Thermal properties measurements of renatured gelatin using conventional and temperature modulated differential scanning calorimetry

Abstract

ABSTRACT:The thermal properties of amorphous gelatin films and gelatin films with renatured structural order were measured by using conventional and temperature modulated differential scanning calorimetry (DSC). Different amounts of gelatin structural order associated with a melting enthalpic change in the DSC measurement were prepared based on different gelatin drying conditions. Two consecutive heating and cooling DSC measurements on the gelatin films showed that there was no change in the glasstransition temperature (T g ) for the amorphous gelatin but there was a decrease in the T g for the structural gelatin on the second DSC scan. This decrease was attributed to the plasticizing effect from the release of originally hydrogenbonded water associated with the structural gelatin. In addition, a reversing endotherm observed upon melting of the structural gelatin during a temperature modulated DSC measurement indicated that the transition of bound water to free water occurred as the partial triple-helix gelatin melted.

Correlations between structural, barrier, thermal and mechanical properties of plasticized gelatin films

“…Unplasticized films presented a wide endothermic peak with a minimum at around 87°C and a high enthalpy value associated (540 J/g). Several authors attribute this endothermic peak to the overlapping of different process such as water evaporation, melting and recrystallization of small and/or imperfect gelatin crystallites, and association of the glass transition of α-amino acid blocks in the polypeptide chain (Dai et al, 2006;Langmaier et al, 2008;Patil et al, 2000). Peak temperature, and moreover enthalpy of this endothermic process are strongly related to film drying conditions.…”

“…Peak temperature, and moreover enthalpy of this endothermic process are strongly related to film drying conditions. This effect has been studied by some authors, among them Dai et al (2006) and Chiou et al (2008).…”

“…As was described previously, moisture increased with plasticizer concentration while T g decreased. According to Dai et al (2006), free water plasticizes the amorphous phase of the matrix, contributing to a depression of T g .…”

“…After the denaturation process the triple helix is broken and polypeptide chains adopt a random configuration. Then, these chains can interact to form a partial collagen-like triple helix called renatured or structural gelatin (Dai, Chen, & Liu, 2006).…”

Knowledge‐Based Tailoring of Gelatin‐Based Materials by Functionalization with Tyrosine‐Derived Groups

“…The melting temperatures T m were taken from the first heating run in TM-DSC experiments, while the glass transition temperatures T g were taken from the second heating run. [24] The functionalized materials showed a reduction of T m (from 144 °C to 123-127 °C) with a simultaneous reduction of the melting enthalpy comparing gelatin and the The influence of the degree of aromatic functionalization and of the related helical suppression can also be seen in the mechanical properties of the films as determined using tensile tests. The introduction of aromatic substituents on gelatin led to a more brittle behaviour of the respective materials.…”