Food hygiene and inspection [autosaved]

COURSE : LCHEH 452
Food H y giene a nd
I nspection
LECTURE NOTE PREPARED BY
N. I. BARDA

B. FOOD HYGIENE AND INSPECTION

INTRODUCTION
FOOD: food is defined as any substance that is when eaten, digested and absorbed,
will produce at least one nutrient, satisfy hunger and constituted no harm to the
consumer. these may include flesh, vegetables, grains, etc.
Food is a more basic need of human than that of shelter and clothing. It provides
adequately for the body’s growth, maintenance, repair, and reproduction. Plant and
animal origin are the sources of foods that contain the essential nutrients such as
carbohydrates, fats, proteins, vitamins, and minerals. Usually after consumption, food
undergoes different metabolic processes that eventually lead to production of energy,
maintenance of life, and/or stimulation of growth

DEFINATION OF TERMS
A food safety hazard: can be defined as any factor present in food that has the
potential to cause harm to the consumer, either by causing illness or injury.
Food Safety Management System (FSMS): means the adoption Good Manufacturing
Practices, Good Hygienic Practices, Hazard Analysis and Critical Control Point as well as
other such practices as may be specified by regulation, for the food business.

DEFINATION OF TERMS
Food hygiene: Food hygiene is the practice of ensuring food is safe, sound and
wholesome, by protecting it from contamination, preventing bacterial multiplication
and by the destruction of harmful bacteria.
Food poisoning: is an illness that occurs usually between 1 and 36 hours after eating
contaminated or poisoned food, the most common symptoms being diarrhoea,
vomiting and dehydration.
Foodborne illness is an illness that occurs when food containing harmful bacteria is
ingested. This term also covers foodborne disease and food poisoning

OBJECTIVES OF FOOD HYGIENE
To ensure that food is safe and is handled safety,
To ensure the health related quality of food and that its quality in other respects
accords with the food regulations,
To ensure that information given about food is truthful, sufficient and not misleading,
To secure a high quality system of food control.
To preserve the nutritive quality of food by preventing them from spoilage due to
microbes and other spoilage agents,
Prolong the shelf life ( preservation) as processed food is more stable than raw food

THE WHO'S TEN RULES FOR SAFE FOOD
PRACTICES:
Choose Foods Processed for Safety. ...
Cook Food Thoroughly. ...
Eat Cooked Food Immediately. ...
Store Cooked Foods Carefully. ...
Reheat Cooked Foods Thoroughly. ...
Avoid Contact Between Raw Foods and Cooked Foods. ...
Wash Hands Repeatedly. ...
Keep All Kitchen Surfaces Clean.

DETERMINE WHOLESOME AND
UNWHOLESOME STATE OF FOOD ITEMS
Most fresh food, particularly those from animals, are highly vulnerable to microbial
contamination and food poisoning. Meat composition makes it an ideal medium for
the growth of a good number of microorganisms due to richness in nutrients.
Majority of foodborne diseases arise from the food of animal origin. Food handler’s
health status and hygiene practice are the foremost determinants of food
contamination. Food poisoning happens as a result of ingesting food contaminated
with microorganisms or their toxins, the contamination springing up from insufficient
protection methods, unhygienic dealing with practices, cross-contamination from food
contact surfaces, or men and women harboring microbes . This can result in quality
deterioration and unwholesome, hence, quantity losses, economic losses, and public
health concerns.

DETERMINE WHOLESOME AND
UNWHOLESOME STATE OF FOOD ITEMS
Food is said to be wholesome when its free from any chemical, biological, or physical
hazards, that may impaired health to the consumer or affect the nutritional value, quality
or safety of the food. This can only achieved if standard operation procedures for food
safety, sanitation and quality assurance are followed and monitored at all level of
production.

FOOD ANALYSIS AND QUALITY CONTROL
Food analysis is the process for both fresh and processed products by the standardized
form and are those most commonly used in the laboratory. These analytical procedures
are used to provide information about a wide variety of different characteristics of foods,
including their composition,
structure, physicochemical properties, phytochemical properties, and sensory attributes.
This information is critical to our rational understanding of the factors that determine the
properties of foods, as well as to our ability to economically produce foods that are
consistently safe, nutritious, and desirable and for consumers to make informed choices
about their diet
Quality control is the standards which maintain the quality of the food products
according to the customer’s acceptability. Physical, chemical, microbiological, nutritional,
and sensory parameters are used for the maintenance of nutritious food. These quality
factors depend on specific attributes such as sensory properties, based on flavor, color,
aroma, taste, texture and quantitative properties, namely, percentage of sugar, protein,
fiber and so on as well as hidden attributes such as peroxides, free fatty acids, enzyme.
The most important element and ultimate goal in food quality control is protecting the
consumer.

Reasons and Importance of Food hygiene:
If food or drink is not safe to eat, you cannot eat or drink. The easiest example of this is safe
drinking water. We would never drink water that did not come from a reputable source. The
very same principle applies to food.
1. Every day, people worldwide get sick from the food or drink they consume. Bacteria, viruses
and parasites found in food can cause food poisoning.
2. There is no immediate way of telling if food is contaminated because you cannot see, taste
or smell anything different from the norm.
3. Food poisoning can lead to gastroenteritis and dehydration or potentially even more serious
health problems such as kidney failure and death.
4. This risk is especially significant for those in the high-risk category: Small children/ babies,
pregnant moms, the elderly and immunocompromised, especially HIV infections and cancer
patients.
Importance of Food hygiene:
1. Food hygiene and safety prevent germs from multiplying in foods and reaching dangerous
levels.
2. Ensures daily healthy family living.
3. Keeping one healthy and preventing the additional cost of buying medication and medical
check-ups. This is especially important in business. Companies worldwide lose Billions of
Dollars per year due to staff downtime.

FOOD ESTABLISHMENT INSPECTION
Restaurant inspections are normally conducted on a routine basis, depending upon:
The complexity of the menu, which affects the risk levels;
How much food is made from raw products (as opposed to precooked products); and
The restaurant’s history of violations and types of violations found during inspections
The possibility of foodborne illness can increase with the number of times that a food
product is handled during preparation. For example: restaurants that handle food more
frequently are inspected more frequently than a restaurant that serves food such as a
sandwich made to order.
The inspection reports for a business can be different depending on the type of
inspection that is being performed. Risk-based inspection starts with the consideration of
hazards associated with the food and a review of the control measures in place to
determine if they are adequate.
Furthermore, having established the quality and safety management system, it is
imperative that management actively promote and monitor compliance. Besides
supervision, management may enhance compliance by posting signs reminding personnel
to wash their hands and to indicate the level of chlorine to be maintained in the wash tank,

METHODS AND PROCEDURES FOR FOOD INSPECTION
Independent food inspection is an examination of food in production as a form of
quality control, through this process, the standards of the product are assessed at
multiple points in the production cycle to ensure conformity at every step.
There are three types of quality inspections (Routine, Follow-up Inspection, Pre-
operational; License Renewal; Hazard Analysis Critical Control Points (HACCP)
complaints). 3 stages of production (Pre-production, In-line and Final) should be
assessed, variety of details must be inspected and approved during each phase in
order to detect and correct quality problems.
The establishments that receive health inspection includes Restaurants, Grocery
stores, retail bakeries, convenience stores, bars, production stands, Mobile food units (
Routine Sanitation Inspection).

