The document provides an overview of fruit and vegetable processing technology, covering definitions, classifications, and essential aspects of harvesting, handling, and storage. It discusses the chemical compositions, processing methods for products like fruit juice and tomato paste, and highlights factors impacting quality and safety. The lecture aims to enable students to understand the importance of these processes in supplying safe, nutritious food throughout the year.

1. Fruit and Vegetable processing
technology
2
Lecturer: Osman Hassan Ali

2. Learning Objectives
• At the end of this Lecture, students should be able to:-
A. Define Fruit and vegetable, Classify them based on different criteria and
their quality and safety attributes
B. Understand important composition (with their respective effect) of Fruit
and vegetable and factors affecting the ripening process
C. Discuss the proper harvesting, handling and storage of Fruit and
vegetable.
D. Explain the production of Fruit juice, tomato paste and tomato ketchup.
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3. 1. Introduction
• Fruits and vegetables,
• the perishable commodities,
• important ingredients in the human dietaries.
• seasonal in nature
• high nutritive value they make significant nutritional contribution to
human well-being.

4. Cont’d
• What is Fruit?
• Fruit is the mature ovaries of plants with their seeds.
• Commonly eaten alone or as a dessert.
• What are Vegetables?
• A vegetable is any edible (eatable) part of a plant that does not
have a role in the plant’s reproductive cycle, such as the roots,
stems, leaves, or flowers.
• Often eaten as part of a main course or a side dish.

5. 2. Classification Of Vegetables
A) Based On Edible Part
• Root crops - carrot, radish, beet, turnip, and sweet potato.
• Stem vegetables -asparagus and potato.
• Leafy crops - lettuce, cabbage, celery, spinach,
• Immature flower buds-cauliflower, broccoli, and artichoke
• Immature fruits -cucumber, okra, sweet corn, and eggplant
• Mature fruits- cucurbits (pumpkin, white gourd, squash,
muskmelon, and watermelon), tomato, and pepper.

6. B) Based On Temperature
• Warm-season crops are adapted to 18~29°C, intolerant to frost and
mostly grown for edible fruits.
• Cool-season vegetables have optimum growth at cooler
temperature and are shallower rooted and smaller sized.
• Asparagus, Brussel sprouts, broccoli, cabbage, celery,
garlic, onion, pea,

7. 3. Classification Of Fruits
A) Depending on shape, cell
structure, and type of seed
• Berries: usually quite small-
• Strawberries, blackberries,
raspberries, blueberries,….
• Citrus fruits : High citric acid
• Sweet limes, oranges,
tangerines, sour oranges,…
• Drupes: Contain single pits-
• Apricot, sweet cherry, peach, plums.

8. Cont’d
• Grapes: Green grapes, black grapes,
seedless grapes.
• Melons: Large and have a tough outer rind
• Musk melon, water melon.
• Pomes : contain many pits-
• Apples, pears.

9. B) Depending on natural habitat
• Temperate-zone Fruits
• Apple, Strawberry …
• Subtropical Fruits
• Orange, Avocado…
• Tropical Fruits-
require warm temperature
• Mango, Banana….

10. 4. Fruit And Vegetable Processing
• The main objective of fruit and vegetable processing is to
Supply, Wholesome, Safe, Nutritious and Acceptable food to consumers
throughout the year.
• Reduce fruit and vegetable losses;
• Replace imported products

11. Cont’d
• The quality of processed fruit products depends on their quality at the
start of processing;
 Maturity at harvest,
 Harvesting methods, and postharvest handling
procedures
 Maintenance in fresh fruits between harvest and process initiation.

12. Cont’d
• Quality attributes of fresh fruits and vegetables include
appearance, texture, flavor, and nutritive value.
• Appearance factors include size, shape, color, and freedom from
defects and decay.
• Texture factors include firmness, crispness, and juiciness.
• Flavor components incorporate sweetness, sourness (acidity),
astringency, bitterness, aroma, and off-flavors.
• Nutritional quality is determined by a fruit’s content of vitamins (A and
C are the most important in fruits), minerals, dietary fiber, carbohydrates,
proteins, and antioxidant phytochemicals (carotenoids, flavonoids, and
other phenolic compounds).

13. Cont’d
• Safety factors that may influence the quality of fresh fruits
include
Residues of Pesticides,
Presence of Heavy Metals,
Mycotoxins Produced By Certain Species of Fungi, and
Microbial Contamination.

14. 5. Chemical Compositions
1. Water-Vegetables contain generally 90-96% water while for
fruit normal water content is between 80 and 90%.
• Contains soluble substances (Sugars, Salts, Water
soluble pigments & Organic Acids)
• Insoluble substances remain as Colloidal
2. Nutritive Components
• Provide plenty of vitamin & minerals
• Poor caloric contribution
• Fruits like bananas give fairly good amount of calories (116
kcal/100g).

