To verify the purity of low acyl gellan gum, there are a few tests you can perform. Here are some common methods:

  1. Infrared spectroscopy (IR): This technique measures the absorption of infrared light by a sample and can be used to identify the presence of specific functional groups in the sample. A pure sample of low acyl gellan gum should show characteristic peaks in the IR spectrum that correspond to its specific functional groups.
  2. Gel permeation chromatography (GPC): This technique separates the components of a sample based on their molecular weight and size. A pure sample of low acyl gellan gum should produce a single peak in the chromatogram that corresponds to its characteristic molecular weight and size.
  3. Differential scanning calorimetry (DSC): This technique measures the heat flow into or out of a sample as a function of temperature. A pure sample of low acyl gellan gum should show a specific melting temperature in the DSC thermogram.

It's worth mentioning that these tests should be performed by a qualified laboratory, as they require specialized equipment and expertise. If you suspect that your supplier is not providing you with 100% pure low acyl gellan gum, you may also consider contacting a third-party testing laboratory to have the sample analyzed.


While the tests I mentioned earlier are the most reliable methods for verifying the purity of low acyl gellan gum, there are some simpler tests that you can perform. However, these tests may not be as accurate as the methods I described earlier and are best used as a preliminary screen. Here are a couple of simple tests you can perform:

  1. Solubility test: Low acyl gellan gum should dissolve in water and form a clear, homogeneous solution. If the sample is not 100% pure, you may observe some undissolved particles or a cloudy solution.
  2. Gel formation test: Low acyl gellan gum forms a gel when it is hydrated and heated. To perform this test, mix a small amount of the sample with water and heat the mixture until it reaches boiling. Allow the mixture to cool and observe the formation of a gel. If the sample is not 100% pure, you may observe some changes in the gel structure or a reduction in gel strength.

It's important to keep in mind that these tests are not as reliable as the methods I described earlier and should not be used as the sole means of verifying the purity of low acyl gellan gum.

The methods for verifying the purity of high acyl gellan gum are similar to those used for low acyl gellan gum. Some of the tests you can perform include:

  1. Infrared spectroscopy (IR): This technique measures the absorption of infrared light by a sample and can be used to identify the presence of specific functional groups in the sample. A pure sample of high acyl gellan gum should show characteristic peaks in the IR spectrum that correspond to its specific functional groups.
  2. Gel permeation chromatography (GPC): This technique separates the components of a sample based on their molecular weight and size. A pure sample of high acyl gellan gum should produce a single peak in the chromatogram that corresponds to its characteristic molecular weight and size.
  3. Differential scanning calorimetry (DSC): This technique measures the heat flow into or out of a sample as a function of temperature. A pure sample of high acyl gellan gum should show a specific melting temperature in the DSC thermogram.

As with low acyl gellan gum, these tests should be performed by a qualified laboratory, as they require specialized equipment and expertise. If you suspect that your supplier is not providing you with 100% pure high acyl gellan gum, you may also consider contacting a third-party testing laboratory to have the sample analyzed.

Simple tests such as solubility and gel formation tests can also be performed, but these may not be as reliable as the more advanced tests.