Молекулярная гастрономия для креативных шеф-поваров (англ. язык) - страница 39

Молекулярная гастрономия для креативных шеф-поваров (англ. язык)

2. Control the temperature of the liquid with the thermocouple.

3. Dip samples of threads into the cooling water, by step of 5°C; observe the “melting” and measure the

rate of “melting” (in the ranges of temperature where a change of behaviour occurs, we make the

measure all the 2.5°C).

Figure 7 : experiment

Figure 5 : « cheveux d’ange. » Figure 6: tools

10 / 63

III.2.2.2. Measure of the melting point of «cheveux d’ange»:

Control the melting point by means of the kofler hot bench.

III.2.3. Results:

III.2.3.1. Measure of the speed of dissolution at different temperatures:

Cf. annexe 3.

Temps de dissolution des cheveux d'ange en fonction de la

temperature du milieu







Temperature du milieu en °C

Serie2 4 4 4 4 2 2 1 1 1 1 1 0 0 0

40 42.5 45 47.5 50 52.5 55 60 65 70 75 80 90 93

We observe that the dissolution of «cheveux d’ange» plunged into water is never immediate;

however, stirring the solution helps this dissolution.

The graph shows that the water temperature has an influence on the dissolution: the higher is the

temperature, the quicker is the dissolution.

III.2.3.2. Measure of the melting point of «cheveux d’ange»:

The melting of « cheveux d’ange » begins at 100°C and is complete at 120°C.

III.2.4. Discussion/ Interpretation:

The melting of «cheveux d’ange» occurs between 100°C and 120°C. Indeed, the cheveux d’ange

material is not pure. However, it is not the fusion which takes place in this phenomenon but a dissolution

of the toffy in solution, because the melting point is superior to the temperatures we used.

The size of the “cheveux d’ange” (their diameter) and the temperature of the solution influence

the dissolution kinetics. Also, because the disappearance in solution of «cheveux d’ange» was realized

with some tap water, it is probably important to take into account the solution concentration to be able to

estimate the speed of dissolution and the efficiency of the solvent at a given temperature. However, a

mechanical agitation can largely facilitate the dissolution.

To improve the dissolution, we can increase the time of contact between the solution and the

Страницы: Пред. | 1 | ... | 37 | 38 | 39 | 40 | 41 | ... | 253 | След.

Еще статьи