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Healthy eating on a plate: eating for health made simple Module 3 – Cooking and Processing Methods, June 2013 Page | i Module 3: Cooking and Processing Methods

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Healthy eating on a plate: eating for health made simple

Module 3 – Cooking and Processing Methods, June 2013 P a g e | i

Module 3: Cooking and Processing Methods

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Healthy eating on a plate: eating for health made simple

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Contents

Module 3: Cooking and Processing Methods .................................................................................... 1

Learning Outcomes ........................................................................................................................... 1

Key Message: .................................................................................................................................... 1

Checklist for session .......................................................................................................................... 1

Session outline: Cooking and Processing Methods ........................................................................... 2

Presenter notes for Module 3: Cooking and Processing Methods .................................................... 3

Which has more vitamins, frozen, canned or fresh? ......................................................................... 3

Fresh versus frozen or canned .......................................................................................................... 5

Reducing vitamin loss ....................................................................................................................... 6

Evaluation ......................................................................................................................................... 8

Group discussion & evaluation ......................................................................................................... 8

Fact sheet.......................................................................................................................................... 8

Website resources: ........................................................................................................................... 9

Appendix A – Resources ………………………………………………………………………………………………………10

Activity Sheet – ‘Circle the best choices to save vitamins’ Activity Sheet - Answers – ‘Circle the best choices to save vitamins’ Fact sheet – ‘Simple ways to reduce vitamin loss’ Appendix B – Script and flashcards…………………………………………………………………………….………14

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Module 3: Cooking and Processing Methods

The best value for money is still to buy fresh produce in season, however depending on how the produce is handled; it may not retain many vitamins by the time it gets to the table. In Australia, modern processing practices, means that produce is canned or frozen very quickly after harvesting. The freshness of the produce when it is frozen or canned offsets to a large degree losses during the canning and freezing process. This module steps participants through practical ways to preserve vitamins when storing, handling and preparing food in the home. Learning Outcomes: By the end of the session participants will be able to:

• Understand how different food processing methods (frozen, canned, fresh) affect the vitamin content of food

• Identify practical ways to prepare fruit and vegetables that will prevent vitamin loss during food preparation and cooking.

Key Messages:

• Buying fruit and vegetables in season is the best value for money • Frozen and canned fruit and vegetables are good alternatives if fresh produce is unavailable.

Checklist for session:

• Script and flashcard set for Module 3: Cooking and Processing Methods • Knife and cutting board • A fresh fruit or vegetable that will brown easily when cut (e.g. an apple) • Lemon juice (about 1 teaspoon) • Pot and access to a stove (this can be done ahead of time) • 2 x clear containers suitable to pour hot water into (this can be done ahead of time) • A vegetable that will lose colour quickly when boiled (e.g. broccoli, carrot) • Plastic milk carton • Activity sheet - ‘Circle the best choices to save vitamins’ • Answer sheet – ‘Circle the best choices to save vitamins’ • Factsheet - ‘Simple ways to reduce vitamin loss’ • Pens

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Session outline: Cooking and Processing Methods

Activity Activity Resources required 2 mins Introduction and overview of the session

• How different processing methods (with an emphasis on canning and freezing) affect the vitamin content of food

• How different cooking methods affect the vitamin content of food • How to prevent vitamin loss when buying, storing and preparing food in the

home.

5 mins Which has more vitamins – frozen, canned or fresh? Discussion points: • What affects the amount of vitamins in food? • Which vitamins are affected most by processing and cooking? • Fresh versus frozen or canned fruit and vegetables • Good reasons to eat a variety of cooked and raw foods

Flashcards: ‘What affects the amount of vitamins in food?’ ‘Fresh, canned or frozen’

10 mins Demonstration Use different visual aids to show how water, light and air affect nutrients: • Fruit goes brown quickly when cut • Nutrient loss in water when vegetables are boiled • Innovations that protect the vitamin content of food (dimples on the top of

a plastic milk carton reflect light and preserves vitamins)

