Cleaner Production in Meat Processing

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1. Introduction

Meat and its products is an important part of diet in many nations, particularly in the developed ones. But also in developing countries the consumption of meat increases. The greatest quantity of red meat is given by beef and pork, but also white meat like poultry indicates an important factor in worldwide meat industry. The largest producers of beef and pork are China and the United States of America followed by Brazil, Mexico, Russia and a number of western countries.

2. General

Life cycle of meat products commences with the production of livestock. Pigs are raised in piggeries, and then they are transported to the abattoir, where they are slaughtered. Carcasses produce sides of meat. Basic steps in this part of cycle are stunning and bleeding, hide removal and hide treatment, evisceration and carcass dressing. Products like carcasses and boned- meat and edible by- products are processed to special products in other meat processing plants or are immediately packaged and retailed. Inedible by- products are converted into animal feed supplements.

The following figures show the main processes in slaughtering pigs or cattle.

Slaughtering of pigs.JPG

Figure 1: Flow diagram of slaughtering pigs

Slaughtering of cattle.JPG

Figure 2: Flow diagram of slaughtering cattel

To get more information about the individual processes in meat producing industry click here

Detailed description on various meat products you will find here

3. By- Products

Beside meat as main product a lot of by- products accrue during the production process. These products can be separated in different groups:

  • Edible offal for consumption of humans like liver, heart, kidney and tongue
  • Edible fats for margarine, sweets and chewing gum
  • Bones for soups for human consumption
  • Blood for human consumption, animal feed, pharmaceuticals and food additives
  • Glycerine
  • Gelatine
  • Rennin
  • Hair for brushes, felts, rugs etc.

4. Environmental impacts

Water consumption:

Water is mostly used for washing and watering livestock, trucks, offal, carcass and cleaning of floors, knives and equipment for assuring hygiene requirements.

Effluent discharge:

Effluents of abattoirs contain many organics because of fat, blood and manure. Other properties are salts, phosphates and nitrates. The dissolved salts can lead to a sality problem because of their soil structure. If the plant is situated near urban areas is it necessary that effluent is discharged to municipal sewage treatment systems.

Energy consumption:

Great part of total consumed energy in abattoirs (80-85%) is thermal energy coming from combustion of fuels for generating steam and water heating. It is used for cleaning, sterilising and rendering. The remaining part (15-20%) is electricity which fuels machinery, refrigeration and ventilation and produce compressed air. Well- working refrigeration and sterilisation are conditions for a good quality of the products. The consumption of energy causes air pollution and greenhouse emissions which is known to be linked to global warming.


By- products can cause problems if they are not handling correctly.

Air emissions:

This aspect is linked to energy consumption. The emissions come from combustion and include oxides of nitrogen and sulphur.


Coming from by- products, effluent stream and biological treatment systems odour can become a serious problem. If we have an upset of microbiological balance hydrogen sulphide and other compound can be released.


Refrigerant systems often use chlorofluorocarbons (CFCs). If they are released to the atmosphere they have a serious effect on the environment. Therefore the systems are often replaced by non- or reduced CFC- systems.


Loud noise can be a problem and should be considered while determining plant location.

5. Cleaner Production opportunities

Water consumption:

The first step is to make an analysis of water use pattern with water meters. The data should be discussed and weak points should be identified. Then a fix minimum rate of water has to be specified to assure the hygiene standards and undisturbed process operations. There is also the possibility to reuse water. Maybe wastewater of one production sector could be used in another one. Defrost water from the refrigeration is generally clean and can be used for non critical applications. Water which was used for washing carcasses can be recirculated. But the reuse of wastewater should not compromise product quality and hygiene and it has to be assured that wastewater lines are not mistaken for fresh water lines. A common technique to remove dissolved solids in wastewater is membrane filtration.

Chechlist watersavings meat.JPG

Figure 3: Checklist of water saving ideas

Effluent discharge:

It is closely linked to “water consumption”. Main object is reducing pollutants in effluents and therefore to capture material like blood and fats before they enter drains. Since blood is one of the greatest sources of organic pollutions in abattoirs its recovery becomes important in respect of CP.

Checklist effluents meat.JPG

Figure 4: Checklist of ideas for reducing effluent loads

Energy consumption:

In this area often no capital investment is necessary and simple better housekeeping and optimisation of existing processes is enough to lower energy consumption. More savings can be made by using improved and more energy-efficient equipment and heat recovery systems.

Checklist energy meat.JPG

Figure 5: Checklist of energy saving ideas

By- products:

Many but not all by- products can be sold on the market. It depends on scale of operation, cultural and culinary characteristics of region and distances to suitable markets. Often it is also possible to convert inedible products into useful product like bone meal and tallow.

Checklist byproducts meat.JPG

Figure 6: Checklist of ideas for maximizing utilisation of by- products

Reference: Cleaner Production Assessment in Meat Processing; prepared by COWI Denmark for UNEP (United States Environment Programs) and Danish Environmental Protection Agency, 2000 Denmark