Dairy Ingredients for Food Processing

Dairy Ingredients in Dairy Food Processing 443

added. After mixing well, the mix is held

at room temperature (22.2 ° C (72 ° F)) until

the pH is 4.5 or titratable acidity is 0.83%

to 0.87%. The incubation time is on the

order of 16 to 18 hours. The bulk starter is

cooled to 7.2 ° C (45 ° F) and used within four

days.

In addition to its use as a beverage, but-

termilk is also used in several foods for its

functional attributes. In the baking industry,

cultured buttermilk is used in pancakes,

waffl es, blintzes, breads, cookies, and cakes.

It imparts a fl uffy texture. Typical quality

issues and their remedies in buttermilk and

sour cream manufacture are given in Table

17.14.

Yogurt

Yogurt is a semi - solid fermented product

made from a standardized mix by the activity

of a symbiotic blend of Streptococcus ther-

mophilus (ST) and Lactobacillus delbrueckii

subsp. bulgaricus (LB) cultures. The per

capita consumption of yogurt has registered

a dramatic rise in the United States; the con-

sumption was 11.8 pounds in 2008 (IDFA,

2009 ). The increase in yogurt consumption

may be attributed to its perceived natural and

healthy image, providing to the consumer

convenience, taste and wholesomeness attri-

butes. Table 17.15 summarizes recent trends

in consumption of refrigerated yogurt and

fermented milk products in the United States.

It is clear that yogurt is a very successful

dairy food of modern times. Figure 17.4

illustrates various forms of yogurt in the U.S.

market.

Dairy Ingredients. Yogurt is a Grade A

product in the United States, and the milk

that it is made from must come from FDA -

supervised Grade A dairy farms and Grade A

manufacturing plant as per regulations enun-

ciated in the Pasteurized Milk Ordinance

(PMO; United States Department of Health

and Human Services, 2007). Yogurt is made

Cultured Buttermilk

Cultured buttermilk is obtained from pas-
teurized skim milk or part - skim milk cul-
tured with lactic acid producing culture
( Lactococcus lactis subsp. lactis/cremoris/
diacetylactis ) and aroma - producing culture
(Leuconostoc cremoris). The term buttermilk
is also used for the phospholipid - rich fraction
obtained as a byproduct during the churning
of cream in butter manufacture. Cultured
buttermilk is a viscous, cultured fl uid milk
beverage possessing a characteristic pleas-
ing aroma and fl avor. It is usually produced
in dairy plants that process milk and other
fl uid milk products. Buttermilk composition
depends on whether it is nonfat or low fat. In
general, the nonfat buttermilk contains 0.1%
milk fat, 10% MSNF, and 0.18% salt. This
formulation is achieved by blending 98.3%
skim milk, 1.5% NFDM and 0.18% dairy
salt. In contrast, low - fat buttermilk contains
1% milk fat and 9% MSNF. The process is
similar to the outline given in Figure 17.3.
The product is packaged in traditional milk
cartons.
The manufacturing procedure consists of
blending NFDM and salt into skim milk and
mixing thoroughly. The blend is heat treated
at 90.6 ° C (195 ° F) for 5 minutes and cooled
to 22.2 ° C (72 ° F). The bulk starter is inocu-
lated at the rate of 0.75% and ripening is
carried out to 0.8% titratable acidity or pH
4.5, usually over 16 to 18 hours. The coagu-
lum is broken and cooled to 1.7 ° C to 4.4 ° C
(35 ° F to 40 ° F). Buttermilk is packaged and
stored at 1.7 ° C to 4.4 ° C (35 ° F to 40 ° F).
Dairy plants can make their own butter-
milk starter from frozen culture purchased
from culture suppliers. Bulk starter is pre-
pared from reconstituted NFDM. Using a
powder funnel, 10.5% NFDM is dispersed
into water. The mixture is pasteurized at
85 ° C (185 ° F) for 30 minutes, cooled to
22.2 ° C (72 ° F), and one can of frozen culture
per the instruction of culture supplier is