Science Projek - Food Preservation

8/7/2019 Science Projek - Food Preservation

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Science Project 2011Science Project 2011

Topik : Food PreservationTopik : Food Preservation

Teacher : Puan Nik HananTeacher : Puan Nik Hanan

Done by : Adrian DassDone by : Adrian DassIyngkaranIyngkaranIsfaroul FeisalIsfaroul FeisalShamilShamil

Kelas : 6 MusytariKelas : 6 Musytari


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F ood SpoilageF ood SpoilageFood is essential for all living organisms to survive.Food is essential for all living organisms to survive.

Plants and animals are the two basic sources.Plants and animals are the two basic sources.

Food can be spoilt when it is not kept properly of left too long.Food can be spoilt when it is not kept properly of left too long.

Food that is spoilt has undergone changes from its normal state andFood that is spoilt has undergone changes from its normal state andit is unsafe to eat.it is unsafe to eat.

We can detect the changes in spoilt food by observing, smelling,We can detect the changes in spoilt food by observing, smelling,tasting and touching the food.tasting and touching the food.


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W ays to preserve foodW ays to preserve food

W ays to preservefood

W axing

Pasteurising

Boiling Cooling

FreezingBottlingcanning

Pickling

Vacuumpacking

DRYING

Salting

Smoking


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D ryingD ryingT he growth fo microorganisms on food can be stopped byT he growth fo microorganisms on food can be stopped byremoving moisture from the food . T his can be done by drying theremoving moisture from the food . T his can be done by drying thefood.food.

Food can be dried byFood can be dried bya) placing it under the suna) placing it under the sun

b) heating it in the oven b) heating it in the ovenc) heating it with a flamec) heating it with a flame

Examples of food preserved by drying are fish, cuttlefish, prawns,Examples of food preserved by drying are fish, cuttlefish, prawns,chillies , fruits and grainschillies , fruits and grains


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B oilingB oilingT he high temperature during boiling can kill manyT he high temperature during boiling can kill manymicroorganismsmicroorganisms ..

Examples of food preserved by boiling are meat, egg,Examples of food preserved by boiling are meat, egg,seafood.seafood.


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C oolingC oolingC ooling involves storing of food in the refrigerator at lowC ooling involves storing of food in the refrigerator at lowtempreature of about 0 C to 5 C .tempreature of about 0 C to 5 C .

C ooling cannot kill bacteria and fungi. It just slows down their C ooling cannot kill bacteria and fungi. It just slows down their growth.growth.

Food is cooled so that it will not decay so fast.Food is cooled so that it will not decay so fast.

Examples of food that preserved by cooling are fruits, eggs,Examples of food that preserved by cooling are fruits, eggs,milk, vegetables, and meatmilk, vegetables, and meat


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V acuum PackingV acuum Packing

V acuum packing is a way of storing food by sealing it in aV acuum packing is a way of storing food by sealing it in aairtight container.airtight container.

Without air ,bacteria and fungi cannot grow. T his preventsWithout air ,bacteria and fungi cannot grow. T his preventsfood from getting spoilt.food from getting spoilt.

Examples of food that are preserved by vacuum packing areExamples of food that are preserved by vacuum packing arefruits, nuts and sausages.fruits, nuts and sausages.


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PicklingPicklingPickling is a method of preserving food by soaking andPickling is a method of preserving food by soaking andsoaring it in acid (usually vinegar), brine (salt solution) andsoaring it in acid (usually vinegar), brine (salt solution) andconcentrated sugar solution.concentrated sugar solution.

T he food preserved through this method is know as pickedT he food preserved through this method is know as pickedfood.food.

T he acid in vinegar stops the growth of microorganisms. T hus,T he acid in vinegar stops the growth of microorganisms. T hus, prevent the food from rotting. prevent the food from rotting.

T he concentrated sugar solution used in pickling fruitsT he concentrated sugar solution used in pickling fruits


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B elow are the steps to makeB elow are the steps to make

pickled mangoes.pickled mangoes.a)a) Green mangoes are cut into slices.Green mangoes are cut into slices.

b) T he slices mangoes are washed and drained. b) T he slices mangoes are washed and drained.

c) T he sliced mangoes are mixed with salt and left for one night.c) T he sliced mangoes are mixed with salt and left for one night.

d) T he sliced mangoes are washed and drained again and put intod) T he sliced mangoes are washed and drained again and put intoa jar.a jar.

e) T he sliced mangoes are soaked in a concentrated sugar e) T he sliced mangoes are soaked in a concentrated sugar solution for several days.solution for several days.

f) Some vinegar is added into the jar.f) Some vinegar is added into the jar.

g) T he jar is sealed tightly.g) T he jar is sealed tightly.


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F reezingF reezingFreezing is a process of keeping food at a very low temperatureFreezing is a process of keeping food at a very low temperatureof aboutof about --10 C in the freezer compartment of the refrigerator 10 C in the freezer compartment of the refrigerator

Freezing cannot kill microorganisms . It only causes them toFreezing cannot kill microorganisms . It only causes them to become frozen , inactive and cannot grow. become frozen , inactive and cannot grow.

As soon as the food is taken out from the refrigerator, theAs soon as the food is taken out from the refrigerator, themicroorganisms become active again .microorganisms become active again .

T hus, it is important to eat the food quickly once it is taken outT hus, it is important to eat the food quickly once it is taken outfrom the refrigerator or to cook it immediately once it is thawed.from the refrigerator or to cook it immediately once it is thawed.


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F reezingF reezingFood preserved by freezing is beneficial as it does not causeFood preserved by freezing is beneficial as it does not causethe food to change in colour, shape , taste and size.the food to change in colour, shape , taste and size.