TYPES OF INSPECTIONS
1.) Routine Inspection: This is a scheduled inspection, unannounced to the restaurant. An inspector will
conduct a complete inspection covering all items in the regulations for compliance.
2.) Follow-up Inspection: This is an inspection for the specific purpose of re-inspecting critical violations
that were not in compliance at the time of the routine inspection.
3.) Critical Control Point Inspection: This type of inspection, which is conducted in food service
operations, involves analyzing recipes and tracking potentially hazardous foods from the loading dock
to the table, to assure all food is safe and wholesome.
4.) Process Review Inspection: This type of inspection, which is conducted in retail food
establishments, involves analyzing recipes and tracking potentially hazardous foods from the loading
dock to the table, to assure all food is safe and wholesome.
5.) Complaint Inspection: This is an inspection conducted as a result of a complaint received by the
Health Department. The specifics of the complaint will be evaluated and discussed with the person in
charge.
6.) Foodborne Illness Investigation: Foodborne illness complaints are received and a food inspector
conducts an inspection at the facility reported to be involved in the foodborne illness. The inspection
focuses on food source, storage practices, food processing techniques, food handling and employee
practices.
7.) Training: The inspector visits the restaurant to present a formal training event for the restaurant's

GENERAL INSPECTION PROCEDURES
The inspector must prepare for an inspection. If a full HACCP system is in place then
an audit (assessment/evaluation) should be performed. Preparation includes consulting
the food control authority’s records to gain an insight into the background of the
operation to be inspected, its history of compliance and the product(s) it handles. This
advance knowledge will accomplish the following.
 • Help the inspector to prepare a list of potential food-borne disease risk factors
identified for the type of product and facility to be inspected.
 • Help the inspector to prepare the necessary inspection wear (unless it is provided
by the establishment), tools and equipment.
 • Help the inspector to make an adequate time allocation for the inspection based
on the size and complexity of the operation.
 • Inform the inspector about the registration status, the identification number of the
facility, and, hopefully, the name(s) of the person(s) to communicate with before,
during and, if necessary for follow-up, after the inspection.
 Preparation also involves taking care of personal aspects such as obtaining
protective clothing (unless provided by the inspected establishment), and preparing
the necessary equipment (e.g. flashlight, thermometer), sampling tools, note-taking
materials and official forms.

GENERAL INSPECTION PROCEDURES
ORGANIZATION OF THE INSPECTION.
1. Notify establishment in advance (except for
follow-up inspections).
2. Consult the establishment’s records.
3. Prepare clothing, equipment, tools and
official forms.
4. Schedule an opening meeting.
5. Conduct a walk-through (counter to product
flow).
6. Plan a closing meeting
AUTHORIZATION, RIGHTS AND RESPONSIBILITIES.
1. The inspector must be properly authorized to enter an
establishment.
2. The inspector (and any assistants or team members)
must have official identification.
3. The inspector must know the applicable laws and
regulations (including any requirements
4. related to the timing and duration of the inspection,
and the length of advance notice required).
5. The staff of the establishment have the right to ask
questions.
6. The establishment has the responsibility to provide
pertinent records and information.

DISPOSING OF CONTAMINATED OR
SPOILED FOOD
Decisions about disposing of food products are usually made by the owner of the
product, along with the appropriate state agency and local authorities. In determining
which contaminated food products should be disposed of, reconditioned or salvaged,
the owners of the products must assess each product's quality, safety and condition.
Depending on the applicable local, state, and Federal regulations, owners may be able
to dispose of contaminated food products in a landfill, by incineration, or rendering.
KEY QUESTIONS TO CONSIDER WHEN DISPOSING OF CONTAMINATED FOOD
INCLUDE:
What is (are) the contaminant(s)?
How the contaminated food is categorized (e.g. hazardous waste, municipal waste,
radiological waste, non-hazardous waste requiring special handling, or unknown)?
What is the quantity of the contaminated product for disposal?
Where is the final disposal facility?

DISPOSING OF CONTAMINATED OR SPOILED FOOD
• What are the logistics for moving the contaminated products from the site to the disposal
facility?
• Is transportation required for the transfer of waste to the final disposal site?
• What are the required permits associated with the disposal process and how are they
procured?
• Is assistance from state, local, and Federal government agencies required?
• Is there a health and safety protection plan for the workers who will be involved in the
disposal process? If so, what is the plan?
• Who and what organizations will be involved in overseeing the disposal process?
• What organizations must be involved and concur with re-introducing the reconditioned
product into the marketplace?

METHOD AND PROCEDURE FOR COLLECTION
OF FOOD SAMPLE FOR EXAMINATION
Testing food samples is one of the verification activities that a food business is
required to undertake. To ensure the integrity of the food sample being taken, there a
several actions that need to be undertaken.
A common question that one need to asked is “What should I get our product tested
for?”. The first thing that needs to occur is understanding why the analysis is required
in the first place. Is it to satisfy a customer requirement? Is it part of a complaint
investigation? Is it to determine the shelf life of the product? Is there a legal
requirement that needs to be achieved?
The reason for sampling will generally dictate what type of analysis is required. For
example, if you are required to assess your product against a customer specification
on an annual basis, you would review the finished product specification. The
specification may state requirements for certain microbiological, chemical, physical
and/or quality criteria. You would then test against these criteria.

I D E N T I F Y T H E
C O R R E C T A N A LYS I S
R E Q U I R E D
Clean Sample Equipment: It is imperative that
whenever you take a food sample the equipment
used and sampling containers are clean and in
some situations sterile. The reason is to prevent
any contamination of the food sample that you
have taken
Good personal hygiene: You as the person taking
the sample can become a source of
contamination to the product if good personal
hygiene is not implemented. This includes
thoroughly and effectively washing your hands
prior to taking the food sample.

I D E N T I F Y T H E
C O R R E C T A N A LYS I S
R E Q U I R E D
 Correct sample size : Always check with the testing
authority how much product will be needed to
perform the analysis that is required. To get a good
representation of the finished product, several
samples of the same batch may be required to be
blended together during the testing process.
 Suitable storage and transport conditions : If your
finished product is one that is usually stored under
refrigerated conditions make sure that you transport
the sample in the same condition. If you have a fair
distance for the sample to travel to the testing
authority you don’t want to subject it to any
temperature abuse. Doing so may result in an
outcome that is not actually reflective of your
process. On the other hand, if you are trying to set
worst case scenario for your product, temperature
abuse may be warranted. Again, this will depend on
the purpose of your testing

HOW TO INTERPRET LABORATORY
RESULTS
It is pointless to send a sample for an analytical test if you do not know what you will
do with the result. Interpretation of results, particularly for food authenticity
verification tests, is not always straightforward. The interpretation can be as complex
as the testing. The sampling protocol that was used is one key factor in the
interpretation and explained in Institute of Food Science & Technology (IFST)
Information Statement ‘Sampling for Food Analysis - key considerations’.
Interpretation will depend upon the purpose of the testing, and upon the
consequences of a ‘fail’ result. Each demands a different level of confidence. You
would expect more confidence in a result that underpinned a decision to recall stock
than a decision to reclean a conveyor belt.
It is important that you have open communication with your laboratory. They need
to understand the purpose and context of the testing, and you need to understand the
uncertainty and caveats around the result and its interpretation.

HOW TO INTERPRET LABORATORY
RESULTS
There is a plenty of available analytical test methods. Overviews are given in the
following IFST Information Statements: ‘Chemical Analysis - key considerations’,
‘Microbiological Analysis - key considerations’ and ‘Physical Analysis - key
considerations’. One way of categorizing methods is by the degree of certainty in
the result. Methods with high confidence that a ‘negative’ result is truly negative
(irrespective of whether a ’positive‘ result is truly positive) are used for cheap high-
throughput screening tests. Methods, with high confidence, where a ’positive
screening result’ is truly ‘positive’ are used for confirmatory testing, but even with the
most confident confirmatory test, there is always a small, maybe negligible, analytical
uncertainty that must be reported and contextualized. Sometimes it is necessary to
carry out a range of confirmatory tests, using different analytical techniques, before
the ’positive screening result’ can be confirmed. In some cases, the same method can
be used for both screening and confirmation. The degree of confidence depends on
how the method is calibrated and the associated quality controls that run

Application example Desired confidence Example method
Negative
screening results
Positive screening results Confirm/ quantify ’positive
screening’ results
Screening - antibiotic
residues in milk
High Low Low Inhibitor test kits
Screening - allergens High Medium Low Lateral flow kits
Total fat content -
online testing for
meat specification
Medium Medium Medium Low-resolution NMR
Confirmation of
allergens
High Medium Medium None available. ELISA is
used but does not give
high confidence in
confirmation of identity
Nutritional label -
total fat content
High Medium Medium Gravimetric tests
Unlabelled meat
species in a meat
product
Medium High Low/Medium Species-specific DNA
testing by PCR or NGS
DNA testing
Undeclared sugars or
syrups
High High Low FT-IR or high-resolution
Complaint
investigation – taint or
flavour compounds
High High High GC-MS/(MS)
Legal/safety
compliance - process
contaminants
High High High LC-MS/(MS) of process
contaminants

GENERAL PRINCIPLES OF FOOD HYGIENE
(i) Food safety and suitability should be controlled using a science-based preventive
approach, for example a food hygiene system. GHPs should ensure that food is
produced and handled in an environment that minimizes the presence of
contaminants.
(ii) Properly applied prerequisite programmes, which include GHPs, should provide
the foundation for an effective HACCP system.
(iii) Each FBO should be aware of the hazards associated with the raw materials and
other ingredients, the production or preparation process, and the environment in
which the food is produced and/or handled, as appropriate to the food business.
(iv) Depending on the nature of the food, food process, and the potential for adverse
health effects, to control hazards it may be sufficient to apply GHPs, including, as
appropriate, some that require more attention than others, as they have a greater
impact on food safety. When the application of GHPs alone is not sufficient, a
combination of GHPs and additional control measures at CCPs should be applied.

GENERAL PRINCIPLES OF FOOD HYGIENE
(v) Control measures that are essential to achieve an acceptable level of food safety,
should be scientifically validated1.
(vi) The application of control measures should be subject to monitoring, corrective actions,
verification, and documentation, as appropriate to the nature of the food product and the
size of the food business.
(vii) Food hygiene systems should be reviewed to determine if modifications are needed.
This should be done periodically and whenever there is a significant change that could
impact the potential hazards and/or the control measures (e.g. new process, new
ingredient, new product, new equipment, new scientific knowledge) associated with the
food business.
(viii) Appropriate communication about the food and food process should be maintained
among all relevant parties to ensure food safety and suitability across the entire food chain.

TRAINING OF FOOD HANDLERS ON FOOD HYGIENE
Without training, individuals and companies are likely to form bad habits that can be costly and difficult to
correct. It may be difficult for some employees to comprehend terms like Listeria monocytogenes, zero
tolerance, defect action levels or spore-forming bacteria. Although most facilities have qualified management
educated in food safety, it is sometimes a challenge to convey the concepts they know and understand so well
to actual manufacturing employees: those who actually touch, handle and process foods. It becomes important,
then, for the food company to determine which concepts will be included in training and the exact approach as
to how to convey these topics. This undertaking must be tailored to each individual company because the
diversity and educational levels of employees differ among companies and within companies.
All food processors should have a well-designed food safety training program that includes a
diverse curriculum and answers the whos, whats and whys associated with food safety activities. A
well-organized training matrix helps ensure good quality, a consistent product and a sanitary
environment under which foods are produced. If carried out effectively, food safety, quality and
sanitation training help to assure a safe product for the end user and ultimately protect your brand.

TRAINING OF FOOD HANDLERS ON FOOD HYGIENE
The food company should make training a normal event within the company. Have employees give
input and interject their questions or concerns during the training. Employees need to know that
management places a strong emphasis on training. The act of training employees helps employees
realize their importance and value to operations, and productivity. Some general approaches to
communicating food safety information to employees will help make training programs effective:
• Explain the purpose, goals and objective of the training. The purpose may be for some corrective
reason (i.e., something wasn’t done exactly right and you want to prevent a second occurrence).
• Regardless of how often, keep sessions brief and to the point.
• Maintain focus on food safety—not other business matters.
• Utilize activities to keep the training concepts interesting. Have employees wash hands, apply some
Glo-Germ, and turn off the lights. They will remember the importance of washing better after seeing
the green glow of bacterial residue.
• Accompany and follow up training by posting or making available materials that remind employees
about what they’ve learned, such as posters.

THE LEGAL REQUIREMENTS OF FOOD
HANDLERS
• Keep the workplace clean
• Keep yourself clean
• Protect food from contamination or anything that could cause
harm
• Follow good personal hygiene practices – e.g. hand washing
• Wear appropriate protective clothing
• Tell your employer if you are suffering from or you are a carrier
of a Foodborne disease

PROCEDURES FOR MAINTAINING FOOD AND KITCHEN HYGIENS
1. Kitchen hygiene 101: wash hands Making sure your hands are clean is at the top of
the kitchen hygiene rules list. It’s easy for bacteria to be transferred, so wash your
hands throughout prepping and cooking food. Regular hand washing is one of the
most essential kitchen hygiene rules for kids too, so make sure the whole family
how to wash their hands properly.
2. Thoroughly cook foods: One of the most important food hygiene rules is to
ensure food is cooked properly. If undercooked, harmful bacteria could lead to food
poisoning. Cut into the food to check that it is cooked through and make sure any
reheated food is piping hot.
3. Correct food storage : Proper cooking is only the first of the essential food hygiene
rules. Another one of the most important food hygiene rules in the kitchen is safe
storage. Make sure leftovers or open food packets are covered with cling film or
sealed in a plastic container. Don’t put warm food into the fridge, and keep your
clear of any items that are out of date.
4. Wipe down counter tops: Wiping kitchen counter tops after every use is one of
the easiest (and most essential) basic kitchen hygiene rules. You’ll not only be
things clean and tidy, you’ll be stopping the spread of bacteria, too.

5. Food hygiene rules: don't cross-contaminate: If you’ve ever had food poisoning,
you’ll understand why avoiding cross-contamination is high on the list of basic
hygiene rules. Use different boards for cutting fish, meat, veg, dairy or bread
colour boards can help with this), and never leave edible food next to raw meat.
simple kitchen hygiene tips will help avoid the spread of potentially poisonous
bacteria.
6. Clean your chopping board after use: Bits of food left on a chopping board will
soon breed bacteria, so scrubbing down your board immediately after use is vital to
stop them spreading. Quick, easy and essential, cleaning chopping boards is one of
the most basic kitchen hygiene rules.
7. Bin basics: Regularly changing your bin is a key aspect of kitchen hygiene. Old
food in a bin will soon decompose and bacteria will start to form, so take your
out on a daily basis to avoid any funny smells.
8. Stop grease in its tracks : Have you ever wiped a greasy mark, only to find it has
transferred from your cloth to every other surface in the kitchen. Try using a piece of
absorbent kitchen towel instead – it’ll stop the spread of grease and bacteria.

9. Keep the fridge clean: Ensuring your fridge is clean is one of the top
10 hygiene rules in the kitchen for good reason. Left alone, spills and
decaying food can spread their nasties to everything else, so use
paper to spot-clean on a daily basis between thorough fridge-cleaning
sessions.
10. Scrub your sink daily: Your sink is used regularly throughout the
day, so it’ll become grimy and covered in bacteria quickly if it’s not
clean. Again, this is one of those kitchen hygiene rules that doesn’t
much time, but that is well worth doing: just give your sink a quick
scrub with a scourer and a spritz of kitchen cleaner once a day. Wipe
any pooled water or spillages round the sink with kitchen towel to
it hygienic between scrubs.
Whether it’s following food hygiene rules, changing your bin often or
keeping your worktops clean, these basic kitchen hygiene rules will

RELEVENT FOOD HYGIENE REGULATIONS
The Food Regulations 1985 is the key supporting
regulation for food safety covering procedures for
samples, labelling, food additives and nutrient
food packaging, and incidental constituent, additionally,
food standards and particular labelling requirements for
more than 380 food items.
to health; Sell food that is not what the customer is entitled
entitled to expect in terms of content or quality; and.
Describe or present food in a way that is falls Under the
Food Safety Act 1990 a food business must not: Cause food
to be dangerous e or misleading.

RELEVENT FOOD HYGIENE REGULATIONS
The Food Hygiene Regulations 2006 require food businesses to carry
out their food tasks safely and hygienically to ensure that consumer
health is not harmed. The Food Hygiene Regulations 2006 make it an
offence for food businesses to supply food which should not be eaten
as it could be harmful to consumers.
Food Hygiene Regulations 2009 (FHR) is a regulation enacted
according to Section 34 of the Food Act 1983 and was gazetted by the
government on February 28, 2009. ... Premises involved in food
catering and food delivering for mass-produced food. Premises
where food is prepared, processed, stored and made available for
sale
food hygiene regulations 2013: The regulations set out the
responsibilities of local authorities when it comes to ensuring that
local businesses are handling, preparing and serving food that's
safe to eat. This includes actively working with businesses to improve

ROLE OF LEGISLATION AND ESTABLISHMENT
CODES IN CATERING INDUSTRIES
The primary purposes of food legislation are to protect the health of the
consumer, to protect the consumer from fraud, and to ensure the
essential quality and wholesomeness of foods. Food law must first
provide the legal authority and an adequate legal framework for the food-
control activities.
The main responsibilities for all food businesses under the Act are to
ensure that: ... the food businesses serve or sell is of the nature,
substance or quality which consumers would expect. the food is
advertised and presented in a way that is not false or misleading.
To reduces any incidents that result in food industry being subject to
inconsistent ... wholesalers, retailers, restaurants and caterers. ... Food Law
Code of Practice (England), was published in 2012. The Code includes
food establishment intervention-rating schemes -

ROLE AND RESPONSIBILITIES OF STAKEHOLDERS IN THE
FOOD CHAIN
For the context of food hygiene, it is essential to point out that, from farmers or fishers to food collectors
and other intermediaries, distributors, processors, retailers, consumers and regulators, everyone
participating in the food chain has a role to play and some responsibility for food safety and quality.
1) Government National authorities: have the responsibility of protecting public health by reducing the
risk of food-borne disease and providing food safety education and information to consumers and the food
industry.
2) Consumers: Consumers are entitled to safe, wholesome food. Consumers also have responsibilities
regarding food safety: observing good hygienic practices when handling food, storing food properly and
following manufacturers’ recommendations on labels; however they cannot be expected to be the sole
providers of food safety. Many consumers, through no fault of their own, lack adequate education
concerning appropriate food handling practices in the home and may have only limited or no access to
information on these practices.
3) The food industry: Ultimate responsibility for food safety lies not with the regulator nor with the
consumer but with food producers, processors, retailers, preparers and servers. Whereas any individual
or firm has the right to produce, process, prepare, serve, import and export food, this right comes with the
inseparable responsibility to ensure
that such food is wholesome and safe and that the conduct of their business is within all applicable laws,
including those regarding fraud. The capacity of producers and processors – and, although not included in

FOOD POISONING
Food poisoning is the pathological condition when a person gets sick after
consuming a particular foodstuff which is mostly contaminated with either pathogenic
bacteria or any other pathogen or virus. In food poisoning, person suffers from
vomiting, abdominal cramps and diarrhea. Sometimes, under severe conditions, there
may be fever and blood in feces etc. Body dehydration is also common due to loss of
liquid from the body during diarrhea.
It has been reported that sometimes, food poisoning may be life threatening. In
fact, many deaths occur annually due to food poisoning. As per recent data released
by the World Health Organization (WHO), on an average, one in ten people falls sick
due to food poisoning every year and there are nearly 420,000 deaths due to food
poisoning every year. Out of these, more than 50% deaths are due to diarrhea

CLASSIFICATION OF FOOD POISONING
I. Based on symptoms and duration of onset
a. Nausea and vomiting within six hours (Staphylococcus aureus, Bacillus cereus)
b. Abdominal cramps and diarrhoea within 8-16 hours (Clostridium perfringens,
Bacillus cereus)
c. Fever, abdominal cramps and diarrhoea within 16-48 hours (Salmonella, Shigella,
Vibrio
parahemolyticus, Enteroinvasive E.coli, Campylobacter jejuni)
d. Abdominal cramps and watery diarrhoea within 16-72 hours (Enterotoxigenic E.coli,
Vibrio cholera O1, O139, Vibrio parahemolyticus, NAG vibrios, Norwalk virus)
e. Fever and abdominal cramps within 16-48 hours (Yersinia enterocolitica)
f. Bloody diarrhoea without fever within 72-120 hours (Enterohemorrhagic E.coli
O157:H7)
g. Nausea, vomiting, diarrhoea and paralysis within 18-36 hours (Clostridium
botulinum)

CLASSIFICATION OF FOOD POISONING
II. Based on pathogenesis
a. Food intoxications resulting from the ingestion of preformed bacterial
toxins. (Staphylococcus
aureus, Bacillus cereus, Clostridium botulinum, Clostridium perfringens)
b. Food intoxications caused by noninvasive bacteria that secrete toxins
while adhering to the
intestinal wall (Enterotoxigenic E.coli, Vibrio cholerae, Campylobacter
jejuni)
c. Food intoxications that follow an intracellular invasion of the
intestinal epithelial cells.(Shigella,
Salmonella)
d. Diseases caused by bacteria that enter the blood stream via the
intestinal tract. (Salmonella typhi, Listeria monocytogenes)

DIFERENT BETWEEN POISONING AND FOOD BORNE INFECTION
• The terms “food poisoning” and “foodborne illness” are frequently used
interchangeably online and in face-to-face conversations. Generally, they are
understood to refer to the same thing, but the truth is that they actually refer to two
distinct concepts. Foodborne illness is any illness caused by eating contaminated
food. It can occur after consuming food contaminated with harmful bacteria or other
pathogens. Food poisoning is a specific subset of foodborne illness. When an
individual suffers from food poisoning, he or she suffers from the effects of
consuming specific toxins
• Food poisoning is a specific type of foodborne illness. Unlike other foodborne
illnesses, food poisoning symptoms can occur as soon as an hour after consuming
the affected food. Examples of food poisoning include Botulism and Ciguatera
poisoning. These toxins cannot be frozen or cooked out of food.
• Symptoms of food poisoning include:
• Nausea;
• Headache;
• Tingling in the limbs and extremities; and

