Fig 1.
Two consecutive frames for a sample with 3.7% of fat and 0.12% of CREMODAN® 719. Color codes intensity of scattered light. Black circles mark exemplary regions where the speckle pattern remains unchanged and, thus, increases correlation.
Fig 2.
Correlation time τc (A) and viscosity index V (B) calculated for all samples in LF mode. Both characteristics increase with increasing CREMODAN® 719. This is related to the rise of viscosity.
Table 1.
It estimates reliable differences that the proposed approaches can distinguish.
Fig 3.
Color codes confidence with which different CREMODAN® 719 concentrations can be distinguished in the samples with the same fat concentration. Confidence was calculated on the basis of Student’s t-test for τc (top panel) and V (bottom panel). Dark red and magenta colors correspond to the confidence above 95%. Viscosity index allows for 95% confidence detection in a wider range of concentrations.
Fig 4.
(A) Shear viscosity μ obtained by a linear fit of rheometery measurements (left axis) and R2 goodness of fit (right axis). With increasing CREMODAN® 719 and fat concentrations the fit quality decreases because of non-Newtonian properties of the diary product. τc (B) and V (C) as functions of μ show almost linear correlation—particularly for low-fat samples. Solid lines correspond to 0.2% fat concentration, dashed lines to 3.7%.
Fig 5.
Autocorrelation g(2) (top panel) and viscosity index V (bottom panel) versus time lag. Time lag is defined as a delay between frames. Color codes CREMODAN® 719 concentrations. Although curves have slightly different forms, they reach minimum within 5–10 ms.