This document summarizes the production process for anhydrous milk fat (AMF) and butteroil. It describes how cream is concentrated, homogenized, and separated to extract milk fat content above 99.8%. The extracted milk fat undergoes refining processes like neutralization, polishing, fractionation, and decholesterolization to reduce impurities. Finally, the purified AMF is packaged under nitrogen gas to prevent oxidation.

1. Anhydrous Milk Fat (AMF)
and Butteroil

2. • Anhydrous milk fat and butteroil are products
consisting of more or less pure milk fat.
• Although they are modern industrial
products, they have ancient traditional roots
in some cultures.
• Ghee, a milk fat product with more protein
and a more pronounced flavour than AMF

3. • Anhydrous Milk Fat must contain at least 99,8 %
milk fat and be made from fresh cream or butter.
No additives are allowed, e.g. for neutralisation
of free fatty acids.
• Anhydrous Butteroil must contain at least 99,8 %
milk fat, but can be made from cream or butter of
different ages. Use of alkali to neutralise free fatty
acids is permitted.
• Butteroil must contain 99,3 % milk fat. Raw
material and processing specifications are the
same as for Anhydrous Butteroil.

5. Principles of production
• Production of AMF principally takes place
according to two methods:
continuous flow direct from cream
 and from reworked butter

6. Manufacture of AMF from cream
• Pasteurised or non-pasteurised cream of 35 –
40 % fat content enters the AMF plant via the
balance tank (1)
• Routed via the plate heat exchanger (2) for
temperature adjustment or pasteurisation
• Centrifuge(4) for pre-concentration of the fat
to about 75 %.

7. • The temperature at preconcentration
and downstream to the plate heat exchanger
(11) is maintained at approx. 60 °C.
• The “light” phase is collected in a buffer tank
(6) to await further processing while the “heavy“
phase, typically called buttermilk, can be
passed through a separator (5) for recovery of
fat which will then be mixed with incoming
cream (3).

8. • The skimmed buttermilk goes back to the
plate heat exchanger (2) for heat recovery and
then to a storage tank.
• After intermediate storage in tank (6), the
cream concentrate is fed to a homogeniser (7)
for phase inversion (disruption of the fat
globules to release the fat), after which it is
passed through the final concentrator (9).

9. • concentrator the product is separated into a light
phase with 99,5 % fat and a heavy phase, with a
substantial amount of fat, which is returned to the
process via balance tank (3)
• As the homogeniser operates at a slightly higher
capacity than the final concentrator, the surplus
product not caught by the concentrator is recirculated
to the buffer tank (6).
• Part of the mechanical energy used in the
homogenisation process is converted into heat; to
avoid disturbing the temperature cycle of the plant,
this surplus heat is removed in the cooler (8).

10. • Finally, the oil consisting of some 99,5 % fat is
pre-heated to 95 – 98 °C in a plate heat
exchanger (11) and routed into a vacuum
chamber (12)
• To obtain a moisture content not exceeding
0,1 %, after which the oil is cooled(11) to
approx. 40 °C, the typical packing temperature

13. AMF refining
• Polishing
• Neutralisation
• Fractionation
• Decholesterolisation

14. • Neutralisation
• Neutralisation is performed to reduce the level of free
fatty acids (FFA) present in the oil. High levels of FFA
give rise to off-flavours in the oil and the products.
• Alkali (NaOH) at a concentration of 8 – 10 % is added to
oil in an amount corresponding to the level of FFA.
• After a hold of around 10 seconds, water is added in
the same proportion as for polishing, and the
saponified FFA is separated out together with the
water phase

15. • Polishing
• Polishing involves washing of the oil with water to
obtain a clear, shiny (bright) product.
• 20 – 30 % water is added to the oil coming
from the final concentrator
• The water temperature should be the same as
the oil temperature.
• After a short hold, the water is separated out
again, taking water-soluble substances (mainly
protein) with it

16. Neutralisation
• Neutralisation is performed to reduce the level of
free fatty acids (FFA)present in the oil
• High levels of FFA give rise to off-flavours in the
oil
• Alkali (NaOH) at a concentration of 8 – 10 % is
added to oil in an amount corresponding to the
level of FFA.
• After a hold of around 10 seconds, water is added
in the same proportion as for polishing,
• the saponified FFA is separated out together with
the water phase.

17. Fractionation
• Fractionation is a process where the oil is
separated into high-melting and low-melting fats.
• These fractions have different properties and can
be used in various products
• The AMF, often polished to obtain the highest
possible degree of purity in the “raw oil”,
• melted and then cooled slowly to a calculated
temperature
• the specified fraction crystallises out while
fractions with lower melting points remain liquid.

18. • The crystals are harvested with special filters.
• The filtrate is then cooled to a lower
temperature at which other fractions
crystallise and are harvested

19. Decholesterolisation
• Decholesterolisation is a process in which
cholesterol is removed from the AMF.
• A frequently used method is to mix the oil with a
modified starch, betacyclo dextrine
(BCD).
• The BCD molecule surrounds the cholesterol and
forms a precipitate, which can be separated out
by centrifugation.

20. • Packaging
• AMF is filled in containers
• an inert gas, nitrogen (N2), is first injected in the
container.
• the N2 gas is heavier than air, it sinks to the
bottom
• When filling the AMF –which is heavier than N2 –
the AMF will sit underneath and the N2 gas will
create an “air-tight lid”, preventing the AMF from
air-induced oxidation.