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Today, the idea that random collisions and interactions offer solutions and business opportunities is no longer acceptable. Instead, partnerships and alignments, both downstream and upstream, are paramount for cross-fertilization and synergy. To survive, and thrive, in today's world of global innovation, alliances based on compatible differences must be sought. Innovation Partnerships and the Sharing-is-Winning model represent a paradigm shift toward accelerating co-development of sustainable innovation, with alignment of the entire value chain with consumer-centric innovations being one of its main pillars. It includes 3 levels of typical joint development: universities, research institutes, and centers; start-ups and individual inventors; a select number of key strategic suppliers. Reinventing R&D in an open innovation ecosystem and increasing success rates in an increasingly competitive marketplace require implementing significant steps--both perceived and tangible. Specific recommendations are provided for 10 major identified topics: leadership, strategy, the consumer, the value chain, internal experts and championship, metrics, IP, culture, academia, and passion. The Sharing-is-Winning model extends the scope of open innovation to sustainable and enhanced processes of co-innovation.

Obesity is a serious public health concern with an increasing prevalence worldwide. The diet contributes strongly to this problem and high-fat food leads to unhealthy conditions. Fat digestion is an energy intensive process as it requires hydrolysis to allow the body to profit from this nutrient. This additional energy expenditure is also present in a highly redundant hormonal regulation system for fat storage which is converted in not a readily accessible form (therefore, an upstream is required in order to tackle fat-related diseases). Due to the low water solubility of oils and fats, the lipase catalyzed reactions take place at a specific locus, the oil-water interface. Despite considerable efforts in the past the effects of the interfacial composition on lipase activity have been only qualitatively understood until recently. It has recently been undertaken a detailed study of the interfacial behavior of lipases, their substrates and products which have contributed to shed light into the mechanism of lipolysis [1-4]. In addition, there are strong evidences that lipase activity is a function of interfacial composition and changes concurrently with lipolytic conversion [1]. In these cases lipase "inhibition" should be attributed to substrate depletion and not to lipase desorption or denaturation as previously hypothesized [5]. This self-limiting effect through the feedback of interfacial composition to the reaction conditions of the enzyme opens a new avenue to control lipase catalysis through the interface. A set of experiments are proposed which can be performed to further characterize and gain a deeper insight into interfacial enzymology. (C) 2010 Elsevier B.V. All rights reserved.

This work describes the influence of two polar lipids, Sn-1/3 and Sn-2 monopalmitin, on the activity of lipase in biphasic systems and in microemulsions. In previous communications, we have shown that Sn-2 monoglycerides can replace Sn-1,3 regiospecific lipases at the oil–water interface, causing a drastically reduced rate of lipolysis. We here demonstrate that even if the lipase is expelled from the interface, it can catalyze esterification of the Sn-2 monoglyceride with fatty acids in both macroscopic oil–water systems and in microemulsions, leading to formation of di- and triglycerides.

It is shown experimentally that the desorption of sodium decyl sulphate from the liquid/air interface is purely diffusion controlled, while the desorption of higher surface active surfactants such as the non-ionic surfactants Triton X-100 and tridecyl dimethyl phosphine oxide obeys a mixed mechanism. The desorption kinetics of beta-lactoglobulin (BLG) and beta-casein is, however, determined by a barrier mechanism. From the analysis of the BLG and beta-casein desorption kinetics at different temperatures the activation energy of desorption is calculated. The values obtained are rather close to the free energy of adsorption. The theoretical model of desorption kinetics predicts that these two energetic parameters are similar if the adsorption activation energy is low. This explains why substances with a higher adsorption activity have a lower desorption rate. Adsorption kinetics studies for beta-casein with and without forced convection show the same equilibrium surface tension values. This leads to the conclusion that the protein adsorption at liquid interfaces is thermodynamically reversible, although the slow desorption kinetics would allow to assume it to be an irreversible process.

The adsorption kinetics of β-casein, β-lactoglobulin and HSA is studied at solution/gas interface with and without forced convection. It is shown that, in spite of a significant difference in the adsorption rates for these two experiments by one order of magnitude, the equilibrium surface tension values are virtually the same. This leads to the conclusion about the thermodynamic reversibility of protein adsorption at the solution/gas interface, in contrast to the kinetic irreversibility of the process.

