The Use of Vibration Principles to Characterize the Mechanical Properties of Biomaterials - Biomaterials: Physics and Chemistry - page 308

can be seen in the figure that correlations of the liquid rheological properties with its
acoustic properties measured by the quality factor Q are strong and that the quality
evaluated at the first peak provides a better representation of the liquid viscosity. This is
also enhanced due to the presence of two peaks for low and moderate solid contents
(measured as Brix), which provides more experimental points to establish the correlation
(see Figure 7 - and compare first peak and second peak data).

9 9 9 9

6 6 6 6

3.5 Brix 3.5 Brix 3.5 Brix 3.5 Brix

3 3 3 3

8.15 Brix 8.15 Brix 8.15 Brix 8.15 Brix

9.5 Brix 9.5 Brix 9.5 Brix 9.5 Brix

2 3 B r ix 23 Brix 23 Brix 23 Brix

0 0 0 0

0 0 0 0 400 400 400 400 800 800 800 800 1200 1200 1200 1200 1600 1600 1600 1600

Frequency (Hz) Frequency (Hz) Frequency (Hz) Frequency (Hz)

Fig. 6. Frequency response spectra of tomato concentrates at different soluble solids
concentrations, measured as Brix. Curves were shifted up for clarity.