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Processing and Preservation of Fruits
By the end of this chapter, you will be able to:
Introduction
Do you know that fruits have a lot of moisture? It is because of this reason that they get spoiled very fast. You must have tasted many types of fruits. You realise that most of them are acidic. This is due to the high vitamin C content. However, many fruits also have plenty of vitamin A. You have also seen the thread-like structure in fruits. This shows that fruits are a good source of roughage. In this chapter, you will learn to
process and preserve fruits into different fruit products. You will do this by drying or using chemicals. This will help you to add value to fresh fruits around you and to ensure a longer
shelf life.
Food spoilage
Activity 5.1
Food spoilage
In pairs,
your class.
Food safety is the handling, preparing and storing in the best way to reduce your risk of becoming sick from food borne illnesses. Its main aim is to prevent food which may result into food poisoning. Food safety starts with cleaning.
The success of processing and preserving any product depends on the cleanliness of the person (processor), the handling of the food, the environment and in which
the food is processed and packed. Most people are very particular about having a food product that has been processed and packed in hygienic conditions.
Any person with a common cold and is sneezing, coughing or having a runny nose should not be allowed to process and package the fruit until he/she has recovered. Any person with any other infectious disease must not be allowed to process or package fruit until he/she has recovered.
Activity 5.2
Working in unhygienic conditions
All persons processing and packaging fruits must maintain personal hygiene before starting any work on the fruit. Their hands, fingers and clothing must be clean. Hair must be covered
with a clean hair covering and clean aprons worn on outer clothing to avoid contamination of fruits.
Activity 5.3
Making a poster about safe preparation and storage of food
In groups,
Food poisoning
Have you ever suffered from food poisoning? What did you experience?
Once food has been harvested, gathered or slaughtered, it starts to deteriorate until it eventually becomes unfit for consumption.
This deterioration is known as decay and leads to food spoilage.
Food spoilage is caused by natural decay within the food itself and contamination by micro-organisms.
Have you ever thought of the reasons why this happens? What do you think causes food to go bad?
When you keep fruits for long, they get spoiled and so cannot be eaten. They therefore have to be thrown away.
You can define food spoilage as any change that renders food unfit for human consumption. These changes may be caused by various factors, including contamination by microorganisms, infestation
by insects, or degradation by enzymes present naturally in the food. In addition, physical and chemical changes, such as the tearing of plant or animal tissues or the oxidation of food, may
promote food spoilage. Foods obtained from plant or animal sources begin to spoil shortly after harvest or slaughter.
Activity 5.4
Discussing the causes of food spoilage
In small groups,
1.Find out the causes of spoilage in fruits.
2.What can be done to prevent this spoilage?
3.Come up with a poster that brings out the safe preparation and storage of food in order to prevent spoilage.
4.You will need a manila paper and a marker to do this.
Study carefully Figure 5.1. What do you notice about the fruits?
You can tell that food is spoiled when you notice some changes in the appearance of colour, texture and sometimes the unpleasant odour or taste.
Have you ever eaten food that had gone bad? How did you feel? Disease causing germs can be found on almost all of the food that you eat. When you heat food during cooking, these disease causing germs are killed. Foods eaten raw are common sources of food poisoning because they don’t go through the cooking
process where heat is applied. Food poisoning is an illness caused by eating food contaminated
with bacteria, viruses, parasites or toxins. These organisms can contaminate food at any point of production or processing. Contamination can also occur at home if food is incorrectly
handled or cooked.
Activity 5.5
Explaining the effects of eating spoiled food
In groups,
l. Explain what happens when you eat food which has got spoiled.
Safe preparation and storage of food is important to avoid food contamination and hence food poisoning. How do you handle food during shopping, preparation, cooking, thawing,
re-freezing, serving and when using leftovers? It is very common for food to get contaminated when you do not wash hands before preparing and cooking it. Fruits are among the foods that easily get contaminated. Others may include meat, eggs, milk and fish.
Discussing food poisoning and safe storage of food
Activity 5.6
In small groups,
Almost everyone suffers from food poisoning at one time or another in their lives. You should however remember that there are groups that are at risk more than others. For example, those with low immunity have a higher risk of infection from food poisoning. Pregnant women are more at risk because
their bodies are coping with changes to their metabolism and circulatory system. The children and the elderly people are also at a greater risk of suffering from food poisoning because their immunity is usually low. These are more easily affected by dehydration from vomiting and diarrhoea.
Principles and methods of food preservation
Food preservation is the process of keeping food from spoilage after harvest or slaughter. You can use different ways to preserve food. What is interesting is that you can preserve your food even at home. Fruits can be preserved for various reasons.