15. Cont’d
A. Carbohydrates
• Digestible and indigestible parts (sugars and starches vs pectin
and cellulose material).
• Ripe fruit contains a higher percentage of sugar than unripe fruit
and the sugar is chiefly in the form of sucrose, fructose and glucose.
• Polysaccharides (Cellulose & Hemicellulose)* * Give rough texture to
Fruits

16. Cont’d
B. Proteins & Fats
• Poor source (Except: Avocado -28% Fat)
C. Vitamin & Minerals
• Their important nutritional aspect
• Vitamin A is found in yellow-orange fruits and vegetables and
leafy, green vegetables.
• Vitamin C is found in citrus fruits, tomatoes and green, leafy
vegetables.
• high in minerals such as (iron and calcium)

17. Cont’d
3. Organic Acids
Lower in concentration
Desirable acid-sugar balance-for pleasant taste.
Changes with maturity and affects flavour.
 Sourness property!
Arise as metabolic product of cells
• Most fruits (Citric & Malic acid)
• Grapes are rich in (Tartaric & Oxalic acid)
• Most vegetables contains Acetic acid, Citric
acid, Formic acid,…

18. Cont’d
4) Pigments
• Reason for diversified fruits and vegetables colour
• Fruits may contain individual or a combination of
pigments
• Example: Orange (Carotenoids + Chlorophyll)
• Types (Water soluble (Flavonoids)& Fat soluble pigments)
• Major Pigments in fruits
Pigment Colour Fruits Type
Chlorophyll Green Unripe fruits Fat soluble
Carotenoids Yellow-orange Mango & Papaya Fat soluble
Anthocyanins Red-purple Grapes, blueberries, Water soluble
Carotenoids: the red and orange pigment
 Pre cursor of vitamin A
Chlorophyll: green pigment of leaves

19. Cont’d
5) Flavour Substances
• Flavour is imparted by volatile compounds*
* Aldehydes, Ketones, Esters & Ethers
• Combination of volatile compounds
Unique & desired flavour
• Some fruits contain essential oils which are also important
flavour contributors.
• Some vegetable have strong flavour - Sulphur compounds
• Irritation behaviour of onion-Volatile sulphur compounds

20. Cont’d
6/ Pectic Substances
• derivatives of carbohydrates
• methylated polymer of galacturonic acid.
• Act as cementing substance between cells
• Stages of Pectic substance
• Protopectic-Insoluble molecule
• Present in unripe fruits
• gives firm texture to unripe fruits.
• Pectin (Pectinic acid)-Intermediate compound in ripe fruit
• Pectic Acid- Present in overripe fruits

21. Cont’d
7/ Polyphenols
Polyphenols are phytochemicals
Responsible for astringency & tartaric taste
Protein-phenolic polymer interaction-
complex formation
Hazy precipitation observed in apple juice

22. 8) Enzymes
contain a number of enzymes
can have undesirable or desirable consequences.
a) the post-harvest senescence and spoilage of fruit and vegetables;
b) oxidation of phenolic substances in plant tissues by phenolase (leading
to browning reaction;
• The phenolase changes the phenols into melanin, which has a brown colour.
Fruit cut
parts come in
contact with
air
Release of
Phenol oxidase
on the cut
surface
Oxidation of Phenol
to produce Quinones
in the presence of
polyphenol oxidase &
air
Polymerization
of Quinones to
form brown
pigment
(melanosis) &
discoloration

23. Cont’d
Factors essential for enzymatic browning are
o Presence of Oxygen
o Presence of enzyme in active form
* Optimum condition (T°=40-50°C; pH= 6-7)
 Ways to prevent enzymatic browning
o Cut of oxygen * CAS & MAP
o Inactivate enzymes * Blanching
o Other methods * Alteration of pH, applying
antioxidants & reducing agents

24. Cont’d
c) Starch-sugar conversion in plant tissues by
amylases;(Ripening)
d) post-harvest demethylation of pectic substances in plant
tissues
CONTROL: temperature, water activity, pH, chemicals which
can inhibit enzyme action, alteration of substrates, alteration
of products and pre-processing control.

25. 6. Harvesting, handling and Postharvest changes
• The total time between harvesting and processing may also be an
important factor in maintaining the quality and freshness of
fruit.
• Minimizing the delays.
• Losses in fresh fruits between harvest and processing may be
• quantitative (e.g., water loss, physical injuries, physiological
breakdown, and decay) or
• qualitative (e.g., loss of acidity, flavor, color, and nutritive value).
• proximity of the processing centre

26. Cont’d
• Different harvest regimes for Fruits and vegetables
• Appropriate maturity stage required for optimum quality
• Cellular Respiration continue after harvest i.e. taking in O2
and giving off CO2 , heat and moisture
• mechanical damage during harvesting hastens respiration
rate and spoilage
Fruits continue to
Respire Mature ripen Overripe

27. Maturity Vs Ripeness
• Maturity is the condition when the fruit is ready to eat or, if
picked, will become ready to eat on further ripening.
• Ripeness is that optimum condition when color, flavor and
texture have developed to the peak.
• Some fruits are picked when they are mature but not yet ripe
(e.g. cherries, peaches, banana…).