Monoglyceride molecules spontaneously self-assemble into various liquid crystalline structures when present in an aqueous environment. The various phases can be used to achieve different functionalities, e.g. to protect molecules from chemical degradation, to solubilize drugs and nutrients, to control release of flavours and drugs or to increase the yield in Maillard reactions. We will review (1) the typical characteristics of monoglyceride self-assembly structures, (2) the most common characterisation techniques, (3) how introduction of guest molecules influences the self-assembly structures, (4) their use for drug delivery and (5) how commercial food grade monoglycerides obtained from sunflower oil can be applied to achieve unique delivery functionalities in food systems.

Background Combinations of foods that provide suitable levels of nutrients and energy are required for optimum health. Currently, however, it is difficult to define numerically what are ‘suitable levels’. Objective To develop new metrics based on energy considerations—the Nutrient Balance Concept (NBC)—for assessing overall nutrition quality when combining foods and meals. Method The NBC was developed using the USDA Food Composition Database (Release 27) and illustrated with their MyPlate 7-day sample menus for a 2000 calorie food pattern. The NBC concept is centered on three specific metrics for a given food, meal or diet—a Qualifying Index (QI), a Disqualifying Index (DI) and a Nutrient Balance (NB). The QI and DI were determined, respectively, from the content of 27 essential nutrients and 6 nutrients associated with negative health outcomes. The third metric, the Nutrient Balance (NB), was derived from the Qualifying Index (QI) and provided key information on the relative content of qualifying nutrients in the food. Because the Qualifying and Disqualifying Indices (QI and DI) were standardized to energy content, both become constants for a given food/meal/diet and a particular consumer age group, making it possible to develop algorithms for predicting nutrition quality when combining different foods. Results Combining different foods into composite meals and daily diets led to improved nutrition quality as seen by QI values closer to unity (indicating nutrient density was better equilibrated with energy density), DI values below 1.0 (denoting an acceptable level of consumption of disqualifying nutrients) and increased NB values (signifying complementarity of foods and better provision of qualifying nutrients). Conclusion The Nutrient Balance Concept (NBC) represents a new approach to nutrient profiling and the first step in the progression from the nutrient evaluation of individual foods to that of multiple foods in the context of meals and total diets.

The recent publication of the Human Genome poses the question: how will genome technologies influence food development? Food products will be very different within the decade with considerable new values added as a result of the biological and chemical data that bioinformatics is rapidly converting to usable knowledge. Bioinformatics will provide details of the molecular basis of human health. The immediate benefits of this information will be to extend our understanding of the role of food in the health and well-being of consumers. In the future, bioinformatics will impact foods at a more profound level, defining the physical, structural and biological properties of food commodities leading to new crops, processes and foods with greater quality in all aspects. Bioinformatics will improve the toxicological assessment of foods making them even safer. Eventually, bioinformatics will extend the already existing trend of personalized choice in the food marketplace to enable consumers to match their food product choices with their own personal health. To build this new knowledge and to take full advantage of these tools there is a need for a paradigm shift in assessing, collecting and sharing databases, in developing new integrative models of biological structure and function, in standardized experimental methods, in data integration and storage, and in analytical and visualization tools.

A food material science approach using microscopy, rheology and denaturation assessment of proteins was applied to describe the behaviour of mixtures of a whey protein isolate (WPI) and a high methoxy pectin (HM-pectin) upon high-pressure treatment (200 to 800 MPa at 25 or 40 °C and holding time of 10 min). The results of high-pressure treatment were compared to a pure heat treatment at 75 °C (5–20 min) and 85 °C (10 min). Similar textures could be obtained after high-pressure treatment of the mix at ambient temperature at all pressure levels tested (200–800 MPa) and after temperature treatments at 75 °C up to 10 min. Significant changes were only obtained in phase separating WPI/HM-pectin mixtures if treated at 40 °C and pressures>400 MPa and after heat-treatment at 85 °C for 10 min, where total WPI denaturation was above 60%. Under such conditions the protein-enriched phase gelled and significantly changed the overall texture as measured by rheology. In the presence of pectin, protein denaturation was decreased in both pressure and temperature treated samples. Microscopic analysis showed that structure formation depends on the processing history. Compared to a pure heat treatment, pressure offers a greater flexibility for fine-tuning the protein denaturation due to an increased freedom in processing parameters (pressure, holding time and temperature).

