454 Chapter 17
replaced with vegetable oil or fat. It is an
alternative for consumers concerned about
saturated fats. Artifi cial sour cream can be
manufactured by the method given in Figure
17.7 , except that artifi cial cream is used in
place of real cream. An artifi cial cream may
be prepared by emulsifying a suitable vege-
table oil, fl avor and color, emulsifi er, and
stabilizer in skim milk by homogenization.Sour Cream Dips
Party dips based on sour cream are made by
blending appropriate seasoning mixes into
cultured cream. By packaging them under
refrigerated conditions, the products have a
shelf life of two to three weeks under refrig-
erated storage. However, for a shelf life of
three to four months, the process shown in
Figure 17.7 is used. To increase body and
stability, 1% to 2% NFDM and 0.8% to 1%
stabilizer are incorporated in sour cream at
80 ° C (176 ° F). The mixture is heat - treated by
holding it for 10 minutes and homogenizing
at 17.2 kPa (2,500 psi) to create a smooth
texture. The seasonings are blended at this
stage while the mix is still at 80 ° C (176 ° F),
followed by hot - packing in sealed containers.
Upon cooling and storage at 5 ° C (41 ° F),
partial vacuum inside the container assists in
the prevention of oxidative deterioration to
yield an extended shelf life of three to four
months.Sour Half and Half
Sour half and half is similar to sour cream
except that its fat content is only 10.5%; thus,
its lower fat and calorie content appeal to
certain consumers. Sour half and half is man-
ufactured from a mix containing 10.5% to
11% fat. To compensate for the reduction in
solids due to the lower fat level, it is custom-
ary to increase the MSNF level to 10% to
12% MSNF with NFDM. The mix is then
processed along the same lines as sour cream,
as shown in Figure 17.7.of higher viscosity is obtained by a long - hold
pasteurization treatment as compared to a
high - temperature - short - time (HTST) pasteur-
ization procedure. However, the stabilizers
compensate for the difference. The bulk
starter (approximately 1% to 3%) is inocu-
lated along with diluted rennet. After mixing
for 20 minutes, the mix is held at 22.2 ° C
(72 ° F) until a pH of 4.5 or titratable acidity
of 0.75% is reached. It is further held for 20
minutes and the curd is broken by starting
agitator and cooled to 18.3 ° C (65 ° F). Sour
cream is packaged using a positive drive
pump fi tted with a sour cream valve for
smoothing the texture. The product is held
at 1.7 ° C (35 ° F) for 24 to 72 hours before
shipping.
The manufacturing procedure given in
Figure 17.7 is a general procedure. By
running the mix through the homogenizer
twice, it is possible to produce sour cream of
increased viscosity. Cultured cream can be
manufactured in bulk fermentation, followed
by cooling and packaging in large containers
for retail market. Individual portions (1 - to
2 - oz) of sour cream are manufactured by
fi lling individual containers with sour cream
mix seeded with sour cream culture, fol-
lowed by incubation and cooling. A heavy -
bodied product is formed on setting. Factors
affecting viscosity of sour cream include
acidity level, mechanical agitation, heat treat-
ment, MSNF content of the mix, rennet addi-
tion, and homogenization treatment.
Long - life sour cream is obtained by a hot -
pack process which destroys the culture cells
and the enzymes present in the fi nished
product. Packaging in a plastic or metallic
container with a hermetically sealed lid
further ensures prevention of recontamina-
tion of microorganisms and protects from
oxidative deterioration of milk fat in the fi n-
ished product.
Artifi cial or Filled Sour Cream
Artifi cial or fi lled sour cream is a product in
which part or all of the milk fat has been