A vegetable that will lose colour quickly when boiled (e.g. broccoli, carrot) Flashcard: ‘Cooking vegetables: boiling vs. steaming’ A fresh fruit or vegetable that will brown easily when cut (e.g. an apple) Flashcard: ‘Preparation of fruit’ Plastic milk carton with dimples on the top Flashcard: ‘Milk’

5mins Reducing vitamin loss Discussion points: • Cooking methods that are quick and use small amounts of water • Simple ways to reduce vitamin loss

Flashcards: ‘Cooking methods’ ‘Simple ways to reduce vitamin loss’

3 mins Recap of main points 5 mins In-class activity

• Participants will complete the activity sheet ‘Circle the best choices to save vitamins’

• Discuss answers as a group. Group discussion: • Discuss what changes participants plan to make at home.

Activity and answer sheets - ‘Circle the best choices to save vitamins’

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Presenter notes for Module 3: Cooking and Processing Methods

Give an overview of what participants can expect to learn during the session. • How different processing methods (with an emphasis on canning and freezing) affect the vitamin

content of food • How different cooking methods affect the vitamin content of food • How to prevent vitamin loss when buying, storing and preparing food in the home.

Display the ‘What affects the amount of vitamins in food’ flashcard

Which has more vitamins, frozen, canned or fresh?

‘What affects the amount of vitamins in food?’ Fruit and vegetables go through many processes on the way to our table and vitamin loss can occur at any stage. The longer the produce takes to get to our tables and the longer it is exposed to the elements the more potential there is for vitamins to be lost. Vitamin loss is affected by:

• heat • light • water • air • time from harvesting to the plate.

Note: minerals (e.g. iron and calcium are not affected)

Which vitamins are affected most by processing and cooking? B-group vitamins and vitamin C are the vitamins most susceptible to heat and light (and therefore transportation, processing and cooking). Some vitamins are affected more than others. These vitamins are termed unstable and include: • Folate • Thiamine (vitamin B12 or cobalamin) • Vitamin C. Other vitamins affected by processing, but not to the same degree include: • Niacin (B3) • Biotin (B7) • Pantothenic acid (vitamin B5) • Vitamin K & D. If food has travelled long distances it can be weeks old before it reaches the table. Vitamin C is a very unstable vitamin and fruit and vegetables can lose up to half of their vitamin C after just one week in the fridge – let alone the time it takes to get to your fridge.

Folate is a B vitamin and gets its name from ‘folium’, which is the Latin word for leaf. It is found in leafy green vegetables, fruit, dried peas and beans. It is an especially important vitamin for pregnant women to ensure the baby develops normally. Folic acid is the synthetic version of this vitamin found in supplements and fortified foods.

Phytochemicals are found in plant foods – grains, fruits and vegetables. (phyto means plant). There are thousands of phytochemicals, but less than 200 have been studied in depth. Those that have been studied have shown many health benefits.

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fertilisers - fertilisers tend to reduce vitamin C

content - even organic ones

milling - when cereals are milled

the husk is removed, which

contains most of the fibre and B-group

vitamins

blanching - fruit and vegetables are

heated very quickly before canning or

freezing, which tends to destroy vitamin C and B-group vitamins

freezing - once a food is frozen there

are no further vitamin losses.

Losses will occur again in the cooking

process

canning - food is heated whilstinside the can to destroy micro-organisms.

High temperatures may affect the foods

appearance and those vitamins

affected by heat will be reduced

dehydrating - drying out foods such as fruit, will

destroy some vitamin C, however concentrate other

nutrients, including fibre

pasteurisation - fruit juice and milk

are heated to destroy organisms.

Some vitamin C may be lost in fruit juice

preparation -peeling and

trimming fruit and vegetables will

reduce vitamins and other nutrients,

such as fibre. Most of the vitamins and fibre lie just under

the skin

cooking - vitamins that dissolve in

water will be lost during cooking.