The solubilization of five hydrophilic water-soluble aroma compounds in self-aggregating triblock amphiphilic copolymers of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), with similar percentages of PEO and different molecular weights, was studied. The five hydrophilic compounds (diacetyl, 2-methylpyrazine, pyrrole, furfural, guaiacol) were carefully selected to represent hydrophilic molecules with a similar molecular weight and molecular volume, but with different abilities to interact with the micellar core of PPO moieties and with the PEO palisade side chains. It was found that the solubilized solute mole fraction increased and the aggregate-water partition coefficients of the solutes decreased with increasing free solute concentration in the aqueous phase. The partition coefficients were smaller than those obtained for hydrophobic compounds and equilibrium was reached at lower solubilization values. Guaiacol was the least hydrophilic molecule and had the highest partition coefficient. Diacetyl was the most water-soluble compound and exhibited the smallest partition coefficient. The data reveal that the higher molecular weight polymers solubilized more solute than the low-molecular-weight polymers. Moreover it is supposed that at low solute concentrations, guaiacol (containing a hydroxyl electron acceptor group) penetrates the core of the micelle and displaces water while at more elevated concentrations it seems to be solubilized in the micelle corona. Diacetyl, the most hydrophilic solute investigated (consisting of electron donor groups), prefers mainly the corona since its affinity for the polymeric core is very weak. The solubilization occurs in the palisade layer and the partition coefficient is independent of the free solute concentration. Selective site (palisade vs core) solubilization of hydrophilic compounds in polymeric micelles can be a powerful tool to protect sensitive materials from reactants present in the continuous water phase and to conduct surface-sensitive organic reactions. Furthermore, selective release properties of reactants and products can be designed. Copyright 2000 Academic Press.

Structured fluids such as emulsions and liquid crystalline mesophases can be used to control aroma release This study shows that the use of a gas sensor array coupled with pattern recognition analysis can be particularly useful in studying volatile profiles A mixture of 8 carefully selected volatile, hydrophilic and hydrophobic compounds was entrapped in 4 different matrices: water, lipids (sunflower oil, unsaturated monoglycerides), emulsion (20% wt water) and cubic phases (20 and 3% wt water) A clear discrimination between the release pattern of the different matrices has been measured by the sensor array system. It has been shown that the cubic phase release patterns is not only controlled by its composition but also depended strongly on ihe lipid/water interfacial area The combined use of structured fluids (structure-release relationship) and sensor arrays allows to control and to distinguish the release patterns of volatile.

The viscoelastic properties of whey protein stabilized emulsions containing varying amounts of protein and oil were investigated during heat treatment using oscillatory rheology. The emulsions were thoroughly characterized prior to gelation by measuring droplet size and protein adsorption. This emulsion characterization permitted the concentration of protein remaining in the bulk phase of the emulsion to be determined, by taking into account both oil exclusion effect and protein adsorption, and to prepare a cream and a whey protein solution corresponding to the emulsion's dispersed and bulk phases, respectively. Gelation of the phases was investigated separately and was used to better understand how the oil droplets and bulk proteins contribute to gelation of the whole emulsion. The rheology of polymeric solutions, giving the gel point as the G ′– G ″ cross-over, could be applied to the whey protein solution during heat treatment. Regarding the cream, its gelation revealed that the proteins adsorbed at the O/W interface gelled and were responsible for droplet–droplet interactions, leading to a particle gelled network. The rheological behavior of the whole emulsion during heat treatment was in-between those of a polymeric gel and a particle gel. The main parameters influencing the rheology were the bulk protein concentration and the aggregation state of the oil droplets. The bulk protein concentration determined the formation of a polymeric network in the aqueous phase of the emulsion, and the aggregation state of the droplets influenced their possible interactions and the formation of a particle network.

Bioavailability is key to the effectiveness of functional foods. Among functional food components minerals have a key function in their essential role for a healthy life. Deficiencies in essential minerals are seen as a major nutritional problem in the world today. This review investigates the impact of food processing on the bioavailability of minerals. The findings of the last decade clearly show that there is no simple relation between food processing and bioavailability. Processing can have a positive impact through separation or partitioning of minerals (enrichment), or through the destruction of inhibitors or, the beneficial complex formation between food components and metal ions, thereby enhancing their availability. However, the impact can also be negative by deactivating enzymes that degrade inhibitors or by generating insoluble metal compounds (e.g. oxidation, precipitation). Potential for the modulation of bioavailability will arise when the speciation of metal ions and their fate in processing and in the body are better understood.

