From Processed Foods to Ultraprocessed Foods: Evolution of an Industry Model and Impact on Dietary Quality, Health, and Society.

The impact of food technology and product development on the nutritional quality of foods is discussed in the context of food classification schemes, clinical research, and sociocultural studies. Food processing operations are analyzed in terms of their beneficial and detrimental consequences for the nutritional value of foods and ingredients. Several classification schemes are discussed, including dietary guidelines, nutrition information panels, and nutritional scores.

Ultra-processed foods: Processing versus formulation.

The four-tiered NOVA food classification defines foods based on their degree of processing and ranges from native unprocessed foods to so-called "ultra-processed" foods. Recent publications have suggested that foods classified as ultra-processed are unhealthy and contribute to the obesity epidemic. It is important to distinguish between formulation and processing of a food.

Texturization of pea protein isolate by micro compounding.

Twin-screw micro compounding is introduced as a novel technique to process and characterize small plant protein samples under conditions that are relevant for meat analogue processing. Small samples of pea protein isolate (PPI) (5 cm, corresponding to ∼7 g of hydrated sample) are batch-processed at water contents between 40 and 70 % w/w and temperatures between 90 and 120 °C. Screw speed (100-400 rpm) and residence time (1-9 min) are varied resulting in values of the specific mechanical energy (SME) between ∼20 and 2000 kJ/kg, which is the range relevant for plant protein extrusion.

Rheology of carbohydrate blends close to the glass transition: Temperature and water content dependence of the viscosity in relation to fragility and strength.

Several modifications of the Williams-Landel-Ferry (WLF) equation that incorporate the water-content dependence of the viscosity are introduced and applied to the fitting the zero-shear viscosity of a systematic series of maltopolymer-maltose blends for water contents w between 4% and 70% (M. Dupas-Langlet et al., Carbohydrate Polymers 213 (2019) 147-158).

Antiplasticization and phase behavior in phase-separated modified starch-sucrose blends: A positron lifetime and solid-state NMR study.

Interactions, organization and dynamics within phase-separated ternary blends of hydrophobically modified starch (HMS), sucrose and water are investigated using solid-state NMR and positron annihilation lifetime spectroscopy (PALS). Antiplasticization of HMS by sucrose is demonstrated by PALS and H NMR T measurements. Selective solid-state C NMR experiments show that a large fraction of sucrose is in molecular contact with HMS even at high sucrose contents, indicating that the HMS-sucrose phase separation is only partial.

Influence of blend ratio and water content on the rheology and fragility of maltopolymer/maltose blends.

The rheological behavior of blends of a fractionated maltopolymer (M = 1.4⋅10 Da) and the disaccharide maltose is investigated as a function of water content and temperature, with emphasis on the viscosity and molecular relaxations in the approach to the glass transition. Shear rheology is combined with dynamic mechanical thermal analysis to probe viscosities between 1 mPa s and 10 Pa s.

Water vapor sorption and glass transition temperatures of phase-separated amorphous blends of hydrophobically-modified starch and sucrose.

This article contains water vapor sorption data obtained on amorphous blends of octenyl succinic acid-modified (denoted as hydrophobically modified starch; HMS) and sucrose (S) in the anhydrous weight HMS/S ratios between 100/0 and 27/75. The water vapor sorption data was obtained gravimetrically. The amorphous state of the blends was confirmed by X-ray diffraction.

Phase separation in amorphous hydrophobically modified starch-sucrose blends: Glass transition, matrix dynamics and phase behavior.

The phase behavior and matrix dynamics of amorphous blends of octenyl succinic anhydride (OSA) modified starch and sucrose was studied as function of blend composition and water content. Phase separation into two amorphous phases, one enriched in OSA starch and the other in sucrose, was confirmed by differential scanning calorimetry (DSC). DSC and H solid-state NMR show that the phase separation is only partial.

Structural and thermodynamic aspects of plasticization and antiplasticization in glassy encapsulation and biostabilization matrices.

The structural and thermodynamic properties of glassy carbohydrate matrices for the encapsulation and biostabilization of sensitive bioactive compounds, such as pharmaceutically active proteins and oxidation-sensitive compounds, are reviewed in the context of the plasticization and antiplasticization of glassy carbohydrates of intermediate and high molecular weight by low molecular weight diluents. Plasticization and antiplasticization may be monitored either by dynamic measures or by structural and thermodynamic features of the glassy matrices. Specifically, it is demonstrated that the decrease in size of the molecular free volume holes with increasing diluent content, as determined by positron annihilation lifetime spectroscopy (PALS), is related to the antiplasticization of glassy carbohydrate matrices, resulting in increased barrier properties of the glassy matrix.

