Abattoir Practices and Animal Products Technology

CLEANING OPERATION

• An ample supply of good, hygienic, soft and hot water at a temperature of not less than 82° C and adequate number of hose points are essential.
• The usual method of applying hot water in meat plant is through high-pressure jet cleaners with 14kg f/cm². 
• The manual operation of spray guns in which the pressure is in the 35-49 kg f/cm² range, the volume of water being low, averaging about 9 litres/minute.  
• Application of detergent followed by sanitizer or a combination of both is necessary for an actual meat premises under adequate pressure and temperature (not less than 14 kg f/cm² and 82°C).
• Dry cleaning should commence immediately after operations have ceased and should embrace the whole premises, where disinfectant should be used.
• This good system will ensure the final daily operation after the completion of slaughtering rendered more effectively.
• Cleansing operations must be done frequently to prohibit any built-up of bacteria on trolleys, hooks, gambrels, etc., which come in contact with the meat.  
• Instead of using highly sophisticated cleansing installations, manual cleansing has been found to be more effective in some parts of the slaughterhouse.
• It is essential to have a schedule of cleansing.
• It involves a constant use of cold hosing and a daily application of hot water (82°C) plus detergent.
• At less frequent intervals other cleansing methods may be necessary.
• Recently two methods of detergency have been introduced which greatly reduce the need for manual work. They are foam and gel cleaning .
• The foam or gel adheres to the surfaces allowing time for the chemical to breakdown the soil, which is then rinsed away with hot water under pressure.
• Depending on whether protein or fat is to be removed an acid or an alkaline compound respectively is used.
• The foam and gel cleaning solutions are usually applied rapidly through a lance from a unit operated by compressed air or by an electrically operated compressor.
• 45 litres of foam solution expands to 729-909 litres, sufficient to cover 55.7 – 92.9 cm² of surfaces in 15-20 minutes.
• The gel does not collapse and can be applied in a very hot form and is useful for thin, tenacious protein or fat films where longer contact times and/or heat may be advantageous.

Advantages of foam cleansing

• It saves on labour. Surface areas can be covered in a relatively short time. It can penetrate inaccessible areas, often eliminating the need for the dismantling of equipment.
• It is economical since the foam clings to surfaces and does not run to waste. Foam can effectively substitute for other cleansing compounds in the cleaning schedule.
• It is biodegradable and does not give rise to effluent problem. Foam does not splash and is comparatively safe to use, although strong alkalis and acids must be used with care.