Advancing textural heterogeneity: Effect of manipulating multi-component model foods on the perception of textural complexity.

The aim of this study was to identify the individual and interacting effects of varying the mechanical properties of two inserts (к-carrageenan beads; 1, 2 and 4% w/w and/or agar-based disks; 0.3, 1.2 and 3% w/w) in pectin-based gels on the perception of textural complexity. A full factorial design was utilised, 16 samples were characterised with sensory and instrumental tests. Rate-All-That-Apply (RATA) was performed by 50 untrained participants. RATA selection frequency provided different information to attribute intensity regarding the detection of low yield stress inserts. In the two-component samples, the perception of textural complexity (n = 89) increased with insert yield stress for both к-carrageenan beads and agar disks. However, with the addition of medium and high yield stress к-carrageenan beads to three-component samples, the increases in perceived textural complexity caused by increased agar yield stress were eliminated. The definition of textural complexity, the number and intensity of texture sensations, as well as their interactions and contrasts, was in line with the results, and the hypothesis that not only mechanical properties but also the interaction of components play a key role in the perception of textural complexity.

Oral processing preference affects flavor perception in dark chocolate with added ingredients.

Chocolate has specific rheological behavior during oral processing that delivers its distinct sensory characteristics. When incorporating functional or flavoring ingredients into chocolate, these properties must be maintained to meet consumer expectation. Water-soluble and fat-soluble ingredients have a potential effect on the properties of chocolate; therefore, successfully adding functional supplements in this medium can have challenges. This study investigated the effect of functional or flavoring ingredients on chocolate microstructure, mouthfeel (texture), and flavor release, during oral processing. Participants were classified by their oral processing "pattern": a chewing preference (CP), a sucking preference (SP), and a mixed group who had a preference for both chewing and sucking (MP). Chocolate samples (72% dark chocolate) were prepared with different flavor ingredients (water-soluble: ginger powder and fat-soluble: menthol). Instrumental testing of chocolate viscosity and hardness showed no significant differences in chocolate with low concentrations of added ingredients (0.5% ginger and 0.1% mint), while chocolate with higher concentration (2.5% ginger and 0.5% mint) showed a significant difference compared to standard chocolate. Modified Qualitative Descriptive Analysis (MQDA) tests showed no significant differences in sensory perception of texture between the formulations, or the oral processing behavior groups. There was an impact on flavor perception both from composition and from oral processing behavior. The CP group rated the chocolate with the lowest flavoring concentration as also having the lowest cocoa flavor intensity. Moreover, the MP and SP groups showed a similar perception of cocoa flavor intensity.

Exploring the Development, Validity, and Utility of the Short-Form Version of the CHoice of Outcome In Cbt for PsychosEs: A Patient-Reported Outcome Measure of Psychological Recovery.

The original CHoice of Outcome In Cbt for psychosEs (CHOICE) measure was designed in collaboration with experts by experience as a patient-reported "Psychological Recovery" outcome measure for cognitive-behavioral therapy for psychosis (CBTp). A short version (CHOICE-SF) was developed to use as a brief outcome measure, with a focus on sensitivity to change, for use in future research and practice. CHOICE-SF was developed and validated using 3 separate samples, comprising 640 service users attending 1 of 2 transdiagnostic clinics for (1) CBTp or (2) therapies for voice hearing or (3) who took part in the treatment as usual arm of a trial. In the initial subsample of 69 participants, items from the original CHOICE measure with medium to large effect sizes for change pre- to post-CBTp were retained to form the CHOICE-SF. Internal consistency, construct validity, and sensitivity to change were confirmed, and the factor structure was examined in 242 participants. Specificity was confirmed by comparison with 44 participants who completed CHOICE at 2 time points but did not receive therapy. Validation of CHOICE-SF was carried out by confirming factor structure and sensitivity to change in a new sample of 354 and a subsample of 51 participants, respectively. The CHOICE-SF comprised 11 items and 1 additional personal goal item. A single-factor structure was confirmed, with high internal consistency, construct validity, and sensitivity to change. The CHOICE-SF is a brief, psychometrically robust measure to assess change following psychological therapies in research and clinical practice for people with psychosis and severe mental illness.

Session 3 Discussion: The microstructure of eating.

The Microstructure of Eating.

Effects of Fat Polymorphic Transformation and Nonfat Particle Size Distribution on the Surface Changes of Untempered Model Chocolate, Based on Solid Cocoa Mass.