New fluorine-containing double-chain surfactants have been prepared from substituted dithioacetamides; a distinctive feature of some of the surfactants prepared is that they contain a polymerizable group located on the ammonium head group. The aggregation behavior of four of the surfactants has been studied by freeze-fracture electron microscopy. The investigation has shown that under bath sonication all surfactants formed vesicles in water.

The synthesis of new fluorine-containing double-chain surfactants from di- and tri-substituted ureas is described; the vesicle-forming behavior is investigated for some surfactants. Under bath sonication mixed-chain surfactants form spherical unilamellar vesicles, while surfactants possessing two perfluoroaklylated segments give polydispersed vesicle populations.

A novel sol-gel nanocomposite material is introduced which was produced by silica sol-gel processes in microemulsion organogels. Microemulsion organogels are formed by a percolating droplet network containing a biopolymer (e.g. gelatin, chitosan, etc.). Microemulsion organogels have water localized in the droplet network which permits the spatial confinement of hydrolysis and polycondensation to microheterogeneous reaction sites. In the case of microemulsion organogels, the oxid gel forms an interpenetrating network with the gelatin maze. While the formation of the microemulsion and the microemulsion organogel is controlled by interfacial processes, the aggregation process of the inorganic oxide particles is objected to gravitational forces. Therefore, we propose this system for sol-gel studies under low or microgravitational conditions. The structural features of the obtained silica-gelatin nanocomposites will be described and compared with silica-biopolymer composites of non-gelling biopolymers in microemulsions (e.g., chitosan). Comparison is made with the silica gels that form in the parent microemulsions.

In the present study, we use a model gastro-intestinal system to study the influence of different food-grade surface-active molecules (Sn-2 monopalmitin, beta-lactoglobulin, or lysophosphatodylcholine) on lipase activity. The interfacial activity of lipase and surfactants are assessed with the pendant drop technique, a commonly used tensiometry instrument. A mathematical model is adopted which enables quantitative determination of the composition of the water-oil interface as a function of bulk surfactant concentration in the water-oil mixtures. Our results show a decrease in gastric lipolysis when interfacially active molecules are incorporated into a food matrix. However, only the Sn-2 monopalmitin caused a systematic decrease in triglyceride hydrolysis throughout the gastro-intestinal tract. This effect is most likely due to exclusion of both lipase and triglyceride from the water-oil interface together with a probable saturation of the solubilization capacity of bile with monoglycerides. Addition of beta-lactoglobulin or lysophopholipids increased the hydrolysis of fat after the gastric phase. These results can be attributed to an increasing interfacial area with lipase and substrate present at the interface. Otherwise, beta-lactoglobulin, or lysophopholipids reduced fat hydrolysis in the stomach. From the mathematical modeling of the interface composition, we can conclude that Sn-2 monopalmitin can desorb lipase from the interface, which, together with exclusion of substrate from the interface, explains the gradually decreased triglyceride hydrolysis that occurs during the digestion. Our results provide a biophysics approach on lipolysis that can bring new insights into the problem of fat uptake.

The adsorption behavior of two globular proteins, lipase from Rhizomucor miehei and beta-lactoglobulin, at inert oil/water and air/water interfaces was studied by the pendant drop technique. The kinetics and adsorption isotherms were interpreted for both proteins in different environments. It was found that the adopted mathematical models well describe the adsorption behavior of the proteins at the studied interfaces. One of the main findings is that unique interfacial properties were observed for lipase as compared to the reference beta-lactoglobulin. A folded drop with a "skinlike" film was formed for the two proteins after aging followed by compression. This behavior is normally associated with protein unfolding and covalent cross-linking at the interface. Despite this, the lipase activity was not suppressed. By highlighting the unique interfacial properties of lipases, we believe that the presented work contributes to a better understanding of lipase interfacial activation and the mechanisms regulating lipolysis. The results indicate that the understanding of the physical properties of lipases can lead to novel approaches to regulate their activity.