Reducing the amount of water by

using alternative methods such as grilling, roasting,

steaming, stir-frying and microwaving will reduce these

losses.

Food cycle The way in which food is grown, harvested, stored and prepared will affect its overall nutritional content.

Vitamin C and some of the B-group vitamins are the most susceptible to processing and cooking, however losses can be minimised by using produce soon after it is purchased, scrubbing vegetables instead of peeling them, reducing the amount of water used in cooking (microwave, steam, roast or grill instead of boiling) and cooking foods as quickly as possible.

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Display ‘Fresh, canned or frozen?’ flashcard

Fresh versus frozen or canned

The way fruit and vegetables are processed and cooked can make them safer and more palatable to eat, however there is a perception that frozen and canned foods do not retain as many vitamins as fresh produce. Generally speaking, canned fruit and vegetables will taste and look different to fresh, however vitamin loss is variable. A test conducted by Choice (2007) showed that there was very little difference in the nutrient content of sweet corn, whether it was fresh, canned or frozen. In fact if fresh produce is not stored correctly, it can actually contain less vitamins than canned or frozen varieties. Canning and freezing factories are generally close to where the food is harvested, so the amount of time the food is exposed to the elements is limited. Once a product is frozen or canned, vitamin loss is dramatically slowed down. More vitamins will be lost once the product is cooked. During the canning process, vitamin C will be lost, however the cooking time is very short, so losses are minimised. Good reasons to eat a variety of cooked and raw foods As well as destroying bacteria, cooking can also enhance flavour and break down food so that it is easier to digest. The best way to get a wide variety of nutrients is to eat a wide variety of food. This includes both cooked and raw fruits and vegetables. The body can actually use some nutrients more efficiently when food has been cooked, such as the phytochemical lycopene.

Demonstrate how water, light and air can affect nutrients

Display ‘Cooking vegetables: boiling vs. steaming’ flashcard

• Vegetables - demonstrate the difference in vitamin losses between microwaving and boiling vegetables (carrot or broccoli work well for this demonstration)

o Microwave the vegetable of your choice with very little water o Boil the same vegetable on the stovetop covered with water o Demonstrate how much colour (and vitamins) have been lost in the water when the

vegetable is boiled when compared to microwaving by pouring off the water into a glass.

Cooking the vegetables can be done ahead of time

Lycopene is found in tomatoes and is thought to be protective against heart disease and prostate cancer.

The cooking process makes more lycopene available for the body to use, so canned and cooked tomatoes (including tomato paste) are higher in lycopene than fresh tomatoes.

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Microwaves work by causing the water particles in food to vibrate at very high speeds. The friction caused by the vibration produces heat – so microwaves actually cook from the inside out.

Display ‘Preparation of fruit’ flashcard

• Fruit - demonstrate how quickly exposure to the air will turn fruit brown

o When fruits or vegetables are harvested, they start to deteriorate. This deterioration is sped up once the skin is damaged, cut or exposed to the air in any way

o Cut an apple at the beginning of the session to demonstrate how quickly it starts to deteriorate

NOTE: Putting lemon juice on half of the cut apple will stop the reaction as lemon juice is high in vitamin C. This vitamin is an anti-oxidant (stops oxidisation). Even though apples contain vitamin C, there is not enough to stop the browning reaction by itself.

An apple can be prepared before the session. Put lemon juice on one half to demonstrate the antioxidant effects of vitamin C

Display ‘Milk’ flashcard

• Milk - demonstrate how food producers use innovation to protect the food supply

o Milk used to be sold in clear, glass containers. It is now sold in opaque containers (not clear) so that light cannot pass through the glass. Light can partially destroy vitamins, particularly riboflavin (vitamin B2). Another method used to reflect light (and slow down the loss of vitamins) is the dimpling around the top of some plastic containers.

Reducing vitamin loss

As soon as fruit or vegetables are harvested they begin to deteriorate and lose vitamins. Loses will depend on how long the produce has been exposed to heat, water, air and heat and how long it has been in storage, in transit, sitting on supermarket shelves or in the refrigerator at home.

