Test Method for Brookfield Viscosity of Gelatin
Gelatin is a natural protein extracted from the bones or skins of animals (such as cattle and pigs). It has no fixed structure, but is soluble in hot water and forms a gel upon cooling. It is commonly used as a thickener in food products (e.g., jelly, yogurt) and also has numerous applications in the pharmaceutical and cosmetic industries.
Experimental Purpose
The main objective of testing the Brookfield viscosity of gelatin is to quantify the flow characteristics of gelatin in aqueous solution, which is a core indicator for evaluating gelatin quality and directly relates to its suitability in food, pharmaceutical and other fields. Generally, a higher viscosity indicates a larger molecular weight and better quality of gelatin, enabling the formation of a firmer gel.
Quality Control: To ensure that gelatin complies with specific industrial standards (e.g., pharmaceutical or food grade) and prevent substandard products from entering the market.
Performance Prediction: To predict the performance of gelatin in practical applications (such as jelly setting and capsule formation) based on viscosity values.
Research & Development and Comparison: To provide a scientific basis for new product development and the performance comparison of different batches of gelatin.
Experimental Sample and Instruments
Experimental Sample: Gelatin
Experimental Instruments: ST-19A Digital Display Brookfield Viscometer, compliant with QB 2354
Experimental Procedures
1.Instrument Calibration：Turn on the super thermostat to stabilize the water temperature in the viscometer jacket at 60 ± 0.1℃.
Check that the capillary tube is clean and free from residual air bubbles.
2.Solution Transfer：Pipette 10 mL of the gelatin solution and quickly pour it into the viscometer funnel, ensuring the liquid level is 2–3 cm above the upper graduation mark. Tap the wall of the funnel gently to remove air bubbles, then adjust the liquid level precisely to the upper graduation mark.
3.Viscosity Measurement：Start the stopwatch and record the time (t, in seconds) for the solution to flow from the upper graduation mark to the lower graduation mark of the capillary tube. Repeat the measurement three times and take the average value to reduce errors.
Experimental Results
The Brookfield viscosity of the Type A bone gelatin is 3.3 mPa·s, which is higher than the required value of 3.2 mPa·s for Type A gelatin. Therefore, this sample meets the standard for pharmaceutical gelatin.