Protein-based surfactants amphoteric

Enzyme-Catalyzed Synthesis of Protein-Based Surfactants Amphoteric Surfactants... 

In order to produce the amphoteric protein-based surfactant, the incorporation of lipophilic amino acid ester was attempted using the one-step method of plastein reaction with papain at pH 9. In a system containing succinylated ttsi-casein as a protein substrate and luecine n-dodecyl ester as a lipophile, the peptide bond between Phe and Tyr of casein was first hydrolyzed, and this is followed by the incorporation of luecine n-dodecyl ester at the same position, forming a new C-terminus [34]. The structure of the macropeptide with respect to the distribution of hydrophilic amino acid residues is shown in Fig. 4 [29,34]. Amphiphilic structure consisting of hydrophilic protein portion and lipophilic luecine n-dodecyl ester was clearly demonstrated. 

Protein-based surfactants are composed of two naturally occurring moieties, amino acid and fatty acid such as acylglutamate. Acylglutamates by themselves are not ultramild surfactants by any means. Their in vitro Zein values are higher than those of alkyl polyglycosides, alkylamphoacetate, amphoteric... 

The protective effect of protein derivatives in detergency has been tested in numerous studies and quantitative data are available in the technical literature. Native proteins, hydrolysates, and condensates are all reported to reduce the irritant effects of tenside on the skin. To compare the protective properties of protein substances with the well-known effect of amphoteric and nonionic tenside in detergent formulations based on anionic surfactants, a study was carried out based on intensive and repeated application on the skin of binary systems containing sodium lauryl sulfate and the anti-irritant test substance, and evaluation of some biophysical parameters for assessing skin damage (122). It was demonstrated that a hydrolyzed protein was as effective as some of the cosurfactants traditionally employed to inhibit the irritation potential of anionic tensides. Some of the results obtained are illustrated in Figure 29. 

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