ABSTRACT
Yogurt is defined as a coagulated milk product that results from fermentation of lactic acid in milk by
Lactobacillus bulgaricus
and
Streptococcus thermophilus
. Other
lactic acid bacteria
(LAB) species can be combined with
L. bulgaricus
and
S. thermophilus
. In the finished product, the LAB must be alive and in substantial amounts. LAB have been used for thousands of years to produce fermented food and milk products. Fermented products contain a variety of fermenting microorganisms belonging to various genera and species, all of which produce lactic acid (Meydani and Ha, 2000).
