Coil-to-helix transition of gellan in dilute solutions is a two-step process / Safronov Alexander P.,Tyukova Irina S.,Kurlyandskaya Galina V. // FOOD HYDROCOLLOIDS. - 2018. - V. 74, l. . - P. 108-114.

ISSN/EISSN:

0268-005X / 1873-7137

Type:

Article

Abstract:

Thermodynamics of coil-to-helix transition of natural polysaccharide-gellan was studied in dilute solutions in 130 mM NaCL in concentration range 0.01-1.5\% using SETARAM C80 3D Calvet calorimeter operated in a passive scanning mode at low cooling rate (0.04 K/min at the transition temperature). It was shown that the negative values of the total enthalpy of the coil-to-helix transition substantially increased in a step-wise fashion if the concentration of the solution decreased below the threshold of coil overlapping in accordance with the results of dynamic light scattering. The shape of thermograms depended on the concentration of solutions. While in semi-dilute solutions with gellan concentration above 0.25\% only one exothermic peak was indicated in the cooling mode, in dilute solutions two distinct peaks of the two-step transition: first-endothermic and second-exothermic were clearly observed. The endothermic and exothermic peaks overlapped for semi-dilute solutions of gellan and became progressively separated as the concentration diminished. The reasons, which underlie the two-step nature of coil-to-helix transition of gellan are discussed based on the origin of molecular interactions involved. (C) 2017 Elsevier Ltd. All rights reserved.

Author keywords:

Gellan; Coil-to-helix transition; Differential scanning calorimetry; Enthalpy CRITICAL SOLUTION TEMPERATURE; GUM AQUEOUS-SOLUTIONS; SOL TRANSITION; POLYSACCHARIDE; HYDRATION; POLYMER; SALTS

DOI:

10.1016/j.foodhyd.2017.07.019

Web of Science ID:

ISI:000410537400014

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	JAN
Publisher	ELSEVIER SCI LTD
Address	THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
Language	English
EISSN	1873-7137
Keywords-Plus	CRITICAL SOLUTION TEMPERATURE; GUM AQUEOUS-SOLUTIONS; SOL TRANSITION; POLYSACCHARIDE; HYDRATION; POLYMER; SALTS
Research-Areas	Chemistry; Food Science \& Technology
Web-of-Science-Categories	Chemistry, Applied; Food Science \& Technology
Author-Email	safronov@iep.uran.ru
ORCID-Numbers	Kurlyandskaya, Galina/0000-0002-3712-1637
Funding-Acknowledgement	Russian foundation for basic research {[}16-08-00609]
Funding-Text	The study was performed with the financial support of the Russian foundation for basic research (grant 16-08-00609). Special support of Ms. O.V. Merkur'eva is appreciated.
Number-of-Cited-References	27
Usage-Count-Last-180-days	20
Usage-Count-Since-2013	20
Journal-ISO	Food Hydrocolloids
Doc-Delivery-Number	FG6WG