Okra Extraction Part Two

1. Decolorize

Step 1. Do crude extraction through ethanol precipitation & drying (Okra Extraction Part One).

Step 2. Dissolve crude mucilage in distilled water to 2–5% (w/v) (e.g. 1 g mucilage in 20–50 mL water)

Step 3. Stir at room temp until fully hydrated and dissolved (this may take hours, especially at higher concentrations.)

Step 4. If it’s very cloudy, centrifuge at full speed for 20 min to remove insoluble particles.

20 min @ 16100 𝘨

Step 5. Transfer supenatant to new tube.

Step 6. Add 1% (w/v) activated charcoal (e.g. 100 mg per 10 mL solution).

Step 7. Stir gently for 60 min at room temp.

Step 8. Centrifuge at maximµmm speed for 3 minutes to pellet charcoal.

3 min @ 16100 𝘨

Step 9. Transfer supenatant to new tube.

2. Dialysis using 12–14 kDa RC tubing

Step 10. Cut a length of tubing, wet it thoroughly, and rinse inside with water to open it up. Tie/clamp one end.

Step 11. Load your mucilage solution into the tubing; avoid filling it more than ~⅔ full so it can move.

Aim for 1–2% (w/v) inside the bag; if it’s too viscous, dialysis will be painfully slow → dilute.

Step 12. Tie/clamp the other end, pushing out obvious air bubbles.

Step 13. Place the tubing in a beaker with 50–100× its volµme of cold distilled water (e.g. 20 mL sample in 1–2 L water.)

Step 14. Gently stir the outside water with a stir bar.

Step 15. Change water after 2 hours.

2 hr

Step 16. Change water again after 6 hours.

Step 17. Change water again next morning.

Step 18. Change water again after six hours.

3. Recovery and drying

Step 19. Remove the bag and collect the solution into a flask.

Step 20. Concentrate by simple evaporation, or in a 40–50 °C incubator if necessary.

Step 21. Freeze-dry to a fluffy, high-purity polysaccharide powder.

Step 22. Store at −20 °C in a sealed container with desiccant.