Viscosity refers to the thickness or resistance to flow of a liquid or semi-solid substance like starch. The viscosity of starch is an important characteristic that can impact its functionality and performance in various applications.
The viscosity of starch can be influenced by various factors, including the type of starch, its concentration, temperature, and pH. Generally, starch solutions exhibit higher viscosity at higher concentrations, lower temperatures, and lower pH values.
In food applications, the viscosity of starch is often used to control texture and mouthfeel, such as in sauces, gravies, and puddings. Higher viscosity starches are generally used in applications where a thicker or creamier texture is desired, while lower viscosity starches are used in applications where a thinner or more pourable consistency is needed.
In non-food applications, such as in papermaking or textile processing, the viscosity of starch can impact the strength, absorbency, and printability of the final product.
Therefore, controlling the viscosity of starch is important for achieving the desired performance and functionality in various applications.
BU stands for Brabender Units, which is a measure of viscosity commonly used to characterize the thickening properties of starch. The Brabender Viscoamylograph is a standard instrument used to measure the viscosity of starch, and the resulting values are reported in Brabender Units (BU).
The Brabender Viscoamylograph measures the viscosity of a starch sample as it is heated and stirred under standardized conditions. The viscosity profile obtained from this test can provide information on the gelatinization temperature, viscosity, and stability of the starch.
The viscosity of starch is an important parameter that can impact its functionality in various applications, such as in food and non-food industries. The Brabender Units (BU) provide a standardized method for measuring and comparing the viscosity of different starch samples.
Brabender Units (BU) of different types of starch
The Brabender Units (BU) of different types of starch can vary depending on various factors such as the source of the starch, processing method, and environmental conditions during testing. Here are some approximate ranges of BU for different types of starch:
- Corn starch: 500-6000 BU
- Potato starch: 200-2500 BU
- Tapioca starch: 250-4000 BU
- Rice starch: 200-1500 BU
- Wheat starch: 300-1500 BU
- Cassava starch: 300-2500 BU
It’s important to note that these values are only approximate and may vary depending on the specific starch sample and testing conditions. The Brabender Units of starch can also vary depending on the concentration and temperature of the starch solution during testing.
In general, higher BU values indicate higher viscosity and stronger thickening properties of the starch. The Brabender Units can be useful for selecting the appropriate type of starch for a specific application based on its viscosity and thickening properties.