AI Article Synopsis
- The study focuses on thermal transitions of two galactomannans, vinal gum and guar gum, to assess their processing features and storage stability, which were particularly significant in the 90s.
- Differential scanning calorimetry (DSC) revealed three endothermal transitions at varying temperatures, with LTT and HTT transitions affected by water content and showing low ΔC values, complicating their classification.
- The mid-transition temperature (MTT) was identified as an enthalpic relaxation that is stable with respect to frequency and water content, linked to changes in mechanical properties and proton mobility.
Article Abstract
The thermal transitions of biopolymers were subject of great discussion in the 90s due to their relevance in structure development during processing and stability on storage. In the present work two galactomannans, vinal gum and guar gum, were evaluated by DSC, DMA and LF-H NMR in order to compare them, establishing their potential operational application range and promoting the use of the non-conventional VG in foods or other products. Three endothermal transitions appeared when heating the samples in the DSC: one at temperatures -90 to -10 °C (LTT), other around 50 °C (MTT) and a third one between 50 and 100 °C (HTT). Both LTT and HTT showed water content dependence and low ΔC values, which difficulted the assignment of a glass transition. MTT appeared as an enthalpic relaxation independent on frequency or on water content. This transition was related to changes in mechanical properties and with the stabilization of proton mobility.
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| http://dx.doi.org/10.1016/j.carbpol.2019.01.092 | DOI Listing |
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