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

Chapter 3 – Milk and dairy product composition 75
Kephir (kefir)
Kephir is a viscous, highly acidic beverage produced from cow, goat, sheep or mare
milks which can contain various amounts of alcohol and carbon dioxide (Sarkar,
2007; Ribeiro and Ribeiro, 2010). The fermentation is initiated by “kephir grains”
(clusters of yeast and bacteria), which are added to milk; hence, kephir belongs to
the yeast–lactic fermentation category. Kephir is made from raw, pasteurized or
UHT-treated milk. The milk is poured into a clean container, the kephir grains are
added and the milk is left to stand for about 24 h. The milk is then filtered to retrieve
the kephir grains, which are used to produce the next batch of kephir. The grains are
passed from generation to generation in households in the Caucasus, where they are
considered a source of family wealth (Lopitz-Otsoa et al., 2006).
While kephir is produced commercially in many countries, particularly in Eastern
Europe, it is made in homes in countries as widespread as Argentina, France,
Portugal, Taiwan and Turkey (Farnworth, 2005, cited in Ribeiro and Ribeiro,
2010). Kephir has both therapeutic attributes and nutritional attributes, such as
high contents of thiamine, riboflavin, pantothenic acid and vitamin C (the vitamin
content varying with milk source and supplementary flora), protein (with a higher
protein content when kephir grains were cultured in whey or soy milk) and minerals
(Sarkar, 2007). Kephir also contains greater amounts of threonine, serine, alanine
and lysine than does milk (Guzel-Seydim et al., 2003, cited in Sarkar, 2007).
According to the CODEX standard for fermented milks (FAO and WHO,
2010f), kephir should contain a minimum of 2.7 percent milk protein m/m and less
than 10 percent milk fat m/m.
Kumys (kumiss, koumiss)
This fermented product, generally made from equine or goat milk, is consumed in
Russia and western Asia primarily for its therapeutic value. Equine milk cannot be
used to produce cheese as no curd is formed on addition of rennet. However, it forms
a weak coagulum under acidic conditions and this is exploited in the production of
yoghurt-type products such as kumys (Uniacke-Lowe, Huppertz and Fox, 2010).
In Mongolia, kumys, called airag, is the national drink and distilled kumys, arkhi,
is also produced (Kanbe, 1992, and Ørskov, 1995, cited in Uniacke-Lowe, Huppertz
and Fox, 2010). Kumys belongs to the yeast–lactic fermentation group, where
alcoholic fermentation using yeasts is used in combination with lactic-acid fermentation
(Tamine and Marshall, 1984, cited in Uniacke-Lowe, Huppertz and Fox, 2010).
Kumys contains about 90 g of moisture /100 g, 2.1 g of protein /100 g (1.2 g of casein
/100 g and 0.9 g of whey proteins/100 g), 5.5 g of lactose/100 g, 1.2 g of fat/100 g and
0.3 g of ash/100 g, as well as the end-products of microbial fermentation, i.e. lactic acid
(1.8 g/100 g), ethanol (0.6–2.5 g/100 g) and CO 2 (0.5–0.9 g/100 g) (Uniacke-Lowe,
Huppertz and Fox, 2010). Up to 10 percent of the equine milk proteins are reported
to be hydrolysed after 96 hours (Berlin, 1962 cited by Uniacke-Lowe, Huppertz and
Fox, 2010; Tamine and Marshall, 1984, cited by Uniacke-Lowe, Huppertz and Fox,
2010). Kumys is thought to be more effective than raw equine milk in the treatment
of various illnesses because it contains additional peptides and bactericidal substances
from microbial metabolism (Doreau and Martin-Rosset, 2002, cited in Uniacke-Lowe,
Huppertz and Fox, 2010). According to the CODEX standard for fermented milks
(FAO and WHO, 2010f), kumys should contain less than 10 percent milk fat m/m.