Fish Microbiology and Quality Assurance

Unit 7 - Sanitation and microbiological quality

7.3. Microbiological standards and criteria
Control on the microbiological quality of food is ensured by the regulatory agencies and food industry. This is done to ensure the safe of food to consumers, extend shelflife and to ensure product consistency from one batch to another in terms of safety and shelflife. Distinguishing the food of acceptable quality from food of non – acceptable quality is made possible with the application of microbiological criteria.

The purpose of microbiological criteria
The purposes of microbiological criteria for foods are to give assurance that;

• The foods will be acceptable from the public health stand point. That is, the food will not be responsible for the spread of infectious diseases or for food poisoning.
• The foods will be of satisfactory quality. That is, the food will consist of good original materials that have not deteriorated or become contaminated during processing, packaging, storage, handling etc.
• The foods will be acceptable from aesthetic view point. That is, it is free from extraneous material such as hair, scales, plastics etc.
• The foods will have keeping quality that should be expected of product.

Establishing microbiological criteria for a food product is based on factors such as total number of organisms, number of indicator organisms and number or absence of pathogens.

Types of microbiological criteria
Three types of microbiological criteria have been defined by the International Commission on Microbiological Specifications for Food (ICMSF). They are;

• Microbiological standard
• Microbiological specification
• Microbiological guideline
  

Microbiological standard
Microbiological standard is a criteria specified in a law or regulation for a specific food. It is a legal requirement that foods must meet and is enforceable by the appropriate regulatory agency.
Microbiological standard is that part of the law or administrative regulation designating maximum acceptable number of microorganisms or specific types of microorganisms as determined by prescribed methods in a food produced, packed or stored or imported into the area of jurisdiction of an enforcement agency.

Microbiological specifications
Microbiological specification is the maximum acceptable number of microorganisms or of specific types of microorganisms as determined by prescribed methods in a foods being purchased by a firm or agency for its own use.
Microbiological specification is the criteria applied in commerce. It is a contractual condition of acceptance that is applied by a purchaser. Failure to meet the condition by supplier will result in rejection of the batch or a lower price.

Microbiological guideline
A microbiological guideline is that level of bacteria in a final product that requires identity and correction of causative factors in current and future production or handling after production.
It is used to monitor microbiological acceptability of a product or process. It differs from standard and specification in that it is advisory in nature rather than mandatory.

Factors to be included in suggesting a microbiological criteria (ICMSF)

• A statement of the food to which the criteria applies. As foods of different origins, composition and processing provide different microbial habitats; different foods pose different spoilage and public health problems.
• A statement of the microorganisms or toxin of concern. These include spoilage and health aspects. A realistic decision has to be made based on microbial ecology of food in question.
• Details of the analytical methods to be used to detect and quantify microorganisms/toxins. Methods elaborated by international agencies, and scientific methods that confirm the compliance with guidelines to be used.
• The number and size of the samples to be taken from a batch of food or from source of concern such as a point in a processing line.
• The microbiological limits appropriate to the product and the number of sample results which must conform with these limits for the product to be acceptable.