28. • Ripening: major post harvest
change in fruits
• Ripening pattern vary , 2
categories
• Climacteric ripen after
harvest
• Non Climacteric ripen
before harvest
Climacteric Non-
Climacteric
Apples
Banana
Mango
Peach
Plum
Pawpaw
avocado
Citrus
Cherry
Pineapple
melon
strawberry

29. 6.1 Changes During Ripening
The process of fruit ripening is chiefly regulated by a gaseous
plant hormone called ethylene and different enzymes.
Colour change (Green Yellow Orange Red)
 breakdown of chlorophyll (chlorophyllase).
 Synthesis or exposure of carotenoids and anthocyanin pigments occur
 Softening
(Protopectin Pectic Pectic Acid)
pectic enzymes
hydrolysis of hemicelluloses

30. Cont’d
Increase in
o Sugar content , Volatile substances, Essential oil,
Astringent property,
Decrease in
o Starch content and Acidity
All these changes produce a pleasant flavour.

31. Cont’d
• The optimum temperature and humidity for ripening are
about 20 oC and 90-95 percent relative humidity.
• Ripening of fruits can also be done artificially by smoking.

32. 6.2 Chemical fruit ripening/Artificial Ripening
 Natural process of fruit ripening is accelerated by using certain chemicals.
 Known as Induced ripening
 Mostly applied for Banana & Mango
 Artificial inducers-smoking of
o Ethylene gas
o Calcium Carbide ( for Mango)
o Ethephon

33. • Controlled storage conditions can extend
the shelf life of produce
• Modified atmosphere packaging (MAP):
Principle is to replace the internal
atmosphere of fresh produce by flushing
with nitrogen or carbon dioxide and this
will lead to extension of shelf life
• GMP & GHP + MAP Inhibit spoilage
/ extend shelf life
7. Storage of Fruits and Vegetables

34. • After flushing the material is sealed in
a package to prevent oxygen entry.
• Normal air composition (78%, Nitrogen;
20% oxygen and 0.03% carbon dioxide) is
modified within the package to:
• Reduces respiration
• Retards growth of aerobic organisms
Cont’d

35. • Controlled atmosphere storage(CAS):
• Principle is similar to MA storage involve modification of the gas
composition.
• Reducing oxygen and increasing carbon dioxide in the store
• Combined with low temperature.
• Reducing rate of respiration

36. 8. Range of products
 Jams,
 Fruit Wines
 Marmalades
 Paste
 Purees
 Tomato Sauce
 Jellies,
 Juices,
 Canned products
 Freeze products

37. Fruit Juice Processing

38. Fruit Juice Processing
* Farm / Market * Mature & mould free
* Remove mouldy & badly damaged fruits
* Use potable water
* size & colour
* Peeling & cutting (optional) * Skin & seed separation
* Pre pasteurized (80-90°C for 10-15min); pre sterilized can /bottles
* Filling unpasteurized juice in bottles; Heating (88-90°C for 10-20min)
* Cooling
* Product name, Manufacturer, Composition, PD , BBF, Batch, Prod. Time
* Cool, dry & Protect from light
Inspection
Washing
Fruit Reception
Sorting/Grading
Pulping/Crushing
Pasteurization Filling
Labelling
Storing
• Depending on the type of Juice
• Deaeration
• Centrifugation
• Preservatives

39. Fruit Juice Processing

40. Tomato Ketchup/ Sauce Processing

41. * Inspection (redness, MC, mature, clean, wholesome)
* Size, Colour
* Soaking in water (50°C), remove mud easily
* T°= 55-60°C
* Pulper (skin & seed separation) *Pulp – flesh part
* Vacuum evaporator * 25% or more TSS * Filling in sterilized bottles / cans
TSS: Total Suspended Solid
* No Ingredient Tomato Paste
* Product name, Manufacturer, Composition, PD , BBF, Batch, Prod. Time
* Storage (0-4°C)
Ingredients
Sorting
Soaking & Washing
Tomato Reception
Slicing, Heating & Crashing
Pulping
Cooking & Concentration
Filling & Pasteurization
Labelling & Storing
Formulation

43. Paste
 Made from any Fruit
 Tomato paste is common
 Production procedure
Mashing any fruit to a smooth & thick mixture
Boiling to evaporate water
Mixing by constant stirring to prevent burning
Concentration of solid in final product to 36%
Pasteurize to prolong shelf life