1. AND VEGETABLES
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2. Classifications..
Compositions..
Ascorbic acid Browning..
Selection & Storage..
Post-harvest Changes..
Climacteric & Non..
Changes During Ripening..
Artificial Ripening..
Bitterness Of Fruits..

3. 1. Berries - Any fruit that has its seeds
enclosed in a fleshy pulp.
2. Drupes – Have a single hard stone that
encloses a seed. Also called stone fruits.
3. Citrus – Has high amounts of vitamin C
and fibre.
4. Melons – Have 95% water and 5% sugar
content.
5. Tropical - Cultivated in countries with
warm climate.
6. Pomes - Fleshy fruits having several seed
chambers.
7. Complex - Not from a single mature ovary
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4. 1. Water..
2. Nutritive components..
3. Carbohydrates..
4. Protein & Fat..
5. Vitamins & Minerals..
6. Other acids..
7. Pigments..
8. Flavor compounds..
9. Celluloses & Pectic substances..
10. Polyphenols..
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5.  Forms a major portion of fruits, 75 – 90%.
 Chiefly found in the vacuoles of the plant
cells.
 Contains soluble substances in dissolved
state...
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6.  Sugars
 Salts
 Water-soluble pigments
 Organic acids
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7.  The nutritive value of fruits is largely due to
minerals and vitamins
 Carbohydrates
 Proteins
 Fats
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8.  Both soluble and insoluble
 Fructose
 Primary soluble sugar
 Complex Carbohydrates..
 Contribute to the roughage content.
* Sugar content 2–20g/110gms
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9.  Polysaccharide - A carbohydrate whose molecules
consist of a number of sugar molecules bonded together.
 Celluloses - An insoluble substance that is the main
constituent of plant cell walls and of vegetable fibers.
 Hemicelluloses - Any of several polysaccharides that
are more complex than a sugar and less complex than
cellulose.
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10.  Avocado – has fat content of about 28%.The
fat in avocados is primarily mono-
unsaturated fat, which is associated with a
heart-healthy diet.
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11.  Most important nutritional aspect of fruits.
1. Vitamin C – main vitamin
 Citrus fruits – rich in ascorbic acid.
2. B-carotene precursor of Vitamin A
 Yellow-orange fruits
 Excellent source: Alphonso Mangoes
3. Vitamin B – occur in low concentration in
fruits
4. Iron
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12.  Malic acid
 Citric acid
 Tartaric acid
 Oxalic acid
Constituents of most fruits.
Grapes are excellent sources.
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13.  Major Pigments..
 2 Most Important Pigments..
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14. Pigments Colors Fruit examples
Chlorophyll Green Country apples,
Guava, unripe fruits
Carotenoids Yellow-orange Mango, Jackfruit,
Papaya, Peaches,
Pineapple
Lycopene Red-orange Tomatoes
Anthocyanins Purple Grapes, Blueberries,
Plums
Anthoxanthins Purplish brown Apple, Gooseberry,
Pears, Custard apple
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15. Carotenoids Anthocyanins
Yellow-orange Purple, brown
Insoluble in water Soluble
Not affected by acid/alkali Change color on reacting with
alkali
Mangoes, orange, papaya Grapes, blueberries
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Anthocyanins’ Property: react with metal iron and release acids
which further erode the cans making holes called PINHOLES
that: Favor microbial growth
Reduces quality
E.g. Production of white wines
Sodium Metabisulphite – Causes bleaching of pigment.
Sodium Benzoate – used as preservative

