BREAD
INTRODUCTION
Bread of today comes in various
shapes & sizes. They are available as round, oval, square, long with a
square or crispy crust. Bread has become internationalized. Central Europe is
the undisputed heart of bread baking culture. Japan has also recently developed
a taste for the baked grain.
HISTORY
Cereals have been part of our diet
for over 10,000years. In early times, people still roasted and ate grains,
later they began to crush them between stones & mix them together with
water to form a paste or dough. This dough was then baked into a flat loaf in
the ashes of the fire or on the stones that were heated by the sun. These early
dough breads were hard & edible only when fresh. Grain & heat are the
fundamental elements in bread making. Strictly speaking, this early bread
cannot really be described as bread, since no raising agent was used. The
discovery of leavened bread is often attributed to the ancient Egyptians.
According to legend, someone once forgot a batch of dough & thus made the
surprising discovery of soft open – crumb bread.
The first reliable written source
recoding the use of leavened bread is found in the Bible in the book of Exodus,
chapter 12, which says that people of Israel already knew how to make bread
with leavening at the time of their flight from Egypt (1400 to 1200 BC)
BREAD AS A SYMBOL
In addition to its importance in the
human diet & in society, bread has always had a high symbolic value &
is considered by all farmers to be scared. In many different cultures, breads
play a role in marriage ceremonies where they symbolize lifelong union &
family. High ranking figures such as kings & politicians are honoured with
gifts of bread, & everyone recognizes bread & salt as simple symbols of
hospitality & good wishes.
GRAINS USED IN BREAD MAKING
Wheat
Rye
Barley
Millet
Oats
Corn
Buckwheat
Quinoa
POPULAR BREADS OF THE WORLD
·
Turkish flat bread
·
Jewish matzot
·
American bagel
·
Italian ciabatta
·
English tea bread
·
French baguettes
·
German crusty bread
·
Irish soda bread
·
Tuscan white bread
·
Kaviarbrot (German
baguette)
·
Swiss baton
·
Pitta bread
·
Focassia
·
Portuguese Country
bread
ROLE OF INGREDIENTS IN BREAD MAKING
Major ingredients are:
1.
Flour
2.
Yeast
3.
Water
4.
Salt
5.
Sugar
6.
Fat
7.
Milk
ROLE
1. FLOUR – It is composed of the following
Starch 71.5 to 74.5%
Moisture 13.5 to 14.0%
Protein (gluten forming) 7.0 to 10.0%
Protein (soluble) 1.0%
Sugar 2.0 to 2.5%
Fat 1.0%
Ash (mineral salts) 0.5%
When starch is heated to 140°F with about six times
of its wt of water, starch cells swell & cell wall bursts. Starch becomes
soluble in water & in concentrated form will form a gel. This process is
known as gelatinization. In breads, water available to starch is insufficient
& inner temperature of bread does not reach gelatinization point until the
last stages of baking. Hence bread is only partially gelatinized.
Flour
contains soluble & insoluble proteins. Soluble proteins are
useful in providing nourishment to yeast for its growth & reproduction
during fermentation process. Two insoluble proteins Gliadin &Glutenin
form a rubbery material when water is added to flour & it is mixed.
This rubbery material is known as
“Gluten” and is responsible for formation of structure of baked products. Glutenin
gives strength to the dough in order to enable it to hold gases during
baking operation & Gliadin gives elastic or stretching properties to
dough.
2. YEAST – helps in the process of fermentation. Bread doughs
are fermented basically for two reasons
·
Production of CO2 gas which gives volume to the product.
·
For maturing or
conditioning the dough (gluten), so that it attains sufficient mellowness to
stretch under the pressure of CO2 gas & form the
structure of the product.
Yeast contains certain enzymes by of
yeast which fermentation activity of yeast is made possible. Zymase is the
specific fermenting enzyme in yeast. Thus the function of yeast is to raise
& condition the dough so it turns from a heavy mass into a light, porous, elastic
products, which when baked, is appetizing, easily digestible & nutrition.
In olden days, most of the bakers
used Barm method of bread making. A liquid media was made with hops
decoction, boiled potatoes, sugar, flour etc. in which wild yeast was cultured.
These days, bakers use either dry
yeast or compressed yeast. Compressed yeast should be used 2 to 2.5 times of
dried yeast & should be stored at above 45°F.
3.
WATER
– water binds together the insoluble proteins of flour, which form gluten. Any
water which is fit to drink can be used for bread making. Water contains
minerals. These minerals in limited quantities have a beneficial effect on gas
production as the yeast requires minerals for vigorous fermentation. The gas
retention of the dough is also improved as minerals have a tightening action on
gluten.
Medium
hard water is considered to be most suitable for bread production.
4.
SALT
–
·
Imparts
taste to bread.
·
Has a
controlling effect on yeast activity (by virtue of controlling enzyme activity,
thus keeps the fermentation speed under check.
·
Has a
tightening action on flour proteins thus improving the gas retention power of
the dough.
·
Being
hygroscopic substance, it helps to keep the bread fresh & moist for longer
time.
·
Indirectly
responsible for giving crust colour.
5.
SUGAR
–
·
Main
function of sugar in bread making is to provide food for yeast, which in turn,
produces CO2 gas that raises the dough fabric.