Display ‘Cooking methods’ flashcard

The longer fruit and vegetables are kept in water or subjected to heat, the more vitamins are likely to be lost. So quick cooking methods that use very little water are the best, such as:

• Steaming • Microwaving • Stir-frying

• Grilling • Roasting

Even if little water is used, if vegetables are over-cooked – that is subjected to heat for too long - the benefits of using a small amount of water will be lost by prolonged exposure to heat. Vegetables should be tender, not soft when cooked.

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Display ‘Simple ways to reduce vitamin losses’ flashcard

As well as cooking vegetables quickly and using small amounts of water, other ways to reduce vitamin losses include: • Washing and scrubbing vegetables instead of peeling off the skin

o Most vitamins are just under the skin and most of the fibre is in the skin as well • Preparing fruit and vegetables as needed

o Sometimes in our busy lives it is necessary to prepare food ahead of time, however soaking pre-cut vegetables in water means losing some of the precious vitamins

• Cutting vegetables into large pieces to cook o The more cuts made in the fruit or vegetable – the more of the surface area is

exposed to air, heat, light and water – and the more vitamins are lost • Using any leftover ‘vegetable water’ in soups, gravies or casseroles

o This is a great way to add back the vitamins that have been leached into the water • Not adding baking soda when cooking vegetables in water

o This is a trick used a few years ago, however we now know that baking soda preserves colour, but destroys vitamins

• Storing ripe fruit in the refrigerator crisper o Fruit can be left at room temperature to ripen, however once ripe it should be

placed in the fridge to slow down the deterioration process. The skin of bananas will go black if they are kept in the fridge, however the flesh is still good to eat

• Buying small amounts of fresh produce and using it soon after purchase o Make sure the produce you buy is fresh. Produce that is colourful and looks fresh

will contain the most vitamins • Choose frozen produce that is free of ice crystals. If the packet is ‘icy’ this may indicate it has

been partially unthawed and re-frozen

Recap main points: • Frozen and canned fruit and vegetables are good alternatives to fresh. Vitamin losses from

canning and freezing are balanced out by the fact they are canned or frozen very soon after harvest

• Eat a variety of fruit and vegetables, including raw and cooked …and remember

• Choose canned fruits in natural juice instead of syrup • Choose canned or frozen vegetables with no added salt if possible These last two points don’t influence vitamin loss, but are healthier choices.

Distribute ‘Circle the best choices to save vitamins’ activity sheet to participants

Give participants enough time to complete the activity sheet and then go through the answers. Clarify any points and collect the sheets. Make a note of how many participants completed the activity sheet correctly.

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Evaluation

Group discussion & evaluation

• What will you take away from today’s session? • Do you feel more confident about how to prepare foods in a way that reduces vitamin loss,

than you were before? • What changes, if any, do you plan to make as a result of today’s session?

Make notes of comments throughout the session and questions asked during completion of the activity sheet and during the demonstration An overall evaluation will be conducted at the end of all the sessions. Fact sheet

• Distribute ‘Simple ways to reduce vitamin loss’

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Website resources:

Better Health Channel, http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Food_processing_and_nutrition ‘Food processing and nutrition’. This website is funded by the State Government of Victoria and provides easy to understand factsheets on a wide range of health issues. This fact sheet summarises how the vitamins in food may be affected by food processing. Choice, http://www.choice.com.au/reviews-and-tests/food-and-health/food-and-drink/nutrition/are-fresh-vegies-better.aspx . Are fresh veggies better? Choice is an independent organisation that advocates for consumer rights. This article presents data from tests that Choice conducted on a range of vegetables comparing canned, frozen and fresh to see which vitamins were affected during processing and storage.

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Appendix A Resources

Module 3: Cooking and processing methods

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Circle the best choices to save vitamins

Scrubbing vegetables or peeling them? Cutting fruit as needed or preparing in advance?

Boiling vegetables or steaming them? Cooking vegetables for a long time or a short time?

