446 Chapter 17
ST and LB is considerably higher than by
either of the two organisms grown separately.
The acid - producing ability of yogurt culture
in mixes containing 8% sucrose is fairly good.
Bacteriophages, virus - like microbes, kill
bacteria by their lytic action. Phage infec-
tions lead to loss in rate of acid production.
The yogurt fermentation process is relatively
fast (two and a half to four hours).
Sweeteners. Nutritive carbohydrates
(mainly sucrose) are frequently used in yogurt
manufacture. High - intensity sweeteners (e.g.,
aspartame, sucralose, neotame, acesulfame
K, etc.) are used to produce light yogurt con-
taining about 60% of the calories of normal
sugar - sweetened yogurt. Low levels of crys-
yogurt starter is shown in Table 17.16. Also,
shown are some additional organisms found
in yogurt or yogurt - like products marketed
in various parts of the world. In some coun-
tries of Europe , Lactobacillus bulgaricus is
replaced with Lactobacillus lactis to produce
“ mild ” yogurt.
The infl uence of temperatures of incuba-
tion on the growth of yogurt bacteria is
shown in Table 17.17. Acid production is
normally used as a means of assessing the
growth of yogurt culture.
Yogurt starter organisms display an obli-
gate symbiotic relationship during their
growth in the milk medium. The rate of acid
production by a yogurt starter containing both
Figure 17.4. Types of commercial yogurt.
YOGURT
Hard and Soft Frozen
Yogurt
Yogurt with fiber,
probiotics,prebiotics
Yogurt for Breakfast
Greek Yogurt
Long Life Yogurt
(UHT)
Yogurt
Smoothies
Plain Yogurt
Whipped
Yogurt
Mousse
Low-calorie/Light
Yogurt
Fruit flavored Yogurt