Fjölrit RALA - 22.03.1979, Side 23

-17-
were, however, too few for drawing concrete conclusions,
but still they point in a certain direction.
The results show that the acidity increases during fil-
tration as does the acid amount. Something is happen-
ing here which restricts the acidity in the conc. whey.
Figure 11 shows how these factors change during filtra-
tion.
• It is of interest to study the ratio between lactic acid
and the dry weight. If figure 10 is studied it may be
seen that this ratio changes greatly during filtration
on the column. This is the explanation for why the
conc. whey does not seem as sour to drink as the origin-
al whey and why it is judged more desirable for mixing
with fruit juices than is the original whey.
• A study was done on how the acidity and acid amount of
A^g change during storage. The conc. whey was stored
at 4°C and 20°C and measured after 8, 18, 29 and 43
days. The results are shown in table 14.
• The results of the study show that changes in the conc.
whey are slight if it is kept refrigerated, but storage
at room temperature gave very poor results and is unsuit-
able.
3. Shelf-Life
• The results of the studies on skyr formation in
(70% conc. whey, 15% orange juice and 15% pineapple juice,
packed) and E* (65% conc. whey, 14% orange juice, 14% pine-
apple juice and 7% grapefruit juice, packed) were that skyr
had formed on the bottom of the cartons after a storage per-
iod of 10 days. During the next 2 weeks, the skyr quantity
increased slightly, but after that time, no change could be
observed during the 6 weeks the study was carried out. The
skyr quantity was the same for the different storage temper-
atures.
• A comparable study was carried out on D** (70% conc. whey
15% orange juice, 15% pineapple juice, packed) after packaging
After 3-4 days, a thin white film had formed on the surface of