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NEETHU ASOKAN
PERIYAR UNIVERSITY
WHAT IS THE DIFFERENCE?
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 mushy rot
– Cottony growth of mold forms black spots of
sporangia covering the foods.
• Alternaria rot
– Caused by Alternaria tenuis
– Greenish-brown to brown black spots
• Fungal spoilage results in water soaked mushy
areas, brown or cream coloured areas. Rots of
juicy fruits result in leakage.
SPOILAGE OF CEREALS
• 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 mycotoxins.
• Acetobacter spp, lactics and Coliforms, Micrococci and
Bacillus are some species causing spoilage.
• 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 occurs.
– 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 sitophila and Geotrichum
aurantiacum can also cause red colouration.
SPOILAGE OF MILK
• An excellent medium
• Souring
– caused by Streptococcus lactis, Enterococci,
Lactobacilli, Micrococci
• Gas production
– caused by Coliform, Clostridium, Yeasts, Bacillus
• Proteolysis
– cause bitter taste, caused by Bacillus, Micrococcus,
Proteus, Pseudomonas, Flavobacterium, Serratia.
• Changes in colour and tastes
SPOILAGE OF MEAT
• Raw meat is subject to spoilage by its own
enzymes and microbial action.
• Excessive autolysis can cause souring
• Factors involving spoilage include
– The greater gut load of animal
– The physiological condition of the animal during
slaughter as like fever, excited or fatigued.
– Rapid cooling
SPOILAGE OF FISH
• Spoiled by autolysis, oxidation or bacterial
activity.
• Under aerobic conditions
– Surface slime
• Caused by Pseudomonas, Moraxella, Alcaligens,
Lactobacillus, Streptococcus,
Leuconostoc,Bacillus,Micrococci.
– Change in colour of meat pigments
• Red colour, green,brown or grey
–Change in fats
• Rancidity
• Lipolysis
• Oxidation of fats
–Phosphorescence
• Photobactererium spp growing on meat
―Surface colours due to pigmentation
• Red spot caused by Serratia marcescens
• Chromobacterium gives a greenish blue colour
• Pseudomonas gives a bluish colour
• Micrococcus or Flavobacterium gives a yellowish
colour.
• Pencillium may cause greenish colour.
• Cladosporium may cause black colour
—Off odours and Off tastes
• Taints, Souring, stale flavour can be caused as a
result of bacterial and fungal growth.
SPOILAGE OF EGGS
• Cracks, leaks, stained or dirty spots on exterior
and blood clots, bloodiness, translucent spots
in the interior are all signs of spoilage
• Pseudomonas, Acinetobacter, Alcaligens,
certain coliform bacteria. Proteus spp,
Aeromonas, Serratia, Sporotrichum all cause
rots in eggs
SPOILAGE OF CANNED FOODS
• Chemical spoilage
– Hydrogen swell
– Discolouration of inside of the can
– Cloudiness of liquors
– Loss in nutritive value
• Biological spoilage
– Attacked by
• Thermophilic and
• Mesophilic bacteria
• Flat sour spoilage:
– Ends of can flatten due to souring
– Bacillus stearothermophilus
• TA spoilage:
– Thermophilic anaerobe
– Forms acid and gas
• Sulfide spoilage:
– Desulfotomaculum nigrificans
– Black colonies
• Clostridium spp:
– Putrefactive or proteolytic organisms
– Produce H2S,ammonia, indole,mercaptans
– CO2 and hydrogen cause can to swell.
SPOILAGE CAN LEAD TO…
• Food Poisoning
• When someone gets sick from eating food or
drink that has gone bad or is contaminated.
• There are two kinds of food poisoning:
poisoning by toxic agent or by communicable
agent.
HOW CAN WE PREVENT?
• FOOD PRESERVATION
• What is food preservation?
• Food preservation is the process of treating and
handling food ,with an aim to stop or slow down
its spoilage while maintaining its nutritional
value, texture, and flavour.
• Food preservation methods either kill microbes
or prevent their growth.
Some methods are:
1. Boiling
2. Dehydration
3. Refrigeration & freezing
4. Canning
5. Using chemical preservatives
6. Using Salt, sugar, oil, or vinegar
7. Pasteurization
“Better pay the chef than the doctor!”
Food spoilage

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Food spoilage

  • 2. WHAT IS THE DIFFERENCE?
