Milk-and-Dairy-Products-in-Human-Nutrition-FAO

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Milk and dairy products in human nutrition
• direct expansion coolers/bulk tanks
• immersion cooling
• solar-powered cooling systems (limited success)
• evaporative cooling using a moist cloth over the metal container or porous
charcoal in an outer ring surrounding the milk container (limited success)
• enzyme-based preservation technologies. FAO has successfully promoted
adoption of the Codex-Alimentarius-approved Lactoperoxidase System to
delay deterioration of raw milk and the commercial sector is exploring
other options.
Whichever system is chosen, it must be cost-effective in the given market.
Milk is processed to extend shelf-life and eliminate pathogens. Heat treatment
is the most common technique. Pasteurization (heating to 72 °C for 15 seconds)
is based on the time–temperature combinations needed to destroy Mycobacterium
bovis (see Chapter 6). Low-cost, in-pouch processing has been successfully introduced
by FAO in a number of countries (Dugdill, 2000).
The ultra-high temperature (UHT) process (heating milk to more than 135 °C
for one to two seconds before aseptic packaging) extends the shelf-life of milk at
room temperature. This obviates the need for a cold chain but does require both
high-quality raw milk for processing and a high level of investment in equipment,
packaging, expertise and infrastructure. There is increasing interest in extended
shelf-life technologies using high-temperature pasteurization and non-aseptic packaging
measures to extend milk-shelf life. The non-aseptic packaging techniques use
much less sophisticated and more easily managed technology, such as in-container
autoclave preservation of long-life milk.
Other techniques such as fermentation, cheese-making, concentration and
dehydration, usually incorporate heat treatment. The choice of process is influenced
by consumer preference, local cultures and traditions and scale of operation.
In South Asia, milk sweets and curds account for a significant percentage
of milk usage while cheese making is the preferred method in Latin America.
In dairy exporting countries, large-scale milk powder, butter and cheese making
operations predominate. Much of the milk processed in developing countries is
handled in small-scale processing units using appropriate processing technologies
for liquid milk and traditional milk products from a range of animal species in the
different regions.
A well-organized collection system linking producers with the market is essential
for the success of DIDPs. A project coordinated by FAO and involving the Government
of Uganda, the African Development Bank, DANIDA, UNDP, WFP and
other partners helped rebuild the Uganda dairy industry after the civil war, boosting
milk availability from only 235 000 litres annually from just 500 farmers in 1986 to
26.1 million litres from 8 000 farmers by 1992. Under this programme the parastatal,
government-owned Dairy Corporation was restructured and returned to profit;
64 milk collecting centres were set up or re-established; donated milk powder was
monetized through the Dairy Development Committee (DDC), which channelled
funding into dairy development; the Entebbe Dairy Training School and processing
plant revived; and the DDC (and residual funds) became the forerunner of the
current Dairy Development Authority. The Dairy Corporation was privatized in