342 Chapter 13
syrup and stabilizer or emulsifi er. Frozen
yogurts can be classifi ed into three groups:
soft, hard, and mousse. The product resem-
bles ice cream with the characteristic sharp
acid taste of yogurt and coldness of ice
cream. The high level of sugar and emulsifi er
or stabilizer added to the product is necessary
to maintain the air bubble structure during
the freezing process (Tamime and Robinson
2007 ).
Soft frozen yogurt is made by mixing a
cold yogurt base (80%) with a 20% fruit
syrup base and stabilizer or emulsifi er, and
then freezing in an ice cream freezer at
− 6 ° C (21 ° F). The frozen yogurt is then
packed and stored at 0 o C (32 o F0 to − 6 o C
(21 ° F). Hard frozen yogurt is made in a
similar manner but with a different composi-
tion of yogurt and fruit base syrup (56%:35%,
respectively). Hard frozen yogurt is stored at
− 25 ° C ( − 13 ° F) rather than − 6 ° C to 0 ° C (21 ° F
to 32 ° F). Mousse - type frozen yogurt is made
my mixing yogurt with a hot mousse mix
containing skim milk, sugar, and stabilizer
or emulsifi er; cooling and whipping in an
ice cream freezer; packing; and then storing
at 0 ° C (32 ° F) (Kosikowski 1981 , Tamime and
Robinson 2007 ).Greek Yogurt
The term Greek yogurt or Greek - style yogurt
used in Europe refers to strained yogurt such
as labneh. It is produced in many countries in
the Balkans, eastern Mediterranean, Turkestan,
and the Indian subcontinent, and is called
by different names. Strained yogurt is a semi -
solid product containing 23 to 25 g total
solids/100 g, of which 8 to 11 g/100 g are fat
(Tamime and Robinson 2007 ). Traditionally,
labneh is produced by straining cold unsweet-
ened yogurt in a cloth bag, animal skin, or
earthenware vessel (Ibrahim et al. 1999 ). In
large - scale production, strained yogurt is pro-
duced using large cloth bags, mechanical
separators, ultrafi ltration, and product formu-
lation (Tamime and Robinson 2007 ).yogurt available for sale. However, yogurts
fl avored with various ingredients are also
being marketed in an attempt to improve
yogurt consumption. The following are some
uses of yogurt as an ingredient.
Salad Dressing
Yogurt - based salad dressings and dipping
sauces are well documented. These include
salad dressing containing salt, spices, dried
onion, garlic, and parsley (Stainberg 1983b )
and yogurt dip containing onion, clam,
cheddar, and blue cheese (Stainberg 1983a ).
Other yogurt dressings include those contain-
ing honey, Dijon mustard, and celery seed;
chopped fresh cilantro, lemon juice, cumin,
and sweet chili sauce; and low - fat yogurt
dressing containing lemon juice, Dijon
mustard, fresh parsley, and fresh chives
(http://www.allrecipes.com).
Yogurt Cheese
Yogurt cheese is a strained yogurt similar to
labneh anbaris. Its preparation includes
heating milk (whole or skim) to 70 ° C (158 ° F)
and cooling it to 46 ° C (83 ° F), followed by
yogurt culture inoculation and stirring. The
mixture is cooled down further to 30 ° C (86 ° F)
without agitation, then annatto, rennet, and
starter culture containing Lc. lactis subsp.
lactis and subsp. cremoris are stirred in
for two to three minutes. After two to three
hours of incubation, the coagulum formed is
coarsely cut (2 to 3 cm), scooped into a cloth
bag, and the whey drained for 24 hours at
20 ° C to 25 ° C (36 ° F to 77 ° F). Further draining
of whey at 5 ° C to 10 ° C (41 ° F to 50 ° F) for 24
hours is carried out before packing and stor-
ing at a refrigerated temperature. Optionally,
sorbate and salt can be added to the curd
before packing (Tamime and Robinson
2007 ).
Frozen Yogurt
Frozen yogurt is a yogurt base mix with
various additional ingredients such as fruit