Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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    We will mail you new results for this query: keywords==emulsifying properties
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Characterisation and use of ß-lactoglobulin fibrils for microencapsulation of lipophilic ingredients and oxidative stability thereof
Serfert, Y. ; Lamprecht, C. ; Tan, C.P. ; Rossier Miranda, F.J. ; Schroen, C.G.P.H. ; Boom, R.M. - \ 2014
Journal of Food Engineering 143 (2014). - ISSN 0260-8774 - p. 53 - 61.
in-water emulsions - spray-drying behavior - emulsifying properties - interfacial rheology - antioxidant activity - lipid oxidation - protein fibrils - amyloid fibrils - ionic-strength - whey proteins
There is a growing interest in using fibrils from food grade protein, e.g. ß-lactoglobulin, as functional ingredients. In the present study, the functionality of fibrillar ß-lactoglobulin from whey protein isolate (WPI) was compared to native WPI in terms of interfacial dilatational rheology and emulsifying activity at acidic conditions (pH 2.0 and 3.0). We report here for the first time data on microencapsulation of fish oil by spray-drying as well as oxidative stability of the oil in emulsions and microcapsules in dependence of WPI conformation. WPI fibrils exerted a significantly higher elasticity at the oil–water (o/w) interface and a better emulsifying activity at a fixed oil content compared to native WPI. Microencapsulation efficiency was also higher with fibrillar WPI (>95%) compared to native WPI (~90%) at pH 2.0 and a total oil and protein content of 40% and 2.2%, respectively, in the final powder. The oxidative deterioration was lower in emulsions and microcapsules prepared with fibrillar than with native WPI. This was attributed to improved interfacial barrier properties provided by fibrils and antioxidative effects of coexisting unconverted monomers, particularly hydrophilic peptides
Surface activity and molecular characteristics of cuttlefish skin gelatin modified by oxidized linoleic acid
Aewsiri, T. ; Benjakul, S. ; Visessanguan, W. ; Wierenga, P.A. ; Gruppen, H. - \ 2011
International Journal of Biological Macromolecules 48 (2011)4. - ISSN 0141-8130 - p. 650 - 660.
emulsifying properties - peroxidation products - functional-properties - fish gelatin - proteins - emulsions - oil - fluorescence - stability - oxidation
Surface activity and molecular changes of cuttlefish skin gelatin modified with oxidized linoleic acid (OLA) prepared at 60, 70 and 80 °C at different times were investigated. Modification of gelatin with OLA could improve surface activity of resulting gelatin as evidenced by the decreased surface tension and the increased foaming and emulsifying properties. Interaction between OLA and gelatin led to the generation of carbonyl groups, loss of free amino content and the increase in particle size of resulting gelatin. Emulsion stabilized by modified gelatin had the smaller mean particle diameter with higher stability, compared with that stabilized by gelatin without modification.
Opposite Contributions of Glycinin- and ß-Conglycinin-Derived Peptides to the Aggregation Behavior of Soy Protein Isolate Hydrolysates
Kuipers, B.J.H. ; Koningsveld, G.A. van; Alting, A.C. ; Driehuis, F. ; Voragen, A.G.J. ; Gruppen, H. - \ 2006
Food Biophysics 1 (2006)4. - ISSN 1557-1858 - p. 178 - 188.