DIFERENT BETWEEN POISONING AND FOOD BORNE INFECTION
• Foodborne illness includes a variety of types illness caused by
bacteria, such as Salmonella. Foodborne illness symptoms are very
similar to flu symptoms and can include nausea, fatigue, fever,
vomiting, and diarrhea. Because of these symptom overlaps,
foodborne illness can be incorrectly diagnosed as influenza. The
symptoms can also take longer to appear than food poisoning
symptoms, sometimes taking 24 to 48 hours or even longer to begin
to manifest.
• Foodborne illness can be prevented by taking precautions in the
kitchen. These include cooking meats thoroughly, storing leftovers at
temperatures below 40 degrees Fahrenheit, and washing hands,
utensils, and cutting boards thoroughly while preparing food and after
meals are finished

DIFFERENT BETWEEN INFECTIVE AND TOXIN TYPE OF FOOD
POISONING
Bacterial food poisoning is of two types: infective, resulting from
the ingestion of food contaminated with large number of bacteria;
toxic, resulting from ingestion of food contaminated with preformed
bacterial toxins. It does not include cholera, enteric fever, and bacillary
dysentery.
Food poisoning occurs through three steps: There must be bacteria on
the food. The bacteria must have the right conditions to grow – that is,
warmth (temperature of between 5 °C and 60 °C – the temperature
danger zone), moisture and a food source. The bacteria must have
time to grow and multiply.
A bacterial toxin is a macromolecule mainly of protein origin, which
can cause toxic damage in a specific organ of the host. Toxins can be
devided in endotoxins and exotoxins:

DIFFERENT BETWEEN INFECTIVE AND TOXIN TYPE OF FOOD
POISONING
Endotoxins or lipopolysaccharides (LPS): These are the components
of the outer membrane of the Gram-negative bacteria; they are
considered the most important antigen of the bacteria; they are
released into the medium after different processes such as lysis and cell
division. This endotoxin is capable of causing endotoxic shock and
tissue damage
• Exotoxins: These are the macromolecules of protein origin, which are
produced and later released to the medium by the microorganism.
Depending on their mechanism of action, exotoxins are divided as
follows:
– Toxins Type I. These toxins modify the host’s cells without internalizing in the
cells; for example, the superantigens produced by Staphylococcus aureus and
Streptococcus pyogenes.
– Toxins Type II. Within this group there are hemolysins and phospholipases; this
group of toxins is characterized by pore formation and/or destroying the
membranes of the host cells. With this virulence factor, the pathogen can invade

DIFFERENT BETWEEN INFECTIVE AND TOXIN
TYPE OF FOOD POISONING
Toxins Type III. These toxins are known as A/B due to
their binary structure. Fraction B has the function of
binding to the receptor of the cell and fraction A is
the unit that possesses enzymatic activity, which,
depending on the toxin and its mechanism of action,
will be the damage to the cell; for example, the Shiga
toxin produced by Escherichia coli O157:H7, the
Cholera toxin (Ctx) produced by Vibrio cholerae, and
the Anthrax toxin produced by Bacillus anthracis

FOODBORNE DISEASES
Bacteria Disease/medical complications
Food products
involved
Salmonella enterica serovar Typhi and
Salmonella enterica serovar Paratyphi
Typhoid and paratyphoid fever.
Undercooked pork,
beef and poultry,
contaminated eggs,
and milk.
Salmonella spp.
Salmonellosis (SalmonellaTyphimurium,
SalmonellaEnteritidis).
Undercooked poultry,
cauliflowers, and
tomatoes.
Vibrio vulnificus
Septicemia in people with underlying diseases or people
who are taking immunosuppressive drugs or steroids.
Seafood, usually
oysters.
Mycobacterium bovis
Cervical lymphadenopathy, intestinal lesions, chronic
cutaneous tuberculosis.
Contaminated milk.
Mycobacterium avium,subspecies
paratuberculosis
Crohn’s disease. Pasteurized milk.
Listeria monocytogenes
Meningitis, encephalitis, sepsis in pregnant women,
intrauterine or cervical infection that can lead to
miscarriage or birth of a dead child.
Raw beef, pork,
poultry, vegetables
and milk, cheese, ice
cream, smoked fish,
and raw fish.

TOXINS PRODUCED BY PATHOGENS INVOLVED IN
FOODBORNE DISEASES
Name Biological effect
Cholera toxin
(Ctx) (A-5B)
It activates the adenylyl cyclase;
increases the levels of intracellular
cAMP promoting fluid and
electrolytes secretion in the intestinal
epithelium, causing diarrhea. It is a
potent exotoxin.
Thermolabile
toxin (LT) (A-5B)
Similar effect as the Cholera toxin.
Thermostable
toxin (ST)
The binding of ST to the guanylyl
cyclase receptor results in an increase
of cyclic GMP, affecting the flow of
electrolytes. It promotes water and
electrolytes secretion from the
intestinal epithelium by causing
diarrhea.
Shiga toxin (A-
5B)
Inactivates the ribosomal subunit 60S
and inhibits protein synthesis causing
the death of susceptible cells.
Botulinum toxin
(A/B)
It is a neurotoxin consisting of a heavy and
a light chain linked by a disulfide bond. It is
a Zn++-dependent protease. It inhibits the
presynaptic release of acetylcholine from
peripheral cholinergic neurons, resulting in
flaccid paralysis. The neurotoxin exists in
seven different serotypes (A-G).
CPE enterotoxin
Lethal, cytotoxic and enterotoxic activity.
Stimulates the adenylyl cyclase allowing
the increase of cAMP in epithelial cells,
which causes diarrhea.

TOXINS PRODUCED BY PATHOGENS INVOLVED IN
FOODBORNE DISEASES
Alpha-toxin
It produces gas gangrene. It has
phospholipase (PLC),
sphingomyelinase, hemolytic, and
dermonecrotic activities. The
mature protein is organized into
two domains; the amino-terminal,
which contains the PLC activity, and
the carboxyl-terminal binding that
depends on calcium. Depending on
the lipid composition of the cell
membrane, the Alpha-toxin may be
hemolytic in the presence of
calcium.
Beta-toxin
It forms selective pores for
monovalent cations in lipid bilayers
and sensitive cells membranes, so it
functions as a neurotoxin capable
of producing arterial constriction.
Epsilon-toxin
Produced and secreted by a prototoxin that, when it
suffers a specific proteolytic cleavage, it acquires its
maximum biological activity. Activation can be
catalyzed by proteases such as trypsin, chymotrypsin,
and a zinc-dependent metalloproteinase.
Iota-toxin
It has dermonecrotic, cytotoxic, enterotoxic activities,
and it causes intestinal histopathological damage.
This toxin is binary and consists of a binding peptide
(Ib) and an enzymatic peptide (ADP-
ribosyltransferase) (Ia). The first one is necessary to
internalize the second one. The Iota-toxin requires
proteolytic removal of a propeptide fragment, which
allows the Ib unit to be inserted into the membrane
and to interact with the Ia portion to form a
heptameric pore that allows the K+ and Na+ ions to
escape; in addition to the Ia portion entrance into the
cell where it ribosylates the G-actin to depolymerize
the actin filaments, with the consequent destruction
of the cytoskeleton. The Iota-toxin is generally activated
by the effect of the proteases present in the intestinal
tract.

