Conformations of different gelatins in solutions and in films an analysis of circular dichroism (CD) measurements

The structural behaviour of gelatins from different raw materials and manufacturing processes at thermal denaturation and isothermal dehydration and rehydration is investigated by CD. At both thermal denaturation and isothermal dehydration with all gelatins examined, the triple helix content decreases. Simultaneously, the appearance of cis peptide bonds is observed. At rehydration, a structural hysteresis occurs, the reconstitution of the triple helix structure being correlated with a decrease in the content of cis peptide bonds. The possibility of the formation of chain reversals upon destruction of the triple helix is discussed.