Food & Technology . FRUITS. Origin. A fruit is the edible part of a plant that contains a seed or the matured ovary of a flower. Fruits are defined botanically as “the matured ovaries of flowers”. Structure. Fruits have 3 sections – the skin, the flesh and the seeds.
The Process of photosynthesis flavours and are generally sweet in taste.
The green pigment in plants (called chlorophyll) uses carbon dioxide in the atmosphere, energy from sunlight and water to produce carbohydrates for energy for growth. The carbohydrate is stored in the fruits we eat.
Pigments underneath and in the skin of fruit break down, causing a colour change. An example is where apples change colour.
The edible pulp surrounding the seed becomes soft and tender as the water content increases.
The starch present converts to sugar, causing the flavour to become sweeter
A fuller and more distinctive aroma develops on ripening
Apples are a good source of fibre & vitamin C
Pears - soft, tender flesh, sweet flavour
Examples – oranges, grapefruit, lemons, cumquats, limes, mandarins
Physical – Firm, thick, lightly dimpled skin present in most varieties. Colours range from green (limes) to orange (mandarin, orange) and yellow (grapefruit, lemon. Internally, made up of juicy flesh that separates into membrane covered segments.
Chemical-good source of vitamins (particularly Vit C) as well as minerals & dietary fibre. Citric acid present.
Sensory– flavour can range from acidic to tangy and reasonably sweet, depending on type of fruit.
Storage – Store at room temperature for about 5 days when the weather is cool to mild but best to refrigerate in hot weather for extended storage time.
Examples – strawberries, raspberries, loganberries, blackberries
Physical – Some (eg raspberries) are clusters of a number of small fruits, each tiny segment is a dupe or juice filled sac. With strawberries, what appear to be seeds on the surface are actually individual fruits (achenes) containing a single seed. Blueberries and cranberries are single fruits formed from the plant’s ovaries.
Chemical-Berries are good sources of Vitamin C, potassium, iron and fibre.
Sensory– . Most have firm flesh and a sweet to slightly tart taste. Their flavour is best when served at room temperature.
Storage – Store in the refrigerator , but wash them just before eating.
Examples – Grapes, passionfruit, kiwi fruit
PROPERTIES - GRAPES
Physical – small, oval shaped fruit, most containing a seed. Colour ranges from green to pale yellow and purple.
Chemical- Provide fibre, Vitamin C sugar, potassium & iron.
Sensory– sweet flavour. Texture is smooth, often crisp outer skin, smooth inside.
Storage – need to be stored in the refrigerator
PROPERTIES – PASSIONFRUIT
Physical – round or oval in shape, outer skin is leathery purple-brownish colour and wrinkles when fruit is completely ripe. Inside contains translucent orange pulp and small black seeds.
Chemical- contains Vitamins A & C, also a good source of fibre
Sensory– fragrant aroma, sour-sweet flavour
Storage – store at room temperature
STONE FRUIT -
Examples - peaches, nectarines, apricots, cherries, plums
Physical – round shaped fruit, size varies depending on type. All have juicy, soft flesh surrounding a stone that contains a seed. Some (such as cherries, nectarines & plums) have smooth skin while peaches and apricots have a ‘downy’ velvety skin. Colours range from red or blue to yellow or orange depending on type.
Chemical- yellow types rich in Vitamin A and often C (eg. apricots)
Sensory– juicy flesh is generally sweet, plums are more acidic in flavour. Flavour is best when served at room temperature.
Storage – place in the refrigerator for three to five days.
Examples - cantaloupe, honeydew, watermelon
Physical - oval or ball shaped, all have a firm outer shell. Flesh comes in a range of colours, depending on the type. Watermelon has a bright pink flesh with medium black oval shaped seeds scattered throughout (unless a seedless variety) cantaloupe has many small, pale coloured contained in the centre surrounded by the orange flesh.
Chemical- cantaloupe are a good source of vitamin A, watermelon is low in kilojoules and an excellent source of Vitamin C
Sensory– Flesh of most are firm and juicy. Sweet flavour. Subtle sweet aroma.
Storage – Can store at room temperature for several days.
Securely cover cantaloupe if placed in the fridge so the aroma doesn’t contaminate other foods.
Examples – bananas, pineapples, mangoes,
Physical – vary greatly in shape, size & colour.
Chemical–Bananas – high starch content before they are ripe, after ripening they are high sugar content. They are also a good source of potassium, mangoes - rich in vitamins, particularly A & C
Sensory- most are aromatic, mangoes have a soft, almost buttery texture. Sweet flavour and a distinctive perfume.
Storage- bananas best stored at room temperature. Pineapple are best eaten soon after purchase and covered if they are put in the fridge due to their strong flavour.
During cooking, the cell walls of the fruit become tender as water passes through the cell membranes, causing the cell walls to swell and burst. As a result, the fruit loses its shape and the pulp becomes soft
If sugar is added when cooking, it strengthens the structure of the fruit and helps to retain the shape.
Applying heat causes some pigment changes and some loss of colour occurs
Changes in flavour occur as the naturally occurring sugars in the fruit begin to caramelise.
The nutrient content is affected – for instance, vitamin C is lost due to its sensitivity to heat and exposure to oxygen.