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id=DzLACdHHg2AC&pg=PA133&lpg=PA133&dq=methods+of+size+r
eduction+in+solid+foods&source=bl&ots=PbcAfnfmMF&sig=FmeGW65NgDfcAmbpAOk0EKQhKV8&hl=e
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uction%20in%20solid%20foods&f=false
Different size reduction techniques of solid foods are classified according to the size range of
particles produced.
Methods of size reduction are:
1. cutting, slicing and dicing:
(a) large to medium (stewing steak, cheese and sliced fruit for canning)
(b) medium to small (bacon, sliced green beans and diced carrot)
(c) small to granular (minced or shredded meat, flaked fish or nuts and shreddedvegetables)
2. Crushing and Grinding eg. Coffee
Milling to powders or pastes of increasing fineness
(grated products > spices > flours > fruit nectars > powdered sugar > starches > smooth pastes)
Mincing / shredding
This technique is use for the size reduction and homogenization of meat.It requires the use of a meat
grinder to mince the meat.This consist of a lightly constructed screw that is press with a cutting plate or
rotating knives at its outlet.The process is a combination of cutting and extrusion (meat passed through a
plate with orifices).
http://www.hyfoma.com/en/content/processing-technology/size-reduction-mixing-forming/cutting-
slicing-chopping-mincing/
Alarge variety of equipment for cutting slicing, dicing, mincing is used for the product to be
processed.Equipments can be electrically powered or manual depending on the size of the operation.
ADVANCES in technology IN SLICING MACHINES:
Noord OST Nederland B.V. (FTNON) in Holland along with other leading companies in the salad
industry food technology has develop a new system for slicing a variety of salads.Salads were originally
sliced with the use of high speed rotating slicing wheels and therefore the force exerted on the
prioducsts are high.disadvantage. and this can cause damage or bruise to the product.with t he FTNON
system these risks are reduced and the result is a perfectly sliced product and attractive.
http://www.hyfoma.com/en/content/processing-technology/size-reduction-mixing-forming/cutting-
slicing-chopping-mincing/ftnon-a-a-perfectly-sliced-product.html
Grinding (milling) is used for the size reductuion of solid dry materials.It also improves the quality and
suitability of the food for further processing.Milling is also used to crush cane sugar to facilitate the
extraction of sugar in sugar and rum factories. Crushing break the skin of the solid food to extract the
substance. For example in the crushing of berries where the berry isd crushed by breaking the skin to
liberate the must.This facilitates multiplication of yeasts and to conduct traditional maceration before
processing.
Field of application
Grinding/milling is applied in animal feed industry , flour mill industry, breweries, sugar industry, dairy
industry( milk powder, lactose)
Processsing techniques, methods and equipments
A whole range of grinding/milling techniques and equipments are available for application of different
types of food.Techniques in clude wet grinding/milling and dry grinding/milling. In
wet grinding/milling smaller particle size is attained. Dry grinding/milling is combined with sieving which
results in particle size fractions.Cyclones are generally used to recover the particulate matter (dust ) in
the extracted air. The recovered material is then processed.
Common types of mills that are used in the food industry are:
Hammer mills
A hammer mill consist of a horizontal or vertical cylindrical chamber lined with a steel breaker plate and
contains a high speed rotor fitted with hammer s along its length.The material is broken apart by
imp[act forces as the hammer drive it against the beaker plate.
Ball Mills
The mill consist of a slow rotating horizontal steel cylinder , half lifted with steel balls (2.5-1.5 cm in
diameter).The final particle size depends on the speed of the rotation and on the size of the balls.
Roller mills
The mill consist of two or more steel rollers which revolve towards each other and pull particles of the
food material through the space between the rollers, the space being known as the nip.The size of the
nip can be adjusted for different food materials.
Disc mills
Disc mill consist of either a single rotating disc in a stationary casing or two disc rotating in opposite
directions.The food material passes through the adjustable gap between the disc and the casing or
between the discs .Pin and discs mills have inter meshing pins fixed on the discs and casing.This
improves the effectiveness of the milling.
http://www.hyfoma.com/en/content/processing-technology/size-reduction-mixing-forming/grinding-
milling-crushing-pulping-pressing/
cutting, slicing and dicing:
Cutting, slicing and dicing function to reduce the size of the food either for further processing or to
improve the quality or suitability of the food fo direct consumption.
Field of Application
These operations are widely used in the proceesing of meats , fish , cheese , vegetables and fruits,
potatoes and various crops.
Techniques, methods and equipments
Alarge variety of equipment for cutting slicing, dicing, mincing is used for the product to be
processed.Equipments can be electrically powered or manual depending on the size of the operation.
Cutting Equipments
The most common cutting equipments are knives, saws,guillotines,wires and shears. Saws are effectively
tooted knives.Guillotines is a type of knife related to choppers and shears and is composed of two
knives. A simple knife maybe straight or curve.Knives can operate independently or maybe part of some
other cutting mechqanism suc as the shear.Guillotines are used in cutting large size foods.Wires are
mainly used in cutting sticky products. It is use effectively in cutting bread because of small surface than
that of a blade producing less waste and crumbs.