heat-induced gelation - soybean proteins - structural characteristics - emulsifying properties - enzymatic-hydrolysis - limited proteolysis - physical-properties - alpha-lactalbumin - gel properties - whey proteins
The aggregation behavior as a function of pH was studied for hydrolysates obtained by hydrolysis of soy protein isolate (SPI) and glycinin- and ß-conglycinin-rich protein fractions with subtilisin Carlsberg. The substrates were hydrolyzed up to degrees of hydrolysis (DH) of 2.2% and 6.5%. Compared with nonhydrolyzed SPI, a decrease in solubility was observed for the hydrolysates of SPI [0.8% (w/v) protein, I¿=¿0.03 M] around neutral pH. At pH 8.0, glycinin hydrolysates had a much lower solubility (~43% and 60%, respectively, for DH 2.2% and 6.5%) than SPI and ß-conglycinin-derived hydrolysates, which were almost completely soluble. Peptides that aggregated were all larger than 5 kDa, and as estimated by size-exclusion chromatography their composition was almost independent of the aggregation pH. The solubility of hydrolysates of SPIs with a varying glycinin and ß-conglycinin composition showed that glycinin-derived peptides are the driving force for the lower solubility of SPI hydrolysates. The solubility of SPI hydrolysates at pH 8.0 was shown not to be the sum of that of glycinin and ß-conglycinin hydrolysates. Assuming that the separate hydrolysis of glycinin and ß-conglycinin did not differ from that in the mixture (SPI), this indicates that ß-conglycinin-derived peptides have the ability to inhibit glycinin-derived peptide aggregation.
Effects of Protein Composition and Enzymatic Activity on Formation and Properties of Potato Protein Stabilized Emulsions
Koningsveld, G.A. van; Walstra, P. ; Voragen, A.G.J. ; Kuijpers, I.J. ; Boekel, M.A.J.S. van; Gruppen, H. - \ 2006
Journal of Agricultural and Food Chemistry 54 (2006)17. - ISSN 0021-8561 - p. 6419 - 6427.
lipid acyl hydrolase - emulsifying properties - tuber protein - patatin - oil - solubility - water - purification - selectivity - expression
In the present study emulsions were made with various potato protein preparations, which varied in protease inhibitor and patatin content. These emulsions were characterized with respect to average droplet size, plateau surface excess, and the occurrence of droplet aggregation. Droplet aggregation occurred only with potato protein preparations that contained a substantial amount of protease inhibitors and could be prevented only at pH 3. The average droplet size of the emulsions made with potato proteins appeared to be related to the patatin content of the preparation used. Average droplet size was found to be dominated by the patatin-catalyzed lipolytic release of surface active fatty acids and monoglycerides from the tricaprylin oil phase during the emulsification process. Addition of monoglycerides and especially fatty acids, at concentrations representative of those during emulsification, was shown to cause a stronger and much faster decrease of the interfacial tension than that with protein alone and to result in a drastic decrease in droplet size. The patatin used was shown to have a lipolytic activity of 820 units/g with emulsified tricaprylin as the substrate. Because of the droplet aggregating properties of the protease inhibitors, the patatin-rich potato preparations seem to be the most promising for food emulsion applications over a broad pH range, provided the lipolytic activity can be diminished or circumvented
Characterisation and foaming properties of hydrolysates derived from rapeseed isolate
Larré, C. ; Mulder, W.J. ; Sánchez-Vioque, R. ; Lazko, J. ; Bérot, S. ; Guéguen, J. ; Popineau, Y. - \ 2006
Colloids and Surfaces. B: Biointerfaces 49 (2006)1. - ISSN 0927-7765 - p. 40 - 48.
brassica-napus l. - emulsifying properties - functional-properties - enzymatic-hydrolysis - beta-lactoglobulin - plant-proteins - peptides - gluten - albumin - whey
Two hydrolysis methods used to obtain rapeseed isolate derivates were compared: chemical hydrolysis performed under alkaline conditions and pepsic proteolysis performed under acidic conditions. The mean molecular weights obtained for the hydrolysates varied from 26 to 2.5 kDa, depending on the level of hydrolysis. Further characterisation showed that, at the same level of hydrolysis, the chemical hydrolysates differed by their charges and hydrophobicity from those derived from enzymatic digestion. Analysis of the foaming properties showed, for both cases, that a limited degree of hydrolysis, around 3%, was sufficient to optimise the foaming properties of the isolate despite the different physicochemical properties of the peptides generated. The study of foaming properties at basic, neutral and acidic pHs showed that the hydrolysate solutions yielded dense foams which drained slowly and which maintained a very stable volume under the three pH conditions tested.
