Protein-based surfactants

Protein-Based Surfactants Synthesis, Physicochemical Properties, and Applications, edited by Ifendu A. Nnanna and JidingXia... 

K. Sakamoto, in J. Xia, LA. Nnanna (Eds.), Surfactant Science Series, Protein-Based Surfactants, vol. 101, Marcel Dekker, New York, 2001. 

In their studies of three-phase capillary air slug (bubble) flow, Stebe and Maldarelli [47] correlated surfactant concentration to equivalent flow rate invoking similar reasoning. At a higher surfactant concentration, flow rate increased with surfactant concentration, due to the relief of surface tension gradients at the air bubble surface. When using protein-based surfactants, retardation of flow due to surface viscous effects (flow rate decreased with an increase in protein concentration) was observed. 

In recent years, protein-based surfactants are finding some applications in personal care products due to their abilities to interact with skin and hair." A-acyl polypeptide condensates (protein derivatives) belong to the mild surfactant category with foaming performance inferior to alkyl sulfates, but they produce creamy lather and leave hair feeling soft and manageable. However, it appears that extra attention and care should be taken to ensure preservation of these protein derivatives due to compatibility with other anionic surfactants when present in shampoo formulations. 

Polychloroprene latexes are aqueous dispersions of synthetic polychloroprene polymers with surfactants. The surfactants of choice are markedly different than the protein-based surfactants contained in natural rubber latex that is reportedly at the root of human hypoallergenic reactions associated with the use of natin-al rubber latex. 

Sakamoto K (2001) In Xia J, Nnanna lA (eds) Surfactant science series vol 101. Protein-based surfactants Ch. 10 261-280 Dekker, New York... 

An Overview of the Basis, Technology, and Surface Phenomena of Protein-Based Surfactants... 

The commercial prospects of protein-based surfactants (PBS) is expected to be huge, especially at the more expensive end of the market, such as pharmaceutical formulations and personal care products, where a broad range of functionality (e.g., safety, mildness to skin, high surface activity, antimicrobial activity, biodegradability) is desired. 

Proteins are by nature amphipathic or amphiphilic molecules that is, they contain both a hydrophobic (nonpolar) and a hydrophilic (polar) moiety. However, natural proteins per se are not used as commercial surfactants. Rather, proteins are modified by chemical or enzymatic means to products with surface-active properties. The use of modified proteins based on casein, soybean, albumen, collagen, or keratin is not new [5]. The Maywood Chemical Company introduced commercial protein-based surfactants (PBS) in the United States in 1937. They were primarily condensation products of fatty acids with hydrolyzed proteins [5], Renewed interest in PBS has occurred not only as products based on renewable raw materials (i.e., proteins and fatty acids), but also as a solution to waste disposal for animal and vegetable protein byproducts [5], Among the commercial PBS, the following trade names have been active Crotein, Lexein, Magpon Polypeptide, Protolate, Sol-U-Teins, and Super Pro. 

The chemical modification of proteins is not desirable, because of the harsh reaction conditions, the nonspecificity, and the difficulty of removing reagents from the final product [2]. Enzymatic reaction has several advantages, such as the mild reaction conditions, high specificity, and fast reaction rates [3]. Moreover, the use of the enzyme, which occurs naturally in living cells, is acceptable by consumers from the viewpoint of safety. We describe examples of the enzyme-catalyzed synthesis of protein-based surfactants in this chapter. 

Synthesis normally means the construction of larger molecules from small building blocks via covalent linkage. However, we also refer to examples of protein-based surfactants produced via a degradation process such as proteolysis and deamidation, in addition to cases of surfactants produced by the covalent attachment of nonproteinaceous moieties. 

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. 

II. PROTEIN-BASED SURFACTANTS AND PERSONAL CARE PRODUCTS... 

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... 

IV. PROTEIN-BASED SURFACTANT APPLICATIONS IN THE DETERGENT AND RELATED INDUSTRIES... 

V. PROTEIN-BASED SURFACTANT PROSPECTS IN FOOD APPLICATIONS... 

VI. POTENTIAL APPLICATIONS OF PROTEIN-BASED SURFACTANTS IN AGRICULTURAL SECTORS... 

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