Table 1 Surface tension of solutions of sugars
Т, °С
С
sugar
, %
Surface tension, J/m
2
of solutions
saccharose
lactulose
fructose
glucose
tagatose
20
10
72.89±0.07
72.99±0.03
74.03±0.05 71.78±0.03 72.09±0.04
20
73.71±0.06
75.1±0.05
74.83±0.07 73.61±0.07 74.05±0.05
30
74.67±0.05
75.97±0.07
75.78±0.02 74.52±0.07 75.18±0.05
40
75.82±0.04
76.96±0.04
76.9±0.07
75.56±0.07 75.91±0.06
50
76.11±0.07
77.55±0.07
77.12±0.02 76.74±0.07 76.84±0.04
30
10
72.03±0.03
72.13±0.03
72.37±0.06 65.27±0.05 69.03±0.03
20
72.86±0.05
73.8±0.07
73.97±0.05 67.03±0.05
70.1±0.04
30
73.85±0.03
75.13±0.02
75.6±0.07
68.91±0.07
72.4±0.05
40
75.01±0.07
75.15±0.05
76.06±0.07 70.92±0.05 73.96±0.03
50
75.33±0.02
75.76±0.03
76.33±0.03 73.07±0.05 74.48±0.05
Table 2 Kinematic viscosity of solutions of sugars
Т,
0
С
C
sugar
, %
Kinematic viscosity of solutions, mm
2
/s,
saccharose
lactulose
fructose
glucose
tagatose
25
5
0.99±0.07
0.96±0.07
1.02±0.08
1.02±0.05
0.98±0.04
10
1.17±0.07
1.16±0.04
1.14±0.08
1.1±0.05
1.1±0.05
20
1.53±0.03
1.5±0.05
1.47±0.04
1.41±0.02
1.42±0.04
30
2.1±0.05
2.11±0.05
1.98±0.06
1.8±0.08
1.87±0.08
40
2.9±0.03
2.92±0.07
2.7±0.04
2.55±0.08
2.5±0.07
50
4.26±0.08
4.29±0.04
3.9±0.08
3.7±0.05
3.6±0.05
Similar tendencies are observed in systems with monosaccharides: fructose
solutions will have a STC of 77.12 ... 76.33 J / m
2
, which is higher than that of glucose
and tagatose (76.74 ... 73.07 and 76.84 ... 74.48 J / m
2
, respectively), and the kinematic
viscosity of fructose solutions (3.90 ± 0.05 m
2
/ s) is higher than glucose solutions (3.70
± 0.1 m
2
/ s) and tagatose (3.60 ± 0.05 m
2
/ s).
However, the higher viscosity of the lactulose and fructose foam provides the
absolute foam stability for a longer shelf life. As it can be seen from the Figure 1, there
is a tendency to stratification and after 2 hours of foam storage, resistance begins to
decrease in samples with saccharose, glucose and tagatose.
Indicators of quality of foaming of dairy cream with sugars have other differences,
Figure 3.
It was found that the highest churning of cream is observed in samples with
saccharose (259%) and glucose (252%); the smallest values –in samples with lactulose
(as in the case of ovalbumin) and tagatose - 233 and 226%, respectively. That is, there
is a different surface activity of milk proteins in systems with different sugars.
It was determined that all systems are stratificated in time, there is a coalescence,
and in two hours all samples lose about 40% of foam. The ultimate resistance of
samples of foam with saccharose is 64%, with lactulose – 60%, glucose – 68%, fructose
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