Skip to Content
Merck
  • Miscibility of Quillaja Saponins with other Co-surfactants under Different pH Values.

Miscibility of Quillaja Saponins with other Co-surfactants under Different pH Values.

Journal of food science (2015-10-13)
Corina L Reichert, Hanna Salminen, Bruno H Leuenberger, Jörg Hinrichs, Jochen Weiss
ABSTRACT

The miscibility behavior of mixed surfactant systems and the influence of extrinsic parameters are crucial for their application as emulsifiers. Therefore, the objective of this study was to evaluate the miscibility behavior of mixed systems composed of commercial Quillaja saponin and a co-surfactant, namely sodium caseinate, pea protein, rapeseed lecithin, or egg lecithin. These mixtures were evaluated macro- and microscopically at different concentration ratios (maximum concentration 5% w/v) at pH 3, 5, and 7 at 25 °C. The individual ingredients were also assessed for their charge properties and surface hydrophobicity. The results showed that Quillaja saponin-caseinate mixtures were miscible only at pH 7, and showed aggregation and precipitation at lower pH due to increasing electrostatic attraction forces. Rheological measurements showed that Quillaja saponin-pea protein mixtures formed gelled structures at all tested pH values mainly via association of hydrophobic patches. Quillaja saponins mixed with rapeseed lecithin were miscible at all tested pH values due to electrostatic repulsion. Quillaja saponin-egg lecithin mixtures aggregated independent of pH and concentration ratio. The microscopic analysis revealed that the lower the pH and the higher the Quillaja saponin ratio, the denser were the formed Quillaja saponin-egg lecithin aggregates. The results are summarized in ternary phase diagrams that provide a useful tool in selecting a surfactant system for food applications.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Sodium phosphate monobasic-16O4, 99.9 atom % 16O
Sigma-Aldrich
Sodium phosphate dibasic solution, BioUltra, 0.5 M in H2O
Sigma-Aldrich
Methanol, NMR reference standard
Sigma-Aldrich
Methanol, HPLC Plus, ≥99.9%, poly-coated bottles
Sigma-Aldrich
Sodium hydroxide solution, 1.0 N, BioReagent, suitable for cell culture
Sigma-Aldrich
Sodium azide, BioXtra
Sigma-Aldrich
Sodium azide, BioUltra, ≥99.5% (T)
Sigma-Aldrich
Sodium hydroxide, BioUltra, for luminescence, ≥98.0% (T), pellets
Sigma-Aldrich
Sodium azide, ReagentPlus®, ≥99.5%
Sigma-Aldrich
Sodium azide, purum p.a., ≥99.0% (T)
Sigma-Aldrich
Sodium hydroxide solution, BioUltra, for molecular biology, 10 M in H2O
Sigma-Aldrich
3-Ethyl-2,4-pentanedione, mixture of tautomers, 98%
Sigma-Aldrich
Methanol, anhydrous, 99.8%
Sigma-Aldrich
Methanol, ACS spectrophotometric grade, ≥99.9%
Sigma-Aldrich
Sodium hydroxide, reagent grade, ≥98%, pellets (anhydrous)
Sigma-Aldrich
Methanol, ACS reagent, ≥99.8%
Sigma-Aldrich
Sodium hydroxide, puriss. p.a., ACS reagent, K ≤0.02%, ≥98.0% (T), pellets
Sigma-Aldrich
Sodium hydroxide, reagent grade, 97%, powder
Sigma-Aldrich
Sodium hydroxide, anhydrous, free-flowing, Redi-Dri, reagent grade, ≥98%, pellets
Sigma-Aldrich
Sodium hydroxide, ultra dry, powder or crystals, 99.99% trace metals basis
Sigma-Aldrich
Sodium hydroxide, BioXtra, ≥98% (acidimetric), pellets (anhydrous)
Sigma-Aldrich
Methanol, ACS reagent, ≥99.8%
Sigma-Aldrich
Methanol, Absolute - Acetone free
Sigma-Aldrich
Sodium hydroxide solution, 5.0 M
Sigma-Aldrich
Sodium hydroxide solution, purum, ≥32%
Sigma-Aldrich
Sodium hydroxide, puriss., meets analytical specification of Ph. Eur., BP, NF, E524, 98-100.5%, pellets
Sigma-Aldrich
Sodium hydroxide, puriss. p.a., ACS reagent, reag. Ph. Eur., K ≤0.02%, ≥98%, pellets
Sigma-Aldrich
Sodium hydroxide, ACS reagent, ≥97.0%, pellets
Sigma-Aldrich
Sodium hydroxide, pellets, semiconductor grade, 99.99% trace metals basis
Sigma-Aldrich
Methanol, ACS reagent, ≥99.8%