Hydrogen bonding in maltooligomer-glycerol-water matrices: Relation to physical state and molecular free volume.

We use Fourier Transform Infra Red (FTIR) Spectroscopy to explore the effects of water and glycerol on the hydrogen bonding of low water content maltooligomer matrices by monitoring the shifts in the position of the peak associated with the fundamental stretching vibration of the hydroxyl groups, νOH. Changes in hydrogen bonding are investigated in relation to the physical state and the molecular packing of the maltooligomer matrices, which are measured by Positron Annihilation Lifetime Spectroscopy (PALS). In the concentration range studied (0-20 wt.

Soft matter approaches to structured foods: from "cook-and-look" to rational food design?

Developments in soft matter physics are discussed within the context of food structuring. An overview is given of soft matter-based approaches used in food, and a relation is established between soft matter approaches and food technology, food creation, product development and nutrition. Advances in food complexity and food sustainability are discussed from a physical perspective, and the potential for future developments is highlighted.

Delivery of Functionality in Complex Food Systems: Physically Inspired Approaches from Nanoscale to Microscale, Wageningen 18-21 October 2009.

The Wageningen Delivery of Functionality symposium covered all aspects involved with food structural design to arrive at high-quality foods which meet demanding customer expectations and regulatory requirements. The symposium integrated aspects from the structural organization of foods at molecular and supramolecular scales to dedicated techniques required to describe and visualize such structures, the gastro-intestinal events and how to model these in a laboratory setting, and finally the impact those food structures and ingredients have on the consumer's physiology and on the human perception. As an interdisciplinary platform, bringing together more than 160 researchers from academia and industry, the symposium meanwhile fulfills an important role in the food science community.

Plasticization, antiplasticization, and molecular packing in amorphous carbohydrate-glycerol matrices.

The molecular packing of amorphous maltodextrin-glycerol matrices is systematically explored by combining positron annihilation lifetime spectroscopy (PALS) with thermodynamic measurements and dilatometry. Maltodextrin-glycerol matrices are equilibrated at a range of water activities between 0 and 0.54 at T = 25 °C to analyze the effect of both water and glycerol on the average molecular hole size and the specific volume of the matrices.

Specific volume-hole volume correlations in amorphous carbohydrates: effect of temperature, molecular weight, and water content.

The specific volume and the nanostructure of the free volume of amorphous blends of maltose with a narrow molecular weight distribution maltopolymer were systematically studied as a function of temperature, water content, pressure, and blend composition. Correlations between the hole free volume and the specific volume were investigated in the glassy and rubbery phases and in solution using positron annihilation lifetime spectroscopy (PALS) and pressure-volume-temperature (PVT) measurements, with the aim to provide a consolidated mechanistic understanding of the relation between changes in molecular packing and at the molecular level and the behavior of the specific volume at the macrolevel. Both specific volume and hole volume show a linear dependence on the temperature, but with a slope which is higher in the rubbery state than in the glassy state.

Food structure and functionality: a soft matter perspective.

The structure and functionality of foods are described from the perspective of recent advances in soft condensed matter physics. An overview is given of the structure and properties of food materials in terms of the physically relevant length scales. Recent developments in the understanding of the physics of gels, micelles, liquid crystals, biopolymer complexes and amorphous carbohydrates are presented.

Molecular packing in amorphous carbohydrate matrixes.

The molecular packing of bidisperse matrixes of amorphous carbohydrates consisting of a fractionated maltopolymer supplemented with various amounts of the disaccharide maltose is investigated by combining Positron Annihilation Lifetime Spectroscopy (PALS) with specific volume measurements. The maltopolymer-maltose blends are equilibrated at a range of water activities between 0 and 0.75 at 25 degrees C in order to investigate the effect of water content and carbohydrate molecular weight distribution on the size of the molecular free volume holes in both the glassy and rubbery states.

Sorption of water by bidisperse mixtures of carbohydrates in glassy and rubbery states.

Water sorption by bidisperse carbohydrate mixtures consisting of varying ratios of a narrow-molecular-weight distribution maltopolymer and the disaccharide maltose is investigated to establish a quantitative relation between the composition of the carbohydrate system and the water sorption isotherm. The sorption of water is approached from two limiting cases: the glassy state at low water content and the dilute aqueous carbohydrate solution. In the glassy state, the water content at a given water activity decreases with increasing maltose content of the matrix, whereas in the rubbery state it increases with increasing maltose content.

