Brookfield Engineering

Mustard

Laboratory Viscometer Application Data Sheet

(Two Methods)

USE: Mustard is a condiment or dressing. It is typically poured, “squirted” or spread onto other foods, such as frankfurters [or “hot dogs”] or other sliced meats or poultry, in making sandwiches, for example.

Method #1

Test Equipment:

  • Spring Torque Range: Various, such as RV
  • Spindle: Various vanes, such as V-73 or V-74
    Immerse to the primary immersion
  • Speed, rpm: 1

The test may be run at room temperature or at refrigerated temperatures.

The choice of Spring Torque Range, spindle and speed may vary widely, depending upon the mustard. We used the Brookfield RVYR-1 with EZ-Yield™ v1.2 software, for automated instrument control and data acquisition. Representative data from the analyses are shown in the Figures, below:


Figure 1: Store brand mustard at room temperature and 41°F.

The mustard at 41°F, shown in green, has a significantly higher yield stress than at room temperature - which is about 70-72°F - shown in blue. The yield stress is the stress applied to a sample that makes the "solid" material begin to flow like a liquid. The yield stress, in this test, corresponds to the maximum stress shown in the above graphs. EZ-Yield™ software initially shows the raw data, Torque, % of full scale range, versus Time, seconds, in the dark blue-framed graph on the left. The calculated stress versus apparent strain results are shown in the brown-bordered plot on the right, in Figure 1, above.


Figure 2: Gourmet and store brand mustards at room temperature.

Figure 2 shows that the gourmet product has a much higher yield stress than that of the store brand, at room temperature. The gourmet mustard data are shown in blue, while the store brand data are in green. The slope of the gourmet material stress-strain data is much higher than that of the store brand data. This corresponds to a much "firmer" material. The V-73 vane spindle produced on-scale results with the store brand mustard. However, the smaller, V-74 vane had to be used with the gourmet mustard, in order to get on-scale data, using the same spring torque range and speed, in this case.

Method #2

TEST EQUIPMENT:

  • Spring Torque Range: Various, such as RV or HB
  • Spindle: Various T-bars, such as T-D, T-E, T-F
  • Accessory: Helipath
  • Speed, rpm: Various, such as 5 rpm

The test may be run at room temperature, or at refrigeration temperatures.

The choice of Spring Torque Range, spindle and speed may vary widely, depending upon the mustard. Brookfield Dial Reading Viscometers may be used with the Helipath Stand system. However, in our example, we used Brookfield RVDV-II+PRO and HBDV-III+ instruments with Rheocalc v3.0 software, for automated instrument control and data acquisition. Representative data from the analyses are shown in the Figures, below:


Figure 3: Store brand vs. gourmet mustard at room temperature.

The gourmet product, shown in gold, is far more viscous than the store brand mustard, shown in red. The Helipath data traces progress from “zero” viscosity – before the spindle drills down into the material – to a “plateau” region where the spindle is in the bulk of the sample. The system then reverses direction, and the measured torque – and calculated viscosity – then drops to “zero” as the spindle rises up and out of the sample. The “plateau” for the gourmet product data are between approximately 50 and 370 seconds, and the store brand “plateau” data lie between approximately 50 and 210 seconds. The gourmet mustard data have a longer plateau region because the spindle drilled deeper into this particular sample.


Figure 4: Store brand mustard at 50 °F and room temperature.

Figure 4 shows that the store brand mustard viscosity is significantly higher at the lower temperature, 50°F, than at the room temperature – which is about 70-72°F. The low-temperature data are represented by the hollow red circles. Temperature may greatly affect the viscosities of many different materials; increasing temperature typically decreases the viscosity of a given substance.