediococcus, Lactococcus,Streptococcus, Vagococcus, a!ong with some!actobaci!!i are homoerme!ters.

Carnobacterium, Oenococcus, Enterococcus,Lactosphaera, Weissells and Lecconostoc and someactobaci!!i are heteroerme!ters

The hetero!actics are more important than the

homo!actics in producing f!avour and aromacomponents such as acet$!a!deh$de and diacet$!.



Fermentation processes for preservation purposes" encourage themu!tip!ication of !actic acid forming bacteria and their metabo!ic activitiesin foods.The acidification during fermentation can be obtained b$ two wa$s i.e."

natura! acidification and artificia! acidification.

N"t%r"l "ci#iic"tio! is achieved b$ a predominant !actic fermentation" whichassures the preservation based on acido-anabios$s princip!e.

Artiici"l "ci#iic"tio! is carried out b$ adding acetic acid which is stab!e inspecific woring conditions. /n this case bio!ogica! princip!es of the preservation are acido-anabios$s and"

to a !esser e%tent" acido-abios$s.



The $e"st i! +eir is "ble to #e"l eectivel$ with &"thoge!ic

$e"sts i! the bo#$. The bacteria0$east team c!eanses and ortiiesthe i!testi!"l tr"ct m"+i!g it more eicie!t "t resisti!g&"thoge!s.

'efir grains are a combi!"tio! o b"cteri" "!# $e"sts in a matri%of proteins" !ipids" and sugars" and this s$mbiotic matri% forms grainsthat resemb!e cau!if!ower. For this reason" a comp!e% and high!$ variab!ecommunit$ of !actic acid bacteria and $easts can be found in thesegrains.

'efir is a fermented mi! drin made with efir grains and isbe!ieved to have its origins in the *aucasus Mountains.

tor"ge "t /01 2) is " goo# metho# to &reserve +eir gr"i!sfor househo!d manufacture of fermented mi!.

3eir



2uring fermentation" the !actose in mare3s mi! is converted into !acticacid" ethano! and carbon dio%ide" and the mi! becomes an accessib!esource of nutrition for peop!e who are !actose into!erant

3(MI

Kumis is m"#e b$ erme!ti!g r"w %!&"ste%ri4e# m"re5s mil+over the course of hours or da$s" often whi!e stirring or churning.

Kumis itse!f has a ver$ !ow !eve! of a!coho!" the common drinof medieva! E%ro&e that a!so avoided the consumption of potentia!!$contaminated water.



Most of these products contain rice or bar!e$ fermentedb$ Aspergillus oryzae

MIOMiso is a traditiona! 4apanese seasoning producedb$ erme!ti!g rice, b"rle$,"!#6or so$be"!s with sa!t and the fungus , the most t$pica! miso being madewith so$.

The mi%ture is a!!owed to ferment for 5 months to 5 $ears" whichproduces an en6$me-rich food.

*ontains a!! esse!ti"l "mi!o "ci#s" maing it a comp!ete protein.7trengthens the immune s$stem and he!ps to lower *D*cholesterol.High i! "!tio'i#"!ts that protects against free radica!s.

/f refrigerated" Miso wi!! !ast a ver$ !ong time. (%act shel lie #e&e!#s

o! the s"lt "!# moist%re co!te!t o the miso.



TEMPEH

+ne of the most important products of I!#o!esi" is tempeh"which is made from so$bean fermented with the mol# Rhizopus

/t is made b$ a natura! cu!turing and contro!!ed fermentation processthat binds so$beans into a cae form.

Tempeh is a natura!!$cho!estero!-free food

High iber co!te!t

)o!t"i!s !"t%r"l "!tibiotics

7oo# or #i"betic &"tie!ts



"%er+r"%t7auerraut is the most we!! nown 8erman food. 7auerraut isfine!$ slice# gree! c"bb"ge th"t h"s bee! erme!te# b$

l"ctic "ci# b"cteri" 9euconostoc" actobaci!!us" andediococcus;. The fermentation process 9a!so nown as pic!ing;gives the cabbage a distinct sour f!avor" which is where it getsthe name 7auerraut 9sour cabbage;.

<ea!th benefits have been c!aimed for raw sauerraut. /tcontains vitamin *" and other nutrients.



Ferme!te# Foo#s o I!#i"

/d!iapadam

2ho!a4a!ebies'urdi'anji



M"i! "#v"!t"ge o Ferme!t"tio!:

Re#%ctio! i! "!ti!%tritio!"l "!# to'ic com&o!e!ts i! &l"!t

oo#s b$ erme!t"tio!

/t was observed in a research which showed *erea!s" !egumes" and tubers thatare used for the production of fermented foods ma$ contain significant amountsof antinutritiona! or to%ic components such as ph$tates" tannins" c$anogenicg!$cosides" o%a!ates" saponins" !ectins" and inhibitors of en6$mes such as a!pha-

am$!ase" tr$psin" and ch$motr$psin.

These components reduce the nutritiona! va!ue of foods b$ interfering with theminera! bioavai!abi!it$ and digestibi!it$ of proteins and carboh$drates.

/n natura! or pure mi%ed-cu!ture fermentations of p!ant foods b$ $easts"mo!ds" and bacteria" antinutritiona! components 9e.g. &h$t"te i! whole whe"t

bre"#s; can be reduced b$ up to =>?@ to%ic components" such as lecti!s i!tem&eh and other fermented foods made from beans" can be reduced up toA=?.



THAN38O(

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