Activity 5.7
Identifying reasons for preserving fruits
In groups,
There are four main principles you can apply when processing and preserving fruits. These are:
O Removal of moisture.
Freezing or lowering the temperature.
O Application of heat or increasing the temperature.
Using chemicals.
There are several methods of preservation. All the methods of fruit preservation you can think about are connected to the above principles of food preservation.
Activity 5.8
Elaborating the methods of preservation
In groups,
1.Identify and discuss the different methods you would use to process and preserve fruits.
2.Choose one method of processing and preserving fruits.
3.Write down the instructions on how this should be done on a flipchart.
4.Present your chart to the class.
Preserving fruits by drying
Drying is one of the oldest methods of preserving fruits to reduce water, and therefore prevent the growth of microorganisms. Fruits can be sun dried or dried in an oven or in a dryer. Dried fruits are
as tasty and almost as nutritious as fresh fruits. They are sweeter than fresh fruits because the water has been removed, thereby concentrating the fruit’s flavor Dried fruits are one of the common products you can do on a small scale for example bananas, pineapples and apples.
Drying removes the water from foods so that the growth of microorganisms is inactive. It also reduces the weight and bulk of foods. This cuts down on transport and storage costs. Sun drying is the simplest and cheapest method of drying but the disadvantage with it is that the processor has very little control
over the drying conditions and the quality of the dried fruit.
Question:
Apart from sun drying, do you remember any other methods of drying?
The methods you used when drying vegetables in Senior One can also be used for drying fruits.
Just like you did when drying vegetables, it is important to treat fruits by blanching in boiling water. This helps to inactivate enzymes and to remove hardness. It also helps to reduce the
amount of micro-organisms in the food.
Conserving nutrients during fruit preservation by drying
The nutritional value of fruits is affected by drying. Vitamin C is easily destroyed with exposure to heat. However, preheating with lemon, orange or pineapple juice increases the vitamin C content. Blanching fruits reduces the loss of vitamin C by oxidation.
Vitamin A is less affected by drying as it is actually retained during the drying process done in the oven or in a solar dryer. However, vitamin A is light sensitive and therefore, care should be taken so that food containing it should be stored in dark places. Dried yellow and dark green vegetables, such as
peppers, carrots, squash, and sweet potatoes with high vitamin A content should be stored in covered containers in dark places.
Activity 5.9
Conserving vitamins during preservation
In groups,
Processing and preserving fruits by drying
Activity 5.10
Listing down the requirements for drying fruits In your notebook,
I. Make a list of the key requirements that you will need when drying your fruits.
The eight steps below explain how fruits can be dried in a solar dryer.
A flow chart showing the process for drying fruits
You can explain the steps in the process using a flow chart
as below:
Washing
You should wash hands and arms thoroughly with clean
water and non-perfumed soap or detergent when peeling fruits.
Always ensure that you clean all working surfaces, containers and equipment before handling fruits.
Wash the fruits using clean water mixed with either lemon
juice or vinegar. Be careful not to break the skin of the fruit. This will contaminate it.
Dryer loading
Drying
Under fine and sunny conditions, the fruit slices should be dry after 2 to 3 full days in the dryer. However, it is essential to test slices. If the slices are not sufficiently dry, they will become mouldy in a short time. A test for dryness is conducted for specific products.
Dryer unpacking
•The dryer should be unloaded immediately when fruits are considered to be dry in the mid morning. The best time to unload is in the afternoon on a sunny day. You must wash your hands and wear clean gloves when handling the fruit. Store the dried fruit temporarily in clean dry baskets before packaging so that the product can cool down.
Packing and labelling
Some pieces will be holding more moisture than others due to size and location during drying.
Conditioning distributes remaining moisture evenly in dried fruit so there is less chance of getting spoiled. To condition, you should place the cooled, dried fruits in large plastic or glass containers to about two-thirds full.
Storing
Activity 5.11
Discussing the advantages and disadvantages of drying fruits
In groups,
Fruits can be dried using different ways. This depends on availability of equipment, amount of time available and personal preference.
Activity 5.72
Finding out the methods of drying fruits
Think about different ways of preserving fruits by drying.
Write down your findings and share with the class using pictures and charts.
In Senior One, you made a solar dryer for drying vegetables. Work in your groups to choose a vegetable of your choice and dry it using a solar dryer. If it got spoilt, work with your group and make a simple one for use in drying the fruits. Use the solar dryer to make a fruit product. Ensure that the product is labelled and packaged well. Extracting juice and pulp for processing and preservation
Processing and preservation of fruits include juice and pulp extraction. It involves washing, extraction, clarification and preservation.
