This report shows the dynamic viscosity of the aqueous extract of tea with Anton Paar DMA4500M and Lovis2000ME, using the steeping time of the tea as a variable, the effect of the amount of extract precipitation on the viscosity at different leaching times.
The sample was made of rock tea produced in northern Fujian, and the steeping time was divided into 30s, 1min, 2min and 4min
1 Experimental Instruments & Tools DMA4500M Density Meter Lovis2000 ME Module.
2. Measuring principle DMA4500M: inject the sample into the U-shaped oscillating tube measuring cell of the digital density meter, because the oscillation frequency or period of the oscillating tube depends on the density of the sample in the oscillating tube, the density of the sample can be measured by measuring the oscillation frequency or period of the sample and the instrument calibration constant.
Lovis 2000 Me: Measure the tumbling time of a ball over a specific distance from an inclined capillary filled with sample, based on the sample density and instrument constant, and the dynamic viscosity value is obtained from the following formula.
3. Experimental procedures.
4.1 Menu --Methods --Method Settings--Load the current method into Lovis Standard 42 In the current method - Measurement mode, select RM repetition mode, enter the selected temperature 43 Home Screen - Quick Setup, Enter Sample Name, OK 44 Aspirate the sample with a syringe and inject it into the measuring cell, drain the air bubbles, and start the measurement 45 Replace the sample with cleaning solution, turn on the air pump and blow dry the tubing.
4. Measurement results.
Analysis: With the increase of soaking time, the density and viscosity showed a gradual upward trend, and the BRIX value increased more obviously. However, the taste of tea soup is not the longer it is brewed, the better, the soluble extract of tea has different effects on the taste, and viscosity is also one of the factors affecting the taste. The more extractables, the higher the viscosity of the tea. In this way, viscosity can also be used as a basis for judgment. Based on the principle of Lovis ball drop test, the difference between the two decimal places of tea viscosity can be analyzed for the measurement of low viscosity. If you want to optimize the method of tea steeping in the future, you can start with the amount of tea, the temperature of the brewing water, the number of brews or the steeping time with a longer intermittent time.
5. Features and Benefits DMA coupled with Lovis is an ideal low-viscosity measurement solution that can cover 0The viscosity range of 3-2000MPas can cover the viscosity range of traditional chemical reagents and organic polymers, which greatly improves the ease of operation compared to traditional solutions. Low sample volume (min. 100 L), sample acceptable**, sealing system for volatile or toxic samples, support for multiple tilt angles, easy to test shear-related flow characteristics The instrument includes a FillingCheck function that monitors sample injection in real time and avoids air bubbles to ensure the most accurate density and viscosity results Both the Lovis 2000Me and DMA 4500M are Peltier constant for short equilibration time and high temperature control accuracy Compatible with autosamplers, which provides sample washing and drying, is ideal for continuous measurement of samples with wide variability, guaranteeing process repeatability.