[article]
Titre : |
Rheological and texture analysis methods for the assessment of viscoelasticity |
Type de document : |
texte imprimé |
Auteurs : |
Slobodanka Tamburic, Auteur ; Milica C. Stevic, Auteur ; Helen Sisson, Auteur |
Année de publication : |
2018 |
Article en page(s) : |
p. 20-25 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Carbomères Les carbomères sont des polymères synthétiques hydrophiles d'acide acrylique.
Les carbomères sont utilisés comme émulsions stabilisatrices ou comme agents épaississants ayant l'apparence d'un gel aqueux dans l'industrie pharmaceutique ou cosmétique. L'aminométhyl propanol permet de les stabiliser sous la forme d'un gel. Cosmétiques -- Analyse Cosmétiques -- Texture Emulsions -- Emploi en cosmétologie Formulation (Génie chimique) Gomme de xanthaneLa gomme xanthane est un polyoside obtenu à partir de l'action d'une bactérie, la Xanthomonas campestris. Elle est soluble à froid et est utilisée comme additif alimentaire sous le code E415 pour ses propriétés épaississantes et gélifiantes afin de modifier la consistance des aliments.
Le xanthane est l'un des exopolysaccharides excrétés par divers microorganismes du sol (bactéries notamment). Il joue un rôle important, à l'échelle moléculaire, dans la formation et la conservation des sols3, tout comme le dextrane, le rhamsane ou les succinoglycanes. Rhéologie Viscoélasticité
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Index. décimale : |
668.5 Parfums et cosmétiques |
Résumé : |
The purpose of this study was to compare the dynamic (oscillatory) rheological method with a novel texture analysis (TA) method for the assessment of viscoelastic properties of cosmetic semisolids.
The instruments used in this study were an air-bearing controlled-stress rheometer (RheoStress RS75, Haake, Germany) and a texture analyser (TA.XT Plus, Stable Micro Systems, UK). The model formulation was a standard semisolid emulsion, containing increasing concentrations of carbomer and xanthan gum, respectively. The rheological methods used were stress sweep (0.5-500 Pa at 1 Hz) and frequency sweep (0.01-10 Hz at 10 Pa). The texture analysis method used was an immersion/de-immersion test with cylindrical probe.
The results were analysed for their consistency with theoretical predictions and the presence of any correlations between the methods. The analysis revealed consistent trends related to two novel TA parameters, stringiness (which decreased with the increase in thickener concentration) and resilience (which has shown a mild increasing trend). Elastic modulus G' and viscous modulus G" (both at 1 Hz) were positively correlated to resilience and negatively correlated to stringiness, indicating that those TA parameters reflect the viscoelastic status of the sample. |
Note de contenu : |
- Fig. 1. : Visual representation of the oscillatory rheology method and texture analysis method
- Fig. 2 : Typical curve obtained by immersion/de-immersion test on texture analyser, expressed as force vs. time
- Fig. 3 : Oscillatory stress sweep results for 0.1% carbomer, showing a decrease in the complex modulus (G* - red line) and an increase in the phase angle (δ- green ling) at stress levels above 20 Pa
- 4. Elastic moduli for the emulsion samples with increasing carbomer concentrations
- Fig. 5 Elastic moduli for the emulsion samples with increasing xanthan gum concentrations
- Fig. 6 : Typical curve obtained by immersion/de-immersion test on texture analyser, expressed as force vs. distance. Stringiness is defined as the distance that the product is extended during de-immersion stage before separating from the probe ; a) emulsion with 0.1% carbomer ; b) emulsion with 0.5% carbomer
- Fig. 7 : TA graphs of the emulsions with increasing concentrations of carbomer, showing two district areas of the positive curve (A3 and A4), which were used to calculate the parameter resilience, as A4/A3
- Fig. 8. Linear regression fit betwen a TA parameter resilience and two oscillatory parameters, elastic modulus G' and viscousmodulus G", for the series of emulsions with carbomer
- Fig. 9. Linear regression fit between a TA parameter stringiness and two oscillatory parameters, elastic modulus G' and viscous modulus G", for the series of emulsions with xanthan gum
- Table 1 : The formulation of the semisolid w/o emulsion used in the study
- Table 2 : Oscillatory rheology parameters obtained at the frequency of 1 Hz for the emulsion samples stabilised with carbomer and xanthan gum. All values represent the mean of 3 measurements, with the coefficient of variation below 5%
- Table 3 : Texture analysis parameters of the emulsion samples stabilised with carbomer and xanthan gum |
En ligne : |
https://drive.google.com/file/d/1NLvR09lbNA2cns_g14Lir8nIUd_pZSno/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30738 |
in SOFW JOURNAL > Vol. 144, N° 6 (06/2018) . - p. 20-25
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