Most of the nutrition contents in the food are maintained.Most of the nutrition contents in the food are maintained.

Examples of food preserved by freezing are meat, fish ,Examples of food preserved by freezing are meat, fish , prawns, chicken and cuttlefish. prawns, chicken and cuttlefish.


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B ottling and C anningB ottling and C anningFood preserved by bottling and canning can last for a long time.Food preserved by bottling and canning can last for a long time.

T he food is heated to a high temperature to kill microorganisms.T he food is heated to a high temperature to kill microorganisms.

T hen the food is placed in cans and added with additives.T hen the food is placed in cans and added with additives.

Air is removed from the cans and the cans are quickly sealed.Air is removed from the cans and the cans are quickly sealed.

Without air, the bacteria and fungi cannot survive.Without air, the bacteria and fungi cannot survive.

Examples of food preserved by bottling and canning are chicken ,Examples of food preserved by bottling and canning are chicken ,meat, fish , peas , fruits, juices and vegetablesmeat, fish , peas , fruits, juices and vegetables


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PasteurisationPasteurisationIt is a process named after a scientist, Louis Pasteur, whoIt is a process named after a scientist, Louis Pasteur, whodiscovered that heat can kill microorganisms in food.discovered that heat can kill microorganisms in food.

Milk is pasteurised by heating it to 70 C for fifteen seconds andMilk is pasteurised by heating it to 70 C for fifteen seconds and

then quickly cooled and packed.then quickly cooled and packed.

Pasteurisation cannot kill all the bacteria but it can destroy harmfulPasteurisation cannot kill all the bacteria but it can destroy harmfulgerms and preserve the flavour of the milk.germs and preserve the flavour of the milk.

However, pasteurised milk can be kept for only a few days.However, pasteurised milk can be kept for only a few days.

Examples of food that can be pasteurised are milk, fruit juice , iceExamples of food that can be pasteurised are milk, fruit juice , icecream and noncream and non- -carbonated beverages.carbonated beverages.


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SaltingSaltingSalting is an ancient way of preserving food.Salting is an ancient way of preserving food.

T he salt draws out water from the food . T herefore, microorganismsT he salt draws out water from the food . T herefore, microorganismscannot grow.cannot grow.

T here are two methods of salting food.T here are two methods of salting food.

T he food is soaked in a salt solution or rubbed with salt.T he food is soaked in a salt solution or rubbed with salt.

T his process is more effective if the salted food is dries under the SunT his process is more effective if the salted food is dries under the Sun

Examples of food that can be preserved by salting are fish, meat ,Examples of food that can be preserved by salting are fish, meat ,

eggs, fruits and vegetables.eggs, fruits and vegetables.


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SmokingSmokingSmoking is the process of drying food with smoke from burning wood inSmoking is the process of drying food with smoke from burning wood inthe smokethe smoke--house.house.

T he chemicals present in the smoke and the drying effect from the smokeT he chemicals present in the smoke and the drying effect from the smoke

help to dry the food.T

his method dries the food without cooking it.help to dry the food.T

his method dries the food without cooking it.

T he heat helps to kill or slow down the growth of microorganisms.T he heat helps to kill or slow down the growth of microorganisms.

Apart from removing water from the food.T

he smoke adds flavour to theApart from removing water from the food.T

he smoke adds flavour to thefood.food.

Smoking is usually used to preserve meat, fish and fruits such as bananasSmoking is usually used to preserve meat, fish and fruits such as bananasand dates.and dates.


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W axingW axingWaxing is a process of coating wax on the surface of the food to replace some of theWaxing is a process of coating wax on the surface of the food to replace some of thenatural waxes removed during washing and cleaning.natural waxes removed during washing and cleaning.

T he wax is obtaine from bees, plants, petroleum sources and beef fats.T he wax is obtaine from bees, plants, petroleum sources and beef fats.

T he wax helps toT he wax helps to-- slow down the loss of water in the foodslow down the loss of water in the food-- slow down the decay of food by retaining moisture andslow down the decay of food by retaining moisture and-- increase the shelf life of the foodincrease the shelf life of the food

Waxing prevents the growth of fungi and protects the fruits from diseases andWaxing prevents the growth of fungi and protects the fruits from diseases and physical damage. Foods coated with wax are not easily infected by microorganisms physical damage. Foods coated with wax are not easily infected by microorganisms

Fruits and vegetables that can be waxed included oranges , bananas, apples, pears ,Fruits and vegetables that can be waxed included oranges , bananas, apples, pears ,tomatoes , cucumbers , melons , brinjals and chillies.tomatoes , cucumbers , melons , brinjals and chillies.


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I mportance of preserving foodI mportance of preserving foodFood preservations allows food to be kept longer without changing itsFood preservations allows food to be kept longer without changing itsvalue as food.value as food.

T he following are the advantages of food preservation.T he following are the advantages of food preservation.

Preserved foods can be stored for a longer time. We can enjoy eating foodPreserved foods can be stored for a longer time. We can enjoy eating foodeven it the food is out of season.even it the food is out of season.Preserved foods are easy to store and pack because they are small and needPreserved foods are easy to store and pack because they are small and needonly small containers to hold them.only small containers to hold them.Preserved foods are also light and require less space. T hus, they are easy toPreserved foods are also light and require less space. T hus, they are easy to

carry and transport.carry and transport.As food can be kept for longer periods . It can be exported to other As food can be kept for longer periods . It can be exported to other countries. T his enable us to enjoy food from other countries.countries. T his enable us to enjoy food from other countries.Preserving food helps to reduce wastage of food. Leftover food can be keptPreserving food helps to reduce wastage of food. Leftover food can be keptin the refrigerator for later consumption.in the refrigerator for later consumption.

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Science Projek - Food Preservation