EPIDEMIOLOGICAL CONCEPT OF SOME
FOODBORNE DISEASES
Vibrio parahemolyticus foodborne Infection
Vibrio parahemolyticus is a pathogenic bacterium, whose natural habitat is the sea. Human
infections occur solely from sea foods such as oysters, shrimps, crabs, lobsters, clams and related
shellfish. . Cross-contamination may lead to other foods becoming vehicles.
Symptoms of the disease
V. parahemolyticus causes gastroenteritis and extra intestinal infections in man. The mean
incubation period is 16.7 hrs (range 3-76 hrs) and Symptoms include: diarrhea (95 %), cramps (92
%), weakness (90 %), nausea (72 %), chills (55 %), headache (48 %) and vomiting (12 %).
Symptoms last from 1 to 8 days with a mean
of 4.6 days.
Salmonellosis
The salmonellae constitute a group of organisms with over 2000 different serotypes. These
organisms are capable of causing disease in animals and man when taken into the body in
sufficient numbers. Many salmonella species have a wide host range. These are the organisms
which commonly cause food poisoning. However, some are restricted to a single host species e.g.
Salmonella abortus ovis causing abortion in ewes, and Salmonella gallinarum the cause of fowl
typhoid. Conversely, some salmonella serotypes are associated with human disease and are not
known to affect animals e.g. S. typhi and Salmonella paratyphi. Salmonellae are ubiquitous in the
gut of human and animals and act as sources of food contamination.

FOODBORNE DISEASES
Salmonellosis cont..
People who are carriers of the salmonellae contaminate the food. A heavy dose up to 10,000 -1,000,000
organisms per gram of food is required to cause infection. Salmonellae grow well on food and can exist for a
considerable period in feces, and on pastures.
Common food poisoning serotypes
Some of the salmonella species involved in food poisoning include; Salmonella typhimurium, Salmonella
enteritidis,
Salmonella dublin, Salmonella softenburg, Salmonella virchow, Salmonella montevideo, Salmonella infantis,
and salmonella newport. These species are also involved in causing diarrhoea in animals
Heat resistance
The salmonellae are killed by temperatures attained in commercial pasteurization, They can remain alive in
moist earth for one year and in dry earth for 16 months, They are not destroyed in carcasses or offal
maintained at chilling or freezing temperatures, or in the usual pickling solutions
Transmission
Salmonellae reach food in many different ways;
a) Directly from slaughter animals to food
b) From human excreta, and transferred to food through hands, utensils, equipments, flies etc. Food
poisoning is more likely to occur if the total number of microorganisms present is high. A smaller number may
have no ill effect.

Salmonellosis cont..
Clinical symptoms
The ordinary symptoms include abdominal pain, headache, diarrhea, fever, vomiting,, prostration and
malaise.
• In severe cases there is septicaemia with leucopenia, endocarditis, pericarditis. Severe cases are
encountered in babies, young children , the sick and in elderly persons. The mortality is upto 13 %.
Control measures
Efficient refrigeration and hygienic handling of food, Consumption of properly cooked meat, Complete
thawing of frozen meats and adequate cooking. Heat processing of meat, milk , fish and poultry to destroy
salmonella organisms in food
Escherichia coli food borne infection
Escherichia coli are potential food poisoning pathogens which are widely distributed in low numbers in food
environments. E. coli strains involved in food borne infection fall into the following groups:
1. Enteropathogenic E. coli (EPEC),
2. Enterotoxigenic E. Coli (ETEC),
3. Enteroinvasive E. coli (EIEC) and
4. Enterohemorrhagic E. coli (EHEC).
Each group is composed of unique O:H serotypes. Each group posses virulence factors characteristic of
that group. The serotypes are characterized by using Osomatic and H-flagella antigens.
FOODBORNE DISEASES

Escherichia coli food borne infection
Control measures
Proper cooking of hamburger and other meats, Avoidance of cross-contamination of foods in the
kitchen, and Good personal hygiene.
Listeria monocytogenes infection
Listeria monocytogenes is a gram positive bacterium that is pathogenic to both animals and human
beings. The organism is widespread in nature and is a transient constituent of the intestinal flora excreted
by 1-10% of healthy humans. It is extremely hardy and can survive for many years in the cold in naturally
infected sources.
Vehicle foods
Listeria monocytogenese occurs after consumption of raw vegetables, salads, raw milk, soft cheese,
meat and meat products. milk, ice cream, cheese, poultry, sauerkraut, Salads, sea foods, meat and meat
products
contaminated by Listeria. Delicatessens and other ready-to-eat foods are important in causing Listeria
food poisoning.
Clinical symptoms
In man, Listeria monocytogenes causes abortion in pregnant women and meningitis in newborn infants
and immuno-compromised adults. Pregnant women, infants and elderly people are particularly at risk of
infection with Listeria
FOODBORNE DISEASES

Clostridium perfringens intoxication
This is a food borne intoxication caused by Clostridium perfringens enterotoxin (CPE) produced in the
gastrointestinal tract by enterotoxigenic strains of C. perfringens. The organism is found in the soil, dust,
water, sewage marine sediments, decaying materials, intestinal tracts of humans and other animals. This
organism is a spore-forming, anaerobic, gram positive bacillus.
Food poisoning strains have a variety of origins including human and animal feces, abattoirs, sewage and
flies. Spores produced by these organisms can resist boiling for 4 or more hours. If the spores are present
as contaminants on raw meat they may resist boiling or steaming, and on slow cooling the spores will
germinate into rapidly multiplying bacterial cells, which produce large amounts of toxin.
Cause of intoxication
Clostridium food borne intoxication is caused by the ingestion of food containing large numbers of
vegetative cells of enterotoxigenic C. perfringenstype A and some type C and D strains. These cells multiply
in the intestine and sporulate
releasing Clostridium perfringens enterotoxin (CPE).
Sometimes CPE may be pre-formed in food, and once the food is consumed, symptoms may occur within 1-
2 hours.
Characteristics of CPE
Clostridium perfringens enterotoxin (CPE) is synthesized during sporulation. CPE is heat labile (destroyed
at 60oC for 10
min) and its activity is enhanced by trypsin. Note: The food poisoning strains are heat resistant and survive
FOODBORNE DISEASES

Clostridium perfringens intoxication
Mode of transmission to foods
1. Directly from slaughter animals
2. Contamination of slaughter meat from containers, handlers, dust, and water.
3. Cross -contamination in the kitchen environment.
Symptoms of disease in man
Symptoms appear 6-24 hours after ingestion of a large number of viable vegetative cells up to
5x108/g food, but not after ingestion of spores. Symptoms include nausea, intestinal cramps,
pronounced diarrhea. Vomiting is rare and the illness takes a duration of 1-2 days.
Prevention
1. Proper cooking of food and eating freshly prepared foods.
2. Thorough washing and sanitation of containers
3. Hygiene handling of cooked food
4. Fast cooling of cooked food. Storing food in small quantities will enhance cooling.
5. Proper reheating of cold cooked food before consumption
6. Storage of leftovers or unused foods in freezers
FOODBORNE DISEASES