Extracting juice and pulp for processing and preservation
Processing and preservation of fruits include juice and pulp extraction. It involves washing, extraction, clarification and preservation.
Identifying the benefits of using chemicals in
Activity 5.13
1.processing fruits
Identify the benefits of using chemicals when preserving fruits.
List them down in your notebooks.
Write a Microsoft word essay of their explanation and present it to your class.
Good practices to apply in processing fruits
When you harvest fruits from the farm, you can take them through various processes depending on how you would want the final product to be. You may choose to chop, cook, freeze, clean or process into a new product. Whatever you choose to do, there are general food safety guidelines to follow in order
to eat foods such as fruits. These guidelines are necessary to protect against contamination of the fruits by micro-organisms. The food-safety procedures can also help you to prevent contaminations due to mishandling during processing, improper packing processes, contamination of containers or
improper temperature management.
Activity 5.14
Applying the good practices in fruit processing
In groups,
Recommended chemicals in fruit preservation
In order to keep your product for a long time, you will have to add a preservative. These are mainly called chemical preservatives.
Activity 5.15
Illustrating the chemicals in fruit preservation In groups,
Preserving of fruit juice and pulp
Unhygienic practices in juice and pulp extraction affects the health of the consumers. They should therefore, be handled in a hygienic manner. Handling food properly and safely is essential to preventing food poisoning.
Importance of hygiene in processing juice or pulp extraction
All foods, if handled properly, can be safe. Most instances of food poisoning do not have to happen. These can be avoided by following simple guidelines. It is important to ensure that fruits are handled safely during processing. Strict hygienic practices should be observed to ensure that the product is safe
to eat, and to stop it from spoiling.
In this section, you will learn how to process and preserve fruits in a proper manner to reduce cases of food poisoning.
Ensuring that the processing equipment is sterile
Activity 5.16
In groups,
Methods for ensuring that equipment used in processing is clean and sterilised
When processing and preserving fruits, you should ensure that a high standard of cleaning and sterilisation is observed.
Activity 5.17
Observing cleanliness and sterilisation in fruit processing
In groups,
General types of sanitisation include the following:
Chemical sanitisation involves the use of an approved
chemical sanitiser at a specified concentration and contact time.
You should always follow proper procedures for cleaning and sanitising. This is very key in processing and preservation. This is important for the fruits but also for the equipment, work surfaces, walls, ceilings, lighting devices, refrigerators, heating, ventilation and air conditioning as well as anything else that could impact food safety.
Extraction of juice and pulp
A wide range of drinks can be made using extracted fruit juice or fruit pulp as the base material. Many are drunk as pure juice without the addition of any other ingredients, but some are diluted with sugar syrup.
You can group the types of drinks from fruit into two basic types: ‘ Those that are drunk straight after opening.
The first type should not require any preservative if they are processed and packaged properly. The second group .must contain a certain amount of permitted preservatives to have a
long shelf-life after opening.
Finding out the stages in juice extraction
Activity 5.18
In groups,
The following points should be observed in the extraction of juice and pulp:
Preserving fruit and pulp
Preserving juice and pulp
Activity 5.19
In groups,
I. Discuss ways in which fruitjuice and pulp can be preserved for future use or sale.
Tips used to help you improve your product
The following tips will help you improve your product and get themost out of your fruits.
Blending Juices
You could try to experiment with juice blends using your mixer. You may have a pineapple or apple as your base and add a small quantity of another stronger flavoured juice such as
passion, or goose berry.
Always taste before you can carry out the heat treatment of the juice. Mix small quantities first to establish a ratio of pineapple or apple that suits your taste before mixing up all the juice.
Processing and preserving fruit products
Fruits can be preserved in different ways. This is important as it provides a variety of products from the same fruit. For example, you can get a drink, concentrated juice or a jam or a jelly, pickles
or marmalades.
Drinks, for example, can be made using extracted fruit juice or fruit pulp as the base material. You can use these as pure juice without the addition of water or sugar. Some are diluted with sugar or syrup. The type of drinks made from fruit can be separated into two groups. These are;
Each of the above products is preserved by a combination of natural acidity, pasteurisation and packaging in sealed containers. Some drinks (syrups and squashes) also contain a high concentration of sugar which helps to preserve them. Any fruit can be used to make fruit juice or squash, but the most
common ones include pineapple, orange, grapefruit, mango and passion fruit. Some juices such as, guava juice are not filtered after extraction and are sold as fruit nectars.
Demonstrating the methods of fruit juice and
Activity 5.20
pulp preservation
In your group,
After producing your product, it is important that you add more value to it. This is done by packaging and labelling it to increase its acceptability. Improving the appearance of the product will
attract more people to buy from you. Packaging also increases the shelf life of the product.