·
Helps in enhancing the flavor of bread.
·
Being hygroscopic substance helps in retention of moisture in bread.
·
Contributes to the familiar golden brown crust colour of bread.
6.
FAT – is used in bread dough at the rate of 1 to 2%.
·
Improves
the nutritional value of bread.
·
Has
lubricating effect on gluten strands enabling the bread to acquire good volume.
·
Helps
in retention of moisture in bread & improves its slicebility.
7.
MILK
–
·
Improves
the nutritional value of bread.
·
Has a
tightening effect on flour proteins which improves the gas retention power of
dough.
·
Improves
the flavor & taste
·
Of
bread.
·
Due
to lactose sugar, the crust colour & water retention power of bread is
improved.
In bakery, it is always advisable to
use skimmed milk powder which has a better shelf life.
8.
Egg –
(optional)
·
Improves
the nutritional value of bread.
·
Softens
the gluten strands.
a.
STEPS
IN BREAD PRODUCTION
o
SELECTION
OF RAW MATERIAL
According to the type of bread to be
prepared, right selection of raw material should be done. The raw materials are
a.
Refined
flour
It is composed of
I.
Starch
II.
Moisture
III.
Protein
IV.
Protein
V.
Sugar
VI.
Fat
VII.
Ash
b.
Yeast
I.
Compressed
yeast
II.
Dried
yeast
c.
Water
d.
Salt
e.
Sugar
f.
Fat
g.
Milk
o
MIXING
It involves
a.
Flying
ferment
b.
Flour
is sifted
c.
Salt
& sugar are dissolved in water
d.
Mixing
of flour, water with salt & sugar
e.
Mixing
by hand or machine
f.
Addition
of ferment, dough is developed
g.
Flour
picks up all water, known as “pick up”.
h.
Gluten
starts forming & takes up water, known as “drying up”.
i.
More
mixing leads to dough pulling away from mixing arm / table top. Known as “clean
up”.
j.
Melted
butter / fat added. Dough absorbs all.
FERMENTATION
It is a process whereby yeast feeds
on sugar & produce CO2 gas and alcohol. CO2 gas
raises the dough fabric. Part of alcohol evaporates & part is converted into
acetic acid & the remaining contributes to the characteristic flavor of
bread.
Sources of sugar in fermenting
dough
Natural sugar present
in the flour
Sugar added in the mix
Sugar produced from
the starch of flour through enzyme action.
ENZYMES
§
INVERTASE
§
MALTASE
§
ZYMASE
§
PROTEASE
Some quantities of glycerin, lactic
acid, acetic acid & succinic acid are also produced. These acid &
protease enzyme together have a mellowing effect on the gluten. Dough should be
fermented in the right environment i.e. 78°F to 80°F with relative humidity 70
to 75%.
After the straight
dough is fermented for 2/3 rd of its estimated fermentation time, it is knocked
back.
Reasons for knock
back
ü
When the dough is
fermenting, the temperature of the upper surface is lower than the temperature of
the bottom part of the dough. This causes uneven fermentation. By knock
back, the temperature of the whole mass of dough gets even & fermentation speed
becomes even.
ü
When dough has
fermented for some time, the yeast cell is surrounded by gas as a result of
which food gets cut off, thus reducing the rate of fermentation. By knockback,
gas is expelled & yeast cell is again in position to carry out its
function efficiently.
ü
After the dough has
fermented for some time, the gluten is in a stretched condition & if it is
allowed to remain so, it will collapse by itself leading to uneven distribution
of gas pockets. By knock-back, condition of dough becomes even.
Ø
Gluten becomes pliable
& in a fit condition for further processing.
·
DIVIDING &
ROUNDING (HANDING UP)
Ø
While dividing,
pulling & breaking should be avoided.
Ø
Dividing should be
done using a regular dough cutter.
Ø
When dough is cut, the
cut surface is exposed while the remaining surface has a stretched gluten film.
Cut surface leads to escape of some gas known as bleeding.
Ø
To counteract
bleeding, dough piece is rounded to make it uniforms. It is known as handing up
also.
·
INTERMEDIATE
PROOFING
Ø
During rounding some
gas escapes & some gluten strands collapse.
Ø
If dough is further
worked upon, can lead to rough surface affecting texture of bread.
Ø
Resting for 10 to 15
minutes should be done.
Ø
Piece is again filled with
gas & gluten comes back to its pliable condition.
·
MOULDING &
PANNING
Ø
Dough moulded to
desired shape.
Ø
Moulding pressure
should be even throughout. Uneven pressure leads gas pockets.
Ø
Too loose moulding
will open up texture to undesirable extent.
Ø
Too tight moulding may
tear off surface.
·
PROOFING
Ø
Done to allow dough to
rise again & acquire volume
Ø
Ideal temperature 95°F
to 98°F. Humidity 80 – 83%.
·
BAKING
Ø
Oven should be
pre-heated 400 – 480°F
Ø
Humidity should be
well maintained.
Ø
Due to increase in temperature,
yeast starts functioning vigorously producing gas which raises volume of the
product known as ‘over spring’.
Ø
Proteins are coagulated
at 172°C.
Ø
Enzymes remain active to
about 170°F, breaking starch into sugar which will give crust colour.
Ø
Partial gelatinization
of starch takes place.
