Elke Scholten

Wageningen University & Research | WUR · Faculty of Agrotechnology and Food Sciences

We studied the effect of dietary linseed oil (LSO) supplementation and DGAT1 K232A (DGAT1) polymorphism on the triacylglycerol composition and crystallization of bovine milk fat. LSO supplementation increased unsaturated triacylglycerols, notably in the C52–C54 carbon range, while reducing the saturated C29–C49 triacylglycerols. These changes were...

In this study, we investigated the contribution of different polysaccharides that varied in conformation and molecular weight, i.e. maltodextrin, xanthan gum, guar gum, carboxymethyl cellulose, and maize starch, to the frictional and sensorial properties of model dairy-based beverage systems, containing 5% emulsion droplets (stabilized either by 0....

Polysaccharides strongly affect the sensorial properties of foods, which is partly related to the lubrication they provide. We investigated the lubrication performance of polysaccharides with different characteristics (i.e. molecular weight, conformation, stiffness, and charge density) to identify the most relevant structural features related to lu...

The objective of this study was to determine the water distribution in maize starch (MS) and pea protein isolate (PPI) composite gels and understand how the separate contributions of MS and PPI affect the mechanical properties of composite gels with varying MS/PPI ratios. A series of MS gels with increasing PPI contents and a series of PPI gels wit...

Hypothesis Capillary suspensions feature networks of particles connected by liquid bridges, which are obtained by adding a small amount of a second immiscible liquid to a suspension. It is possible to link the network formation as well as the rheological behaviour of capillary suspensions to the intermolecular interactions of their constituents. E...

In this study we investigated the individual contribution of different ingredients to the lubrication properties of dairy-based model beverages containing whey protein (native or aggregated), micellar casein and emulsified oil in different combinations. In single-component systems, whey protein isolate (WPI) solutions showed the lowest friction coe...

This research aimed to investigate the effect of starch gelatinization and swelling degree on the lubrication properties of starch aqueous suspensions. Three types of maize starch with different amylose content of 70% (HAS), 25% (NS), and <1% (WS) were used to vary the swelling capacities. The granule suspension of NS showed the highest swelling fa...

Hypothesis: The rheology of milk fat, which is strongly related to its functionality, reflects multiscale structural transitions in the colloidal network formed by crystallizing triacylglycerols. Experiments: To relate rheology to structure, early stages of milk fat crystallization at 15-22 °C were studied combining different techniques; XRD and...

Condiments such as spreads, dressings, or sauces are usually consumed together with carrier foods such as breads or vegetables. Dynamic interactions between condiments and carriers occur during consumption, which can influence aroma release and perception. This study investigated in vivo aroma release (PTR-MS) and dynamic sensory perception (time-i...

Hypothesis We hypothesise that interaction strength between oil droplets determine the rheological properties of oil-in-water (O/W) emulsions by simultaneous formation and break-up of bonds between droplets. Using small (SAOS) and large (LAOS) amplitude oscillatory shear measurements, we aim to distinguish different classes of emulsions based on th...

When undergoing compression during oral processing, stacked gels display different mechanical properties that shape perceptions of texture contrasts (Santagiuliana et al., 2018). However, to date, characterizing the mechanical responses of individual gel layers has been impossible. In this study, an ultrasound (US) technique was developed, that all...

The relationship between gel strength and structure on the micro- and nano-scale has been investigated for oleogels prepared in a range of triglyceride (TAG) oils (sunflower, olive, medium chain triglyceride) using mixtures of oleic acid (OA) and sodium oleate (SO) as gelling agents. Microscopy indicated a reduction in crystal size with increasing...

This study focused on the influence of the particle size distribution (PSD) of ingredients used for chocolate preparation (cocoa powder and sugar) on viscosity of model chocolates with different fat contents. Model chocolates with varying PSDs and two particle size ratios (cocoa particles : sugar of 1 : 4 and 1 : 6) were prepared by mixing highly d...

The quantitative study of polymorphism in fats is complicated due to their complex composition and consequent intricate crystallization behavior. We aimed to illustrate how quantitative phase analysis can be performed in crystallizing complex fats. The advantages of our proposed method are that detailed structural information or internal standards...

Condiments are rarely consumed on their own. Although addition of condiments to carrier foods is known to affect oral processing behavior and sensory perception, an understanding of how different condiment...

Food and energy intake can be effectively lowered by changing food properties, but little is known whether modifying food shape is sufficient to influence intake. This study investigated the influence of cracker shape and cheese viscosity on ad libitum intake of cracker-cheese combinations. Forty-four participants (13 males, 23±3 years, BMI 21±2 kg...

Addition of particles to foods, such as fruit pieces to dairy products or vegetable pieces to soup, is a convenient approach to alter nutritional composition, appearance, perception and acceptance. The aim of this study was to investigate the effect of addition of peach gel particles to yogurt on oral behavior, sensory properties and liking of cons...

This study aimed to determine the effect of clustering of protein-stabilised oil droplets with proanthocyanidins on mechanical, tribological and sensory properties of o/w emulsions and emulsion-filled gels. Whey protein-stabilised oil droplets in o/w emulsions were cross-linked with proanthocyanidins, which led to the controlled formation of dense...

This study investigated whether the addition of macroparticles or fat can be used to compensate for negative texture sensations in quark. Cellulose beads were added as model microparticles (1.5% w/w; average size: 263 µm) to quark (0% fat) to induce unpleasant gritty sensations. The addition of microparticles to quark significantly increased gritti...

Practical approaches to increase consumption of healthy foods such as vegetables are needed. Controlling eating rate is a promising strategy, since faster eating rates have been related to higher food intake. Food properties can be modified to influence eating rates, but little is known about the impact of vegetable dimensions and condiment additio...

This study explored how product familiarity and physiological characteristics of participants affect detectability of microparticles in viscous and semi-solid foods. Cellulose particles differing in size (50-780 µm) were added (1.5% w/w) to two dairy products, quark (viscous curd cheese) and processed cheese. Discrimination thresholds for added mic...

This study investigated how exteroceptive and interoceptive cues influence sensory perception and liking of novel, heterogeneous foods. Twelve heterogeneous cheeses were prepared by adding bell pepper pieces to homogeneous processed cheese matrices. Bell pepper pieces differed in size, hardness, and concentration. Consumers (n=73) evaluated cheeses...

This study investigated the effect of mechanical contrast and particle flavour concentration of carrot particles added to soups on expected and perceived sensations and liking. The properties of a chicken...

In this study the effect of various emulsifiers (whey protein isolate (WPI), Na-caseinate, and Tween 20) and thickeners (xanthan and pectin) present in the outer water phase, w2, on oil droplet size and yield of the inner water phase, w1, of (w1/o/w2) double emulsions was investigated. Double emulsions stabilized by Tween 20 had smaller oil droplet...

Although mostly known for their gelling ability in water, proteins can also be used to structure oil into so-called oleogels. To create these oleogels, protein aggregates (d ∼190 nm) were formed by heat treatment in an aqueous environment and then suspended in oil using a solvent exchange procedure. To control the interactions between colloidal pro...

Oil body extracts from sesame seeds and hazelnuts were subjected to centrifugation to recover oil body concentrated creams, which were then suitably diluted with gelatin solutions to prepare mixtures of 25.0 wt% of oil and 2.0 to 6.0 wt% of gelatin. The gelling behaviour of the mixtures was followed by applying dynamic rheometry while gradually low...

Proteins are known to be effective building blocks when it comes to structure formation in aqueous environments. Recently, we have shown that submicron colloidal protein particles can also be used to provide structure to liquid oil and form so-called oleogels.1 Preventing extensive agglomeration of these submicron building blocks is a prerequisite...

The aim of this study was to assess the effect of oil type on the network formation of heat-set protein aggregates in liquid oil. The gelling properties of such aggregates to structure oil into so-called ‘oleogels’ are related to both the particle–particle and particle–solvent interactions. To change these interactions, four different oils (medium...

Double (w1/o/w2) emulsions are potential fat replacers in foods. Fats are known for their lubricating properties, which contribute to texture perception. It is therefore of interest to understand how the composition of double emulsions influences lubrication properties. This study focuses on the understanding of the influence of the fraction of inn...

The Rate-All-That-Apply (RATA) method, an intensity-based Check-All-That-Apply (CATA) variant, has recently been developed for sensory characterization involving untrained panellists. The aim of this study was to investigate the sensory profiles of ten model (double) emulsions with subtle perceptual differences obtained from the Rate-All-That-Apply...

In this research we use heat-set whey protein aggregates (diameter ? 200 nm) as novel building blocks for structure formation in liquid oil to form oleogels. To transfer the aggregates to the oil phase, a solvent exchange to sunflower oil was applied using acetone as an intermediate solvent. We found that agglomeration of the aggregates was prevent...

The aim of this work was to determine the effect and magnitude of matrix inhomogeneity on the rheological properties of emulsion-filled gels. To this end, we have investigated the rheological properties in casein gels containing different volume fractions of dispersed fat droplets with varying hardness. Rheological properties of the filled gels wer...

The use of double emulsions (w1/o/w2) has been acknowledged as a promising strategy to reduce oil content in several food applications. Despite the potential of double emulsions for oil reduction, their sensory properties have not been investigated. In this study, we investigated sensory perception of double emulsions by descriptive sensory profili...

The sensory perception of foods is directly related to gel morphology. The aim of this research was to investigate the relationship between gel water holding and stiffness for gels with a different morphology. Whey protein gels were prepared by varying ionic strength to create fine and coarse-stranded gels. These gels were characterized for their c...

We investigated the use of whey protein isolate (WPI) as oleogelator in liquid oil. First, heat-set WPI hydrogels were prepared varying in microstructure and network density. Then, by applying a stepwise solvent exchange procedure via an intermediate solvent, full replacement of the internal aqueous phase within the protein matrix by sunflower oil...

The aim of the present study was to explore the potential use of chitin nanocrystals, as colloidal rod-like particles, to stabilize aqueous foams. Chitin nanocrystals (ChN) were prepared by acid hydrolysis of crude chitin and foams were generated mainly by sonicating the respective dispersions. The foamability of the chitin nanocrystals was evaluat...

To create materials with novel functionalities, the formation of gels within hydrophobic media has become popular. This is often accomplished through the assembly of low molecular weight organogelators into a variety of complex phases through intermolecular interactions. In the case of edible materials, the assembly of saturated fatty acids to form...

In this paper, we show that biodegradable and biocompatible organogels can be formed with chitin as the filler material and triglycerides as the continuous hydrophobic phase. When crude chitin was used, large degree of aggregation was observed that prevented the formation of stable organogels. Two approaches were used to diminish this degree of agg...

Design of particles for controlled assembly into complex 3D structure has been extensively investigated. However, their use in the preparation of such 3D structures has received less attention due to low availability. Here, we use a Janus-type particle in the form of a tri-block of natural origin, the protein zein, to create such 3D structures in t...

Amongst the different mechanisms that have been proposed and used to structure organogels, selfassembly of the gelators into supramolecular structures linked through non-covalent bonds is the most interesting. The gelator activity of LMGOs is often found most effective when micellar or lamellar phases are obtained, which is dependent on the gelator...

Pasta and noodles were enriched with concentrations of broccoli powder (BP) up to 30% (v/v). To ensure the benefits from the broccoli nutrients, their leakage during cooking should be prevented. Such leakage is determined by the microstructure. In a previous study we have shown that the microstructure can change dramatically in such broccoli-enrich...

Oleosins are low molecular mass proteins that are distinguished from other proteins for their extended central hydrophobic domain which covers almost half of its entity. For this work, they were extracted from isolated maize germ oil bodies. The purification steps included washing with diethylether and a chloroform–methanol–water mixture. Their amp...

Chitin nanocrystals (ChN) have been shown to form stable Pickering emulsions. These oil-in-water emulsions were compared with conventional milk (whey protein isolate, WPI, and sodium caseinate, SCn) protein-stabilized emulsions in terms of their lipid digestion kinetics using an in vitro enzymatic protocol. The kinetics of fatty acid release were e...

High volume fractions of dried broccoli particles (up to 20% v/v) were incorporated in a starch dough. The concentration of pre-gelatinized starch was varied between 10 and 30%. The addition of 20% v/v dried broccoli powder, causes a significant increase in the shear modulus. For pure starch, the modulus increased with increasing pre-gelatinized st...

Background Vacuum impregnation is seen as a valuable technique for flavor pairing in the catering industry. One of the applications of this technique is the creation of edible cocktails by impregnating fruits with liquors, leading to an interplay of different flavors. However, the effect of the impregnation of sugar and alcohol into the fruit will...

a b s t r a c t Oil-in-water emulsions (10%, w/w, oil) were prepared at pH 5.7 by using electrostatically formed complexes of 0.5% (w/w) sodium caseinate (Na-CAS) and 0e0.6% (w/w) chitosan. Emulsions stabilized by complexes with increased levels of chitosan (>0.2% w/w) had a smaller average droplet size and exhibited greater stability during storag...

Oil-in-water emulsions (10% w/w n-tetradecane) were prepared at pH = 5.7 by using, as surface active agents, electrostatically formed complexes of sodium stearoyl lactylate (SSL) at a concentration of 0.4% (w/w) and chitosan (CH) in a concentration range between 0 and 0.48% w/w. The use of complexes in emulsions with a low concentration of CH (<0.2...

Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and tetramethylene glycol as the soft segments were electrosp...

Carbamazepine (CBZ) microparticles of different sizes and shapes, including spheres, q-tips, elongated spheres, and tear-shaped particles, were formed by electrospraying solutions of different CBZ concentrations. The particle characteristics were determined by the interplay between jet formation, droplet breakup, solvent evaporation, and eventual p...

The well-known alcoholic beverage Pastis becomes turbid when mixed with water due to the poor solubility of trans-anethol, the anise-flavored component of Pastis in the water solution formed. This destabilization appears as the formation of micrometer-sized droplets that only very slowly grow in size, thus expanding the life of the anise-flavored b...

In this paper we show that interfaces in aqueous phase-separated biopolymer mixtures are permeable for all components present in the system. In spinning drop experiments, droplets of the low-density phase decreased up to 90% in volume over a time span of days to weeks, when inserted in a matrix of the high-density phase. We propose an expression fo...

The objective of this work was to investigate interfacial properties of biopolymer-based water-in-water emulsions, and to determine the effect of these interfacial properties on the kinetics of phase separation and the deformation behavior of emulsions droplets in shear flow. Since the experimental determination of interfacial properties, such as i...

Phase separation in aqueous biopolymer mixtures results in the formation of an interface, separating two aqueous bulk phases. The properties of that interface are key parameters to understand and predict phenomena, such as the phase-separation process and deformation of droplets in a flow field. In these processes, the structures and sizes of the m...

Phase separation in aqueous biopolymer mixtures results in the formation of an interface, separating two aqueous bulk phases. The properties of that interface are key parameters to understand and predict phenomena, such as the phase separation process and deformation of droplets in a flow field. In these processes, the structures and sizes of the m...

In this paper, we show that for aqueous phase-separated biopolymer mixtures (water-in-water emulsions) both interfacial tension and permeability of the interface are important for the relaxation process of deformed droplets. We give an expression for the characteristic relaxation time that contains both contributions. With this description, the int...

We discuss the coarsening of domains in bicontinuous structure of aqueous polymer mixtures, driven by hydrodynamic flow. Taking into account the bending energy as a contribution to the interfacial energy, we derive a general expression for the coarsening rate in these mixtures. Examining the limiting behavior of small and large length scales, we fi...

Using equations for the interfacial properties for a two-phase multicomponent system, we present a new model for the interfacial tension and bending rigidity for liquid-liquid interfaces between semidilute polymer phases. Using this model, we calculate the interfacial thickness and the bending rigidity for two different gelatin/dextran systems and...

Many protein/polysaccharide mixtures phase separate when the concentrations ofthese biopolymers are sufficiently high. One of the properties involved in this phenomenon is the interfacial tension. Here we present measurements of the interfacial tension of two different protein/polysaccharide mixtures. The protein gelatin was mixed with either dextr...