Dietary fat has long been recognized as an essential component in nutrition. However, most of the lipids present in food need to be converted into more bioavailable compounds. Lipases have a crucial role in converting triglycerides into more polar lipids with increased water solubility and a tendency to form micelles. However, the surface active molecules generated by lipolysis may have a detrimental effect on the interfacial biocatalysis. In the present work we evaluate the interfacial properties of lipase-generated molecules during fat digestion. By using the pendant drop technique we assessed the amphiphilic character of fatty acid salts, monoglycerides, and diglycerides as individual surfactants and mixtures. The experimental results are fitted with a mathematical model, which assists in the determination of the interfacial properties of the surfactants. Our results show that monoglycerides have considerably higher interfacial activity than fatty acid salts and diglycerides. Therefore, the interface will soon be dominated by monoglycerides. The pH dependency of the interfacial activity of fatty acids is also explored in the current work. We believe that our results can contribute to a better understanding of the complex interfacial phenomena occurring during fat digestion.

Lipases are acyl hydrolases that play a key role in fat digestion by cleaving long-chain triglycerides into polar lipids. Due to an opposite polarity between the enzyme (hydrophilic) and their substrates (lipophilic), lipase reaction occurs at the interface between the aqueous and the oil phases. Hence, interfaces are the key spots for lipase biocatalysis and an appropriate site for modulating lipolysis. Surprisingly enough, knowledge about the effects of the interfacial composition on lipase catalysis is still limited and only described by the term "interfacial quality". Recent systematic studies based on a biophysical approach allowed for the first time to show the effects of the interfacial microenvironment on lipase catalysis. These studies demonstrate that lipase activity as a function of interfacial composition is more attributed to substrate inaccessibility rather than to enzyme denaturation or inactivation, as it is often hypothesized. A detailed analysis of the interfacial properties of all compounds involved in triglyceride digestion revealed that lipolysis is a self-regulated reaction. This feedback mechanism can be explored as a new avenue to control lipase catalysis. To substantiate this hypothesis, oil hydrolysis in a model gastro-intestinal system was performed, which can be seen as an interfacial engineering approach to enzyme reactivity control. The presented characterization of the interfacial composition and its consequences provide a new approach for the understanding of lipase reactions at interfaces with direct impact on biotechnological and health care applications.

Mixtures of single-chain surfactants usually form micellar aggregates. However, catanionic mixtures exhibit spontaneous reorganization to vesicles under proper conditions. The strong electrostatic interactions of the head-groups cause the formation of a closed-shell bilayer structure. We have synthesized long-chain acylated amino acid salts to study the influences of charge, polarity, size, rigidity, and chirality of the anionic headgroups on the self-assembling processes when being mixed with N-dodecyl pyridinium chloride (DPC). — Vesicles are formed upon gently mixing of the parent micellar solutions. Investigating the whole range of catanionic compositions by light scattering, we could distinguish areas of mixed micellar and unilamellar vesicular aggregates, which were evidenced by various microscopic techniques. — By 1H-NMR the electrostatic interactions between the cationic DPC and anionic SLS (Sodium N-lauroylsarcosinate) headgroups were found to cause small but significant changes in the chemical shift of the methylene protons adjacent to the carboxyl group. Spin-spin relaxation (T 2, T 2⋆) measurements reveal a strong immobilization of the anionic headgroups due to membrane formation. We also found significant changes in the configuration distributions of SLS accompanying the membrane formation in the vesicles. — These findings evidence the importance of configurational and conformational states of the amphiphiles for the micellar-vesicular transformations.

Ammonium-type F-alkylated surfactants characterized by the presence of two tails RF/R′F or RF/R′F have been prepared, and the vesicular behavior of some double-chain surfactants has been studied in ultrasound-treated aqueous dispersions. Stable vesicular aggregates were found which showed unilamellar membrane structures. Their shapes, hydrodynamic radii and size distriubtion were determined by dynamic light scattering and electron microscopy. The phase transition temperatures of aqueous dispersions of double-chain surfactants were measured by differential scannig calorimetry.

For many years food manufacturers have been trying to meet the rising expectations of consumers for nutritionally balanced and healthy foods. The current way to address this challenge is to ‘enhance’ nutritional functionality within a product by adding to a common food base various bioactives such a...

In the modern type of food formulation, it is of increasing importance to have the essential components arranged in such a way that their functionality and bioavailability are optimized. This must be achieved and understood on the molecular level. Thus, self-assembly is a central mechanism for effic...

