218 Chapter 9
the surface of the biscuits, however, if the
standard butter used has a higher solid fat
content greater than this at room temperature
(18 ° C to 20 ° C; 64.4 ° F to 68 ° F). The fat
bloom is caused by fractional crystallization
of large beta crystals of the higher - melting
milk fat triacylglycerols, with an accompany-
ing grayish white discoloration. The problem
can be avoided by using a blend of low - and
medium - melting milk fat fractions for this
bakery application.
Cakes require fat to provide structure and
lightness by helping entrap air during the
creaming process, interrupting formation of
the gluten network during baking, and pro-
viding emulsifying properties to retain liquid
and keep the cake moist. Standard butter is
not the best choice for cakes; it incorporates
air well during creaming but its low
solid : liquid ratio at room temperature means
that the batter will break down easily.
However, blends of medium and high -
melting fractions of milk fat or blends of
butter oil with margarines, especially with
added emulsifi er, can improve functionality.
Cheese
Processed cheese is made by blending differ-
ent types of natural cheeses with emulsifi ers
and certain salts. Butter, butter oil, or AMF
may be added to processed cheese to increase
the fat content, either to produce a high - fat
processed cheese or to compensate for reduc-
tion of fat in dry matter of the material after
addition of emulsifying salts or other fat - free
substances. Adding fat reduces the viscosity
of the processed cheese and gives it a softer
texture. There has been some research inter-
est in the application of selected milk fat
fractions in reduced - fat and low - fat cheese
manufacture. Achieving the ideal physical
attributes in the curd during manufacture is a
problem with these cheeses, but the inclusion
of lower melting milk fat fractions has been
shown to modulate this (Rosenberg 2000 ).
Inclusion of AMF and low - and high -
melting milk fat fractions in milk for moz-
zarella cheese manufacture also has been
investigated (Rowney et al. 2003 ). Cheeses
made with AMF contained predominately
beta prime milk fat crystals; the hard - melting
fraction contained predominately beta crys-
tals, while the low - melting fraction contained
more alpha milk fat crystals than the other
cheeses. The implications here for cheese
quality were that the cheese produced with
the low - melting fraction had a lower
solid : liquid milk fat ratio, resulting in more
free oil in the cheese. Free oil formation in
mozzarella cheese is a problem that can arise
due to large seasonal variation in milk fat
composition and melting point. The inclusion
of a high - melting fraction with a higher
solid : liquid milk fat ratio is an option to help
manage the problem when seasonal soft milk
fat is supplied to the factory.Other Products
Satisfactory quality vanilla ice cream des-
serts (10% fat) have been made by substitut-
ing cream with AMF, a low - melting milk
fat fraction, or a very - high - melting milk fat
fraction. However, some differences between
milk fat sources were observed during manu-
facture. The highest amount of solidifi ed fat
was found in the mix containing the very -
high - melting milk fat fraction, while the mix
containing the low - melting milk fat fraction
had the lowest amount of solidifi ed fat but
the highest amount of adsorbed protein at the
surface of the fat globules. The hardness of
the ice cream was not affected by the fat
source but the ice cream made using the very -
high - melting milk fat fraction showed great-
est resistance to melting, a useful property in
hot countries (Abd El - Rahman et al. 1997 ).Quality Assurance of Milk Fat
Products and Spreads
The Commission Regulation (EC) 273/2008
lays down detailed rules for the application
of Council Regulation (EC) No. 1255/1999
regarding methods for the analysis and qual-