29 May - 28 July, 2000

 

E-mail conference on
"Small Scale Milk Collection and Processing
in Developing Countries"

 

Poster Paper: The Lactoperoxidase System (LP-s) of Milk Preservation

 


 

 

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(Topic 1: From Farm to Collection Point, Milk Collection, Preservation and Transport)

By: A. Bennett, Dairy Consultant, FAO Rome
 

Background 

Milk represents one of the fastest returns for small-scale livestock keepers.  It is a key element for household food security.  The generation of surplus milk brings income to women and children who are usually in charge of the milk-producing animals such as goats, sheep and cows.  Milk can frequently generate the only regular income for rural families and is therefore essential for their survival.  In remote areas where there is a huge demand for fresh, good quality milk, small-scale milk producers face a major problem in accessing distant markets. Most of the small farmers have no direct access to the market. Middlemen therefore take the biggest share of the consumer milk price. Milk can usually be transported unrefrigerated for up to 20 km but after a certain period will begin to deteriorate. Souring sets in and the milk quickly becomes useless.

 

 


Milk is the last nutritional link between a mammalian mother and her offspring.  As well as providing a complete and balanced diet for the newborn calf, kid or human baby, milk also contains antibacterial agents to protect the sucking young from various infectious diseases.  The knowledge that milk, and particularly colostrum contains immune factors essential for the survival of offspring is not new, and research in Sweden on colostrum in the 1960's led to the discovery of a naturally occurring enzymatic preservation system in milk.  The enzyme is called Lactoperoxidase and through in depth research a system of reactivation was developed using simple activators.  The result is a system of milk preservation, which maintains the keeping quality of milk for 7-8 hours at ambient tropical temperatures (30C). 
 

The system

Lactoperoxidase is an enzyme, which is naturally present in milk.  One of its unique biological functions is an antibacterial effect in the presence of hydrogen peroxide and thiocyanate.  Both of these substances are naturally present in milk in varying concentrations.  The method of activating LP-s in milk to add about 10 PPM of Thiocyanate (preferably in powder form) to the raw milk to increase the overall level to 15 PPM (Parts Per Million, 5 PPM naturally present).  The solution is thoroughly mixed for 30 seconds and then an equimolar amount (8.5 PPM) of hydrogen peroxide is added (generally in the form of a granulated sodium carbonate peroxyhydrate). The activation of the Lactoperoxidase has a bacteriostatic effect on the raw milk and effectively extends the shelf-life of the raw milk under tropical conditions for 7-8 hrs.  This means that producers can then transport the milk from the collection point to a processing centre and thereby significantly increase the income generated at farm and producer group level.

After 15 years of field experiments in developed and developing countries, a Code of Practice for the use of an alternative milk preservation method based on the activation of the natural enzymatic antibacterial complex in milk (Lactoperoxidase system) was approved by the FAO/WHO Expert Committee on Food Additives in 1989 and by the Codex Alimentarius Commission in 1991.  The system is cheap, easy to use and readily applicable in developing countries with a minimum of training requirements.

The World Bank estimates that 20% of all milk produced is wasted in developing countries.
The use of LP-s in raw milk means that a larger quantity of milk can be collected and processed from areas where there is a lack of dairy infrastructure.  Small scale producers, (often women), will therefore have increased incomes through the sale of surplus production, there is a ‘liquid’ benefit to the consumer and milk production will be stimulated.
They will have an increased opportunity to market their surplus milk to the urban centres and also to reduce milk losses.  This will result in a substantial increase in cash income for the household. Up to 40% of an increase in production of milk available for processing can result when the system is adopted. The penultimate beneficiaries will be the consumers who will have fast access to safe, quality milk.
 
 

Adoption

In countries with an advanced dairy industry, cooling safeguards the bacterial quality of the raw milk and prevents spoilage. However cooling is rarely an applicable preservation technique for small-scale producers in developing countries due to the absence of reliable electrical supply or economic constraints.

