Dairy Ingredients for Food Processing

Butter and Butter Products 221

tion of processing parameters, and handling

and storage of the fi nished product.

Other Quality Aspects

Purity of the milk fat, that is freedom from

adulteration with other non - milk fat sources,

may be tested using gas chromatography

(Commission Regulation (EC) No. 273/2008)

or traditional chemical tests (Reichart - Meissl,

Polenske, and Kirschner values) based on the

content of water - soluble and water - insoluble

fatty acids present (Fearon 2003). Milk fat

fatty acid composition varies naturally with

season and the cows ’ diet. Summer grazing

of fresh grass and supplementation with oil-

seeds increases unsaturated fatty acids in

milk fat, whereas feeding combinations of

fi sh oil and a vegetable oil rich in linoleic

acid has been shown to increase the con-

tent of conjugated linoleic acid (CLA)

(AbuGhazaleh 2008 ).

The content of cholesterol in dairy and

non - dairy products containing milk fat has

frequently been criticized by health profes-

sionals. It is now possible to purchase a

variety of cholesterol - reduced butters and

spreads, and decholesterolization also has

been applied to AMF. One method used in

fl avor and was unacceptable for some uses.
A drawback of the PV test is that it measures
early oxidation intermediate products, hydro-
peroxides, which can break down during
storage and thus give a low PV result.
Hydrolytic deterioration of milk fat with
FFA formation is caused by the action of
lipolytic enzymes secreted by bacteria or
native to the milk on milk fat triacylglycer-
ols. Microbial lipases are secreted by psy-
chrotrophic bacteria such as pseudomonads,
which favor low temperatures for growth. A
low count, however, may be misleading
because enzymes may have already been pro-
duced by the bacteria before numbers were
reduced by heat treatment. Moisture is
required for lipolysis, so minimizing levels
in the product helps inhibit the reaction.
FFA content may be measured by titration
with a weak alkali with test results typically
expressed as “ % oleic acid ” (1 ml 0.1 M
NaOH is equivalent to 0.0282 g oleic acid).
Typical FFA levels in AMF from a large -
scale modern factory may be 0.15 to 0.25%
as oleic acid. Management of fl avor quality
of milk fat is critical in the management of
overall product quality, and prevention of
fl avor deterioration must be uppermost
during selection of the raw material, applica-

Table 9.6. Scoring of butter for sensory evaluation.

Parameter Maximum Description Required

Appearance 5 Very good; equal dry 4

Consistency 5 Very good; well spreadable 4

Flavor/Aroma 5 Very good; fi nest pure aroma 4

Adapted from Commission Regulation (EC) 273:2008

Table 9.7. Examples of some butter defects.

Parameter Description

Appearance Free moisture; not uniformly colored; streaky; oil

separation; open texture; foreign matter; moldy

Consistency Brittle or crumbly; doughy and greasy; sticky;

hard; soft

Flavour and Aroma Without fl avor; foreign fl avor; stale; cheesy;

acid; yeasty; cooked fl avor; feed fl avor;

oversalted; malty; chemical fl avor

Adapted from Commission Regulation (EC) 273:2008