This is your assignment for today:
What viscosity does melted cheese need to have to allow it to be sucked up through a straw? Are the temperatures needed harmful to either the mouth or the straw? Which types of cheese are the most viable for sucking up through a straw taken the temperature limits? Make a table showing cheese types, viscosity and temperatures of at least three kinds of cheese! Create a table for each chosen cheese for viscosity to temperature!
Procedure
Here, we investigated three melted cheeses using METTLER TOLEDO's Excellence Dropping Point System. Cheddar, emmentaler and mozzarella were subjected to simultaneous duplicate experiments, with each sample measured three times (n=6). The Excellence instrument permits video observation during and after the measurement.
During the course of an SP experiment, the flow distance is monitored constantly. SP temperature can be determined at the moment when the sample has flowed a distance of 19 mm.
Because factors such as motion affect the flow of the sample from the cup, the overall force experienced by the flowing sample can be mathematically formulated as follows:
d = c0 + c1*T + c2*[exp(c3*T+ c4)]
(eq. 1)
where:
d is the vertical flow distance
T is the temperature
c0 and c1 are linear terms
c2, c3 and c4 are parameters of the exponential term
The most important parameter is c3, because it indicates how rapidly the exponential function decays – or in experimental terms, how quickly the cheese softens.
In the conventional signal processing field, c3 is known as the time constant (τ) and can be expressed as a reciprocal. Since we are considering temperature and not time dependence, we call this term the temperature constant τT. τT can be obtained after curve fitting and can be used to distinguish between SP samples.
Results
Table 2 summarizes the results of the three melted cheeses. They indicate that, for both SP and τT, there is a progression of results with increasing temperature, and τT from cheddar to emmentaler to mozzarella.
Mozzarella exhibits the highest SP of 72.5 °C – a full 10 °C higher than the other two. The SPs of cheddar and emmentaler are close: 60.1 °C and 62.7 °C, respectively. Should two different cheeses share a similar SP, τT values assist in distinguishing between them.