Novel oral microscope gives mechanistic insights into colloidal drivers of friction in oral biofilms.

Texture and mouthfeel are central to the sensory enjoyment of food and beverages. Yet our incomplete understanding of how food boluses are transformed in the mouth limits our texture prediction ability. As well as thin film tribology, the interaction of food colloids with the oral tissue and salivary biofilms plays a key role in texture perception via mechanoreceptors in the papillae.

Dihydronicotinamide riboside: synthesis from nicotinamide riboside chloride, purification and stability studies.

In the present work, we describe an efficient method for scalable synthesis and purification of 1,4-dihydronicotinamide riboside (NRH) from commercially available nicotinamide riboside chloride (NRCl) and in the presence of sodium dithionate as a reducing agent. NRH is industrially relevant as the most effective, synthetic NAD precursor. We demonstrated that solid phase synthesis cannot be used for the reduction of NRCl to NRH in high yield, whereas a reduction reaction in water at room temperature under anaerobic conditions is shown to be very effective, reaching a 55% isolation yield.

Colloidal dynamics of emulsion droplets in mouth.

The interaction of emulsions with the tongue is key to the sensory appeal of food and can potentially be exploited for oral/buccal pharmaceutical delivery. Whilst there is good understanding of the different mucoadhesive forces governing emulsion interaction with the tongue, their relative importance is not well understood. In addition, the physical location of emulsions within the saliva papillae on the tongue is not understood at all.

Directed Discovery of Tetrapeptide Emulsifiers.

Oil in water emulsions are an important class of soft material that are used in the food, cosmetic, and biomedical industries. These materials are formed through the use of emulsifiers that are able to stabilize oil droplets in water. Historically emulsifiers have been developed from lipids or from large biomolecules such as proteins.

Synthesis, Stability, and Bioavailability of Nicotinamide Riboside Trioleate Chloride.

Nicotinamide riboside chloride (NRCl) is an effective form of vitamin B3. However, it cannot be used in ready-to-drink (RTD) beverages or high-water activity foods because of its intrinsic instability in water. To address this issue, we synthesized nicotinamide riboside trioleate chloride (NRTOCl) as a new hydrophobic nicotinamide riboside (NR) derivative.

Stability to oxidation and interfacial behavior at the air/water interface of minimally-processed versus processed walnut oil-bodies.

Oil bodies (OB), the form of triacylglycerol storage in seeds, are interesting natural assemblies for nutritional applications. In walnuts, OB contain an important amount of polyunsaturated fatty acids that could be interesting food ingredients but may be prone to oxidation. The oxidative and interfacial behavior of walnut OB, either minimally-processed or after processing, were compared with processed complex walnut juice.

Depletion-Induced Flocculation of Concentrated Emulsions Probed by Photon Density Wave Spectroscopy.

Stable, creaming-free oil in water emulsions with high volume fractions of oil (ϕ = 0.05-0.40, density matched to water) and polysorbate 80 as an emulsifier were characterized without dilution by Photon Density Wave spectroscopy measuring light absorption and scattering behavior, the latter serving as the basis for droplet size distribution analysis.

Effects of interesterified lipid design on the short/medium chain fatty acid hydrolysis rate and extent (in vitro).

Short/medium chain fatty acids have well known health effects such as gut immune regulation and ketogenesis. The ability to realise these health effects is potentially limited by their rapid gastro-intestinal lipolysis. It was proposed that synthesising novel interesterified lipids via an interesterification reaction to generate a combination of short/medium and long chain fatty acids would modulate their gastrointestinal digestion.

Hierarchically structured phase separated biopolymer hydrogels create tailorable delayed burst release during gastrointestinal digestion.

The on demand delivery of novel peptide actives, traditional pharmaceuticals, nutrients and/or vitamins is a ever present challenge due to the digestive and metabolic degradation of the active and the delivery vehicle. Biodegradable biopolymer hydrogels have long held promise as candidates for creating tailored release profiles due to the ability to control gel porosity. The present study describes the creation of novel hierarchical biopolymer hydrogels for the controlled release of lipids/lipophilic actives pharmaceutical ingredients (APIs), and mathematically describes the mechanisms that affect the timing of release.

Microstructured Fibers for the Production of Food.

Food engineering faces the difficult challenge of combining taste, i.e., tailoring texture and rheology of food matrices with the balanced intake of healthy nutrients.

Correlation between in vitro and in vivo data on food digestion. What can we predict with static in vitro digestion models?

