Functional Ingredients from Dairy Fermentations 367fl avor is desired (Kerry, 2004d ). The detailed
manufacturing processes for these products
are proprietary.Intense Dairy Flavors and Flavor Blocks
Composite intense dairy fl avors are produced
by the combined use of selected microorgan-
isms used in food fermentations and enzymes.
Seitz (1990) , in his excellent review, refers to
these products “ as fl avor bases or complex
fl avoring materials containing volatiles, non -
volatiles or both. ” Such fl avorings are used
in compounded fl avors to impart desirable
fl avoring in cheese foods, processed cheese,
baked products, convenience foods, butter
substitutes, confectionaries, etc. Dairy sub-
strates used for such fl avor bases include
casein, butterfat, and cheese (and cheese slur-
ries). Sometimes fl avor bases derived from
non - dairy substrates are combined with those
derived from dairy substrates to formulate
cost - effective, highly intense compounded
fl avors that may be used at low levels (about
0.1% to 0.5%) in foods that require dairy
fl avors.
The production of such intense fl avors is
a multi - step process, as outlined by Seitz
(1990) , that requires sensory evaluation of
the fl avoring at various stages of develop-
ment at appropriate dilutions in food systems
such as cheese sauce, milk, acid - sugar solu-
tions, etc. Such evaluations yield important
information on the fl avor characteristics,
intensities, and cost/use that is needed for
commercial applications. For a fairly detailed
discussion of dairy fl avor bases, see Seitz
(1990).
In many instances, such complex fl avor-
ing bases cannot be produced as a single,
composite entity. In such cases separate
fl avor blocks are skillfully combined to
create a compounded fl avor base. The basic
fl avor blocks known in the fl avoring trade
include umami (or savory), kokumi sensa-
tion, sharpness or bite (also called piquant),
and bitterness. Other blocks needed in dairylactis ssp. lactis ) NIZO 4/25. Both cultures
are grown separately in 16% (w/v) reconsti-
tuted skim milk for 18 to 22 hours at 21 ° C
(69.8 ° F). The material cultured with 4/25 is
then mixed with lactic permeate at a ratio of
2:3 to reduce the pH from about 4.9 to 3.2.
The lactic permeate is made by fermenting
whey with a strain of Lactobacillus helveti-
cus, centrifuging the cells and any sediment
out, and concentrating the supernatant to
obtain a lactic acid level of about 12%. After
acidifi cation, the 4/25 cultured material is
vigorously aerated for 30 minutes, during
which the α - acetolactate generated is con-
verted into high levels (about 150 mg/ml or
15%) of diacetyl. This material containing
the high concentration of diacetyl is mixed
with a suffi cient amount of milk cultured
with Fr 19 and is worked into butter to give
a diacetyl concentration of about 2 micro-
grams (2 ppm)/g of butter. The culture Fr 19
is needed to remove the green taint intro-
duced by the acetaldehyde generated by the
diacetylactis component in NIZO 4/25. This
process is used by a large commercial
company that produces butter and margarine
in Europe and the United States.
A modifi cation of the NIZO 4/25 proce-
dure was adapted for large - scale fermenta-
tion involving continuous feeding of citrate
(as an additional diacetyl precursor), mechan-
ical aeration and agitation and stabilization
of high concentration α - acetolactate, and
subsequent drying to a powder with high
fl avor - generating potency. The high levels of
diacetyl precursors in the powder, when used
in various dairy products, confectionaries,
and dressings, are converted into diacetyl
during heat - processing and agitation used in
the manufacture of these products. Such
powders are currently available (Kerry
2004c ).
Powders made from large - scale yogurt
fermentations in which the desired acetalde-
hyde concentrations are stabilized for com-
mercial spray - drying are also available for
dry dairy and baking mixes in which yogurt