354 Chapter 13
The proper choice of stabilizers and process-
ing procedures also prevents a grainy product
as well as whey syneresis (Meunier - Goddik
2004 ).Shelf Life of Sour Cream
The shelf life of sour cream under refriger-
ated temperature is about six weeks (Warren
1987 ) or roughly 25 to 45 days (Meunier -
Goddik 2004 ). The shelf life is determined
mainly by the quality of the milk used to
produce the milk cream and its pretreatments.
Quality attributes often decrease as a sour
odor and bitter taste increases.Use of Sour Cream
Sour cream is commonly added to baked
potatoes and Mexican foods such as burritos.
Its heat - stable characteristics make it a highly
suitable ingredient for such foods. The fl avor
attributes of sour cream remain appreciable
when served with food such as baked pota-
toes, ham, and pineapple, or baked potatoes
with chili corn carne. However, in fl avor - rich
foods such as Mexican foods, the mild fl avor
of sour cream can easily be masked; hence it
is of little signifi cance.
Sour cream also is used in combination
with cottage cheese and cream cheese in
preparation of cheesecake such as New York -
Style cheesecake. While most cheesecakes
are served as cold food, this cheesecake is
usually served as it comes out of oven with
a coat of sour cream (Horn et al. 1997 );
hence, the importance of the heat - stable
texture of sour cream.References
Adapa , S. , Schmidt , K.A. 1998. “ Physical properties
of low - fat sour cream containing exopolysaccharide
producing lactic acid. ” Journal of Food Science 63 :
901 – 903.
Ailsa , J. , Gilles , A.J. , Dahl , S.C. 1969. “ Pilot scale man-
ufacture of quark — An acid style soft cheese. ”
Australian Journal of Dairy Technology. 24 : 22 – 28.fl avor and texture parameters. Sour cream is
highly vulnerable to lipid - associated off
fl avors such as rancidity and oxidized fl avor.
Other off - fl avors such as lack of fi ne fl avor,
lack of cultured fl avor, high acid, and bitter-
ness are common quality concerns (Meunier -
Goddik 2004 ).
The rancid fl avor of sour cream is due to
lipolysis of fatty acid by lipase that originates
from the milk itself or from the culture.
Lipolysis only occurs if the milk fat globule
breaks and the lipase can gain access to the
milk fat. This can be avoided by pasteurizing
the milk before or immediately after homog-
enization to deactivate most of the enzymes
in the raw material. The oxidized fl avor, also
known as metallic, comes from oxidation of
milk fat and phospholipids that are catalyzed
by divalent cations such as iron and copper.
Therefore, avoiding contact of the raw mate-
rial with these metals, such as in parts of
pipes, protects the product from developing
this fl avor (Meunier - Goddik 2004 ).
The choice of starter culture can affect the
cultured fl avor and acidity of sour cream.
Lack of fl avor or high acid renders the
product unpleasant. These problems can be
solved by changing the culture composition
(Meunier - Goddik 2004 ). Bitterness is due to
the activity of proteolytic enzymes in the raw
material. The bitter taste may develop during
storage. The choice of good - quality raw
material and a higher pasteurization tempera-
ture can limit the possibility of sour cream
developing a bitter taste.
Texture is an important characteristic of
sour cream. It is usually served with warm
foods; therefore, it must remain highly
viscous when in contact the surface of warm
foods. This textural parameter is a function
of the cheese pH. High pH increases melt-
ability, decreases fi rmness, and causes a
swollen structure (Monteiro et al. 2009 ).
Incorporation of proper stabilizers is impor-
tant to produce sour cream that will not cling
to the spoon (too fi rm) or melt when in
contact with a hot food surface (too weak).