Storing ripe fruit in the fridge crisper or storing ripe fruit in a bowl? Cutting vegetables into smaller pieces or larger pieces to cook?

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Answer sheet - Circle the best choices to save vitamins

Scrubbing vegetables or peeling them? Most of the vitamins are just under the skin of fruit and vegetables and the skin is where most of the fibre is.

Cutting fruit as needed or preparing in advance? The longer fruit is exposed to air and light the quicker it deteriorates and loses vitamins

Boiling vegetables or steaming them? More water means more opportunity for precious vitamins to end up in the water – an down the drain! Any water from cooking can be used in gravies, casseroles or soups.

Cooking vegetables for a long time or a short time? The longer fruit and vegetables are cooked the longer the exposure to water and heat – and the more vitamins are lost

Storing ripe fruit in the fridge crisper or storing ripe fruit in a bowl? Fruit can be stored in a bowl until it is ripe, however once ripe it should be placed in the crisper

in the fridge to slow down the deterioration process and minimise exposure to light, heat and air.

Cutting vegetables into smaller pieces or larger pieces to cook? The more cuts that are made the greater the surface area of the fruit or vegetable is exposed to air and light and potentially water while cooking, which means more vitamins are lost.

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Vitamins are essential for good health and one of the best sources of vitamins is fruit and vegetables. However, it is important to remember that as soon as fruit and vegetables are picked (harvested), they begin to deteriorate and lose vitamins. The way in which fruit and vegetables are processed (including how they are stored, handled and cooked at home) after they are harvested can influence how much of the vitamins are still in the food once they reach the table. To make the most of fruit and vegetables, they need to be prepared and stored in a way that slows down the loss of vitamins. This means reducing the amount of time they are exposed to heat, water, air and light. Make the most of your fruit and vegetables by:

1. Reducing the cooking time - fruit and vegetables should be tender not soft 2. Using small amounts of water – steaming or microwaving are the best methods

− roasting or grilling vegetables are also good alternatives to boiling 3. Washing and scrubbing vegetables instead of peeling off the skin

− along with the vitamins and the fibre 4. Preparing fruit and vegetables as needed

− and avoiding soaking pre-cut vegetables in water 5. Cutting vegetables into large pieces to cook 6. Using any leftover ‘vegetable water’ in soups, gravies or casseroles 7. Not adding baking soda to cooking water

− Baking soda preserves colour, but destroys vitamins 8. Storing ripe fruit in the refrigerator crisper 9. Buying small amounts of fresh produce and using soon after purchase.

…and remember • Frozen and canned fruit and vegetables are good alternatives to fresh • Choose canned or frozen vegetables with no added salt if possible • Choose canned fruits in natural juice instead of syrup • Eat a variety of fruit and vegetables, including raw and cooked.

Simple ways to reduce vitamin loss

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Appendix B Script & flashcards

Module 3: Cooking and processing methods

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Script for Module3: Cooking and Processing Methods

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Today we are going to be talking about cooking and processing methods. We’ll be looking at:

• How different food processing methods (frozen, canned, fresh) affect the vitamin content of fruit and vegetables

• Practical ways to prepare fruit and vegetables that prevent vitamin loss during food preparation and cooking • Nutritious alternatives when fresh fruit and vegetables are not available

Food processing is any process that a food undergoes from the field to the plate. In Australia, almost all food has undergone some sort of process before it is eaten. For example milk is fermented into yoghurt, meat is dissected and vegetables are washed.

Food is processed for a variety of reasons including:

o To make it last longer (e.g. canned or frozen food) o To kill bacteria or germs (e.g. pasteurising milk) o To change the flavour, texture or colour of the food (e.g. homogenising milk, so the fat doesn’t rise to the top) o To reduce preparation time (e.g. cutting raw oats into smaller bits that cook quicker) o To restore or raise the nutrient level of food (e.g. vitamins added back to bread)

Food processing can impact on the amount of vitamins in food. Particularly foods that contain vitamins that are more susceptible to food processing – like fruit and vegetables. Today we are going to discuss ways to reduce the amount of vitamins lost, so that we get the most out of our food.

