copyright © 2012-2016 marshall cavendish international (singapore) pte ltd 02 january 2012. chapter...

Copyright © 2012-2016 Marshall Cavendish International (Singapore) Pte Ltd

02 January 2012.

Chapter 13:

Food

Commoditi

es – Fruit

and

Vegetables


02 January 2012.

By the end of this chapter, you will be able to:• identify the different types of fruit and vegetables;• list the nutritional content of fruit and vegetables;• list the ways of choosing fruit and vegetables;• identify ways to minimise the loss of nutrients in fruit and vegetables;• explain how fruit and vegetables are used in cooking.

Learning Outcomes


02 January 2012.

What are the types of fruit?

• Most fruit contain a rich variety of vitamins and mineral. They are also high in dietary fibre and water, and low in fats.

• Fruit are classified into the following groups:- citrus fruit;-tropical fruit;-melon;-pome;-dried fruit;-berry;-drupe.


02 January 2012.

Citrus fruit

- They have an acidic,

tangy, sweet or sour taste.

Tropical fruit

- They are cultivated in

warm countries.

Melon- They have a tough rind

and flesh high in water

content.

Pome- They have

a central core where many seeds are found.

Dried fruit- They

have low water

content.

Berry- They are small and fleshy with

many seeds

inside or on the skin.

Drupe- They have a

fleshy part surrounding the pit.

Types of fruitTypes of fruit


02 January 2012.

What is the nutritional value of fruit?

• The main nutrients found in fruit are stated below:- carbohydrates;- fats;- vitamin A;- vitamin C;- other vitamins;- minerals.

• Fruit is in high dietary fibre and water content


02 January 2012.

Carbohydrates

• The three types of carbohydrates found mostly in fruit are glucose, fructose and sucrose.

• The sugars in fruit provide a good source of instant energy for our body.

• Dried fruit tends to be sweeter than fresh fruit due to the concentrated sugar present.


02 January 2012.

Fats

• Fruit is generally low in fats except for coconuts, olives, avocados and durians.

• Olives, avocados and durians contain mostly monounsaturated fats.

• Coconuts contain mostly saturated fats.

Avocados and coconuts are high in fats


02 January 2012.

Vitamin A• Orange and yellow-coloured fruits such as

peach, apricot and mango are rich in vitamin A in the form of beta-carotene.

Vitamin C• Fruit is an excellent source of vitamin C

especially citrus fruit, kiwi fruit, guava and melon.

• When fruit is processed into jams and canned, most of the vitamin C is lost due to the heat treatment during processing.


02 January 2012.

Other vitamins• Trace amounts of B-group vitamins,

vitamins E and K can be found in a variety of fruit such as berries.

Minerals

• Fruit contains small amounts of minerals such as potassium, phosphorous, calcium, magnesium, manganese, copper and zinc.

• Dried fruit contains small amounts of iron.


02 January 2012.

Dietary fibre and water• Fruit is high in dietary fibre and water

content.

• It is rich in both soluble and insoluble dietary fibre.

• The dietary fibre content can be found on the the skin surface, seeds and cell walls of fruit.

Guavas are high in dietary fibre.


02 January 2012.

How do we choose fruit? • Fresh fruit should:

- have a bright and vibrant colour;- be firm when touched; - not have visible damages caused by insects; - be free of punctures, bruises and decay.

How is fruit used in cooking?

• Fruit can be used:- as a puree to make desserts or jams;- as a garnish to make meals more appealing; - in cooking, including frying, boiling, stewing

and baking; - in salads.


02 January 2012.

What are the effects of heat on fruit?

• When fruit such as pineapple is cooked, the heat softens the cellulose and hemicellulose.

• The pectin in the acidic fruit dissolves in the warm acidic condition, softening the tissues.

• Cooking fruit for a long period of time destroys most of the B-group vitamins and vitamin C.

Apricot and strawberry jam

Fruit tart


02 January 2012.

What are the types of vegetables?

• Vegetables refer to plants or parts of the plants which are edible.

• Vegetables are classified into the following groups:- stems;- tubers;- leaves;- roots;- bulbs- flowers;- fruits.


02 January 2012.

Stems - The part of

the plant which holds up the plant

structure

Tubers- They are

swollen and fleshy stems which grow

underground.

Leaves- The part of

the plant which carries

out photosynthesi

s

Roots- They are

starchy vegetables anchored to the ground.

Bulbs- They are

short, fleshy

underground stems above the

roots which

store food for the leaves.

Flowers

- The flowering

part of the plant which

can be eaten

Fruits- The part

of the plant which is

developed from the

flower but is usually not sweet

Types of vegetablesTypes of vegetables


02 January 2012.

What is the nutritional value of vegetables?

• Apart from tubers and root vegetables, vegetables generally contain small amounts of starches and sugars.

• Most vegetables are low in fats.

• The main nutrients found in vegetables are stated below:- carbohydrates;- vitamins;- minerals;- dietary fibre and water.


02 January 2012.

Carbohydrates

• The three types of carbohydrates found mostly in vegetables are in the form of starch, glucose and fructose.

• Tuber and root vegetables such as potatoes and yam are high in starch.

• Vegetables such as onions, peas and tomatoes contain considerable amounts of fructose and glucose.


02 January 2012.

Vitamins

• Vitamins A and C can be found mostly in bright-coloured vegetables.

• The leaves, stems, bulbs and fruit contain varying amounts of B-group vitamins.

• Small amounts of vitamin E can be found in both leaves and flowers.

• Green leafy vegetables are good sources of vitamin K.


02 January 2012.

Minerals• Vegetables contain varying amounts of:

- calcium;- potassium;- phosphorus;- magnesium;- sulphur;- iron.

Dietary fibre and water• Similar to fruit, vegetables contain high

amounts of dietary fibre and water.


02 January 2012.

How do we choose vegetables?

• When choosing and buying vegetables, they should:- have a strong and rich colour; - be free from insect-eaten holes

and leafy vegetables should be firm and crisp;

- be free from blemishes and signs of sprouting on root vegetables;

- be bought in season to maximise the quality and freshness.

E.g. Avoid buying tomatoes which are bruised.


02 January 2012.

How should vegetables be used in cooking?

• During cooking, the cellulose in vegetables is softened, causing the vegetables to shrink.

• In moist-heat cooking, the starch granules in the vegetables swell and gelatinise.

• Vegetables can be cooked in a variety of ways such as frying, boiling, steaming, stewing and grilling.

E.g. Stir-fried vegetables


02 January 2012.

• The points listed below, are tips on how nutrient loss can be minimised when preparing or cooking vegetables:- ensure that vegetables are fresh;- rinse leafy vegetables gently to prevent

bruising the leaves;- keep the leaves of vegetables intact;- peel the vegetables thinly as most nutrients

are found under the skin surface; - do not soak vegetables in water;- prepare vegetables just before cooking;- cook vegetables in a fairly short time;- boil vegetables in a small amount of water;- serve salads immediately.

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