Formation of Surface Active Gelatin by Covalent Attachment of Hydrophobic Chains

Toledano, Ofer; Magdassi, Shlomo

doi:10.1006/jcis.1997.5030

Cited by 48 publications

(19 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Grafting of C 10 or C 12 alkyl chains to peptides resulted in molecules more effective than C 14 in decreasing the surface tension, which is in agreement with the foaming properties previously observed for these acylated peptides [6]. The influence of the hydrophobic chain of a molecule on the surface tension has been evaluated in alkylglycosides [3,4] and in proteins [9,10]. In general, within a series of proteins or sugars, the length increase of the hydrophobic chain results in lower surface tension values.…”

Section: Surface Tension Measurements At Air-water Interfacesupporting

confidence: 78%

Emulsifying properties of acylated rapeseed (Brassica napus L.) peptides

Sánchez‐Vioque¹,

Bagger²,

Larré³

et al. 2004

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

Section: Surface Tension Measurements At Air-water Interfacesupporting

confidence: 78%

Emulsifying properties of acylated rapeseed (Brassica napus L.) peptides

Sánchez‐Vioque¹,

Bagger²,

Larré³

et al. 2004

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

“…In spite of the fact that grafting of aliphatic chains of four atoms of carbon was reported as a valuable means to prepare proteins with improved foaming properties (38), acylation of rapeseed peptides using butyric anhydride was detrimental for foaming formation. Thus, fractions CH-B, NH-I-B, and NH-II-B exhibited poorer foaming properties than native peptides ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Emulsifying and foaming properties of native and chemically modified peptides from the 2S and 12S proteins of rapeseed (Brassica napus L.)

Malabat

nchez-Vioque

Rabiller³

et al. 2001

J Americ Oil Chem Soc

View full text Add to dashboard Cite

The 2S and 12S proteins of rapeseed were isolated and subsequently hydrolyzed by pepsin or a combination of pepsin plus trypsin. The resulting hydrolysates had a 15% degree of hydrolysis and were purified by gel filtration chromatography in order to obtain homogeneous peptide fractions. Three major fractions, having an average peptide chain length of 7.5-11 amino acids, were recovered. Purified peptide fractions were acylated with butyric anhydride and sulfamidated with ptoluenesulfonyl chloride. The degree of modification was always higher than 90%. Emulsifying and foaming properties of native and chemically modified peptides were studied and compared to those of sodium dodecyl sulfate (SDS) as standard. A peptide fraction from the 15% hydrolysis of the 12S protein exhibited the best foaming properties. After sulfamidation, this peptide fraction showed a foam formation similar to that of SDS. Whereas the attachment of toluene groups generally improved the surface properties, the incorporation of an aliphatic chain of four atoms of carbon was detrimental in most of the cases. On the other hand, none of the native or hydrophobized peptide fractions was able to form a stable emulsion.Paper no. J9679 in JAOCS 78, 235-241 (March 2001). KEY WORDS:Chemical modification of peptides, cruciferin, enzymatic hydrolysis of proteins, foaming and emulsifying properties, napin.Proteins are recognized to be much more than a simple source of nutrients. Because of their amphiphilic nature, proteins are also involved in functional aspects of foods, such as the formation of emulsions and foams. Proteins can be adsorbed at oil-water and air-water interfaces, decreasing surface tension values, and, hence facilitating the formation of emulsions and foams. This adsorption is believed to occur in three distinct steps. First, protein molecules diffuse to the subsurface just below the interface; second, they are adsorbed; and finally, they unfold at the interface to adopt a thermodynamically optimized conformation. In addition, proteins form a continuous viscoelastic film around the oil droplets or air bubbles that stabilize emulsions and foams (1). Therefore, the formation of a stable foam or emulsion is a complex phenomenon that depends on the physicochemical characteristics of the protein, such as net charge, solubility, hydrophobicity, flexibility, etc.(2). Protein structure can be intentionally modified in order to improve these surface properties. Such protein modifications can be easily performed by enzymatic or chemical treatments. Enzymatic hydrolysis improves the solubility of proteins, even if the degree of hydrolysis is low. The increase of ionic groups after hydrolysis makes the peptides more soluble with respect to the original protein throughout the pH range (3,4), and consequently enhances the diffusion of the protein and facilitates the formation of emulsions (5). In addition, enzymatic hydrolysis can increase the surface hydrophobicity of peptides by exposing hydrophobic groups that are generally buried in the core of nat...

show abstract

“…Covalent hydrophobization results also in enhancement of emulsifying and foaming activities, and emulsions and foams are more stable in the presence of modified proteins as compared to the native proteins (8 -10). Ovalbumin (11), gelatin (12), and human IgG (13) with covalently attached alkyl chains displayed enhanced surface activity at the air/water interface. The affinity of the proteins for hydrophobic surfaces also increased after hydrophobization, and more compact monolayers were formed.…”

Section: Introductionmentioning

confidence: 99%