Module 3 Cooking and Processing

Methods

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Module 3 Cooking and Processing

Methods

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Script for Module3: Cooking and Processing Methods

Page 2

‘What affects the amount of vitamins in fruit and vegetables?’

Fruit and vegetables go through many processes on the way to our table and vitamin loss can occur at any stage. The longer the fruit and vegetables take to get to our tables and the longer it is exposed to the elements the more potential there is for vitamins to be lost. Vitamin loss is affected by: • heat • light • water • air • time from harvesting to the plate.

Note: minerals (e.g. iron and calcium are not affected)

B-group vitamins and vitamin C are the vitamins most susceptible to heat and light ( and therefore transportation, processing and cooking).

If food has travelled long distances it can be weeks old before it reaches the table. Vitamin C is a very unstable vitamin and fruit and vegetables can lose up to half of their vitamin C after just one week in the fridge – let alone the time it takes to get the food to your fridge.

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What affects the amount of vitamins in food?

Page 3

Light Water Air Heat

Time on the shelf Time being transported

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Script for Module3: Cooking and Processing Methods

Page 3

Which has more vitamins, frozen, canned or fresh?

The way fruit and vegetables are processed and cooked can make them safer and more pleasant to eat, however many people think that frozen and canned foods don’t have as many vitamins as fresh fruit and vegetables.

Generally speaking, canned fruit and vegetables will taste and look different to fresh, however the vitamin content can vary. For example, tests show that there is very little difference in the vitamin content of sweet corn, whether it is fresh, canned or frozen. In fact if fresh sweet corn is not stored correctly, it can actually contain less vitamins than canned or frozen varieties

Canning and freezing factories are generally close to where the food is harvested, so the amount of time the food is exposed to heat and light is limited. Once a food is frozen or canned, vitamin loss slows down dramatically – and then vitamins are lost again once the produce is thawed or cooked.

During the canning process, vitamin C will be lost, however because this process is very short, the losses are small.

Good reasons to eat a variety of cooked and raw foods

As well as destroying bacteria, cooking can also make food taste better (for example cooking potatoes) and start the process of breaking down the food so that it is easier to digest.

It’s a good idea to eat a wide variety of foods to get a wide variety of nutrients. This includes both cooked and raw fruits and vegetables. Sometimes nutrients are trapped in food and cooking them allows the body to use them better.

For example tomatoes contain a substance called lycopene that has been shown to protect against some cancers – lycopene can actually be used by the body better when tomatoes have been cooked (canned tomatoes, tomato sauce, tomato paste)

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Fresh, canned or frozen?

Page 4

Canning – overall cooking time is less (salt may be added)

Frozen or canned within a few hours of harvesting

Freezing – stops any further loss of vitamins

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Script for Module3: Cooking and Processing Methods

Page 4

How does water affects vitamin loss?

Sometimes you can see how vitamins are lost during preparation and cooking. Different cooking methods can lead to more vitamin loss than others.

Firstly, let’s look at how water affects vitamin loss.

(**hold up vegetables that have been boiled**)

These vegetables have been boiled on the stove in a pot of water for about 10 to 15 minutes.

(**pour water from boiled veg into a clear glass and show to participants**)

If you look at the water you will see that it is quite strongly coloured. When vegetables lose colour they also lose vitamins.

(**hold up the vegetables that have been steamed in the microwave**)

These vegetables have been steamed in a small amount of water in the microwave for about three minutes.

(** pour water from steamed veg into clear glass and show to participants**)

Notice how there is less water and not as much colour (and therefore vitamins) have been lost in the water using this method.

Demonstration

Vitamins leaching from vegetables

Demonstrate how water, light and air can affect nutrients

• Vegetables - demonstrate the difference in vitamin losses between microwaving and boiling vegetables (carrot or broccoli work well for this demonstration) o Microwave the vegetable of your choice

with very little water o Boil the same vegetable on the stovetop

covered with water o Demonstrate how much colour (and

vitamins) have been lost in the water when the vegetable is boiled compared to microwaving by pouring the water into a heatproof glass container.

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Cooking vegetables: boiling vs. steaming

Page 5

Less water

Shorter cooking time

Less leaching of vitamins

More water

Longer cooking time

More leaching of vitamins

Boiling

Steaming

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Script for Module3: Cooking and Processing Methods

Page 5

How does air affect vitamins?

As we mentioned earlier, exposure to air is one of the factors that affects the amount of vitamins in our food. Once the skin of fruit and vegetables is cut the flesh is exposed to air and this starts the food deteriorating – and losing vitamins.

(**hold up the apple (or whatever you have decided to use) that was cut at the beginning of the session**)

This apple was cut at the beginning of the session. Notice how the flesh has turned brown? This is because the air has reacted with substances in the fruit and caused it to go brown. This process is call oxidisation. As the fruit turns brown, vitamins are also being lost. Vitamin C will stop the browning process – so the fresher the apple and the more vitamin C it contains – the slower this process will be – because vitamin C is an anti-oxidant.

• It is best to cut fruit and vegetables just before eating or cooking them to reduce the amount of time they are exposed to the air.

• If you are preparing fruit ahead of time, squeeze some citrus juice such as lemon or orange juice on it. The extra vitamin C in the lemon or oranges will help slow down the oxidation or browning process.

Demonstration

How air affects the vitamins in fruit

An apple can be prepared before the session. Put lemon juice on one half to demonstrate the anti-oxidant effects of vitamin C • Fruit - demonstrate how quickly exposure to the

air will turn fruit brown o When fruit or vegetables are harvested, they

start to deteriorate. This deterioration is sped up once the skin is damaged, cut or exposed to the air in any way

o Cut an apple at the beginning of the session to demonstrate how quickly it starts to deteriorate

NOTE: Putting lemon juice on half of the cut apple will slow down the reaction as lemon juice is high in vitamin C. This vitamin is an anti-oxidant (stops oxidisation). Even though apples contain vitamin C, there is not enough to stop the browning reaction by itself.

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Preparation of fruit

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Prepared prior to eating Cut just before eating

• Flesh exposed to the air over a period of time

• Browning of flesh due to oxidation

• More vitamin loss

• Flesh received minimal exposure to air

• Flesh is not brown • More vitamins

Fresh fruit

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Script for Module3: Cooking and Processing Methods

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How does light affect vitamins?

Food producers are constantly trying to find ways to improve the food we eat and stop vitamins from being lost.

Milk is an example of this. It used to be sold in clear, glass containers. It is now sold in opaque containers (not clear) so that light cannot pass through. This is because some of the vitamins that milk contains can easily be destroyed by light, such as vitamin B2 (riboflavin).

(** hold up the milk container and highlight that it is not clear and that is has dimpling around the top to reflect the light**)

Some milk is also produced in plastic containers with dimpling around the top. The dimpling is designed to reflect light and therefore slow down vitamin loss.

Demonstration How light affects vitamins and why

milk containers are dimpled

Milk - demonstrate how food producers use innovation to protect the food supply

o Show 2 litre milk containers with the dimpling around the top.

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Milk

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Milk was previously packaged in glass containers. It was often delivered and left outside.

Milk is now either packaged in cardboard cartons or opaque (not clear) plastic containers.

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Script for Module3: Cooking and Processing Methods

Page 7

How do microwaves work?

They cause the water particles in food to vibrate at very high speeds. The friction caused by the vibration produces heat – so microwaves actually cook from the inside out.

Reducing vitamin loss

Remember that as soon as fruit or vegetables are harvested (picked) they begin to deteriorate. The greater the

length of time fruit and vegetables are in storage, in transit and sit on supermarket shelves, the greater the vitamin losses.

