At the present time the best method of dissolving starch with true molecular dispersion and without degradation is by using dimethylsulfoxide containing a small amount of LiCl. Please see reference by Cave et al(Biomacromolecules 10(2009)2245-2253.I hope this helps.
Hi Erik
Starch is not a unique molecule..what kind of starch do you use? What source, what chainlength and what distribution of Amylose/Amylopektin?
Starch can be dissolved in ionic liquids and some DES-deep eutectic solvents,but I have got no experience with SEC, so I don't know if these solvents will be suitable in this method (water can act as precipitating agent for dissolved polysaccharide)
http://www.sciencedirect.com/science/article/pii/S0144861706001834 http://www.sciencedirect.com/science/article/pii/S0144861711004474
http://yadda.icm.edu.pl/yadda/element/bwmeta1.element.baztech-article-BAT4-0009-0011 (you can also download from my profile)
Hi Frank,
I tried to find that information on the package, but there's nothing of it - I guess, it's pretty old sample, only information I can provide is sample name on the box (Amylum solubile p.a.). But thanks anyway.
M. Zdanowicz: Thank you for these publications. I'll try it and hope it will work in SEC too.
Hi Frank,
most starch (and other polyglucosan) particles can be solubilized by boiling in alkaline solution. I worked with native starch prepared from wildtype and diverse Arabidopsis mutants, from Curcuma rhizomes and potatos, from seeds of Corn, Rice, Barley, as well as from unicellular algae ... ALL of them could be solubilized in 0.2M KOH. You can easily neutralize with a small amount of 1M acetic acid. The product would be starch solved in ca. 0.2M potassium acetate. It's a pretty easy way to get it done and it's part of most starch quantification methods from plant tissue.
BE AWARE: Freezing and cooling might lead to re-precipitation of starch - so you better avoid that once you've solubilized the starch.
All the best, Felix.
Dear Colleagues,
Dissolving starch without degradation is a task not simply nor easy because of extremely high molecular mass of starch. Using alkaline solvents results in molecular distribution of starch but is accompanied by its degradation.
I have obtained quite good results using a mixture of 90% of DMSO with 10% of water. Solution of starch in this solvent is full transparent and viscous, and starch is not degraded. However SEC analysis with triple detection proved that thermodynamic quality of this solvent is not very good. The last literature recommendation for dissolving starch is using solution of LiCl in DMF. However I have not any laboratory experience with that solvent. May be my colleague dr. Artur Szwengiel from my University (Poznań Universityof Life Sciences) could add something to my information.
Regards
At the present time the best method of dissolving starch with true molecular dispersion and without degradation is by using dimethylsulfoxide containing a small amount of LiCl. Please see reference by Cave et al(Biomacromolecules 10(2009)2245-2253.I hope this helps.
In addition to our discussion I would like to recommend you our new paper in which we discuss the advantages and disadvantages of different protocols for dissolving of starch.
I would like to synthesize Nonnewtonıan materials as an example cornstarch-water suspensıon.Everyone knows that starch is not soluble in water even water is polar.My prepared suspensıon behaves like liquıd and solid according to force you can apply.This is the maın characterstıc of nonnewtonıan fluıds.However when the time is passed; starch is precipıtated and water is evoporated.How can I solve this problems? My purpose is that suspensıon should not lose their fludity and starch must not precıpıtate at the bottom of beaker.I have seen some advicesto dissolve starch above but I am doubtful about to add DMSO in our suspensıon if the fluıdıty could lose.Thank you for cooperatıons.
does any modified starch can dissolve in water in a concentration higher than 10%?
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