ABSTRACT
Although there are no records available regarding the origin of yogurt, it is thought that it was rst found as early as 2000 bc in mid-Eastern civilizations as a way to preserve milk. The word yogurt is Turkish in origin. The ancient Assyrian word for yogurt, “lebeny” meant life. Surprisingly, the word “probiotic” can literally be translated to “for life.” There has been a longstanding belief that eating yogurt or the consumption of some types of cultured milk products is associated with longevity due to the friendly bacteria’s ability to ght disease. According to the legends, Abraham owned his fruitfulness and longevity to yogurt. This legend was later turned into a theory by Elie Metchnikoff (1845-1916) who devoted the last decade of his life to investigating the means of increasing human longevity and advocating the consumption of lactic acid-producing bacteria. His works toward understanding the role of lactic acid bacteria in the improvement of the immune system wheeled the scienti c researches on yogurt and fermented milks. In parallel to the development in human history, yogurt production evolved as well. This evolution can be summarized as follows:
The use of the same utensils in the manufacture• The addition of fresh milk onto fermented milk to provide sustainability in • production Boiling of milk in open vats to obtain a more viscous product with extended • shelf life The use of the previous day’s soured milk to ferment the fresh milk• Improvement of the aroma/ avor of yogurt by incorporating acid-resistant • lactic acid bacteria in the manufacture
Since the mid-19th century, a rapid evolution in yogurt science and technology was noted. The developments in the eld of yogurt science, technology, and microbiology are chronologically presented below:
1910-1925 The longevity theory developed by Metchnikoff stimulated the researches on the relationship between yogurt consumption and healthy life.