Emulsion properties of sunflower (Helianthus annuus) proteins
Gonzalez-Perez, S. ; Koningsveld, G.A. van; Vereijken, J.M. ; Merck, K.B. ; Gruppen, H. ; Voragen, A.G.J. - \ 2005
Journal of Agricultural and Food Chemistry 53 (2005)6. - ISSN 0021-8561 - p. 2261 - 2267.
seed storage proteins - functional-properties - physicochemical properties - emulsifying properties - charge heterogeneity - globulin fraction - chlorogenic acid - soy proteins - albumin - meal
Emulsions were made with sunflower protein isolate (SI), helianthinin, and sunflower albumins (SFAs). Emulsion formation and stabilization were studied as a function of pH and ionic strength and after heat treatment of the proteins. The emulsions were characterized with respect to average droplet size, surface excess, and the occurrence of coalescence and/or droplet aggregation. Sunflower proteins were shown to form stable emulsions, with the exception of SFAs at neutral and alkaline pH values. Droplet aggregation occurred in emulsions made with SI, helianthinin, and SFAs. Droplet aggregation and subsequent coalescence of emulsions made with SFAs could be prevented at pH 3. Calcium was found to cause droplet aggregation of emulsions made with helianthinin, at neutral and alkaline pH values. Treatments that increase conformational flexibility of the protein molecule improved the emulsion properties of sunflower proteins.
Gelation and interfacial behaviour of vegetable proteins
Vliet, T. van; Martin, A.H. ; Bos, M.A. - \ 2002
Current Opinion in Colloid and Interface Science 7 (2002)5-6. - ISSN 1359-0294 - p. 462 - 468.
surface functional-properties - reduced soy glycinin - rheological properties - emulsifying properties - foaming properties - gel formation - wheat gluten - air/water interface - ionic-strength - lupin protein
Recent studies on gelation and interfacial properties of vegetable proteins are reviewed. Attention is focused on legume proteins, mainly soy proteins, and on wheat proteins. The rheological properties of vegetable protein gels as a function of heating time or temperature is discussed as well as the interfacial gelation upon adsorption of soy and wheat proteins at the air/water interface. It is shown that modification of proteins improves protein functionality and application. Author Keywords: Gelation; Rheology; Interfacial properties; Vegetable proteins
Interfacial rheological properties and conformational aspects of soy glycinin at the air/water interface
Martin, A.H. ; Bos, M.A. ; Vliet, T. van - \ 2002
Food Hydrocolloids 16 (2002)1. - ISSN 0268-005X - p. 63 - 71.
oil-water interface - surface functional-properties - emulsifying properties - molecular-structure - active properties - ionic-strength - 11s globulin - proteins - behavior - films
Interfacial (rheological) properties of soy glycinin were studied at different pH. At acidic and high alkaline pH glycinin (11S form, Mw~350 kDa) dissociates into smaller subunits, the so called 3S form (Mw~44 kDa) and 7S form (Mw~175 kDa). This dissociation behaviour is expected to affect the interfacial rheological properties of glycinin. Adsorption kinetics at the air/water interface were followed with an automated drop tensiometer (ADT) and ellipsometer. The changes in surface concentration, surface pressure, dilational modulus and layer thickness were determined. At acidic pH where glycinin is in the 3S/7S form, it adsorbs much faster at the air/water interface giving a higher surface concentration and a higher dilational modulus than at pH 6.7 (where glycinin is in the 11S form). Surface shear viscosity measurements showed that after short ageing times glycinin gives a protein network that is much more resistant to deformation in shear at pH 3 than at pH 6.7. After ageing for 24 h, the surface shear viscosity is about the same at both pH. Foaming experiments failed to give a glycinin stabilised foam at pH 6.7 while at pH 3 glycinin behaves as a good foaming agent. All results indicate that changing the pH influences the conformation of glycinin and that this has a great impact on the interfacial rheological properties and foaming properties. Based on the results a model is postulated for the modes of glycinin adsorption at pH 3 and pH 6.7, respectively. Author Keywords: Soy glycinin; Interfacial rheology; Foaming properties; Air/water interface
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