Clostridium botulinum foodborne Intoxication
Clostridium botulinum food borne intoxication (botulism) is a type of food poisoning caused by
consumption of enterotoxins produced by strains of Clostridium botulinum. C. botulinum is an obligate,
spore-forming anaerobe, and Gram positive bacilli. The strains are divided into proteolytic and non-
proteolytic types according to whether they hydrolyze proteins or not.
The intoxication is caused by botulinal toxins A, B, E, F and G, produced by C. botulinum type A, B, E, F
and G, while the organism grows in food. C. botulinum types C and D produce toxins C and D that cause
disease in animals. Type E strains are non-proteolytic while the rest are proteolytic. Spores of C.
botulinum type A can survive temperatures of 120oC.
Types of foods implicated
Foods associated with anaerobic conditions such as spoiled canned meat, or hams and bacon stacked
without air access, are particularly liable to be infective. Home made fermented foods have been
incriminated, together with smoked, pickled and canned foods that are allowed to stand and then eaten
without adequate cooking. Uncooked fresh foods are safe because they are eaten before the toxin has
had time to develop, while, if foods are cooked, the toxin is destroyed.
Role of preservatives in meat
Nirates/nitrites are used in canned meat as preservatives. The salts reduce chances of growth of C.
botulinun and inhibit toxin production. The danger of botulism has been the deciding factor in the
formulation of food processing techniques, especially canned meat .
FOODBORNE DISEASES

Mode of transmission
1. Contamination of food due to improper handling.
2. Insufficient heating of food to destroy spores.
3. Spores present in animal tissues e.g. meat and fish.
Symptoms of the disease in man
Adult botulism
The period of incubation in man is usually 12-72 hrs). Symptoms include nausea, vomiting, fatigue,
dizziness, headache, dryness of skin, mouth and throat, constipation, lack of fever, nerve paralysis and
great muscular weakness, double vision, respiratory failure and death. Duration of illness 1-10 days and
mortality is high up
to 60-100% of affected persons. The earlier the appearance of symptoms, the higher the mortality rate.
Infant botulism
Occurs in infants less than 1 year of age following ingestion of spores in honey and syrup. The spores
germinate in the gastrointestinal tract with toxin production. A high number of spores are found in feces
of infants during acute phase of the disease. The number reduces as recovery progress. Symptoms are
similar to adult botulism
FOODBORNE DISEASES

Preventive measures
Ensuring proper manufacturing practices e.g. ensure proper sterilization
and preservation of canned meat
• Preserved foods possessing rancid or other odors should be rejected
• Proper heating of food before consumption to destroy heat labile
neurotoxins. Food should be heated to 80oC and temperature maintained
for at least 10 min before eating.
• Picked foods are rendered safe if the brine used contain not less than 10
% common salt, in weaker brines, microorganisms can continue to multiply.
Ensuring fast cooling of food. This will ensure that spores that may be
remaining do not germinate in food.
• Utmost care should be taken in the manufacture of cans, their transport,
handling, storage and subsequent use during packaging of product.
FOODBORNE DISEASES

CHEMICAL FOODBORNE
INTOXICATION
This is a type of food borne intoxication arising from consumption of food containing poisonous
chemicals, These may be intentionally or unintentionally added to foods as a result of producing,
processing, transporting or storage. A number of substances can enter the food chain from the
environment and through their use as
growth promoters or veterinary therapeutics giving rise to chemical residues.
Chemical substances involved
Chemical food borne intoxication involve the following substances:
• Heavy metals e.g. antimony, mercury, arsenic, flouride, lead, cadmium, cyanide etc.
• Pesticides and insecticides e.g. DDT, BHC Organochlorines and organophosphates.
• Herbicides
• Fungicides e.g. organomercurials
Chemical substances involved..
• Preservatives e.g. nitrites, nicotinate, etc
• Antibiotics e.g. pencillin, tetracyclines, chloramphenicol etc.
• Radionuclides e.g. cesium, strontium, radium, molybdenum, barium, ruthenium, lanthanum, iodine
isotopes etc

How chemicals enter foods
 • Accidental contamination by Heavy metals, Pesticides, and radionuclides.
 • Intentional addition e.g preservatives such as nitrite and sodium nicotinate for color preservation and
fungicides used as dressing during storage.
 • Leaching from containers e.g zinc galvanized containers by acid foods, copper surfaces, lead pipes,
asbestos roofs.
 • Usage: Presence of such chemicals in food as a result of use of their use in animal and crop
husbandry
 • Maliciously added to cause harm (is rare).
Preventive measures
 • Do not use utensils or containers that are able to leach chemicals such as antimony, cadmium, zinc,
copper, etc.
 • Use of coloured pesticides and proper storage of the same.
 • Prevent contamination of foods when using insecticides.
 • Prevent acid foods or carbonated liquids from contact with exposed copper.
 Prevent misuse or avoid use of dangerous additive e.g. sodium nicotinate.
 • Education of persons preparing food (e.g. possibility of Zn poisoning).
 • Ensure that withdrawal periods are observed after use of pesticides and antibiotics in animal and
CHEMICAL FOODBORNE INTOXICATION

FIRST AID MEASURES IN THE COURSE OF
FOOD POISONING
First Aid Guide
If you become sick from foodborne illness, resting and drinking plenty of liquids is key.
 Drink Gatorade or water to prevent dehydration.
 Once illness subsides, slowly ease back into eating by trying bland, easy-to-digest foods, such as
crackers, plain toast, bananas, rice, and chicken. Note: Stop eating if your nausea returns. Avoid
dairy products, caffeine, alcohol, nicotine, and fatty or spicy foods for a few days.
 Consider acetaminophen (Tylenol) for relief of discomfort, unless you have liver disease.
 Note: Don't use anti-diarrheal medications; they may slow elimination of bacteria from your system.
Foodborne illness can be prevented by following these general
guidelines:
 Wash your hands before handling food.
 Wash you hands after using the toilet, changing diapers, smoking, blowing your nose, coughing, or
sneezing.
 Wash your hands after touching raw meat or eggs.
 Use plastic (rather than wooden) cutting boards for cutting raw meats.
 Thoroughly clean all surfaces and utensils that came into contact with uncooked meat or eggs.
 Cook meats and eggs thoroughly before eating.
 Do not eat or drink foods made from raw or undercooked eggs, meats, or unpasteurized dairy
products.

SOURCES OF FOOD CONTAMINATION
Food products are rich in nutrients required by microorganisms and
may become contaminated. Major contamination sources are water, air,
dust, equipment, sewage, insects, rodents, and employees.
Contamination of raw materials can also occur from the soil,
sewage, live animals, external surface, and the internal organs of meat
animals. Additional contamination of animal foods originates from
diseased animals, although advances in health care have nearly
eliminated this source. Contamination from chemical sources can occur
through accidental mixing of chemical supplies with foods. Ingredients
can contribute to additional microbial or chemical contamination.
Contamination can be reduced through effective housekeeping and
sanitation, protection of food during storage, proper disposal of garbage
and litter, and protection against contact with toxic substances.

PHYSICAL AND CHEMICAL FACTORS
AFFECTING MICROBIAL GROWTH
Obligate microbes have strict requirements for survival, while facultative microbes can adjust to tolerate
other environmental conditions, such as pH, temperature, oxygen, salinity, and hydrostatic pressure.
Different microorganisms (microbes) need different factors in order to grow and survive. These factors are
physical or chemical properties that define the environment of the microbe. An organism that has a strict
requirements for specific factors in order to survive is said to be obligate for them. Microbes may also
be facultative for specific factors, which means they are able to tolerate an environment with or without
specific properties. There are a variety of environmental factors that affect microbial growth. The most
important physical factors are pH, temperature, oxygen, pressure, and salinity.
pH measures how acidic or basic(alkaline) a solution is, and microbes may grow in either acidic, basic, or
neutral pH conditions. An organism that grows in acidic (low pH of usually 2 or below) conditions is called
an acidophile. An organism that grows in basic (high pH of usually 8.5–11) conditions is called an
alkaliphile. An organism that grows in neutral pH (between 6.5 and 7.5) conditions is called a neutrophile.
Most microbes grow in neutral pH conditions of around pH 7.0, but a number of bacteria can grow in acidic
or basic conditions. Helicobacter pylori is an obligate acidophile bacteria found in the human stomach,
which is a highly acidic environment. The facultative alkaliphile, Bacillus halodurans, is a soil bacterium
whose morphology is dictated by the soil pH; at neutral pH the bacterium takes a coiled shape, and at
basic pH it assumes a rod shape. Many human pathogens are neutrophilic, such as the bacteria E. coli and
Streptococcus pyogenes and the protozoa Naegleria fowleri.

