We are trying to evaluate the thermal properties of gelatin. Few methods were followed and modified based on literature and understanding. However, based from previous experience of hydrophobic polymer, we thought of identifying the crystallization temperature, Tc for gelatin. Thus, we ramped the DSC towards negative celcius to obtain any Tc peak. Unfortunately, we are not getting any peak. Most of gelatin literature only reporting the presence of the glass transition, Tg and melting temperature, Tm. No clear literature mentioned about this matter. Up to now, we only got the information that protein that bound water does not freezing down to -60 C to -70 C. Hope to get further clarification and explanation regarding the matter. Thank you for your kind response.
On heating, the triple helix unfolds to produce random chains of gelatin. Also, the endothermic peak, that can be assigned as a first order transition is not reversible on
successive scans in the dry state. In that case, only a jump of the specific heat is observed around 200-300 °C, which is attributed to the glass transition of denatured collagen (i.e., gelatin), characteristic of its amorphous nature
Please check the following discussion for its possible interest: https://www.researchgate.net/post/What_is_the_melting_point_of_photographic_gelatin
Hi Hanisah Gelatin is a thermoreversible material that forms H bonds between the glycine residues that occur regularly along its primary aa structure to form the helical 'crystalline' material. The Tg of gelatin is bound water content dependent as predicted by the Gordon-Taylor equation and also dependent upon the gelatin Type, molecular wt (or Bloom strength) and species source (i.e. fish gelatin is lower than mammalian due to the primary aa sequence). Type A and B mammalian gelatin with an water content of < ~ 4 wt-% will have a Tg of around 75 - 120 dC (if I remember correctly) and the Tm will be ~ 175 dC above 200 dC you will start to see degradation and between 70 - 120 dC water loss that can mask the Tg. As gelatin is thermoreversible (if heated to below the Td onset (i.e. just above the Tm peak) with no degradation hence its gelation properties) you can measure Tc by isothermal DSC but the process is slow and iso temp-dependent so I did iso T holds and than assessed the % renaturation by DSC after specific time periods - There are a good few on this but these are older publications I'll send you titles if you need them. Hope this helps
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