16.  Are imparted by:
1. Sugars
2. Tannins - substances obtained from bark and fruit of many
plants, used as an astringent.
3. Mineral salts
4. Volatile compounds
 Aldehydes – Obtained by oxidation of primary alcohols.
 Ketones – Poisonous acidic chemicals produced by the body
when fat instead of glucose is burned for energy.
 Esters - Correspond to the inorganic salts.
 Acids - are characterized by a sour taste.
 Alcohols - Colorless volatile flammable liquids that are the
intoxicating constituent of wine, beer, etc.
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17.  Pectic substances – act as cementing substances between
cells.
FORMS STAGES
Propectin Unripe
Pectin / Pectinic acid Ripe
Pectic acid Overripe
Propectin – imparts fruits’ firm texture and framework
Pectin – the pectin substance when only a limited amount of
degradation occured; becomes Pectinic as the degradation
continues.
Pectic - does not have the gel-forming ability.
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18.  Responsible for the astringency & tart taste
of fruits...
 Responsible for the dark color and rusting
smell of canned foods...
 Responsible for enzymatic browning...

19. E.g. Wines, apple ciders, fruit juices
 Flavanols – causes the feeling of puckering/tightening
of mouth after consuming strong ciders or wines.
*ciders - fermented alcoholic beverage made from fruit
juice.
 Protein-phenolic polymer interaction – causes hazy
precipitate in beer / wine.
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20.  The lower the polyphenolic content, the
lower will the astringency be.
 Therefore, unripe fruits taste more
astringent & bitter than ripe ones.
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21. Causative
Essential Factors:
1. Oxygen
2. Presence of enzyme in
active form
3. Optimum pH 6 and 7
4. Optimum temp. 43ºC to
50ºC.
Preventive methods:
1. Blanching - is a cooking process
wherein the food is plunged into
boiling water then plunged into iced
water.
2. Alteration of pH – adding citric
acid or malic acid.
3. Cutting off the oxygen supply
Ways: a. Dip cut fruit in fluid
b. Covering with a wet cloth
c. Sprinkling sugar/salt
d. Packaging in vacuum
4. Using reducing agents &
antioxidants:
sulphurdioxide, sulphites, &
bisulphites also preserves ascorbic
acid level.
E.g. Pineapple juice
is a chemical process
which occurs in fruits and
vegetables which results in
brown pigments.
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22.  Brown discoloration in fruit
juices, concentrates & canned vegetables.
 Due to the reaction between ascorbic acid &
amino acid.
 The changes in theforms are due to ripening
& under the influence of heat which
deisintegrate the tissue of fruits.
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23.  Selection critera: Quality & Quantity
1. Since they are perishables, selection should
be made on use basis.
2. Clean, fresh, firm, and bright fruits.
3. Overripe fruits should not be selected.
4. Fruits with off aroma should not be
selected.
5. The best time for a particular fruit is its
season.
6. Purchase single fruit than amounts of large
quantity.
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24.  Storage cardinal rule:
Store fruits for short periods or
else, spoilage is inevitable because even
after plucking a fruit, physiological changes
take place.
 Don’t store for more than 3 to 5 days.
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25.  Are the changes occuring once they have
been harvested & plucked.
Unripe stage > Ripe > Harvested >
Fleshy tissues mature & ripen further >
Senscence
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26. Climacteric:
 Respiration rate reaches maximum just
before senescence.
 Have the ability to ripe after harvesting.
 Peaches, mangoes, pears, papaya, apricot,
apples, banana, tomato, plum
Nonclimacteric:
 Best when ripened before harvesting.
 Grapes, citrus, melons, pineapple,
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27. 1. Color changes – green to yellow-orange, red
2. Softening – firm/tough to soft
3. Decrease of acidity, increase of sugar
content, increase of volatile substances
4. Decrease of starch content as sugar
increases
5. Development in astringent property
6. Development in pleasant flavor
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28.  Also called as Induced Ripening / Smoking
 Exposure to artificial inducers like:
ethylene gas
calcium carbide
smoke
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29.  This is due to the presence of 2 classes of compounds:
1. Limoninoids – aka Triterpenes
- bitter taste & astringence of citrus fruits.
Formed when:
 fruit is cut & exposed
 Citrus fruits are heated
2. Flavonoids – present in grapefruit.
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