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

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Milk and dairy products in human nutrition
The demand for milk in developing countries is expected to increase by 25 percent
by 2025 (FAO, 2008a). Small-scale livestock holders supply the vast majority of this
milk, and dairy animals provide household food security and a means of fast returns
for them. About 180–200 million people belong to pastoral societies that raise livestock
using natural rangelands as the main forage (Degen, 2007). These rangelands are in
deserts, mountains and steppes – land that cannot be cultivated or used for agricultural
purposes – and cover almost 25 percent of the world’s land surface (Degen, 2007).
Pastoralists traditionally keep more than one species of livestock in order to make
the most of the rangelands, as some species are mainly grazers (e.g. sheep and cattle),
while others are better browsers (e.g. goats and camels). Diversifying in this manner
also reduces risk from disease or extreme environmental conditions (Degen, 2007).
The majority of papers published on milk composition relate to fat and fatty acid
(FA) profiles. Milk protein is also well covered, total protein content being one of
main quality criteria applied to milk payment to producers in many countries where
milk is priced according to composition (others being fat and solids-non-fat) (FAO,
2004). The literature mainly deals with cow milk, followed by goat and sheep milks;
buffalo milk is poorly represented, given that globally buffalo milk production
is second only to cow milk. The composition of milk from minor dairy animals
(animals other than cows, buffalo, goats and sheep, which contribute 0.2 percent of
world milk production) has so far received little research attention. This is unfortunate,
as some of them (donkey, reindeer, yak, Bactrian camel, moose, musk ox,
llama, alpaca and mithun) are underutilized, that is, “species with underexploited
potential for contributing to food security, health and nutrition, income generation
and environmental services” (FAO, 2008b).
Knowledge of differences in nutrients in milk from various species facilitates
development of products for consumers with specific needs, e.g. substitutes for
cow milk for people with cow milk allergy (Park and Haenlein, 2006; Suutari et al.,
2006), and milks formulated for the rehabilitation of malnourished individuals and
other nutritionally vulnerable groups.
In the future, the composition of milk could be tailored to meet demand within
each national economy: for example, the American and Canadian markets have an
oversupply of lactose, which is disposed of for minimal returns, while the British
market has an unmet demand for fat and an oversupply of protein (Karatzas and
Turner, 1997). Specific industrial demands could also be met, such as milk with a
high casein content for the cheese industry.
There are difficulties associated with using the available literature to draw
meaningful conclusions about the milk composition of different species because few
studies provide detailed information on management, season, feed etc – factors that
affect milk composition (see Section 3.2.3 Factors affecting milk composition). The
multiplicity and variation in analytical methods (e.g. for assessing protein, fat and
carbohydrate contents) can also lead to differences in results. The testing methods
can also vary: some are actual research studies under controlled conditions, while
others analyse data gathered from records.
In this chapter we examine the composition of milks consumed by humans that
are produced by both major and minor dairy animals. The second part of the chapter
focuses on current FAO definitions and classifications of milk products, together
with the impact of processing on nutrient profiles. FAOSTAT definitions are given