We developed a method that enables differentiation between liquid crystalline-phase particles corresponding to different space groups. It consists of controlled tilting of the specimen to observe different orientations of the same particle using cryogenic transmission electron microscopy. This leads to the visualization of lattice planes (or reflections) that are present for a given structure and absent for the other one(s) and that give information on liquid crystalline structures and their space groups. In particular, we show that we can unambiguously distinguish among particles having the inverted micellar cubic (space group Fd(3)m, 227), the inverted bicontinuous gyroid (space group Ia(3)d, 230), the inverted bicontinuous diamond (space group Pn(3)m, 224), and the inverted bicontinuous primitive cubic structure (space group Im(3)m, 229).

Polar lipids, such as monoglycerides and phospholipids, are amphiphilic molecules commonly used as processing and stabilization aids in the manufacturing of food products. As all amphiphilic molecules (surfactants, emulsifiers) they show self-assembly phenomena when added into water above a certain concentration (the critical aggregation concentration). The variety of self-assembly structures that can be formed by polar food lipids is as rich as it is for synthetic surfactants: micelles (normal and reverse micelles), microemulsions, and liquid crystalline phases can be formulated using food-grade ingredients. In the present work we will first discuss microemulsion and liquid crystalline phase formation from ingredients commonly used in food industry. In the last section we will focus on three different potential application fields, namely (i) solubilization of poorly water soluble ingredients, (ii) controlled release, and (iii) chemical reactivity. We will show how the interfacial area present in self-assembly structures can be used for (i) the delivery of functional molecules, (ii) controlling the release of functional molecules, and (iii) modulating the chemical reactivity between reactive molecules, such as aromas.

Starting from gold chips, we have tailor-made three surfaces by the self-assembly monolayer technique: one entirely hydrophobic, one hydrophobic with dispersed carboxyl groups, and one hydrophilic, containing hydroxyl groups. Rhizomucor miehei lipase has been adsorbed to the hydrophobic and the hydrophilic surfaces and covalently bound to the surface containing carboxyl groups. The adsorption of two substrates-capric acid (decanoic acid) and monocaprin-on the lipase-covered surfaces was monitored by the surface plasmon resonance (SPR) technique. Biocatalysis was also performed in the SPR instrument by circulating a solution of the substrate, dissolved in an 85:15 water-glycerol mixture at a(w) = 0.81, through the instrument, thus exposing the capric acid or the monocaprin to the lipase-covered surfaces. The product composition was found to depend on the type of surface used. Lipase adsorbed at the hydrophilic surface favored hydrolysis, and capric acid was the main product formed when monocaprin was used as substrate. Lipase adsorbed at a hydrophobic surface and, in particular, lipase covalently bound to a hydrophobic surface favored condensation. More dicaprin than capric acid was formed in experiments with monocaprin as the substrate. Reactions performed outside the SPR instrument showed that small amounts of triglyceride were also formed under these conditions. We believe that this work constitutes the first example of the SPR instrument being used for in-situ biotransformation.

Summary Low molecular weight surfactants, for example monoglycerides and phospholipids, form a multitude of self-assembled structures, such as inverted cubic or hexagonal mesophases, if brought into contact with water/oil. These mesophases can be dispersed in water using adequate surface-active materials such as low molecular weight surfactants or surface active polymers. In order to use such mesophase particles for incorporating drugs and aromas, it is essential to determine their internal crystallographic structure and to understand their mechanism of stabilization. Cryo-transmission electron microscopy was used to investigate the internal structure of different dispersed particles at various temperatures and oil contents. It is shown here that cryo-transmission electron microscopy, in combination with fast Fourier transform and tilting experiments, is effective in obtaining information on crystallographic structure, space group and morphology of particles with reversed bicontinuous cubic and hexagonal structures. In particular, using the presence or the absence of the {111} reflections and viewing the same particle under different axes of observation allows one to discriminate between the Im3m and Pn3m space groups. A major advantage of cryo-transmission electron microscopy is the ability to analyse single particles. This allows the identification of particles present at very low concentrations and the coexistence of particles with different internal self-assembly structures. With this technique we have obtained strong evidence for the presence of two cubic internal self-assembly structures with different space groups within the same dispersion. In addition, we found that cryo-transmission electron microscopy combined with tilting experiments enables the analysis of internal particle morphology, allowing the discussion of mechanisms for hexosome stabilization.