Organization and mobility of water in amorphous and crystalline trehalose.

The disaccharide trehalose is accumulated by microorganisms, such as yeasts, and multicellular organisms, such as tardigrades, when conditions of extreme drought occur. In this way these organisms can withstand dehydration through the formation of an intracellular carbohydrate glass, which, with its high viscosity and hydrogen-bonding interactions, stabilizes and protects the integrity of complex biological structures and molecules. This property of trehalose can also be harnessed in the stabilization of liposomes, proteins and in the preservation of red blood cells, but the underlying mechanism of bioprotection is not yet fully understood.

Influence of fermentation medium composition on physicochemical surface properties of Lactobacillus acidophilus.

The effect of the simple and complex basic components of a fermentation medium on the surface properties of Lactobacillus acidophilus NCC2628 is studied by physicochemical methods, such as electrophoresis, interfacial adhesion, and X-ray photonelectron spectroscopy, and by transmission electron microscopy. Starting from an optimized complete medium, the effect of carbohydrates, peptones, and yeast extracts on the physicochemical properties of the cell wall is systematically investigated by consecutively omitting one of the principal components from the fermentation medium at the time. The physicochemical properties and structure of the bacterial cell wall remain largely unchanged if the carbohydrate content of the fermentation medium is strongly reduced, although the concentration of surface proteins increases slightly.

Probing bacterial interactions: integrated approaches combining atomic force microscopy, electron microscopy and biophysical techniques.

Recent developments in the application of Atomic Force Microscopy (AFM) and other biophysical techniques for the study of bacterial interactions and adhesion are discussed in the light of established biological and microscopic approaches. Whereas molecular-biological techniques combined with electron microscopy allow the identification and localization of surface constituents mediating bacterial interactions, with AFM it has become possible to actually measure the forces involved in bacterial interactions. Combined with the flexibility of AFM in probing various types of physical interactions, such as electrostatic interactions, specific ligand-receptor interactions and the elastic forces of deformation and extension of bacterial surface polymers and cell wall, this provides prospects for the elucidation of the biophysical mechanism of bacterial interaction.

Carbohydrate polymers in amorphous states: an integrated thermodynamic and nanostructural investigation.

The effect of water on the structure and physical properties of amorphous polysaccharide matrices is investigated by combining a thermodynamic approach including pressure- and temperature-dependent dilatometry with a nanoscale analysis of the size of intermolecular voids using positron annihilation lifetime spectroscopy. Amorphous polysaccharides are of interest because of a number of unusual properties which are likely to be related to the extensive hydrogen bonding between the carbohydrate chains. Uptake of water by the carbohydrate matrices leads to a strong increase in the size of the holes between the polymer chains in both the glassy and rubbery states while at the same time leading to an increase in matrix free volume.

Poisson-Boltzmann theory of the charge-induced adsorption of semi-flexible polyelectrolytes.

A model is suggested for the structure of an adsorbed layer of a highly charged semi-flexible polyelectrolyte on a weakly charged surface of opposite charge sign. The adsorbed phase is thin, owing to the effective reversal of the charge sign of the surface upon adsorption, and ordered, owing to the high surface density of polyelectrolyte strands caused by the generally strong binding between polyelectrolyte and surface. The Poisson-Boltzmann equation for the electrostatic interaction between the array of adsorbed polyelectrolytes and the charged surface is solved for a cylindrical geometry, both numerically, using a finite element method, and analytically within the weak curvature limit under the assumption of excess monovalent salt.

The cell wall of lactic acid bacteria: surface constituents and macromolecular conformations.

A variety of strains of the genus Lactobacillus was investigated with respect to the structure, softness, and interactions of their outer surface layers in order to construct structure-property relations of the Gram-positive bacterial cell wall. The role of the conformational properties of the constituents of the outer cell-wall layers and their spatial distribution on the cell wall is emphasized. Atomic force microscopy was used to resolve the surface structure, interactions, and softness of the bacterial cell wall at nanometer-length scales and upwards.

Imaging of lactic acid bacteria with AFM--elasticity and adhesion maps and their relationship to biological and structural data.

The adhesion of lactic acid bacteria to the intestinal epithelium is one of the most important factors determining probiotic ability of a bacterial strain. Studying bacterial adhesion requires knowledge of the structure and properties of the bacterial surface, which can be studied by atomic force microscopy under native conditions. The observation of the surface topography of bacteria from the species Lactobacillus crispatus, L.