Determination of kinetic and thermodynamic parameters of food hydrocolloids/water interactions by means of thermal analysis and viscometry

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F18%3A63518836" target="_blank" >RIV/70883521:28110/18:63518836 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61989592:15310/18:73587432

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.colsurfa.2018.07.009" target="_blank" >http://dx.doi.org/10.1016/j.colsurfa.2018.07.009</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.colsurfa.2018.07.009" target="_blank" >10.1016/j.colsurfa.2018.07.009</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Determination of kinetic and thermodynamic parameters of food hydrocolloids/water interactions by means of thermal analysis and viscometry

Popis výsledku v původním jazyce

The aim of this study was to determine thermal properties of pseudoplastic polysaccharides (guar gum, κ-carrageenan and xanthan gum) which find many applications as food hydrocolloids in food industry. There was an obvious relationship between thermal dependency of heats of fusion of hydrocolloids in powder form and activation parameters of hydrodynamic flow in solutions, respectively. Results of thermal analysis confirmed, that powder samples of hydrocolloids as typical foodstuffs of low moisture content less than 15 w% after room conditioning, exhibited varying ability to bind water as depending on their molecular structure. The peak temperature of the endothermic polysaccharide order-disorder phase transition process was found in the temperature range of 50–85 °C. It was influenced simultaneously by the applied heating rate and the samples moisture content. Studied samples moisture content was ranging between 9–40 w.% as was obtained after different conditioning. Observed reaction enthalpy (ΔH) associated with phase transition and water evaporation (proved by appropriate weight loss of the samples Δmw) was ranging from 140 to 670 J/g. Activation energy (Ea) of this process in powder samples was calculated from the kinetic parameters using three kinetic models developed by Friedman, Kissinger and model-free kinetics. The latter kinetic models were compared with the Arrhenius model, which was used to determine Ea of polysaccharide solutions on reflecting sensitivity of their molecular structure to the temperature and the solvent. According to the Arrhenius model, there were obtained the highest values of Ea for κ-carrageenan solutions, indicating the highest resistance of their molecular structure to temperature. This fact can be related to the observed the lowest value of the reaction enthalpy in the case of powder samples, suggesting that energy obtained during the order-disorder transition to change the carrageenan powder structure is limited. On the other hand, xanthan gum was the least temperature dependent sample; activation energy of xanthan solutions was only in the range of 2–6 kJ/mol. Concurrently, ΔH of xanthan powder was determined as the largest of all samples under study. In general, there was found an indirect relationship between activation energy of the solutions determined by viscometry and reaction enthalpy of the powders determined by thermal analysis. Results of the Arrhenius model also indicate that the energy necessary to promote viscous flow of solutions is higher for hydrocolloids in distilled water rather than in 0.07 M KCl aqueous solutions, suggesting the suppression of the polyelectrolyte effect. In both cases, Ea was substantially reduced by application of higher shear rate.

Název v anglickém jazyce

Determination of kinetic and thermodynamic parameters of food hydrocolloids/water interactions by means of thermal analysis and viscometry

Popis výsledku anglicky

The aim of this study was to determine thermal properties of pseudoplastic polysaccharides (guar gum, κ-carrageenan and xanthan gum) which find many applications as food hydrocolloids in food industry. There was an obvious relationship between thermal dependency of heats of fusion of hydrocolloids in powder form and activation parameters of hydrodynamic flow in solutions, respectively. Results of thermal analysis confirmed, that powder samples of hydrocolloids as typical foodstuffs of low moisture content less than 15 w% after room conditioning, exhibited varying ability to bind water as depending on their molecular structure. The peak temperature of the endothermic polysaccharide order-disorder phase transition process was found in the temperature range of 50–85 °C. It was influenced simultaneously by the applied heating rate and the samples moisture content. Studied samples moisture content was ranging between 9–40 w.% as was obtained after different conditioning. Observed reaction enthalpy (ΔH) associated with phase transition and water evaporation (proved by appropriate weight loss of the samples Δmw) was ranging from 140 to 670 J/g. Activation energy (Ea) of this process in powder samples was calculated from the kinetic parameters using three kinetic models developed by Friedman, Kissinger and model-free kinetics. The latter kinetic models were compared with the Arrhenius model, which was used to determine Ea of polysaccharide solutions on reflecting sensitivity of their molecular structure to the temperature and the solvent. According to the Arrhenius model, there were obtained the highest values of Ea for κ-carrageenan solutions, indicating the highest resistance of their molecular structure to temperature. This fact can be related to the observed the lowest value of the reaction enthalpy in the case of powder samples, suggesting that energy obtained during the order-disorder transition to change the carrageenan powder structure is limited. On the other hand, xanthan gum was the least temperature dependent sample; activation energy of xanthan solutions was only in the range of 2–6 kJ/mol. Concurrently, ΔH of xanthan powder was determined as the largest of all samples under study. In general, there was found an indirect relationship between activation energy of the solutions determined by viscometry and reaction enthalpy of the powders determined by thermal analysis. Results of the Arrhenius model also indicate that the energy necessary to promote viscous flow of solutions is higher for hydrocolloids in distilled water rather than in 0.07 M KCl aqueous solutions, suggesting the suppression of the polyelectrolyte effect. In both cases, Ea was substantially reduced by application of higher shear rate.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/LO1305" target="_blank" >LO1305: Rozvoj centra pokročilých technologií a materiálů</a><br>

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Colloids and Surfaces A: Physicochemical and Engineering Aspects

ISSN

0927-7757

e-ISSN

—

Svazek periodika

555

Číslo periodika v rámci svazku

20 October

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

270-279

Kód UT WoS článku

000443153100031

EID výsledku v databázi Scopus

2-s2.0-85049500479