Whilst these conditions are out of our control, once we have purchased the fruit and vegetables there are things that we can do

to minimise vitamin loss. For example, there are certain cooking methods that reduce vitamin loss.

Cooking methods which are quick and that use very little water are the best, such as:

• Grilling • Microwaving • Steaming • Roasting • Stir-frying

Even if a little water is used, if vegetables are over-cooked – that is subjected to heat for

longer than necessary - the benefits of using a small amount of water will be lost as heat also

destroys vitamins – this is why it is best to use quick methods as well as those that use little

water.

Remember - vegetables should be tender, not soft and mushy when cooked.

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Cooking methods

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Grilling Roasting

Microwaving

Stir-frying

Steaming

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Script for Module3: Cooking and Processing Methods

Page 8

As well as cooking vegetables quickly and using small amounts of water, other ways to reduce vitamin losses include: • Washing and scrubbing vegetables instead of peeling off the skin

• Most vitamins are just under the skin and most of the fibre is in the skin as well • Preparing fruit and vegetables as needed

• Sometimes in our busy lives it is necessary to prepare food ahead of time, however soaking pre-cut vegetables in water means losing some of the precious vitamins

• Cutting vegetables into large pieces to cook • The more cuts made – the more of the surface area of the vegetable is exposed to air, heat, light and water – and the

more vitamins are lost • Using any leftover ‘vegetable water’ in soups, gravies or casseroles

• This is a great way to add back the vitamins that have been leached into the water • Not adding baking soda when cooking vegetables

• This is a trick used a few years ago, however we now know that baking soda preserves colour, but destroys vitamins • Storing ripe fruit in the refrigerator crisper

• Fruit can be left at room temperature to ripen, however once ripe it should be placed in the fridge to slow down the deterioration process. The skin of bananas will go black if they are kept in the fridge, however the flesh is still good to eat

• Buying small amounts of fresh produce and using it soon after purchase • Make sure the produce you buy is fresh. Produce that is colourful and looks fresh will contain the most vitamins.

• Choose frozen produce that is free of ice crystals. If the packet is ‘icy’ this may indicate it has been partially unthawed and re-frozen – and vitamins have been lost.

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Simple ways to reduce vitamin loss

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Swap long for short cooking times – less heat

Swap peeling for scrubbing – more fibre and vitamins

Swap small pieces for large pieces – less exposure to the air

Swap boiling for steaming, roasting or grilling – less water

Add any ‘vegetable water’ to soups, gravies or casseroles

Brightly coloured fresh produce will have more vitamins than produce that looks old

Prepare fruit and vegetables as needed – less exposure to the air

Store ripe fruit and vegetables in the refrigerator – less exposure to light and heat

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Script for Module3: Cooking and Processing Methods

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Explain the activity sheet to participants.

Circle the preparation method that will preserve the most vitamins Give participants them about 3 minutes to

complete the activity and then discuss the answers as a group.

Recap main points:

• Frozen and canned fruit and vegetables are good alternatives to fresh. Vitamin losses from canning and freezing are balanced out by the fact they are canned or frozen very soon after harvest

• Eat a variety of fruit and vegetables, including raw and cooked

…and remember to • Choose canned or frozen vegetables with no added

salt if possible • Choose canned fruits in natural juice instead of syrup

These things don’t affect vitamin loss – but are healthier choices

Distribute activity sheets and factsheet

Group discussion What will you take away from the session?

Do you feel more confident about how to prepare foods in a way that reduces vitamin loss, than you were before?

What changes, if any, do you plan to make as a result of today’s

session?

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Circle the best choices to save vitamins

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Scrubbing vegetables or peeling them? Cutting fruit as needed or preparing in advance?

Boiling vegetables or steaming them? Cooking vegetables for a long time or a short

Storing ripe fruit in the fridge crisper or storing ripe fruit in a bowl?

Cutting vegetables into smaller pieces or larger pieces to cook?

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Script for Module3: Cooking and Processing Methods

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