Enterococcus faecium

The Development of Probiotic-Containing Functional Foods 27
all of which will be discussed in the following sections. This chapter will review
developments in probiotic foods, with particular emphasis on the introduction of
probiotic lactobacilli and bifidobacteria into foods for human consumption, and on
approaches that have been tested for the enhancement of probiotic viability in food
systems to the end of shelf life.
2.2 History of Consumption of Fermented Dairy Foods
The consumption of fermented milks containing bacterial cultures has long been
associated with beneficial health effects, and probiotic cultures have had a long
association with dairy food products. In 76 B.C., the Roman historian Plinio suggested
the administration of fermented milk products for treating gastrointestinal
infection. 10 The original observation of the positive role on health of some bacteria
can be credited to the Russian scientist Metchnikoff. The works of Metchnikoff are
regarded as the birth of probiotics. 11 In 1907, he suggested that the consumption of
foods such as yogurt, kefir, and sour milk containing lactic acid bacteria (LAB) was
associated with good health and longevity, and in his book The Prolongation of
Life he reported that Bulgarian peasants who consumed large quantities of Bulgarian
sour milk lived longer. 12 The Bulgarian sour milk contained the microorganism
Bulgarican bacillus, which was later renamed Lactobacillus bulgaricus, and Metchnikoff
reasoned that these bacteria eliminated putrefactive bacteria from the GIT. 13
Also around the beginning of the 20th century, Tissier, in parallel with Metchnikoff,
proposed that bifidobacteria might be effective in preventing infections in infants,
as they were the predominant component of the intestinal microflora of breast-fed
infants. 14 In 1926, Henneberg proposed the use of an intestinal isolate, Lactobacillus
acidophilus, to produce what he called “acidophilus-milch,” or “reform yogurt.” 15
This concept finally became a success in the 1980s in Germany and other Western
European countries, and the Lactobacillus species used for the fermented product
(referred to as “yogurt mild”) were selected on the basis of their technological properties,
and not their potential health benefits. 15
Probiotic food constitutes a sizeable proportion of the functional food market, 16
and production continues to grow at an exponential rate. The market for fermented
foods containing probiotics is most active in developed countries in Europe, Japan,
Australia, and the United States. 16,17 Within Europe, the dairy sector is the most
developed segment of the market, with probiotic yogurts and fermented milks,
particularly in “daily dose” format, the most widely used. In 1997, these products
accounted for 65% of the European functional foods market, valued at $889 million;
followed by spreads, valued at $320 million and accounting for 23% of the
market. 18 Some probiotic yogurt drinks and yogurts now also contain other bioactive
ingredients such as plant stanols or sterols that lower cholesterol levels. Functional
breakfast cereals and probiotic yogurt drinks and yogurts together accounted for
more than three-quarters of the functional foods market, by value, in 2005–2006,
with cholesterol-lowering margarines, soya milk, and cereal bars representing much
of the balance. Probiotic dietary supplements have been slow to gain acceptance in
Europe, but new applications are emerging all the time.