Illustrates the sources of microbial contamination and their risk assessment technique followed in Food Industries.

1. Microbiological assessment
in
Food Industry
by
A Rehman
B Tech Food Technology

2. Introduction to Microbiological assessment
• Man's food supply consists primarily of plants and animals and
products derived from them.
• Microorganisms are naturally present in the soil, water, and air, and
therefore exterior surfaces of plants and animals are contaminated
with a variety of microorganisms.
• They play an important role in the assessment and maintenance
of food quality and safety in food processing and manufacturing
industries.
• The purpose of microbiological testing is to identify and restrict
harmful microorganisms, which can spoil foods, and ensure safety
from foodborne diseases

3. Sources of Microorganisms in Foods
• From the time of slaughter, catch, or harvest, the surface and interior
tissues of animals and plants are subject to contamination.
• This is due in part to the breakdown of normal defense mechanisms,
particularly in animals.
• Each processing step subjects the raw material to additional
opportunities for contamination.
• Sources of contamination include surfaces of the harvested plant or
slaughtered animal, water, equipment, utensils, workers, and the
processing environment.

4. Control of Microorganisms in Foods
Control must be exercised over
three different categories of
microorganisms that may be
present in foods:
Potential for producing
foodborne disease
Cause food spoilage, and
Grow in food and produce
desirable changes.

5. Control of Microorganisms in Foods (in contd).
• Effective food control programs eliminate the potential for foodborne
illness in a variety of ways.
• Processing techniques that cause destruction of pathogens may be
employed, e.g., the pasteurization of milk to destroy Coxiella
burnetii and Mycobacterium tuberculosis and less heat resistant
pathogens such as the diphtheria bacillus, salmonellae, and pyogenic
streptococci.
• In other cases, toxigenic and infectious microorganisms are controlled
by product formulation (acetic acid in mayonnaise) or storage
conditions (the refrigeration of perishable pasteurized canned cured
meats to control the growth of C. botulinum).

6. Control of Microorganisms in Foods (in contd).
• The control of food spoilage is a prime economic objective of control
programs.
• For products designed to be shelf-stable, control is accomplished
through processing and/or formulation procedures that result in the
inhibition of spoilage organisms.
• With perishable foods, the object is to achieve the longest possible
shelf-life consistent with product safety.
• Since shelf-life and initial level of contamination are usually directly
related in perishable foods, control of remaining microorganisms is
most often achieved by proper refrigerated storage.

7. Microbiological risk assessment in Food Industry
• It is one of the most important tools in food safety management.
• Provides a structured way of identifying and assessing microbiological risks
in food.
• Those responsible for the implementation and maintenance of food safety
plans in processing plants are frequently preoccupied with questions such
as:
How best to identify hazards?
How to determine whether hazards are important or significant?
Where to find information on hazards?

8. Conducting Microbial Risk Assessment (MRA)
There are four main steps in conducting a Microbiological Risk
Assessment:
1. Hazard Identification
2. Hazard Characterization
3. Exposure assessment
4. Risk Characterization

9. Step I: Hazard Identification
• Identifies the micro-organism(s) of concern that may be present in
the food you manufacture.
• The hazards of concern may come from a variety of sources including:
Raw materials
Methods of production, and
Intended use of the food

10. HACCP decision tree template: Hazard identification

11. Step II: Hazard Characterization
• Hazard characterization is an assessment of the pathogen and the
nature of the problems it can cause.
• These questions include:
1
• What is the disease caused by the pathogen?
2
• What are the symptoms and how long before their onset?
3
• What are the range and likelihood of adverse outcomes, e.g. death?
4
• What is the minimum dose required to produce symptoms?
5
• Who are the main 'at risk' groups in the population?

12. Step III: Exposure Assessment
• It determines the level of the microorganism (or toxin) likely to be
present in the food at the time of consumption
Following observations need to be done:
The microbiology of the raw material, e.g. raw meat will have certain pathogens associated with it
Initial contamination levels of raw materials
The effects of production, processing, handling, etc. on the levels of pathogens in the final product
Sanitation standards in your processing plant
Potential for re-contamination after a specific control point, e.g. cooking
Characteristics of the food being produced
Product usage and instructions

13. Step IV: Risk Characterization
• This is the final
step and is
basically the total
score produced at
the bottom of the
model.
• It is the measure
or character of the
risk as assessed by
you.

14. Inspection of Facilities and Operations: USDA vs FDA
• Inspections of facilities and operations are
commonly used to evaluate adherence to
good handling practices.
• The U.S. Department of Agriculture (USDA)
relies almost entirely upon this approach
in the regulation of meat and poultry
operations.
• The FDA inspection program is designed to
determine whether or not processors are
operating in compliance with the Federal
Food, Drug and Cosmetic Act.

15. The Hazard Analysis Critical Control Point
(HACCP) System
• The HACCP system provides a more specific and critical approach to
the control of microbiological hazards than that achievable by
traditional inspection and quality control procedures.
• The system consists of:
identification and assessment of hazards associated with growing,
harvesting, processing-manufacturing, marketing, preparation,
and/or use of a given raw material or food product
determination of critical control points to control any identifiable
hazard(s) and
establishment of procedures to monitor critical control points.