Milling of wheat
Lecture No. 3
Dr. Hradesh Rajput
Assistant Professor,
Dept. of Food Technology, CSJMU, Kanpur
1
OUTLINES
• Introduction of Milling
• Objective
• Types of wheat milling
• Assignment/exercise
• Learning Outcomes
• References
2
BSFT-303
WHAT IS MILLING????????
➢Most cereal grains are used either for the production of animal feed or
for the milling of flour for human consumption
➢The grinding of wheat for human consumption has to meet higher
standards of quality and is called milling
➢ The aim of milling is two fold;
1. To grind cleaned and tempered cereal
2. To completely separate the bran and germ from the mealy
endosperm and to thoroughly pulverize the mealy endosperm
into middings, semolina and flour in case of wheat.
SELO: 1 Reference No.: R1
3
BSFT-303
OBJECTIVE
To be understand the types of milling
To be described the different milling techniques
SELO: 1 Reference No.: R1
4
BSFT-303
NUTRIENT COMPOSITION
Whole Endosperm Bran Germ
grain
Protein 16 13 16 22
Fat 2 1.5 5 7
Carbs 68 82 16 40
Dietary 11 1.5 53 25
fiber
Minerals 1.8 0.5 7.2 4.5
others 1.2 1.5 2.8 1.5
SELO: 1 Reference No.: R1
5
BSFT-303
WHEAT MILLING
➢ Wheat is commonly consumed in the form of flour obtained
by milling the grain while a small quantity is converted into
breakfast foods, such as wheat flakes, puffed wheat and
shredded wheat
➢ Two types of milling process are;
1. Traditional milling
2. Modern milling
SELO: 1 Reference No.: R1
6
BSFT-303
1. TRADITIONAL MILLING
➢ The traditional procedure for milling wheat in India has been stone
grinding (chakki) to obtain whole meal flour (Atta). It contains bran,
germ and endosperm.
➢ This is an ordinary method of milling. In this method, two circular thick
stones are used, one lying on top of the other. The surface of the stones
are rough. This rough surface helps to crush the wheat.
➢ This method results in 90-95% extraction rate flour which retains almost
all the nutrients of the grain while simultaneously eliminating that part of
the grain which is most indigestible like cellulose and phytic acid which
binds and carries away minerals
SELO: 1 Reference No.: R1
7
BSFT-303
TRADITIONAL MILLING
SELO: 2 Reference No.: R1
2. MODERN MILLING
SELO: 1 Reference No.: R1
9
BSFT-303
MODERN MILLING
• Wheat is subjected to cleaning – remove various types
Of impurities and damaged kernels
• 12 steps are involved
1. VIBRATING SCREEN
➢Removes bits of straw and other
Coarse materials and also
foreign particles like seeds
SELO: 2 Reference No.: R2
2. ASPIRATOR
➢ Lifts of lighter impurities in the wheat
➢ Stream of grains directed across screen while air sucks of
dust and lighter particles
SELO: 2 Reference No.: R2
3. DISC SEPARATOR
➢ Discs revolving on horizontal axis
➢ Surface of disc catch individual grains but reject larger/ smaller
materials
SELO: 2 Reference No.: R2
4. SCOURER
➢ Machine in which beaters attached to central shaft
➢ Throws wheat violently against surrounding drum
➢ Buffs each kernel and breaks kernel hairs
SELO: 2 Reference No.: R2
5. MAGNETIC SEPARATOR
➢ Pulls out iron and steel particles
Contaminated during harvesting
6.WASHER STONER
➢ High speed rotators spin the wheat in the water bath
➢ Excess water thrown by centrifugal force
➢ Stones drop to bottom and removed
➢ Lighter materials float off leaving only
the clean wheat
SELO: 2 Reference No.: R2
7.TEMPERING
➢ Wheat tempered before the start of grinding
➢ Process in which moisture is added
➢ Aids in separation of bran from endosperm and helps to
Provide controlled temperature and moisture throughout Milling
➢ 3 important factors in tempering
% of moisture, length of soaking, time of temperature
➢ Outer layer- tend to brittle
➢ Tempering toughens the bran coat permit complete Separation of
endosperm
SELO: 2 Reference No.: R2
8. ENTOLETER
➢ Entoleter mills use centrifugal force to break and remove hulls from
grains and seeds. The controlled speed of specially designed rotors
breaks the hull.
SELO: 2 Reference No.: R2
9. GRINDING BINS
➢ The wheat kernels are milled into flour. The 'first break' rolls begins the
separation of bran endosperm and Starch
10. SIFTER
➢ Broken particles of wheat and bran go into a boxlike sifter where they are
shaken through a series of cloth/screens to separate larger from smaller
particles
SELO: 1 Reference No.: R2
11. PURIFIER
➢ Divide them into bran and endosperm according to their quality
➢ Cloth / screen separate and grade coarse fractions by size and quality
SELO: 1 Reference No.: R2
12. DOWN PURIFIER
➢ Reduce the wheat particles as
free from bran as possible
➢ Germ particles being somewhat
SELO: 1 Reference No.: R2
Sifters, purifiers process is repeated over and over again until maximum
amount of flour is separated consisting of about 72% of wheat
SELO: 1 Reference No.: R2
20
BSFT-303
References
1. https://www.slideshare.net/NimishaK4/wheat-milling-nimisha-and-
nesna?from_action=save
2. https://www.slideshare.net/FaseehaFaseeha/wheatmilling-
technology-and-wheat-processed-products?from_action=save
21
BSFT-303
BSFT-303 22
