Beat Migration Bloom on Chocolate Products by Optimizing ... - AAK

<strong>Beat</strong> <strong>Migration</strong> <strong>Bloom</strong> by Optimizing Your Process
Why do these
special heat or
cooling treatments
sometimes improve
bloom stability in
filled products?
In general, it is a
question of compensating
for some
defects in the
basic production.
DSC Peak Values
Peak values
Figure 4
33.5
33.4
33.3
33.2
33.1
33.0
32.9
32.8
32.7
32.6
32.5
Figure 2 shows that when making a temper
test at a low cooling temperature the same
chocolate would be undertempered if it had
been measured at a higher cooling tempera-
ture, which actually is more similar to the tem-
perature used in production lines.
The lower the cooling temperature, the lower
the inflection point, see Figure 3.The only ex-
planation for this kind of lower inflection point
for the same chocolate and lower values for
dsc peak (Figure 4) must be the different ratio
between Forms IV and V in the final chocolate
samples. The more the cooling, the more Form
IV crystals are generated in the final chocolate.
Pure Form IV crystals are very unstable and
for that reason they will quickly transform into
Form V depending on fat composition and tem-
Peak value Linear (Peak value)
y = 0.0622x = 32.17
R² = 0.92
7 9 11 13 15 17 19
Cooling temperature °C
Cooling Rates vs. Melting Peak Values
Cooling Peak value °C
Rates melting curve
28°C –> 15°C 32.3
Rate 0.3°C/min
10 min at 15°C
15°C –> 60°C with 5°C/min
28°C –> 15°C 32.0
Rate 0.5°C/min
10 min at 15°C
15°C –> 60°C with 5°C/min
28°C –> 15°C 31.6
Rate 1.5°C/min
10 min at 15°C
15°C –> 60°C with 5°C/min
Figure 5
4 May 2010 • Reprint from The Manufacturing Confectioner
perature. Smaller amounts of Form IV crystals
in mixtures with a lot of Form V will probably
make the chocolate unstable, too, but how
much probably depends on the ratio between
the two polymorphs and the above-mentioned
factors. Nobody knows how much Form IV
“contamination” you can have in a chocolate
without influencing contraction, gloss, etc.
Figure 5 shows a well-tempered dark choco-
late cooled on a dsc with three different cooling
rates.
The chocolate is tempered on a 50 kg three-
zone tempering unit and a small sample is
weighed into preheated dsc cups and placed in
the dsc equipment. The samples are stored for
2 minutes at 28°C and then cooled with three
different rates to 15°C, kept at 15°C for 10 min-
utes and then remelted at 5°C/min from 15°C
to 60°C. The different values for the melting
peaks are shown in Figure 5.
These results show the same tendency as
seen from the results mentioned in Figures 3
and 4.
The faster the cooling, the lower the peak value
and the wider the melting curves.
SPECIAL HEAT OR COOLING
TREATMENT
Individual companies sometimes use different
types of special treatment to optimize bloom
stability. Some store in cool conditions for a
week or more, others store in hot conditions for
a few days up to one week.
Why do these special heat treatments or
special cooling treatments sometimes improve
bloom stability in filled products? And why is
this effect different from application to applica-
tion and time to time?
In general, it is a question of compensating
for some defects in the basic production. It
seems that a heat treatment compensates for