[article]
| Titre : |
Effects of alkali and acid on the solubility and molecular weight of collagen hydrolysates extracted from bovine hide |
| Type de document : |
texte imprimé |
| Année de publication : |
2022 |
| Article en page(s) : |
p. 412-421 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Collagène
Cuirs et peaux de bovins
Hydrolysats de protéines
Hydroxyde de sodiumL'hydroxyde de sodium, appelé également soude caustique7, est un corps chimique composé minéral de formule chimique NaOH, qui est à température ambiante un solide ionique. Fusible vers 318 °C, il se présente généralement sous forme de pastilles, de paillettes ou de billes blanches ou d'aspect translucide, corrosives et très hygroscopiques. Il est très soluble dans l'eau et légèrement soluble dans l'éthanol.
La solution d'hydroxyde de sodium, souvent appelée soude, est une solution aqueuse transparente. Concentrée, elle est corrosive et souvent appelée lessive de soude.
Les propriétés chimiques de l'hydroxyde de sodium sont surtout liées à l'ion hydroxyde HO- qui est une base forte. En outre, l'hydroxyde de sodium réagit avec le dioxyde de carbone (CO2) de l'air et se carbonate.
La solubilité de la soude caustique dans l'eau augmente avec la température, à pression constante ou ambiante.
Poids moléculaires
Solubilité
Sulfurique, Acide
|
| Index. décimale : |
675 Technologie du cuir et de la fourrure |
| Résumé : |
Preparation of collagen hydrolysates with high molecular weight to meet its industrial demand is a crucial step for resource utilization of solid waste of animal skins/hides. However, it is very difficult to achieve both higher molecular weight and solubility of collagen hydrolysates through the traditional methods. In this study, we attempted to prepare bovine hide collagen hydrolysates with high molecular weight and solubility through the application of NaOH or different types of acid. Influences of the concentration of alkali and acid, hydrolysis temperature and time on the molecular weight and solubility were studied, respectively. The results showed that NaOH has a strong hydrolysis effect on bovine collagen, making it a suitable candidate for the preparation of collagen hydrolysates with medium or low molecular weight. Under these optimized NaOH treatment conditions, i.e., NaOH concentration of 0.13 mol/L, hydrolysis temperature of 60 - 70°C and time of 5 h, we achieved 96% of solubility for hide pieces and the molecular weight of collagen hydrolysates were in the range of 25 - 30 kDa. By contrast, the molecular weight of the hydrolysates prepared through H2SO4 hydrolysis method was higher than that of NaOH hydrolysis method. Under the optimized H2SO4 treatment conditions, i.e. H2SO4 concentration of 0.5 mol/L, hydrolysis temperature of 50°C and time in the range of 5 - 7 h, the solubility of hide pieces reached up to 80 - 97%. Additionally, in the H2SO4 hydrolysates, the proportion of macromolecular components with molecular weight of about 100 kDa was 41 - 55% and that of medium molecular components with molecular weight of about 20 kDa was 45 - 59%. This study showed that high solubility and high molecular weight collagen products can be obtained by H2SO4 hydrolysis under specific conditions. Thus, this study provided a useful scientific method and process parameters to guide the controlling of molecular weight and the industrial application of collagen from waste on a bigger scale. |
| Note de contenu : |
- MATERIALS AND METHODS : Materials - Preparation of bovine hide hydrolysates through NaOH hydrolysis method - Preparation of bovine hide hydrolysates through acid hydrolysis method - Determination of hypro by chloramine T method - Determination of molecular weight of bovine hide hydrolysates by GPC method
- RESULTS AND DISCUSSION : Effect of NaOH hydrolysis conditions on the molecular weight of collagen hydrolysate - Effect of NaOH concentration - Effect of NaOH hydrolysis time - Effect of NaOH hydrolysis temperature - Effect of acid hydrolysis conditions on the molecular weight of collagen hydrolysates - Effect of acid type - Effect of H2SO4 concentration - Effect of H2SO4 hydrolysis temperature - Effect of HSO4 hydrolysis time
- Table 1 : Conditions of hydrolysis by different acids
- Table 2 : Molecular weight of different acid hydrolyzed collagen hydrolysates
- Table 3 : Molecular weight and distribution of collagen hydrolystes with varying H2SO4 concentrations
- Table 4 : Molecular weight and distribution of collagen hydrolysates by H2SO4 hydrolysis with different H2SO hydrolysis temperature (CH2SO4 = 0.5 mol/L, 5h)
- Table 5 : Molecular weight and distribution of collagen hydrolysates by H2SO4 hydrolysis with varying time (CH2O4 = 0.5 mol.L, 50°C) |
| DOI : |
https://doi.org/10.34314/jalca.v117i10.6181 |
| En ligne : |
https://drive.google.com/file/d/1icwFY3afKUPxPe1ggPfep0XQmjiahBYR/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38227 |
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 10 (10/2022) . - p. 412-421
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Effects of alkali and acid on the solubility and molecular weight of collagen hydrolysates extracted from bovine hide in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 10 (10/2022)