The stability of liposomes was found to be considerably improved by the incorporation of perfluoroalkylated lipids. Therefore we have developed an easy synthesis procedure to obtain vesicle-forming perfluoroalkylated double-chain surfactants for liposome technology applications. This paper describes new fluorine-containing liposomes obtained by sonication of highly fluorinated mixed-chain surfactants and by gentle mixing of perfluoroalkylated cationic and anionic single-chain surfactants. The observation of liposomes by electron microscopy reveals the existence of unilamellar polydispersed aggregates whose mean sizes were measured by quasi-elastic light scattering.

Aroma is central to a pleasurable eating/drinking experience but is one of the most labile components of food. Coffee is an outstanding example. Attempts to avoid or control aroma degradation are often frustrated by ignorance of the microscopic mechanisms that are responsible for it. One of the processes most frequently invoked is radical formation, yet the identity of the radicals and their involvement in aroma degradation are poorly understood at the molecular level. Here a step forward in the fundamental understanding of this complex problem is taken by identifying the most relevant radicals and their products using first-principles calculations. Over 100 radicals originating from key aroma compounds found in coffee and other foods have been studied and classified according to an unambiguous criterion: their thermodynamic stability relative to common radical sources. This classification scheme predicts that most aroma molecules are resistant to both peroxidation and attack from phenolic antioxidants but are unstable with respect to radicals such as •OH. Dimers – generated from radical reactions – were also considered, and the most volatile species, which may further contribute to coffee aroma degradation, were focused on. Those – which are very few indeed – that have this potential have been identified.

Microemulsions based on five-component mixtures for food applications and improved oil solubilization have been studied. The compositions included water, oil phase [such as R(+)-limonene and medium-chain triglycerides (MCT)], short-chain alcohols (such as ethanol), polyols (propylene glycol and glycerol), and several surfactants and their corresponding mixtures (nonionic, such as ethoxylated sorbitan esters, polyglycerol esters, sugar ester, and anionic, such as phosphatidylcholine). The phase behavior of these systems is discussed with respect to the influence of polyols and short-chain alcohols on the degree of solubilization of oils in the aqueous phase. The alcohol and polyols modify the interfacial spontaneous curvature and the flexibility of the surfactant film, enhancing the oil solubilization capacity of the microemulsions. The solubilization of R(+)-limonene was dramatically improved in the presence of the alcohol and polyols, whereas the improvement of solubilization for triglycerides containing MCT was less pronounced. In some systems high oil solubilization was achieved, and some of them can be easily diluted to infinity both with the aqueous phase and with the oil phase. Viscosity measurements along selected dilution lines [characterized by a single continuous microemulsion region starting from a pseudo binary solution (surfactant/oil phase) to the microemulsion (water/polyol corner)] indicate that at a certain composition the system inverts from a W/O to an O/W microemulsion.

Thermal reactions of cysteine/furfural and cysteine/ribose mixtures were studied in model systems to gain more insight into the influence of structured fluids such as L(2) microemulsions and cubic phases on the generation of aroma compounds. Formation of 2-furfurylthiol from cysteine/furfural was particularly efficient in L(2) microemulsions and cubic phases compared to aqueous systems. The reaction led to the formation of two new sulfur compounds, which were identified as 2-(2-furyl)thiazolidine and, tentatively, N-(2-mercaptovinyl)-2-(2-furyl)thiazolidine. Similarly, generation of 2-furfurylthiol and 2-methyl-3-furanthiol from cysteine/ribose mixtures was strongly enhanced in structured fluids. The cubic phase was shown to be even more efficient in flavor generation than the L(2) microemulsion. It was denoted "cubic catalyst" or "cubic selective microreactor". The obtained results are interpreted in terms of a surface and curvature control of the reactions defined by the structural properties of the formed surfactant associates.

Aqueous submicron-sized dispersions of the binary monolinolein/water system, which are stabilized by means of a polymer, internally possess a distinct nanostructure. Taking this as our starting point, we were able to demonstrate for the first time that the internal structure of the dispersed particles can be tuned by temperature in a reversible way. Upon increasing the temperature, the internal structure undergoes a transition from cubic via hexagonal to fluid isotropic, the so-called L2 phase, and vice versa. Intriguingly, in addition to the structural changes in topology, the particles expel (take up) water to (from) the aqueous continuous phase when increasing (decreasing) the temperature in a reversible way. At each temperature, the internal structure of the dispersed particles corresponds very well to the structure observed in nondispersed binary monolinolein with excess water. This agreement is independent of any thermal history (including phase transitions), which proves that the structures in the dispersed particles actually are in thermodynamic equilibrium with the surrounding water phase.