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Fruit and Vegetables

characteristics

Widya Dwi Rukmi Putri 2014

students know and understand the characteristics of fruit and vegetable, and be able to identify the effect of processing on f-v physicochemical properties

Course learning outcomes :

Fruit and vegetable differences

Similarities of fruit & vegetables

High water content > 70-80%

High in carbohydrate content (digestable and indigestable carbohydrate)

Sources of vitamin, mineral and pigments

Low in protein < 3,5% and lipid < 0,5 % contents

Horticultural Commodity

Fruit ◦ Climacteric ◦ Non climacteric

Vegetable ◦ Non climacteric

Flower ◦ Non climacteric

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• Visual appearance (shape, size, color)

• Physical indicator (texture, softness)

• Chemical analysis

• Physiological analysis

Harvest time

indicators

• Appropriate harvest time

• Good handling

• Suitable storage methods

Post harvest quality

Quality of fresh fruit and vegetables

FRUITS

Classification of fruits

Harvest time

•Seasonal fruit •Non seasonal fruit

Climate

• Tropical fruit (tropical temperatures, > 25°C)

• Sub tropical fruit (sub tropical temperature max 22°C)

Respiration pattern

• Climacteric fruit

• Non climacteric fruit

Fruit chemical compositions

Influenced by several factors:

Variety Climatic condition during growth Plant maintainance Harvest methods Maturity level at harvest Storage condition

VEGETABLE

Non climacteric Have a short life compare

to fruit (< 1 year) Non seasonal plants A variety of characteristics

(color, taste, aroma, texture, etc)

Source of vitamin and mineral

VEGETABLE CLASIFICATIONS

PART OF PLANTS

• Roots • Tubers • Stem • leaf • flower • fruit • sprouts

CLIMATE WHERE THE PLANTS GROW

• Tropical climate (temperature ≥25°C)

• Sub tropical climate (temperature max 22°C)

FRUIT AND VEGETABLE TEXTURE

Influenced by turgor pressure of plant cell Turgor pressure are the pressure of the cell

content againts the cell wall Plant cell wall has elastic properties If the content of the cell is reduced (out)

the frut/vegetable will be wilt If the content of the cell is full then the

texture of fruit/vegetable will be tough

FACTORS INFLUENCED CELL TURGOR PRESSURE

1. The concentration of component inside the cell will determine the osmotic pressure

2. Protoplasmic permeability

3. Cell wall elasticity

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Fruit and vegetables nutritional composition Carbohydrates Represent more than 90 % of dry matter Sugar such as glucose, fructose, maltose and sucrose, all share

the following characteristics : - supply energy for nutrition - readily fermented by …… - may used as a preservative - on heating they darken colour .. - combine with … to give dark colour as …

Starches - supply energy in nutrition - firming of plant tissues

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Pectin and carbohydrates gums - in colloidal solution contribute to

viscosity - in solution with sugar and acid are the

basis of jelly

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Cellulose and hemicellulose - act primarily as supporting structures - insoluble in cold and hot water - not digested, not yield energy

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Mineral Substances 0,6 – 1,80 % ( K, Na, Ca, Mg, Fe, Mn, Al, P,

Cl, S) salt of organic acid complex organic combination (chlorophyll,

lecithin, etc) Ca and P essential for calcium fixation

(Ca/P) : 0,7 for adults and 1,0 for children vegetable rich in P and Ca : green bean,

cabbage and onion fruit rich in P and Ca : pears, lemon,

oranges

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Vitamins function as enzyme systems which

facilitate the metabolism Divided into two major groups (fat

soluble and wet soluble) Examples : Vitamin A/ Retinol found in the orange

and yellow fruit/vegetables and green leafy vegetables

Vit C / ascorbic acid and Vit E favours the absorption of iron and easily destroyed by oxidation at high temp.

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Organic acids such as citric acid, malic acid, tartaric

acid, etc these acids gives some function : 1. Fruit tartness and flavour 2. Slow down bacterial spoilage 3. Influence the colour of food

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Pigment sources of colour classified into four major groups :

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Chlorophylls - oil soluble, bound to protein

molecules - C alone is highly unstable (acid

pH) - C changes becoming pheophytin

(on heating), can be protected by addition alkali to the cooking or canning water

Carotenoids - fat soluble

- fairly resistant to heat, change in pH and water leaching

- very sensitive to oxidation

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Flavonoids - water soluble 1. Anthocyanin

shifting of color with pH

violet/blue in alkaline or metal ions

red in acid media 2. Anthoxanthin

pH sensitives deeper yellow (in pH

>8) and whiter yellow (in pH

<6)

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Enzymes biological catalyst promote biochamical reaction Hidrolase (lipase, invertase, tannase, etc) oxidoreductase (peroxide, catalase, etc)

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Some properties : control the reaction

associated of ripening responsible for changing

of flavor, color, texture and nutritional properties

activity of enzyme is characterized by an optimal temp and pH

CONTINUED……

Topic for next meeting :

The effects of processing on fruit and

vegetables characteristics