350 Chapter 13
level of aroma - producing bacteria in the
starter culture mix should not exceed 20% in
order to produce cultured buttermilk with a
balanced mix of aroma and lactic acid. The
acetaldehyde content of cultured buttermilk
should not exceed 1 mg/kg because it will
give a yogurt - like aroma, considered a defect
in buttermilk. This correct level be achieved
by using Leuc. mesentorides subsp. cremoris
instead of Lc. lactis subsp. lactis biovar.
diacetylactis (Walstra et al. 2006 ).Manufacture of Cultured Buttermilk
Cultured buttermilk is made from pasteurized
skim milk or homogenized, pasteurized low -
fat milk, usually containing less than 1% fat
(Walstra et al. 2006 ). After high temperature
pasteurization the milk is cooled to 22 ° C
(72 ° F) and inoculated with about 1% to 3%
mesophilic starter. The milk is fermented at
19 ° C to 22 ° C (66 ° F to 72 ° F) for 15 to 20 hours
until a pH of 4.6 to 4.7 is reached. The coagu-
lum is formed and stirred slowly and the
resulting product is cooled and packaged.
Fruit condiments, essences, and butter fl akes
may be added to the plain cultured buttermilk
(Kosikowski and Mistry 1997 , Walstra et al.
2006 ).
Cultured buttermilk manufacture is char-
acterized by the use of low - fat milk, high
temperature pasteurization, lactic acid fer-
mentation, and quick refrigeration of the fi nal
product. The milk is pasteurized at about 85 ° C
(185 ° F) for 30 minutes, which increases the
viscosity of the product, prevents wheying -
off, permits rapid growth of cultured micro-
organisms, and destroys bacteriophages and
other undesirable bacteria (Kosikowski and
Mistry 1997 ). Lactic acid fermentation of the
raw material results in a smooth and fairly
thick body due to the coagulation of milk
proteins, and the aroma produced by the fer-
mentation of citric acid and lactose. The
texture varies according to the total solids of
the raw material (Walstra et al. 2006 ).protein, lactose, and minerals. It also includes
material derived from the milk fat globule
membrane (MFGM), which is disrupted
during the churning and mostly migrates
to the buttermilk fraction (Corredig and
Dalgleish 1997 ).
Buttermilk contains phospholipids, which
are very sensitive to autoxidation due to a
high concentration of polyunsaturated fatty
acid. Therefore, buttermilk can easily develop
an off - fl avor, often called metallic, which can
become quite pungent. The shelf life of but-
termilk is comparably short, especially for
buttermilk with high - fat cream content, even
if antioxidants such as ascorbic acid have
been added. Cultured buttermilk, on the other
hand, is a product from mesophilic acid bac-
teria fermentation of pasteurized skim milk
that possess a mild acidic taste with an aro-
matic diacetyl fl avor and a smooth viscous
texture (Walstra et al. 2006 ). It contains less
phospholipid and has a longer shelf life.
Cultured Buttermilk Formulations
Unlike conventional buttermilk, cultured but-
termilk uses pasteurized skim milk or homog-
enized, pasteurized low - fat milk that contains
less than 1% fat (Walstra et al. 2006 ). Addition
of milk - solids - not - fat (MSNF) and partly
skim milk containing 0.7% to 2% fat also is
common (Kristoffersen and Gould 1966 ).
Starter culture containing Lc. lactis subsp.
cremoris and lactis , Lc. lactis subsp. lactis
biovar. Diacetylactis, and Leuc. mesenteroi-
des subsp. cremoris are used for lactose fer-
mentation. Lc. lactis subsp. lactis biovar.
diacetylactis also may be included in the
starter culture. The fi rst two species are
known as lactic acid producers, thus they are
responsible for the production of lactic acid.
The latter two species are known as the
aroma producers; they produce aromatic
compounds, mostly diacetyl and acetalde-
hyde, which are responsible for the charac-
teristic aroma of cultured buttermilk. The