hard dough biscuits
Hard dough biscuit manufacturing is a process involving three phase of process line pre baking, baking and post baking. The main raw materials are wheat flour, sugar, vegetable fat, Food grade additives, etc. Dough is prepared using basic required ingredients then the dough is sheeted for continuous sheeter and cuted for required size and shapes. After this process shaped biscuits are baked in the oven up to desired temperature and removed through conveyor here oil is sprayed on the biscuit to keep them shiny and more appealing. After this process the biscuits are stacked using stacking unit and sent to packing machine for required type of packing.
Laminating, sheeting and cutting type:
Here The dough is passed through lamintors to produce sheets these multilayer sheets are then fused into single sheet of desired thickness .This sheet is then passed onto cutter of various shape and sizes of cups/dies.
marie gold ,
salt n sugar cracker
Biscuit manufacturing consists of four major process:
Mixing is a process where all ingredients are put together in right proportion for
dough formation. These ingredient are then fed into Mixers where mixing is done and dough is prepared for molding .Major ingredients are flour , fat ,sugar and others as per the product one would like to have..
Mixing can be done in One stage ,two stages or three stages.
One stage or all in One is type of mixing where all ingredients and water are added once . Mixing is allowed till satisfactory dough is prepared . Normally this type of mixing is used for hard Dough.
Two - Stage mixing :
Creaming : All ingredients are added with water and mixed 4-5 minutes except for flour .
2nd stage :Flour with chemicals are then mix with the creaming product to form a consistent dough .
Three stage mixing :
Stage One : fat , sugar with other ingredient like milk, chocolate, malt , honey etc are mixed and cream is prepared with portion of water .
Stage two: Salt , chemical and flavours with colors are mixed with water.
Stage three : Flour with water is then added to the prepared cream and mixed till satisfactory dough is prepared .
Mixing process have following characteristics which have be monitored for better
Mixing time : Normally any mixing could be achieved within 15-25 minutes .
Much depends on mixing speed of mixer , flour characteristic's or temperatures required for dough.
Dough Temperatures : Very important factor the temperature ranges between
35 deg c - 42 deg c as per biscuit variety .Temperatures are maintained by refrigerant equipments like chillers , direct expansion type chillers . In winter dough temperatures are maintained by heating equipments.
Dough consistency:This is done manually by checking dough and stretching the dough it should not break neither should it be so elastic . These methods are mastered by bakers by trial and error method.
For cracker variety dough had additional ingredient yeast and dough are kept for 10- 24 hrs .
Forming sections the dough is passed through several rolls to form sheets , these
sheets are then converted into One uniform sheet of desired thickness.
Moulders and cutters are used to cut sheet or convert dough into desired shape and size
Stages in forming
Dough after mixing in tipped into laminators hoppers r with some mechanical
/pneumatic tilting . There are two type of laminators.
Horizontal type laminators :
If space is not the constraint then horizontal type laminators
are the best selection as the maintenance and repairs are easily done. The lamination and
the controls are visible . Changing webs and rolls are very easy .Pneumatics and servo
motors are used in now modern day laminators for automated speed to be synchronised
with rest of the plant .11-14 sheet per batch
Vertical type laminators :
Vertical type of laminators have been there for very long its
useful if space is aconstraint.Dough is passed through three stage rollers and after
lamination of sheet it cut into sheets which are then carried to rollers through inclined
Gauge roll stands . Reduction in sheet is achieved through numerous gauge roll s stand .
Popular are three stand gauge rolls or four stand gauge roll . Reduction are achieved in
stages as not to create too much stress on the sheet , webs are provided in between for
relaxation even an additional web is provided prior to cutter to release stress from dough
sheet.Best results are achieved through four stand gauge rolls
Dough sheet conditioning : Dough sheet conditioning is done as per the ambient
conditions in the plant .
Steam spray: to moist the web surface
Blower : to dry the dough surface.
Flour dusting : to dry the wet surface of the dough .
Toppings : Toppings are done through mechanical, vibratory or sprays . means where a
hopper is placed above the plant line after the cutter . The toppings could be milk , salt ,
sugar or cashew , pista bits .
Rotary cutter :
Rotary cutter consists of cups which are a attached to the cutter shell.This shell is then
fixed to the shaft and drive mechanism . Two types of rollers are popular One is complete
on mould shell where cups are attached in the cavity designed for the cups with dowel pins .
Second concepts is also very popular when shell has several rings fitted over it .
This helps in easy removal of damaged part and also very helpful in taking various trials .
Cuter is coupled with rubber roller of shore hardness approx -80-85 . Rubber roller or the
pressure roller helps in releasing wet biscuit .
RPM : Rotary cutter speed is set as per plant capacity and baking time , Variety .
Band coverage efficiency : It is ratio of total surface area of cutter -moulder / no biscuit cups
Moulding Roller :It is applied for short dough ,The dough is prepared in lumps these are
then fed to die roll through either reciprocating conveyor to The hopper or a rotary
conveyor which allows these dough crumbs to spread uniformly on The die roller surface .
These die roller have dies engraved into it . Dough pieces are then released by feed
roller which pushes The dough into The dies.
