Fundamental Food Microbiology, Third Edition - Fuad Fathir

444 FUNDAMENTAL FOOD MICROBIOLOGY
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. 1–4
E. Equipment
The most important microbiological criterion to be considered during the design of
food-processing 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
F. 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, 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.
Many types of detergents are available, and they are selected based on the need.
The effectiveness of a cleaning agent to remove soil from surfaces depends on several
characteristics, such as efficiency of emulsifying lipids, dissolving proteins, and
solubilizing or suspending carbohydrates and minerals. In addition, a detergent
should be noncorrosive, safe, rinsed easily, and compatible, when required, with
other chemical agents. The detergents frequently used in food-processing facilities
are synthetic, which can be anionic, cationic, or nonionic. Among these, anionic
detergents are used with higher frequency. Examples of anionic detergents include
sodium lauryl sulfate and different alkyl benzene sulfonates and alkyl sulfonates.
Each molecule has a hydrophobic or lipophilic (nonpolar) segment and a hydrophilic
or lipophobic (polar) segment. The ability of a detergent to remove dirt from a
surface is attributed to the hydrophobic segment of a molecule. They dissolve the
lipid materials of the soil on the surface by forming micelles with the polar segments
protruding outside in the water. The concentration of a detergent at which micelle
formation starts is called the critical micelle concentration (CMC), which varies
with the detergent. The concentration of a detergent is used above its CMC level.
Generally, this is ca. 800–900 ppm, but could be 1000–3000 ppm if skin contact
does not occur (as in the clean-in-place or CIP method) or where a heavy-duty
cleaning is required.