  • 3. 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.
  • 4. 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
  • 5. 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.
  • 6. 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.
  • 7. • 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.
  • 8. 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
  • 9. 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
  • 10. • 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
  • 11. • Rhizopus soft rot – Caused by species of Rhizopus – Soft and mushy rot – Cottony growth of mold forms black spots of sporangia covering the foods. • Alternaria rot – Caused by Alternaria tenuis – Greenish-brown to brown black spots • Fungal spoilage results in water soaked mushy areas, brown or cream coloured areas. Rots of juicy fruits result in leakage.
  • 12. SPOILAGE OF CEREALS • 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 mycotoxins. • Acetobacter spp, lactics and Coliforms, Micrococci and Bacillus are some species causing spoilage.
  • 13. • 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 occurs. – 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 sitophila and Geotrichum aurantiacum can also cause red colouration.
  • 14. SPOILAGE OF MILK • An excellent medium • Souring – caused by Streptococcus lactis, Enterococci, Lactobacilli, Micrococci • Gas production – caused by Coliform, Clostridium, Yeasts, Bacillus • Proteolysis – cause bitter taste, caused by Bacillus, Micrococcus, Proteus, Pseudomonas, Flavobacterium, Serratia. • Changes in colour and tastes
  • 15. SPOILAGE OF MEAT • Raw meat is subject to spoilage by its own enzymes and microbial action. • Excessive autolysis can cause souring • Factors involving spoilage include – The greater gut load of animal – The physiological condition of the animal during slaughter as like fever, excited or fatigued. – Rapid cooling
  • 16. SPOILAGE OF FISH • Spoiled by autolysis, oxidation or bacterial activity. • Under aerobic conditions – Surface slime • Caused by Pseudomonas, Moraxella, Alcaligens, Lactobacillus, Streptococcus, Leuconostoc,Bacillus,Micrococci. – Change in colour of meat pigments • Red colour, green,brown or grey
  • 17. –Change in fats • Rancidity • Lipolysis • Oxidation of fats –Phosphorescence • Photobactererium spp growing on meat ―Surface colours due to pigmentation • Red spot caused by Serratia marcescens • Chromobacterium gives a greenish blue colour • Pseudomonas gives a bluish colour
  • 18. • Micrococcus or Flavobacterium gives a yellowish colour. • Pencillium may cause greenish colour. • Cladosporium may cause black colour —Off odours and Off tastes • Taints, Souring, stale flavour can be caused as a result of bacterial and fungal growth.
  • 19. SPOILAGE OF EGGS • Cracks, leaks, stained or dirty spots on exterior and blood clots, bloodiness, translucent spots in the interior are all signs of spoilage • Pseudomonas, Acinetobacter, Alcaligens, certain coliform bacteria. Proteus spp, Aeromonas, Serratia, Sporotrichum all cause rots in eggs
  • 20. SPOILAGE OF CANNED FOODS • Chemical spoilage – Hydrogen swell – Discolouration of inside of the can – Cloudiness of liquors – Loss in nutritive value • Biological spoilage – Attacked by • Thermophilic and • Mesophilic bacteria
  • 21. • Flat sour spoilage: – Ends of can flatten due to souring – Bacillus stearothermophilus • TA spoilage: – Thermophilic anaerobe – Forms acid and gas • Sulfide spoilage: – Desulfotomaculum nigrificans – Black colonies • Clostridium spp: – Putrefactive or proteolytic organisms – Produce H2S,ammonia, indole,mercaptans – CO2 and hydrogen cause can to swell.
  • 22. SPOILAGE CAN LEAD TO… • Food Poisoning • When someone gets sick from eating food or drink that has gone bad or is contaminated. • There are two kinds of food poisoning: poisoning by toxic agent or by communicable agent.
  • 23. HOW CAN WE PREVENT? • FOOD PRESERVATION • What is food preservation? • Food preservation is the process of treating and handling food ,with an aim to stop or slow down its spoilage while maintaining its nutritional value, texture, and flavour. • Food preservation methods either kill microbes or prevent their growth.
  • 24. Some methods are: 1. Boiling 2. Dehydration 3. Refrigeration & freezing 4. Canning 5. Using chemical preservatives 6. Using Salt, sugar, oil, or vinegar 7. Pasteurization
  • 25. “Better pay the chef than the doctor!”