WHAT IS SPOILAGE? • Spoilage is the process in which food deteriorates to the point in which it is not edible to humans, or its quality of edibility becomes reduced OR • Any change which renders a product unacceptable for human consumption. • Complex event in which a combination of microbial and biochemical activities may interact. • One of the major reason that led to preservation. FACTORS DETERMINING THE SPOILAGE • Microbial colonization depends on – characteristics of product – The way processed – The way stored • Factors are characterized into four: – Intrinsic parameters – Extrinsic parameters – Modes of preservation and processing – Implicit parameters INTRINSIC PARAMETERS • Physical, chemical and structural properties. • Inherent in the food itself. • Important factors include water activity, acidity, redox potential, available nutrients and natural antimicrobial substances. EXTRINSIC PARAMETERS • Factors in the environment where food is stored • Temperature, humidity and atmosphere conditions. MODES OF PRESERVATION AND PROCESSING • Physical or chemical treatment • Change characteristics of food product • Determine the micro flora associated with the product IMPLICIT PARAMETERS OR MICROBIAL INTERFERENCE • These are the result of the development of synergistic or antagonistic microbes • It can be said as the destruction of one organism by another species releasing H2 O2 , bacteriocin and other di-acetyl compounds. • Synergistic: Production or availability of essential nutrients due to the growth of certain organisms, which allow the growth of another group which were otherwise unable to grow. • Antagonistic : Competition for essential nutrients, changes in pH value or redox potential or formation of antimicrobial substances. TYPES OF SPOILAGE Two types of Spoilage: • Microbial spoilage • Non- Microbial Based on rate of spoilage: • Highly perishable – Meat, fish, poultry, eggs, milk, most fruits and vegetables. • Semi perishable – Potatoes, some apple varieties, nutmeats • Stable or non-perishable – Sugar, flour, dry beans SPOILAGE OF FRUITS AND VEGETABLES • The organism responsible for taints are acid tolerant bacteria: – Lactobacillus spp. • Deterioration can be caused by action of animals, birds, bruising, wounding, cutting, freezing, dessication or other mishandling and growth of microorganisms; environmental conditions, contact with spoiled foods. • Microbial spoilage maybe due to: – Plant pathogens acting on stems, leaves, flowers or roots – Saprophytic organisms • Types of spoilages: – Baterial soft rot • Caused by Erwinia carotovora, ferment pectins • Pseudomonas marginalis, Bacillus and Clostridium cause water soaked appearance, a soft, mushy consistency and bad odour. – Anthracnose • Caused by Collectotrichum lindemuthianum. • Spotting of leaves and fruits – Black mold rot • Caused by Aspergillus niger • Dark brown to black masses of spores of the mold termed as smut • Rhizopus soft rot – Caused by species of Rhizopus – Soft and mu

2. Food Spoilage and Micro-organism
Definition
Food spoilage is a
metabolic process that
causes foods to be
undesirable or
unacceptable for human
consumption due to
changes in sensory
characteristics.

3. Food Spoilage Introduction
 Microbial food spoilage occurs as a consequence of
either microbial growth in a food or release of
extracellular and intracellular enzymes in the food
environment.
 A food product is defined as “spoiled” if “sensory
changes make it unacceptable to the consumer ”
 Indications of spoilage include: development of
“off-flavors,” odors, slime/biofilm, color change,
bad taste, or any other characteristic that is
undesirable to the consumer
 Spoilage is usually caused by the decomposition and
formation of metabolites resulting from microbial
growth
 Food capable of spoiling is referred to as
“perishable food”

4. Its Still Good to Eat, Right?
Spoilage is the process in which food deteriorates to
the point in which it is not edible to humans or its
quality of edibility becomes reduced. It involves
any change which renders food unacceptable for
human consumption.
No!

5. Why Do Foods Spoilage?
Foods decompose from the moment they are
harvested due to attacks from enzymes, oxidation
and microorganisms. These include bacteria, mold,
and yeast.
As microbes enzymatically digest the food and use
it for themselves, they produce metabolic by
products – some of these may be health hazards
Spoilage microbes do not have to be pathogenic,
they usually just produce toxic waste
The toxic effects from consuming spoiled food are
referred to as "food poisoning", and more properly
as "foodborne illness”

6. How Can We Identify
Spoilage Foods
Spoilage of food is identified by:
 change in color,
 a change in texture,
 an unpleasant odor,
 or an undesirable taste.
 softening of vegetables, fruits, and slime
production.

7. Where Food Spoilage Can Arise?
Spoilage may arise from:
 insect damage,
 physical damage,
 and indigenous enzyme activity in food
 or by microorganisms (bacteria, viruses, fungi).

8. Factors Cause Food Spoilage
Various factors cause food spoilage:
 making items unsuitable for
consumption.
 Light, oxygen,
 heat, humidity,
 temperature and spoilage bacteria
can all affect both safety and quality
of perishable foods.
When subject to these factors, foods
will gradually deteriorate.

9. When foods are affected by micro-
organisms?
Microorganisms occur everywhere in the
environment, and there is always a risk of
spoilage when foods are exposed to
unsuitable conditions. Microbial spoilage
results from bacteria, molds, and yeast.
While microorganisms may or may not be
harmful, the waste products they produce
when growing on or in food may be
unpleasant to taste.

10. From Where Microbes Inhibits?
The spoilage microbe’s common
inhabitants are soil, water, or the
intestinal tracts of animals or they
are dispersed through the air and
water. Food spoilage by
microorganisms depends upon:
• intrinsic (pH, water activity,
• nutrient content,
• oxidation-reduction potential,
• antimicrobial property)
• and extrinsic factors
(temperature,
• relative humidity,

11. Micro-organisms Effects In Human
o Different spoilage-causing
microorganisms have different
nutrients requirements.
o Microorganisms are the biological
agents that cause foodborne
diseases when consumed however
the microorganisms not only
cause spoilage, some of them are
beneficial for food fermentation.

12. Types Of Micro-organisms In Food