Ice recrystallisation inhibition by polyols: comparison of molecular and macromolecular inhibitors and role of hydrophobic units
2013
Deller, Robert C. | Congdon, Thomas | Sahid, Mohammed A. | Morgan, Michael | Vatish, Manu | Mitchell, Daniel A. | Notman, Rebecca | Gibson, Matthew I.
The ability of polyols to act as ice recrystallisation inhibitors (IRI), inspired by antifreeze (glyco)proteins are studied. Poly(vinyl alcohol), PVA, a known IRI active polymer was compared to a panel of mono and polysaccharides, with the aim of elucidating why some polyols are active and others show no activity. When corrected for total hydroxyl concentration all the carbohydrate-based polyols displayed near identical activity with no significant influence of molecular weight. Conversely, PVA was several orders of magnitude more active and its activity displays significant dependence on molecular-weight implying that its mechanism of action is not identical to that of carbohydrates. In a second step, the role of hydrophobicity was studied and it is observed that monosaccharide IRI activity is enhanced by alkylation. Dye-quenching assays demonstrated that PVA is able to present a hydrophobic surface without self-aggregation. Therefore, the ability to present a hydrophobic domain is hypothesised to be essential to obtain high IRI activity, which has many biotechnological applications.
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