- Tytuł:
- $\text{}^{1}$H NMR and Rheological Studies of the Calcium Induced Gelation Process in Aqueous Low Methoxyl Pectin Solutions
- Autorzy:
-
Dobies, M.
Kuśmia, S.
Jurga, S. - Powiązania:
- https://bibliotekanauki.pl/articles/2043388.pdf
- Data publikacji:
- 2005-07
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
82.70.Gg
87.15.By
87.15.Rn
82.56.-b
87.15.He
83.10.-y
87.15.La - Opis:
- The $\text{}^{1}$H NMR relaxometry in combination with water proton spin-spin relaxation time measurements and rheometry have been applied to study the ionic gelation of 1% w/w aqueous low methoxyl pectin solution induced by divalent Ca$\text{}^{2+}$ cations from a calcium chloride solution. The model-free approach to the analysis of $\text{}^{1}$H NMR relaxometry data has been used to separate the information on the static (β) and dynamic (〈τ$\text{}_{c}$〉) behaviour of the systems tested. The $\text{}^{1}$H NMR results confirm that the average mobility of both water and the pectin molecules is largely dependent on the concentration of the cross-linking agent. The character of this dependency (β,〈τ$\text{}_{c}$〉 and T$\text{}_{2}$ vs. CaCl$\text{}_{2}$ concentration) is consistent with the two-stage gelation process of low methoxyl pectin, in which the formation of strongly linked dimer associations (in the range of 0-2.5 mM CaCl$\text{}_{2}$) is followed by the appearance of weak inter-dimer aggregations (for CaCl$\text{}_{2}$ ≥ 3.5 mM). The presence of the weak gel structure for the sample with 3.5 mM CaCl$\text{}_{2}$ has been confirmed by rheological measurements. Apart from that, the T$\text{}_{1}$ and T$\text{}_{2}$ relaxation times have been found to be highly sensitive to the syneresis phenomenon, which can be useful to monitor the low methoxyl pectin gel network stability.
- Źródło:
-
Acta Physica Polonica A; 2005, 108, 1; 33-46
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł