Rheo F4
30
User’s manual
07/2015
3.8 Interpreting the results
z
Gas release curve
Tx
1h
2h
3h
0
H'm
T1
1cm
2cm
A1
A2
H’m:maximum height of the gas release curve.
T1: time required to obtain H’m
Tx: dough porosity time (time when the dough starts to loose
CO
2
).
Total volume: total volume of gas release in ml (A1+A2 of the
curve).
volume of CO
2
lost: carbon dioxide volume in ml that the dough
has lost during proofing (
A2
).
Retention volume: carbon dioxide volume in ml still retained in
the dough at the end of the test (
A1
).
The gas release curve is used to determine the retention
coefficient R. It is defined as the ratio in % of the volume retained
in the dough over the total volume of gas produced during the test.
R is very close to 100 with the flours extracted from healthy grain
almonds. It may drop to 50 for flours derived from the outer layers
of the endosperm (end of grinding or reduction in the milling
diagram) or for flours extracted from damaged or poorly stored
grains. It is clear that prolongation of CO
2
release in time is a
crucial factor. Moreover, as measures are taken at temperatures
between 27°C and 30°C, action of the fungal enzymes is highly
visible with the Rheo F4.
To see reference curves, refer to
the Appendix 1 page 36
