Fjölrit RALA - 22.03.1979, Blaðsíða 24

-18-
the liquid in the containers. This film is not a continuous
one and disappears completely when the mixture is poured from
the container into a glass. The film became somewhat larger
each passing day but this does not pose a serious problem
because after a storage period of 8 days, it dissolves com-
pletely when the beverage is poured out of the container.
No precipitation was visible on the bottom of the contain-
ers after an 8-day storage period.
• Results were very positive from the study in which conc.
whey (A^), whey (A^), D* and were centrifuged and filtered
through Whatman no. 1 filter paper in order to remove the skyr
precipitate.
A considerable amount of precipitation occured in the cen-
trifuge tubes. Similar amounts were observed in A^, D* and E^
but less in A^ as was to be expected. The supernatent liquid
was then poured off of the precipitate into graduated cylinders,
heated and refrigerated. Precipitation occurred immediately dur
ing heating in A^
The results of these tests show, that the precipitation in
the graduated cylinders containing mixtures put directly into
the cylinders without being centrifuged, is as much after one
day as in the same mixtures centrifuged before putting them
in the cylinders, after 8 days. The precipitation in the
former class of graduated cylinders increased in the next
10-12 days but after that there was no visible increase.
In the mixtures which had been centrifuged, this pro-
cess occurred more slowly. After one day, a small amount
of precipitate was visible in all the cylinders. There was
least precipitate in A^ but similar amounts in A^, D*'and E * .
The precipitate increased in all the cylinders the first week,
but after that, changes were insignificant. The amount of pre-
cipitate is, however, so small that it does not cover the bot-
tom of the cylinders, and is only a fraction of a mm thick.
The only exception is A^ which was heated. It contained a
precipitate approximately 3 mm thick.
• If unheated A^ is compared to A^ which has been centri-
fuged, it can be seen that after one week, there is three
times as much precipitation in the former as in the latter
after three weeks.