Different microorganisms have evolved to live in different types of environments. Some are able to
live in acidic environments with a pH of 2 or below-these are called acidophiles. H. pylori (scanning
electron microscope) is able to withstand the acidic environment of the human stomach. Other
organisms are able to live in very basic environments of pH 8.5-11 (alkaliphiles), while yet others
require a more neutral environment of around pH 7. E. coli(scanning electron microscope) is an
example of this type of microorganism and is called a neutrophile.
Temperature is another factor that affects microbial growth. Microbes live in all sorts of environments
around the world and have adapted to survival in harsh environments. A mesophile is an organism
that grows at temperatures between 20°C and 45°C. A psychrophile is an organism that grows best
at temperatures below 20°C. An organism that lives in extreme heat is a thermophile, which grows
best between 50°C and 60°C, while hyperthermophiles grow at hot temperatures of up to 120°C.
The presence or absence of molecular oxygen (O2) is a significant factor for microbial growth and
survival. An obligate aerobe is an organism that requires oxygen for survival. Mycobacterium
tuberculosis, the causative agent of tuberculosis, is an obligate aerobe.
Different microbes have different requirements for nutrients, as well as the amount of each nutrient,
that they must acquire. A macronutrient is a nutrient that organisms need in higher concentrations,
while a micronutrient is a substance required in small amounts for an organism's survival. A trace
element is a nutrient that is needed in very small amounts.
PHYSICAL AND CHEMICAL FACTORS
AFFECTING MICROBIAL GROWTH

CAUSES OF FOOD SPOILAGE
There are mainly three types of causes of food spoilage viz. biological, chemical and physical causes.
Biological causes comprise of growth and activity of microorganisms such as bacteria, yeast
and moulds; activity of food enzymes and damage due to pests, insects and rodents etc. Chemical
causes include reaction with oxygen and light and chemical reactions within food constituents.
Physical causes consist of temperature and physical abuse.
All of these factors can act together. For example, bacteria, insects, and light, all can be operating
concurrently to spoil food in a field or in a warehouse. Similarly, heat, moisture, and air at the same
time affect the multiplication and activities of bacteria and chemical activities of food enzymes.
The major types of spoilage that occur in foods are due to microbiological, biochemical, physical and
chemical changes. These include:
Growth and activity of microorganisms such as bacteria, yeast and moulds
Activities of food enzymes, present in all raw foods, promote chemical reactions within the food
affecting especially the food colour, texture and flavour
Inappropriate holding temperatures (heat and cold) for a given food
Gain or loss of moisture
Reaction with oxygen and light causing rancidity and colour changes due to oxidative reactions
Physical stress or abuse
Damage due to pests, insects and rodents etc.
Non-enzymatic reactions in food such as oxidation and mechanical damage

CAUSES OF FOOD SPOILAGE
Spoilage due to growth and activity of microorganisms:
Most significant deteriorative changes occur in foods due to
microorganisms present in air, soil, water and on foods. They use
our food supply as a source of nutrients for their own growth,
which results in deterioration of food and render our food supply
unfit for consumption. Microbes spoil any food in many ways viz.
by increasing their number; by utilizing nutrients; by producing
enzymatic changes; by contributing off-flavours; by breakdown of
a product; and by synthesis of new compounds. The three major
types of microorganisms which cause food spoilage
are bacteria, yeasts andmoulds.

FOOD PRESERVATION METHODS
Food Preservation
Food preservation is the process of treating and handling food to stop or slow down food
spoilage, loss of quality, edibility, or nutritional value and thus allow for longer food storage.
Preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), and other
microorganisms, as well as retarding the oxidation of fats which cause rancidity.
Methods of Food Preservation
A number of methods of prevention can be used that can either totally prevent, delay, or
otherwise reduce food spoilage. Preservatives can expand the shelf life of food and can lengthen
the time long enough for it to be harvested, processed, sold, and kept in the consumer’s home for
a reasonable length of time.
Maintaining or creating nutritional value, texture and flavor is an important aspect of food
preservation, although, historically, some methods drastically altered the character of the food
being preserved. In many cases these changes have now come to be seen as desirable qualities,
as with cheese, yogurt, and pickled onions.
Drying is one of the most ancient food preservation techniques, which reduces water activity
sufficiently to prevent bacterial growth.
Refrigeration preserves food by slowing down the growth and reproduction of microorganisms
and the action of enzymes which cause food to rot.

Freezing is also one of the most commonly used processes for preserving a very wide range of food
including prepared foodstuffs which would not have required freezing in their unprepared state.
Vacuum-packing stores food in a vacuum environment, usually in an air-tight bag or bottle. The
vacuum environment strips bacteria of oxygen needed for survival, thereby slowing spoiling. Vacuum-
packing is commonly used for storing nuts to reduce the loss of flavor from oxidation.
Salting or curing draws moisture from the meat through a process of osmosis. Meat is cured with
salt or sugar, or a combination of the two. Nitrates and nitrites are also often used to cure meat and
contribute to the characteristic pink color, as well as inhibition of Clostridium botulinum.
Sugar is used to preserve fruits, either in syrup with fruit such as apples, pears, peaches, apricots,
plums, or in crystallized form where the preserved material is cooked in sugar to the point of
crystallisation and the resultant product is then stored dry. This method is used for the skins of citrus
fruit (candied peel), angelica, and ginger. A modification of this process produces glacé fruit such as
glacé cherries where the fruit is preserved in sugar but is then extracted from the syrup and sold, the
preservation being maintained by the sugar content of the fruit and the superficial coating of syrup. The
use of sugar is often combined with alcohol for preservation of luxury products such as fruit in brandy or
other spirits. These should not be confused with fruit flavored spirits such as cherry brandy. Smoking
is used to lengthen the shelf life of perishable food items. This effect is achieved by exposing the food to
smoke from burning plant materials such as wood. Most commonly subjected to this method of food
preservation are meats and fish that have undergone curing. Fruits and vegetables like paprika,
cheeses, spices, and ingredients for making drinks such as malt and tea leaves are also smoked, but
mainly for cooking or flavoring them. It is one of the oldest food preservation methods, which probably

Preservative food additives can be antimicrobial. These inhibit the growth of bacteria or fungi,
including mold, or antioxidant, such as oxygen absorbers, which inhibit the oxidation of food constituents.
Common antimicrobial preservatives include calcium propionate, sodium nitrate, sodium nitrite, sulfites
(sulfur dioxide, sodium bisulfite, potassium hydrogen sulfite, etc.), and disodium EDTA. Antioxidants
include BHA and BHT. Other preservatives include formaldehyde (usually in solution), glutaraldehyde (kills
insects), ethanol, and methylchloroisothiazolinone.
Pickling is a method of preserving food in an edible anti-microbial liquid. Pickling can be broadly
categorized into two categories: chemical pickling and fermentation pickling.
Canning involves cooking food, sealing it in sterile cans or jars, and boiling the containers to kill or
weaken any remaining bacteria as a form of sterilization. Foods

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