Activity 5.21
Packaging, labelling, advertising and selling fruit products
Package, label, advertise and sell the fruit product that you have made.
Write a report of how you have done this and demonstrate it in your class using pictorial presentation of charts.
Questions
1.Study the samples of the processed fruits in Figure 5.11.
Can you do something similar to them?
2.Can you think of some other packages?
3. Try out with your friends to prepare a pack that you will use to package the fruits you will choose to preserve.
Ways of preserving fruits
You will realise that for most of the fruit-based products preserved using chemicals, the first stage is the extraction of juice or pulp from the fruit. The major stages you have to take
will include the following:
Discussing the factors that make fruits suitable
Activity 5.22
for preserving
In groups,
PowerPoint) charts or chalkboard demonstration.
Question
Taking note of all you have learnt above, can you now come up with a product ready for sell?
1.
2.
Making products from fruits
1. Using the skills that you have learnt, work in groups to preserve a fruit.
2. Choose a fruit and make a product of your choice. You may need the following equipment:
peeler
Knives (stainless steel)
Juice extractor
Thermometer
Measuring cylinder
Analytical balance
Stainless steel saucepan
2kg scales
You will also need cleaning equipment (brushes, scourers, cloths, hosepipes) 2 gas cylinders, 2 or 3 ring burners. You also need a building with large preparation table, smaller table for gas burners, shelves for products, sink, draining board, taps, cupboard for labels and dry ingredients.
Processing fruit into jam
Making jam and jelly is another means of preserving fruit. The high sugar content of the jam or jelly does not allow bacteria, yeast and mould to grow and spoil the product. This means
that the nutritional qualities of the fruit can be maintained at the same time as providing a tasty product. Jam is made from
the pulp of the fruit whereas jelly is made from the juice only. Jam has a strong fruit flavour and solid appearance. Jelly has a weaker fruit flavour, is sweeter and has a transparent appearance. Fruits which have a large bulk of fleshy pulp are therefore, most suitable for making jam. Recommended fruits
for making jam are;
Utensils required
The principles in jam making
Before you think of making a good jam0elly, three main ingredients are needed. These are pectin, sugar, and acid. The pectin forms the gel structure, which makes the jam0elly firmer rather than a runny pulp of juice. The sugar and acid are necessary to make the pectin set into a firm gel.
Pectin
Pectin is found in most fruits although some have large amounts and others have very little. In unripe fruits, there is a lot of pectin and this gives the fruit its firm and hard texture. As the fruit
ripens, the pectin is broken down and the fruit becomes soft and easy to eat. Some fruits provide enough pectin for jam or jelly making whilst others need to have pectin added from another source. A fruit, which has high pectin content, can be added to one with a low pectin content to give an adequate
amount.
Sugar
Sugar is present in all fruits but it is not enough to preserve the jam or jelly. In order to preserve the jam or jelly. a higher sugar content is also needed to help the pectin to form a firm gel structure. Usually an equal amount of sugar is added to the fruit
pulp or juice and then any excess water is boiled off to give the
high sugar content.
Acid
Acid is necessary for the 3 purposes. It helps the pectin to set into a firm gel. Acid reacts with some of the sugar so that it will not crystallise when the jamoelly sets. It also helps to give a better flavour as it overcomes the high sweetness of the sugar that is added.
All fruits contain acid but the amount in different fruits varies. Some fruits provide enough acid for a good jarnoelly while others need to have acid added from another source. The acids in fruit are citric acid, malic acid and tartaric acids. These can be added to the jamTJelly in powdered form.
Choices of fruits for jam or jelly
You should note that only few fruits contain a sufficient amount of pectin and acid to produce good jelly or jam. Other fruits may be rich in pectin but low in acid or vice versa. Such inadequacies
can be compensated for by adding commercial pectin and/or acid (lemon juice, citric acid, vinegar).
Always remember that both the pectin and acid decrease as the fruit ripens. You are therefore advised not to use over-ripe fruit as it may result in a very soft gel or no gel at all. You can use a combination of fully ripe and less ripe fruit to get the best results. The under ripe fruit provides pectin and acid and the
mature fruit gives flavour and colour
Fruits are grouped according to their pectin and acid content:
Pectin rich fruits: apples, lemons, partially ripened oranges, pomegranate, cranberries, partially ripened grapes, sour cherries, and melons.
Pectin poor fruits: peaches, strawberries, pineapple, grapefruit, and guavas. Low pectin in these fruits can be compensated for by adding some green apple, apple pectin stock, or orange pectin stock.
