1. MUTHAYAMMAL COLLEGE OF ARTS
AND SCIENCE
welcome to
contamination, spoilage & preservation of vegetables and
fruits
Submitted To:
Dr.S.Shahithaa
Submitted
By:
Suganthi
Angamuthu
18PAM1048
Msc AMB

2. Synopsis:
 Introduction.
 Contamination of fruits and vegetables.
 Spoilage of fruits and vegetables.
 Involved Microorganisms.
 Preservation of fruits and vegetables.
 Methods of preservation.

3. INTRODUCTION:
All living creatures, including humans, depend on nature for their
food.
 Fruits and vegetables provide an abundant & inexpensive source of
energy, body-building nutrients, vitamins and minerals.
Most of our food consists of agricultural products, which are usually
seasonal and spoil quickly.
Humans are mostly stored fruits and vegetables in refrigerated for
prevention of spoilage.
 Nowadays the rotting process can be postponed by adding
preservatives, optimizing storage condition or applying modern
techniques.

5. CONTAMINATION OF FRUITS AND VEGETABLES
Latin word contaminant - “Made impure”
Contaminate - Pollute
Contaminate something – Impure or Hazardous
Source of Contamination
During harvesting and storage
Mechanical damage during transportation
Soaking, handling, and washing (reused water)
Hot water blanching-add thermophilic bacteria
Inclusion of decayed (mixed with spoiled fruits and
vegetables)
Added ingredients such as sugar, starch-add thermophilic
bacteria

6. • Trimming, peeling, cutting, pitting & coring of spoiled
parts removes micro organism but additional
contamination during handling.
• Spraying with water or packed with chipped ice is
done.
• Sweating of fruits & vegetables during handling.

8. Possible source of contamination in fruits and
vegetables such as
Trays, tanks, aprons,blanchers, filters, pipes, filters,
bins, tables, screens, blets, containers etc..

9. SPOILAGE OF FRUITS AND VEGETABLES:
• The action or process of spoiling of perishable goods.
• Spoiled food- damaged / injured food undesirable for
human consumption.
• Food spoilage causes due to
Physical injury
Enzyme activity
Microbes
Spoiled Fruits and
Vegetables

10. SPOILAGE OF FRUITS AND VEGETABLES
Deterioration of raw vegetables and fruits due to:
 Physical spoilage
Action of their own enzyme
Microbial action
Mechanical damage
Action of animals, birds and insects
Wounding
Bursting
Freezing
Desiccation (drying)
Temperature
Other mishandling

11.  Contact with spoiling fruits and vegetables may
transfer micro organisms & increasing wastages .
 Mostly spoilage occurring due to microbial action such
as bacteria, yeast, & moulds.
 Bacteria & Yeast cannot be seen with the naked eyes.
Bacterial soft rot:
caused by Erwinia caratovora
Pseudomonas,
Clostridium, &
Bacillus sps may also
isolated from these rots

12. Rhizopus soft rots:
Caused by Rhizopus stolonifer
cottony growth of mold with small,
black dots
Rot is often soft and mushy
Black Mold Rot:
Caused by Aspergillus niger
Dark brown to black masses
spores Of the mold termed
“Smut”

13. INVOLVED MICRO ORGANISMS:

14. PRESERVATION OF FRUITS AND VEGETABLES:
• The action of preserving something.
• Food preservation- action of preserving food in order to
maintain it as desirable for human consumption.
• Control temperature and humidity will reduce Mo’s.
• Boxes, lugs, baskets and containers should cleaning &
sanitation during harvesting will reduce from Mo’s
contamination.
• Mo’s removal through washing but leaves much of the natural
normal flora.
• Fruits and vegetable wash with good bacteriological quality
water, it will reduce load of Mo’s.
• Mo’s growth mostly occur on the moisten surface of the fruits &
vegetables.

15. PRESERVATION
Vegetables
 Asepsis
 Removal of micro
organisms.
 Use of heat
 Use of low temperatures
 Chilling
 Hydrocooling
 Freezing
 Drying
 Use Of preservation
 Added preservative
 Preservation by irradiation
Fruits
 Asepsis
 Removal of micro
organisms.
 Use of heat
 Use of low temperatures
 Chilling
 CA storage
 Freezing
 Drying
 Use of preservatives

16. METHODS OF PRESERVATION:
Use of Heat- Inactivate their enzymes & reduce the
multiplication & load of Mo’s.
Use of low temperature- For example Apple, Potatoes can
be preserved for a limited time.
Chilling- Using cold water, ice or mechanical refrigerator or by
vacuum cooling.
-Cold water spray for
precooling after harvesting.
-Each fruits has its
own Optimum temperature
& relative Humidity
for chilling storage.

17. Freezing: During storage in frozen condition, it will
decrease the number of organisms.
-In fruits for freezing, undesirable changes may
takes place such as darkening, deterioration in flavor
& spoilage of micro organisms especially molds.
- For example yeast
(Saccharomyces,
Cryptococcus sps.),
Molds (Aspergillus,
Mucor, Rhizopus sps.) have been
Reported organism in
Frozen fruits.

18. Drying- The number of micro organisms in dried
fruits & vegetables is comparatively low and that
spores of bacteria and molds are likely to be the most
numerous.
- This result in additional loss of water
(dehydrate), but more number a porous network of
capillaries is formed in the
product. The increased
porosity simplifies further
drying and imparts
good reconstituting ability.

19. Use of preservatives- Chemicals have been applied to
fruits chiefly as a dip or spray or impregnated in wrappers for
fruits
-Among substances that have been applied to the outer
surfaces of fruits & vegetables are waxes, hypochlorite’s,
biphenyl, and alkaline sodium o-phenyl phenate.
-Sodium chloride is the only added chemical preservatives
in common use.
-Zinc carbonate eliminate most mold on lettuce, beets,
Biphenyl vapors will control Fusarium sps.