Thermal transitions in gelatin: Optical rotation and enthalpy changes

✍ Scribed by D. D. Macsuga

• Publisher: Wiley (John Wiley & Sons)
• Year: 1972
• Tongue: English
• Weight: 752 KB
• Volume: 11
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1972.360111211

✦ Synopsis

Abstract

Enthalpy changes [as determined by differential scanning calorimetry (DSC)] and optical rotation changes over the helix → coil transition were measured for various gelatin solutions and films. From these studies it has been concluded that: (1) a linear correlation between Δ__H__ and Δ[α] exists for gelatin solutions, independent of the temperature at which gelation occurred; (2) the amount of triple helical structure regained when a melted gelatin solution is quenched can be calculated from DSC data, but the values obtained will be dependent on assumptions about the number and strength of hydrogen bonds; (3) the anomalously high levorotation values found for cold‐dried films of gelatin do not reflect the presence of an extraordinarily large amount of triple helical structure; rather, the large rotations appear to be the result of orientation of helices in the plane of the film.