High acid fruits: currants, raspberries, apples and grapes. Low acid fruits: pears, peaches, sweet apples, sweet cherries, and melons.
Fruit preparation for making a Jelly
In this section, you will follow the steps in the sample to prepare a fruit product. Wash the fruit and discard any damaged parts. Remove the stem and the ends of the flower. Do not remove skins, piths, seeds and cores as these contain most pectin. You will filter at the end.
Filtering
How to test for the correct consistency of jam and jelly
finger. If it has formed a skin on top that wrinkles a bit when pushed, it is done. If it is still quite liquid and your finger runs right through it, it’s not done yet.
Presenting the steps in processing a fruit product
Activity 5.24
In groups,
Project work: processing and presenting fruits You have learned to process and preserve fruits into various products. You have learned that fruits can either be preserved by drying or by the use of chemicals. You are now going to apply skills you acquired in fruit processing and preservation to make a product of your choice as an individual. Make sure that you package and label your product to be ready for sell.
Packaging, labelling and pricing fruit product
After processing and preserving fruits, it is important that you ensure safety and long life. This is done through proper packaging. Packaging helps you to keep the product safe from exposure to any agents of spoilage after processing. It is also important that you label the product especially if you are
not going to consume it immediately or if you are packaging it for sell.
Both packaging and labelling helps you to add value to your product as it improves the appearance and more people will be tempted to buy. You need to calculate the amount of money that you used to buy the fruits and other materials used. This will help you to sell the product at a cost that will enable you to
earn some profit.
Project work: processing and preserving fruits
either: Microsoft or chalkboard demonstration.
Sample recipes for processing fruits
Making Jam
Jams and jellies can be made from any fruit or berry, and also from tomatoes, wine, and herbs.
Jam is a mixture ot fruit and sugar made either from fruits that are high in pectin content or with added pectin. The fruit is usually chopped very finely, or crushed.
Jelly is the same as jam except that the cooked fruit has been strained to give a clear spread. Jellies are usually made from fruits high in pectin or with added pectin. In jelly, the fruit contained is in the form of juice. That is why it’s easier to spread. In jam, the fruit contained is in the form of
pulp.
Method
Peel the pineapple and grate or blend the pulp out of it.
method
Method
Method
Orange Squash
Method
Method
Apple and Date Chutney
Method
Tomato Marmalade
Method
Make syrup by combining the preserving sugar with 425ml of water. Bring to the boil and simmer for 10 minutes. Wrap the lemon pips, root ginger and chilli in muslin and place in the boiling syrup with the sliced tomatoes and lemons.
Boil the mixture fast, skimming from time to time until the setting point is achieved. Discard muslin bag.
Add the diced peel. Stir to combine. Put in sterilised jars and cover.
Apple Chutney
Method
Note:
Green mangoes or green tomatoes may be used in the place of apples.
fruits jelly
Method
Line an 8-by-5-inch loaf tin with foil. Oil foil and set aside.
Pour 1 cup of water into a bowl; stir in gelatin and let soften for 5 minutes.
Heat juice and 1/2 cup sugar until sugar is dissolved. Add softened gelatin and stir until melted. Pour mixture into prepared pan. Let it stand at room temperature or refrigerate until firm, about 1 hour.
Unmold jelly slab onto a work surface and cut into I-inch pieces with a large, sharp knife or mini cookie cutters. If desired, roll jellies in more sugar just before serving.
Mixed Fruit Jelly
Method
Measure out the sugar into a container where it is easy to pour.
Pour in a container and place it near. Have a timer handy.
Get the jars and lids ready. Sterilise the jars and lids by heating, for a better seal.
The pan should be large enough for the boiling process so that it doesn’t boil over.
Measure the juice into the pan on the stove, whisk in
powdered pectin until it is thoroughly dissolved. Add margarine.
Increase the temperature to high heat and bring to boil.
When boiling, add the sugar and stir in well until it is dissolved.
Keep stirring until it is boiling rapidly. Let it continue to boil for 1 minute while stirring.
Set the timer for 1 minute or watch the clock, you can go over.
Remove from heat and skim the foam off.
Pour immediately into prepared jars, put lids and rings on and set on a towel, in a dry place with little air flow.
Chutney
It is a spicy mixture of fruits and spices cooked with sugar and vinegar.
How do you know when the chutney is ready?
When the chutney appears thick enough, make a channel with a wooden spoon across its surface. If it leaves a channel imprinted for a few seconds, then it is ready.
How to make chutneys and pickles
Assignment
ASSIGNMENT : LSC S2:Processing and Preservation of Fruits Sample Activity of Integration MARKS : 10 DURATION : 1 week, 3 days