Chia seed gum (CSG) is a water-soluble hemicellulose that can form a gel through hydrophilic functional groups and can crosslink between chains.
Its texture, appearance, stability and biocompatibility make it a very useful material across a variety of industries including: medicine, cosmetics and gastronomy.
Step 1: Hydration
The ideal chia:water ratio is 1:40.
For Example: 1L of water will require 25g of chia seeds.
Heat your desired mass of water to 80 degrees (C) and add this to the equivalent mass of chia seeds.
Mix together for 3 hours at room temperature. Try your best to avoid seeds clumping together, (which they like to do), so it’s best to stir as constantly as possible.
Step 2: Drying
A: DRYING BY CENTRIFUGATION:
Aliquot the mixture into 15 or 50mL tubes.
Centrifuge for 30 minutes at 1400g. Any over the counter centrifuge will work just fine, we recommend searching eBay for one.
Pipette off the supernatant (the hydrated gum sitting on top) into a non-stick pan.
Place in a preheated oven at ~ 60 degrees (C) for +3 hours until fully desiccated.
B: DRYING BY MESH SIEVE
If you don’t have a centrifuge, you can pour the hydrated chia mixture into a non-stick pan.
Place the pan in an oven at ~ 60 degrees (C) for +3 hours until fully desiccated.
Sift the desiccated mixture through a #44 mesh sieve to separate out the hydrogel from the chia seed husk.
Step 3: Forming the Hydrogel
Reconstitute 2% (w/v) dried chia gum in water.
For Example: 200mg of chia gum into 10mL of water.
Gradually add in 16.7% (w/v) sodium alginate to the reconstituted chia gum.
For Example: 1.67g of sodium alginate into 10mL of water.
You should now have a sticky hydrogel!
Step 4: Crosslinking With Calcium Chloride
Mould the gel into the shape you desire – be creative and have some fun!
Once you’re happy with the shape immerse in a 1M CaCl2 for up to 10 minutes.
Note: The longer the gel is immersed, the more crosslinks are created and the more rigid the gel becomes.
Step 5: Warning
Please be mindful of sterility!
Work fast, do not leave the product out. Keep it covered and refrigerate.
For laboratory settings, it is possible to sterilize the dry seeds with UV sterilization or autoclave after the mixing on a standard liquid cycle.