Moulders and Cutters
Moulders and cutters are the base for any biscuit industry . Plant design is based on output
from these moulders and cutters .Different kind of shapes and sizes can be generated
through cups and dies . Basic material for moulder or cutters is gunmetal with anti-sticking
plastic inserted on to the cups .
Plant output is calculated= no of cups in row x no of columns x rpm
One piece roller: Moulder or cutter has one solid roller on which dies or cups are
fitted.Moulder is fixed to the line with help of flanges at end .
Rings type roller : Rings are fitted on roller instead of one complete roller .This helps in
changing damaged section with a new ring.Depending on rollers length the rings are put
into moulder .
Engraved roller : Instead of dies or cups biscuit pattern is engraved in moulder or cutter.The
disadvantage of this moulder is that we have to change complete set of moulder .
Reciprocating cutter : For smaller bakeries where we have plates rather than oven band for
baking .These type of moulder is useful for smaller bakeries.
Cutters : These are basically used for sheet varieties here the cups are installed and have
edges which cuts the sheet into desired shape and size .cups can be of metal or plastic .
It is advisable to put metal detector prior to cutters and moulders for any damage to the
moulding unit . Change over from one type to other type of moulder can be done by chain
hoist OR Hydraulic cranes .Size could vary from length 0.8 , 1.0 , 1.2 , 1.5 meters to dia 8" ,
10" , 12" .
Rubber rollers or pressure rollers: These are roller which are placed beneath the moulders of
cutters for providing base to cut or to release dough on web .Rubber rollers can be re
rubberised to maintain the hardness as with time we would find that it has become very hard. The ideal hardness of rubber rollers is between 70 -80 shores .
Forcing rollersor Feed Rollers :These rollers are provided for moulding varieties where it
forces dough into moulders cups or dies .These are heavy and solid rollers.
Knife : Knives are provided at these moulders to scrap through the dough so that we get
flat and uniform biscuits.
Cups /Dies - metallic or plastic.: Various type of cup and dies are available as per requisite
size and shape .
Wet dough pieces of desired weight and shape are then passed on to oven band through
swivel panner web .Ovens are of different types classified into following categories .
a. type of heating b. type of fuel c. type of design d. width of oven band
e. Number of zones .
Heat is transferred to biscuit on band through all the three ways of heat transfer ie
conduction , convection , radiation .
Following are the chemical and physical changes which occurs in oven ,When dough piece
is passed on to oven .
Physical changes .
1. Formation of crust 2. Melting of fat 3.gas expansion in dough piece due to co2
expansion at higher temperatures . 4. Water converted into steam .
Escape of gases and steam would result in collapse of biscuit structure , Hence these are
passed on to different zones with gradual increase or decrease of temperature .zones are
1. Heating zone
2. Baking zones
1. Gas formation
2. starch gelatization
3. Protein changes
4. caramelisaion of sugar
Cooling process is as important than any other process , When biscuit comes out with
oven the temperatures of biscuit are around 70-95deg c, These biscuit can be cooled by
letting it travel for distance of 1.5 times of baking time . so if you have a oven of 200 ft
then cooling conveyor length would be approx 300 - 350 . In some places forced cooling is
also done due to space constrain or for special features .Cooling brings temperatures to
room temperature for handling of biscuit for packing
Bakery packaging has certain specification which are unique for bakery
products .Major packaging are Biscuit packaging and bread packaging
Biscuits are fed into packing machines in continuos stacks this is either manual or with help of auto feeders with help of feeding chutes .Biscuits are fed into packing machines in continuos stacks this is achieved through stacker which converts free flowing biscuits into uniform achieved through stacker which converts free flowing biscuits into uniform stacks .These are done through guidelines which could be adjusted as per type of biscuits .per type of biscuits .
Major function of packaging are
1. Protect from mechanical damage in transit and loading and unloading
2. Protect from loss of moisture and any foreign odour contaminations
3. Protect from Foreign body infestation.
4. Legal compliance for values and ingredients for consumers
Biscuit are wrapped with packing machines and wrappers are sealed as long and ends. These are sealed with helps of heaters .Coders are synchronised with machine speed to print details to the packing material .
Packs could be of various size and shape . Popular are pillow pack and family packs with wt ranging from 25 gms to 400gms . These packs are then put into cartons are then taped by passing through carton taping machines .Now biscuits are ready for dispatch .
Various type of packing material is used in biscuit industry.
Primary packaging: Laminate/Wrapper , Wax Paper and Bopp films .
These are tailored made for various packs where the cut-off-length and
width are decided prior to packing material production .
Basic properties for laminates n corrugated boxes are Bursting strength , GSM and thickness of films measured in microns .Values varies from one product to other.
Selection have to be done on above parameter.
Primary function of packaging are protecting biscuit from foreign body infestation ,
increasing shelf life , product and manufacturer info and transportation .
Technological innovation has made possible to have various shape , sizes and colours for
biscuit packaging .
The important groups of packing material are
- CARTON BOXES
- DISPLAY BOXES
- BOPP FILMS(flexible packaging)
printed clear film
- BOPP TAPES
- TEAR TAPES
- SHRINK FILMS
- POLYPROPYLENE SHEETS
- PVC TRAYS
- WAX PAPER