Dairy Ingredients for Food Processing

254 Chapter 10

Mechanization in the

Cheese Industry

As indicated earlier in the chapter, there have

been immense advances in the automation

and mechanization of cheese manufacture

(Robinson and Wilbey, 1998 ; Bylund, 2003 ).

Figure 10.6 indicates a schematic fl ow chart

of present day mechanized cheddar cheese

manufacture.

The use of automated cheese milk stan-

dardization equipment and advances related

to cheese cultures has been highlighted in pre-

vious sections. This section describes some of

the modern technologies presently practiced

in the industry for cheese manufacture.

Coagulation, Cutting, and Cooking

the Curd

Cheese making has traditionally involved

square or oval double - jacketed open vats to

perform the coagulation of cheese milk, fol-

lowed by subsequent cutting and cooking of

the curd. Open vats are still used in smaller

cheese plants as well as for artisan cheese

manufacture. However, commercial manu-

facture of cheese is now done in enclosed

double jacketed vats with mechanical cutting

and stirring devices. These vats have cutting

and stirring blades that rotate on a shaft,

either vertically or horizontally. The rotation

is controlled by a variable speed drive,

ranging from 2 to 15 rpm as desired.

Various manufacturers have developed

various patented vat designs. Some of the

present ones include Double O Vat ® (cutting

blades on a vertical shaft) and HCV ® (hori-

zontal cheese vat) from Tetra Pak (Vernon

Hills, IL) and Horizontal II Vat ® (cutting

blades on a single horizontal shaft) (Stoelting,

Kiel, WI). These vats can hold up to 70,000 lbs

of milk. Horizontal vats are gaining popular-

ity because their use leads to an improvement

in cheese yield (less fi nes production and less

fat losses) due to improved cutting and stir-

ring designs. They also have been found to

content are legal obligations, they are impor-
tant criteria of functionality (performance)
and application in food processing. Conse-
quently, processing parameters should be
examined with a goal of minimizing fat
losses in whey.
The cheese yield for cheddar cheese can
be predicted by the classical Van Slyke and
Price formula:

%.(. .)

%

Yield F C M

Where F fat in milk,

Cc

=× +−

=

=

109 093 01 1

aasein content of milk,

M=moisture content of cheese.

It is assumed that casein losses in whey
are 0.1%, and 1.09 is a factor representing
recovery of minerals, lactose, and other whey
components in cheese.
Assume that milk has 3.7% fat and 2.4%
casein, and cheese has 37% moisture or 0.37
moisture fraction:

Predicted yield

=××+−[]( − )

=×

109 093 37 24 01 1 037

109 3

.(. ...).

[].(.^4 441 2 3+ .) .0 63 9 933=. %

This formula has drawbacks but it is
advisable to calculate one ’ s own predicted
yield from daily analytical data.
Milk composition data should include the
percentages of fat, protein, lactose, ash, and
total solids in incoming milk. Similar data
should be collected on cheese and whey.
The salt content of cheese also should be
analyzed. The composite data helps to
monitor the percentage of loss of fat and
solids in whey and the percentage of recov-
ery of fat and solids in cheese. Data collected
over a year should reveal seasonal variation
in milk and the actual percentage of yield as
well as composition and salt content of the
cheese variety. It also helps in correlating
peak cheese yield with percentage of transfer
of fat, protein, and salt in a given cheese
variety, as well as the processing parameters
to achieve the best yield.