During the last decade, there has been a growing interest in understanding food's digestive fate in order to strengthen the possible effects of food on human health. Ideally, food digestion should be studied in vivo on humans but this is not always ethically and financially possible. Therefore, simple in vitro digestion models mimicking the gastrointestinal tract have been proposed as alternatives to in vivo experiments.

The Dynamics of Gastric Emptying and Self-Reported Feelings of Satiation Are Better Predictors Than Gastrointestinal Hormones of the Effects of Lipid Emulsion Structure on Fat Digestion in Healthy Adults-A Bayesian Inference Approach.

Limited information exists on the relation between fat emulsion structure and its effect on the release of gastrointestinal hormones and feelings of satiation. We investigated the impact of fat emulsion droplet size, gravitational and acid stability, and redispersibility on gastrointestinal responses and sought to deduce the relative importance of the hormones ghrelin, cholecystokinin, glucagon-like peptide-1, and peptide YY (PYY) in controlling fat emptying and related satiation. Within a randomized, double-blind, 4-armed crossover study, an extensive data set was generated by MRI of gastric function, analysis of hormone profiles, and ratings of satiation in healthy participants [10 women and 7 men with a mean ± SD age of 25 ± 7 y and body mass index (in kg/m) of 22 ± 1] after intake of 4 different fat emulsions.

Comparison of lipases for in vitro models of gastric digestion: lipolysis using two infant formulas as model substrates.

The aim of this study was to find a lipase suitable as a surrogate for Human Gastric Lipase (HGL), since the development of predictive gastrointestinal lipolysis models are hampered by the lack of a lipase with similar digestive properties as HGL. Three potential surrogates for HGL; Rhizopus Oryzae Lipase (ROL), Rabbit Gastric Lipase (RGL) and recombinant HGL (rHGL), were used to catalyze the in vitro digestion of two infant formulas (a medium-chain triacylglyceride enriched formula (MC-IF) and a predominantly long-chain triacylglyceride formula (LC-IF)). Digesta were withdrawn after 0, 5, 15, 30, 60 min of gastric digestion and after 90 or 180 min of intestinal digestion with or without the presence of pancreatic enzymes, respectively.

Infant digestion physiology and the relevance of in vitro biochemical models to test infant formula lipid digestion.

Lipids play an important role in the diet of preterm and term infants providing a key energy source and essential lipid components for development. While a lot is known about adult lipid digestion, our understanding of infant digestion physiology is still incomplete, the greatest gap being on the biochemistry of the small intestine, particularly the activity and relative importance of the various lipases active in the intestine. The literature has been reviewed to identify the characteristics of lipid digestion of preterm and term infants, but also to better understand the physiology of the infant gastrointestinal tract compared to adults that impacts the absorption of lipids.

Impact of microemulsion inspired approaches on the formation and destabilisation mechanisms of triglyceride nanoemulsions.

Even after 30+ years of research, there are still few examples of physically stable transparent nanoemulsions despite their high potential to revolutionise pharmaceutical, personal care, and food products. In this study, we examine how low-energy "microemulsion inspired" (co-solvent/co-surfactant) approaches impact the formation and destabilisation mechanisms of homogenised triglyceride nanoemulsions. The addition of n-alcohol co-solvents and Span 80 co-surfactants had two effects on nanoemulsion droplet diameter; a beneficial one that reduced droplet diameter from 120 to 50 nm and a deleterious one that caused destabilisation.

Impact of gastric pH profiles on the proteolytic digestion of mixed βlg-Xanthan biopolymer gels.

The understanding of how foods are digested and metabolised is essential to enable the design/selection of foods as part of a balanced diet. Essential to this endeavour is the development of appropriate biorelevant in vitro digestion tools. In this work, the influence of gastric pH profile on the in vitro digestion of mixtures of β-lactoglobulin (βlg) and xanthan gum prior to and after heat induced gelation was investigated.

Impact of Protein Gel Porosity on the Digestion of Lipid Emulsions.

The present study sought to understand how the microstructure of protein gels impacts lipolysis of gelled emulsions. The selected system consisted of an oil-in-water (o/w) emulsion embedded within gelatin gels. The gelatin-gelled emulsions consisted of a discontinuous network of aggregated emulsion droplets (mesoscale), dispersed within a continuous network of gelatin (microscale).

Imaging gastric structuring of lipid emulsions and its effect on gastrointestinal function: a randomized trial in healthy subjects.

