Dairy products and milk-based food ingredients - Natural Food Additives, Ingredients and Flavourings - page 436

using ground lactose to initiate crystal formation and cooled in a stepwise manner
to maximise the production of α -lactose (characterised by tomahawk and prism
shaped crystals) which is of low solubility and non-hygroscopic. Lactose crystals
are separated by means of decanter centrifuge from the 'mother liquor' which
contains whey proteins, vitamins and minerals, has a residual lactose content of
some 15-18%, is rich in ribofl avin giving it a creamy-yellow colour, and is often
used in animal feeds. The sequential washing of lactose crystals with water and
de-watering with decanter centrifuges yields a product of high purity, which can
be dried in a fl uidised bed at 90-92°C with a residence time of 15-20 minutes.
Care is taken to keep the lactose temperature below 93.5°C to prevent the
formation of hygroscopic β -lactose crystals.
Lactose is used widely as a food ingredient to replace sugar and reduce
sweetness. It serves as a humectant in, for example, baked goods and confectionery
where it also provides texture. It is used as a fi ller to make formulations up to
100% and as a fl avour carrier. Concentrated food fl avours may need to be used in
small amounts which can present problems with some applications (e.g. coating
of snack foods). However, concentrated fl avours may be blended with lactose
crystals to be carried on the surface of the crystals, which may then be dusted onto
products or added to formulations.
Pharmaceutical grade lactose is used widely as the exipient (inactive ingredient)
in tablet manufacture. Its compressibility and subsequent stability in tablet shape
make it an excellent carrier of pharmaceutically active ingredients and binding
material. In the manufacture of pharmaceutical lactose, food grade lactose is
dissolved in water and the solution is exposed to virgin activated carbon which
adsorbs proteins, proteose-peptone polypeptides derived from β -casein, and
ribofl avin which are present in very small amounts. The activated carbon is
separated from the lactose solution by fi ltration and the solution is re-concentrated
by evaporation to give lactose crystals which are washed and dried to achieve a
product of very high purity.

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17.4.4 Enzyme modifi ed cheese
Enzyme modifi ed cheese (EMC) pastes and powders are used as cheese fl avour
sources in the manufacture of processed cheeses, snack foods and baked goods.
EMC products are often made from down-grade and young cheeses, which are
exposed to proteolytic and lipolytic enzymes in EMC processing to break down
proteins and milkfat to liberate fl avoursome compounds. EMC is manufactured
by size reducing cheese, heating and incorporating polyphosphates to liquefy the
cheese and adjust the pH to 6.6-6.8. The liquefi ed cheese is homogenised and
pasteurised to destroy cheese starter bacteria and contaminant organisms. It is
cooled to the optimum incubation temperature of the proteolytic and lipolytic
enzymes.
Although enzymes of animal origin may be utilised, microbial enzymes are
commonly used. Enzymes derived from Rhizopus oryzae , Aspergillus oryzae and
Aspergillus mellus break down cheese curd and acid casein, while those derived