An opportunity now exists for the women smallholders, who have the responsibility for marketing of surplus milk, due to the following reasons:
 

  • There is an increasing trend to privatise the dairy industry in developing countries and countries in transition. 
  • Many small milk processing industries have emerged and are trying to develop their milk collection system 
  • The demand for fresh milk by the urban population is growing very fast.

One of the limiting factors is the availability of a safe, cheap and easy to use system of milk preservation. With a cheap, flexible method of preservation of milk from farm to the dairy many families can have their household income increase by a minimum of 50% within 6 months.

LP-s does not function as an end product treatment.  It is a processing aid, which enhances the naturally occurring antibacterial system in milk.  It is therefore essential that the quality of the raw milk is good and thus training in clean milk production is complementary to the demonstration of the Lactoperoxidase system of milk preservation.  The system is described by Codex Alimentarius as intended for utilisation in the following situations:

"3.1 The method should be used only in situations when technical, economical and/or practical reasons do not allow the use of cooling facilities for maintaining the quality of raw milk.  Use of the LP-s system in areas which currently lack an adequate infrastructure for collection of liquid milk, would ensure the production of milk as a safe and wholesome food, which otherwise would be virtually impossible.

3.2 The method should not be used by the individual farmers but at a suitable collection point/centre.  These centres must be equipped with proper facilities for cleaning and sanitising the vessels used to hold and transport milk.

3.3 The personnel responsible for the collection of milk should be in charge for the treatment of the milk. They should be given appropriate training including training in general milk hygiene, to enable them fulfil this in a correct way.

3.4 The dairy processing the milk collected by use of the Lactoperoxidase system should be responsible for ensuring that the method is used as intended.  This dairy should set up appropriate control methods to monitor usage of the method, raw milk quality and quality of the milk prior to processing.

3.5 The method should be used to prevent undue bacterial multiplication in raw milk during collection and transportation to the dairy processing plant under condition stated in 3.1.  The inhibitory effect of the treatment is dependent on the temperature of the stored milk and has been found to act for the following periods of time in laboratory and field experiments carried out in different countries with raw milk of an initial good hygienic standard:
 

Temperature (C)  Time (h)
             30                  7-8
             25                11-12
             20                16-17
             15                24-26

Source: CAC/GL 13-1991

The use of the Lactoperoxidase system does not exclude the necessity of pasteurisation of the milk before human consumption.  Neither does it exclude the normal precautions and handling routines applied to ensure a high hygienic standard of the milk"
 

Implementation

In recognition of the huge potential and demand for the use of such a safe and cheap system of raw milk preservation, FAO, with the support of the Swedish government prepared to disseminate and advise developing countries on the adoption of the LP-s.  A panel of 11 experts drawn from the 5 continents convened in Uppsala in 1998 to launch the Global Lactoperoxidase Programme, which is based at FAO HQ in Rome.  The objective of the programme is to facilitate the uptake of the system in developing countries and countries in transition.

The main activities of the programme will include national and regional demonstrations of the application of the system at field level including the provision of training as detailed in the guideline.  Participating government will in collaboration with regional and national institutions identify areas or zones in which milk infrastructure is inadequate for collection of milk produced. The programme will invite participation of both public and private parties to demonstrations but with an emphasis on women who are the main decision-makers regarding milk and milk marketing in the majority of developing countries

A total of 80 countries have to date registered their interest in participating in the FAO Global Lactoperoxidase Programme.  FAO, with the support of the Swedish, Irish, Hungarian and Czech Governments is promoting the uptake of Lactoperoxidase as a safe and effective method of milk preservation. 

For further information contact:
Jeanclaude.lambert@fao.org
The Global Lactoperoxidase Programme Secretariat
Animal Production and Health Division
FAO, 00100, Rome, ITALY
Tel: 003906 57053327
Fax: 003906 57055749

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The Codex Alimentarius approved guideline CAC/GL 13-1991 
 
 

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