Background: Efficient fat digestion requires fat processing within the stomach and fat sensing in the intestine. Both processes also control gastric emptying and gastrointestinal secretions.

Objective: We aimed to visualize the influence of the intragastric stability of fat emulsions on their dynamics of gastric processing and structuring and to assess the effect this has on gastrointestinal motor and secretory functions.

In vitro digestion of citric acid esters of mono- and diglycerides (CITREM) and CITREM-containing infant formula/emulsions.

CITREM is an emulsifier used in the food industry and contains citric acid esters of mono- and diglycerides (GCFE). It is generally recognized as safe but no publication on its digestibility under gastrointestinal conditions and impact on fat digestion was available. It was shown here that fatty acids are released from CITREM by gastric lipase, pancreatic lipase, pancreatic-lipase-related protein 2 and carboxyl ester hydrolase.

Conformational changes of α-lactalbumin adsorbed at oil-water interfaces: interplay between protein structure and emulsion stability.

The conformation and structural dimensions of α-lactalbumin (α-La) both in solution and adsorbed at oil-water interfaces of emulsions were investigated using synchrotron radiation circular dichroism (SRCD) spectroscopy, front-face tryptophan fluorescence (FFTF) spectroscopy, and dual polarization interferometry (DPI). The near-UV SRCD and the FFTF results demonstrated that the hydrophobic environment of the aromatic residues located in the hydrophobic core of native α-La was significantly altered upon adsorption, indicating the unfolding of the hydrophobic core of α-La upon adsorption. The far-UV SRCD results showed that adsorption of α-La at oil-water interfaces created a new non-native secondary structure that was more stable to thermally induced conformational changes.

Revisiting β-casein as a stabilizer for lipid liquid crystalline nanostructured particles.

Lipid liquid crystalline nanoparticles such as cubosomes and hexosomes have unique internal nanostructures that have shown great potential in drug and nutrient delivery applications. The triblock copolymer, Pluronic F127, is usually employed as a steric stabilizer in dispersions of lipid nanostructured particles. In this study, we investigated the formation, colloidal stability and internal nanostructure and morphology of glyceryl monooleate (GMO) and phytantriol (PHYT) cubosome dispersions on substituting β-casein with F127 in increasing proportion as the stabilizer.

Structural rearrangement of β-lactoglobulin at different oil-water interfaces and its effect on emulsion stability.

Understanding the factors that control protein structure and stability at the oil-water interface continues to be a major focus to optimize the formulation of protein-stabilized emulsions. In this study, a combination of synchrotron radiation circular dichroism spectroscopy, front-face fluorescence spectroscopy, and dual polarization interferometry (DPI) was used to characterize the conformation and geometric structure of β-lactoglobulin (β-Lg) upon adsorption to two oil-water interfaces: a hexadecane-water interface and a tricaprylin-water interface. The results show that, upon adsorption to both oil-water interfaces, β-Lg went through a β-sheet to α-helix transition with a corresponding loss of its globular tertiary structure.

Proton transfer reaction mass spectrometry and time intensity perceptual measurement of flavor release from lipid emulsions using trained human subjects.

The effect of the fat component of liquid emulsions on dynamic "in-nose" flavor release was examined using a panel of trained human subjects (n = 6), proton transfer reaction mass spectrometry (PTR-MS), and time intensity (TI) sensory evaluation. A rigorous breathing and consumption protocol was developed, which synchronized subjects' breathing cycles and also the timing of sample introduction. Temporal changes in volatile release were measured in exhaled nostril breath by real-time PTR-MS.

Slowly and rapidly digested fat emulsions are equally satiating but their triglycerides are differentially absorbed and metabolized in humans.

Little is known about the effect of dietary fat emulsion microstructure on plasma TG concentrations, satiety hormones, and food intake. The aim of this study was to structure dietary fat to slow digestion and flatten postprandial plasma TG concentrations but not increase food intake. Emulsions were stabilized by egg lecithin (control), sodium sterol lactylate, or sodium caseinate/monoglyceride (CasMag) with either liquid oil or a liquid oil/solid fat mixture.

Effect of the ionic strength of pulsed electric field treatment medium on the physicochemical and structural characteristics of lactoferrin.

Pulsed electric field (PEF) treatment (35 kV cm(-1) for 19.2 μs using bipolar 2 μs pulses) was conducted on bovine lactoferrin (LF; 0.4 mg mL(-1)) prepared in simulated milk ultrafiltrate (SMUF), at concentrations between 0.