Fish Microbiology and Quality Assurance

Unit 7 - Sanitation and microbiological quality

7.4.2. Clean- up procedure
The absolute cleanliness of personnel, equipment and premises is very important at all stages of food production. The main objective of cleaning is to minimize the risk of cross contamination between foods and also from waste food material left on equipment and food contact surfaces.
The clean-up procedure in food processing industry assures;

• Protection of food from contamination by pathogenic microorganisms that can cause disease in consumers.
• Protection of food from spoilage organisms that can cause deterioration in the quality of food.
• Maintenance of good standards of cleanliness which helps minimizing the risk of rodent and insect infestation.

A good clean-up procedure generally consists of initial cleaning procedure followed sanitation phase.
Cleaning phase
Cleaning can be defined as the removal of all dirt, slime, blood, curry, oil, grease and any food soil from all food contact surfaces. This operation is accomplished with the aid of a detergent which when added to water helps to remove all kinds of dirt effectively.The basic steps involved in cleaning phase are initial rinsing with cold water followed by scrubbing with warm water and detergent, and final rinsing with cold water.
Sanitizing phase
Sanitizing or disinfecting phase is the parts of the cleaning operation wherein surfaces and equipment are rendered microbiologically clean by using sanitizers. Sanitizing is done after cleaning phase and it involves cleaning using sanitizers followed by final rinse with cold water.

The cleaning operation involves separation of dirt/soil from the object to be cleaned, carrying the dirt away and its suitable disposal using detergent, leaving the surface being cleaned in the desired condition and disinfection when desirable.
Selection of a suitable cleaning solution or detergent is necessary to achieve effective cleaning as it depends on various factors such as neutralization, pH, alkalinity, buffering capacity, surface tension, wetting ability, mechanical action, emulsification, deflocculation, etc. Several types of mechanical aids are available for use in food industry for cleaning and sanitation purpose.

Guidelines for the use of sanitizers
The following guidelines should be followed in attaining effective sanitation in a food industry.

• Sanitizer should never be used as a substitute for thorough cleaning.
• Sanitizers should be used as an additional safeguard to thorough cleaning.
• Should not be used where sterilization need to be achieved. Because, sterilization aims at destroying or removing all microbial life, whereas sanitization does not kill all microorganisms, but help to reduce microbial load.

The detergents used for cleaning purpose should be inexpensive, approximately neutral (pH 6-8), biologically degradable, easy to wash away, non-toxic and approved by the appropriate regulatory body for food use.
The sanitizer used in the food industry should possess good bactericidal activity and active against a wide variety of organisms, be non-toxic or low in toxicity, not affect the colour, odour and flavour of the food, be fairly cheap, be easy to dispense and wash away, should not adversely affect the operators and food handlers and should not cause damage to surfaces being sanitized (Ex. equipments).

Common sanitizing agents
The most commonly used sanitizing agents in food industry are chlorine, iodine and phenolic compounds. Chlorine is more commonly used than the other two in food processing plants. It is the least expensive and readily available in several forms. Iodine is more expensive and is not easily available, but is more effective than chlorine even in low concentrations. Phenolic compounds are not used in fish processing plant as their use even in very small quantities leaves a long lasting odour and bad taste.

Degree of cleanliness
Equipment, object or any food contact surface is considered clean only when it is clean physically, chemically and microbiologically. The object or the surface is considered physically clean when it appears clean by sight and feel. This is easy to achieve as this can be easily tested by close observation. Chemica cleanliness of an object or surface refers when the object or surface is free from traces of undesirable chemicals (too small to be seen or felt, but sufficient to influence the quality of the product). Even traces of some chemicals can affect the taste, odour, colour or keeping quality of the food product. – The object or surface is considered microbiologically clean when it is free from undesirable microorganisms. This kind of cleanliness can be tested by determining the kind and number of microorganisms left on the object cleaned, decrease or increase of bacterial load of the product at the end of the processing line, and keeping quality of the product.