This document discusses food spoilage, which is the process by which food deteriorates and becomes unacceptable for human consumption due to microbial or biochemical changes. It identifies several factors that influence spoilage, including intrinsic properties of the food itself as well as extrinsic environmental conditions. Specific examples of spoilage are provided for various foods like bread, sugar, honey, maple syrup and candies. Microbial growth and activities like production of gases or pigments are identified as primary causes of spoilage in different foods. Maintaining proper moisture levels and packaging are emphasized as ways to prevent or delay spoilage.

1.  Submitted to- Dr Neha Batra
 Submitted by –Muskan Bhardwaj Bsc(pc)
Sem (VI)

2. 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.

3. *Microbial colonization depends on
-Characteristics of product
-The way processed
-The way stored
* Factors are characterised in to four
-Intrinsic parameters
-Extrinsic parameters
-Modes of preservation and processing
-Implicit parameters

4. 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.

5. 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 hydrogen peroxide,
bacteriocin and other di-acetyl compounds.

6. # 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.

7. 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, nut meats
#Stable or non perishable
-sugars,flour,dry beans

8. # Moisture content above 12 to 13 percent may cause
spoilage of cereals.
# Little moisture cause mold growth and high
moisture may cause growth of yeasts and bacteria.
# Microbial content, physical damage and
temperature are also some factors.
# Aspergillus, penicillium, mucor, Rhizopus,
Fusarium are some common molds : produce
mycotoxin.
# Acetobacter spp, lactis and coliforms, Micrococci
and Bacillus are some species
causing spoilage.

9. # Cause flour dough to develop an odour of acetic
acid and esters.
# Ropiness of bread is common in home baked
bread
-caused by Bacillus subtilis, b. licheniformis and
other species
- Due to the capsulation of Bacillus ropiness occur
- First odour is evident , then discolouration and finally
softening of the crumb with stickiness and stringiness.
# Red bread is caused by the pigmented growth
of Serratia marcescens. Molds such as
Neurospora sitophlia and Geotrichum
aurantiacum can also cause red colouration.

12. # Spoilage of suagrs or concentrated solution of
sugars is limited to that caused by osmophilic or
xerotolerant microorganisms.
#Certain yeast,especially those of the genus
Saccharomyces, and certain molds would be the
principal spoilage flora .
# Some species of bacteria have also been suggested
as possible spoilage problems, including species
of Bacillius and Leuconostoc, as the sugar
concentrations decrease, increasing numbers of
kinds of organism can grow.

14. # Sugarcane
# Soil
# Handlers
# Transportation
# Air
# Debris/fine particles on the sides/joints of
troughs at the plant
# Industrial equipments & machines

16.  During the manufacture of sugar, the original
cane or beet juice becomes more and more
purified toward sucrose and the concerntation
of sugar in solution becomes greater and
greater until finally crystalline sugar is attained
plus molasses that is high in sugar. The purer
the product, the poorer it becomes as a culture
medium for microorganism; the more
concentrated it gets, the fewer kinds of
organisms can grow in it.

18. # Sap from the sugar mapple becomes
contaminated when drawn. Although a
moderate amount of growth may improve
flavor and colour, the sap often stands under
conditions that favour excessive growth of
microorganisms and hence spoilage.

19.  Five chief types of spoilage are
recognised:
(1) Ropy or stringy sap, usually caused by
Enterobacter aerogenes, although Leuconostoc
spp. May be responsible.
(2) Cloudy, sometimes greenish sap resulting from
the growth of Peudomonas fluorescences, with
species of Alcaligenes and Flavobacterium
sometimes contributing to cloudiness.
(3) Red sap coloured by pigments of red
bacteria,e.g.,Micrococcus roseus, or of yeasts or
yeastlike fungi.

20.  Five chief types of spoilage are
recognised:
(4) Sour sap, a catchall grouping for types of
spoilage not showing a marked change in
colour but having a sour odour and caused by
any of a variety of kinds of bacteria or yeasts,
and
(5) Moldy sap, spoiled by molds.

21.  Mapple syrup can be ropy because of
Enterobacter aerogenes, yeasty as the result of
growth of species of Saccharomyces yeasts,
pink from the pigment of Micrococcus roseus,
or moldy at the surface, where species of
Aspergillus, penicillium, or other genera may
grow .The sirup may become dark because of
alkalinity produced by bacteria growing in the
sap and inversion of sucrose.

25.  Honey is variable in composition but must
contain no more than 25 percent moisture.
Because of its high sugar content, 70 to 80
percent, mostly glucose and levulose, and its
acidity ,pH 3.2 to 4.2, the chief cause of its
spoilage is osmophillic yeasts : species of
Zygosaccharomyces, such as Z.mellis,richteri.
 Most molds do not grow well on honey,
although species of penicillium and mucor
have developed slowly.

26. Most honey yeasts do not grow in the laboratory in
sugar concentrations as high as those usually found
in honey. Therefore, special theories for the
initiation of growth of yeasts in honey have been
advanced:
(1) Honey, being hygroscopic, becomes diluted at the
surface, where yeasts begin to multiply and soon
become adapted to the high sugar concentrations.
(2) Crystallisation of glucose hydrate from honey
leaves a lowered concentration of sugars in solution,
or
(3) On long standing, yeasts gradually become adapted
to the high sugar concentrations.

30.  Most candies are not subjected to microbial
spoilage because of their comparatively high
sugar and low moisture content.
 Exceptions are chocolates with soft centers of
fondant or of inverted sugar, which under
certain conditions, burst or explode.
 Yeast growing in these candies develop a gas
pressure which may disrupt the entire candy or
more often will push out some of the sirup or
fondant through a weak spot in the chocolate
coating.

31.  Often this weak spot is on the poorly covered
bottom of the chocolate, where a cylinder of
fondant squeezes out.
 The defect is prevented by using a filling that
will not support growth of the gas formers and
by coating the candy with a uniformly thick
and strong layer of chocolate.