|
|
E-mail conference on Poster
Paper: The Lactoperoxidase System (LP-s) of Milk Preservation |
|
||
|
|
|
|||
|
|
|
(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. |
||
|
|
|
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. 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:
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) 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: |
||
