Control of Access of Microorganisms: Cleaning, Sanitation, and Disinfection ◾ 437
Pseudomonas spp. This is particularly important for foods kept at low temperatures for extended
shelf life. The ice used for chilling unpackaged foods also should not contaminate a food with
pathogenic and spoilage bacteria or viruses. Water used for chilling products, such as chicken at
the final stage of processing, can be a source of cross-contamination of a large number of birds
from a single bird contaminated with an enteric pathogen. Similarly, the warm water used to
defeather chickens can be a source of thermoduric bacteria.
Brine and curing solutions used in products, such as ham, bacon, turkey-ham, and cured beef
brisket can be a source of microbial contamination. To reduce this, brine and curing solutions
should be made fresh and used daily. Storing brine for extended periods before use may reduce the
concentration of nitrite through formation and dissipation of nitrous oxide and may reduce the
shelf life of the products.
Quality of Air
Some food-processing operations, such as spray drying of nonfat dry milk, require large volumes
of air that come into direct contact with the food. Although the air is heated, it does not kill all the
microorganisms present in the dust of the air and thus can be a source of microbial contamination
of foods. The installation of air inlets to obtain dry air with the least amount of dust and filtration
of the air is important to reduce microbial contamination from this source.
Training of Personnel
A processing plant should have an active program to teach the plant personnel the importance of
sanitation and personal hygiene to ensure product safety and stability. The program should not
only teach how to achieve good sanitation and personal hygiene but also monitor the implementation of the program. People with an illness and infection should be kept away from handling the
products. Some kind of incentive to the workers might help make the program efficient. 4,5
Equipment
The most important microbiological criterion to be considered during the designing of foodprocessing equipment is that it should protect a food from microbial contamination. This can be
achieved if the equipment does not contain dead spots where microorganisms harbor and grow
or that cannot be easily and readily cleaned in place or by disassembling. Some of the equipment,
such as meat grinders, choppers, or slicers and several types of conveyor systems, may not be
cleaned and sanitized very effectively and therefore serve as a source of contamination to a large
volume of product. This is particularly important for products that come in contact with equipment surfaces after heat treatment and before packaging. 1,4
Cleaning of Processing Facilities
Cleaning is used to remove visible and invisible soil and dirt from the food-processing surroundings and equipment. The nature of soil varies greatly with the type of food processed, but chemically, it consists of lipids, proteins, carbohydrates, and some minerals. Although water is used for
some cleaning, to increase efficiency of cleaning and to break down fatty micelles, heat, chemical
agents, or detergents are used with water. In addition, some form of energy with the liquids, such
as spraying, scrubbing, or turbulent flow, is used for better cleaning.
Pseudomonas spp. This is particularly important for foods kept at low temperatures for extended
shelf life. The ice used for chilling unpackaged foods also should not contaminate a food with
pathogenic and spoilage bacteria or viruses. Water used for chilling products, such as chicken at
the final stage of processing, can be a source of cross-contamination of a large number of birds
from a single bird contaminated with an enteric pathogen. Similarly, the warm water used to
defeather chickens can be a source of thermoduric bacteria.
Brine and curing solutions used in products, such as ham, bacon, turkey-ham, and cured beef
brisket can be a source of microbial contamination. To reduce this, brine and curing solutions
should be made fresh and used daily. Storing brine for extended periods before use may reduce the
concentration of nitrite through formation and dissipation of nitrous oxide and may reduce the
shelf life of the products.
Quality of Air
Some food-processing operations, such as spray drying of nonfat dry milk, require large volumes
of air that come into direct contact with the food. Although the air is heated, it does not kill all the
microorganisms present in the dust of the air and thus can be a source of microbial contamination
of foods. The installation of air inlets to obtain dry air with the least amount of dust and filtration
of the air is important to reduce microbial contamination from this source.
Training of Personnel
A processing plant should have an active program to teach the plant personnel the importance of
sanitation and personal hygiene to ensure product safety and stability. The program should not
only teach how to achieve good sanitation and personal hygiene but also monitor the implementation of the program. People with an illness and infection should be kept away from handling the
products. Some kind of incentive to the workers might help make the program efficient. 4,5
Equipment
The most important microbiological criterion to be considered during the designing of foodprocessing equipment is that it should protect a food from microbial contamination. This can be
achieved if the equipment does not contain dead spots where microorganisms harbor and grow
or that cannot be easily and readily cleaned in place or by disassembling. Some of the equipment,
such as meat grinders, choppers, or slicers and several types of conveyor systems, may not be
cleaned and sanitized very effectively and therefore serve as a source of contamination to a large
volume of product. This is particularly important for products that come in contact with equipment surfaces after heat treatment and before packaging. 1,4
Cleaning of Processing Facilities
Cleaning is used to remove visible and invisible soil and dirt from the food-processing surroundings and equipment. The nature of soil varies greatly with the type of food processed, but chemically, it consists of lipids, proteins, carbohydrates, and some minerals. Although water is used for
some cleaning, to increase efficiency of cleaning and to break down fatty micelles, heat, chemical
agents, or detergents are used with water. In addition, some form of energy with the liquids, such
as spraying, scrubbing, or turbulent flow, is used for better cleaning.