This study aims to understand the bloom process in untempered chocolate by investigating the polymorphic transformation of cocoa butter and changes in chocolate surface. Cocoa mass with varying particle size distributions (PSD) were used to produce untempered model chocolate. Optical microscopy showed that during 25 d of storage, the chocolate surface gradually became honeycombed in appearance with dark spots surrounded by white sandy bloom areas. In conjunction with X-ray diffraction this indicates that the polymorphic transformation of form IV cocoa butter to more stable form V crystals caused the observed surface changes with the most significant changes occurring within 6 d. As bloom developed the surface whiteness increased, but the PSD of nonfat particles showed limited impact on the changes in whiteness. Moreover, scanning electron microscopy showed separated fat crystals on fat-rich dark spots and empty spaces between particles in bloom areas suggesting redistribution of fat in the chocolate matrix. PRACTICAL APPLICATION: The results reported in this work can facilitate the understanding of fat bloom formation in untempered chocolate with respect to the changes in microstructure and surface appearances. It also contributes to show the details of IV-to-V polymorphic transformation in the fat phase as time went by.

Dimensional Changes of Tracheids during Drying of Radiata Pine (Pinus radiata D. Don) Compression Woods: A Study Using Variable-Pressure Scanning Electron Microscopy (VP-SEM).

Variable-pressure scanning electron microscopy was used to investigate the dimensional changes in longitudinal, tangential and radial directions, on wetting and drying, of tracheids of opposite wood (OW) and three grades of compression woods (CWs), including severe CW (SCW) and two grades of mild compression wood (MCW) (MCW1 and MCW2) in corewood of radiata pine (Pinus radiata) saplings. The CW was formed on the underside and OW on the upper side of slightly tilted stems. In the longitudinal direction, the shrinkage of SCW tracheids was ~300% greater than that of OW tracheids, with the shrinkage of the MCW1 and MCW2 tracheids being intermediate. Longitudinal swelling was also investigated and hysteresis was demonstrated for the tracheids of all corewood types, with the extent of hysteresis increasing with CW severity. A statistical association was found between longitudinal shrinkage and the content of lignin and galactosyl residues in the cell-wall matrix. The galactosyl residues are present mostly as (1→4)-ß-galactans, which are known to have a high capacity for binding water and swell on hydration. The small proportions of (1→3)-ß-glucans in the CWs have similar properties. These polysaccharides may play a functional role in the longitudinal shrinking and swelling of CW tracheids. Tangential shrinkage of tracheids was greater than radial shrinkage but both were greatest for OW and least for SCW, with the MCW1 and MCW2 being intermediate.

Oral processing and texture perception influences satiation.

This article offers a brief review of the state of understanding of the role of oral processing and food texture on satiation. Food texture is a sensory property that contributes to the manner in which food transits the oral cavity. Several studies have shown the impact of oral transit time on satiation, with longer times relating to enhanced satiation response. Recent studies have also begun to show an impact of texture on satiation independent of oral processing time. There are still many questions to answer before the underlying mechanisms of these impacts are understood.

Increased textural complexity in food enhances satiation.

For the first time this study has shown a direct effect of food textural complexity on satiation. Independent of oral processing time, increasing the textural complexity of a food significantly decreased food intake. Foods with complex textures stimulate many sensory perceptions during oral processing, with a succession of textures perceived between first bite and swallow. Previously the impact of texture on satiation (commonly tested by increasing viscosities of semi-solids) has been explained by texture's influence on oral processing time; a long oral processing time enhances satiation. The results of the current study show that subjects in a randomised cross-over trial who consumed a "starter" (preload) model food with high textural complexity went on to eat significantly less of a two course ad libitum meal. Subjects who consumed a "starter" model food with low textural complexity, but with the same flavour, energy density and oral processing time, ate significantly more of the same ad libitum meal. The results show that increasing the number of textures perceived during chewing of a solid food triggers the satiation response earlier than when chewing a less texturally complex food. Increasing textural complexity of manufactured foods, to allow for greater sensory stimulation per bite, could potentially be used as a tool to enhance the satiation response and decrease food intake.

The effect of textural complexity of solid foods on satiation.

Previous studies have shown that food texture affects satiation by influencing the eating rate, bite size and oral transit time. However, investigations into the direct effect of texture on satiation are limited. The objective of the current study was to investigate the effect of textural complexity on satiation, independent of oral processing time and energy density. A preload-test meal design was used in this study; model foods with three levels of textural complexity (low, medium and high) were consumed as preload foods followed by a two-course ad libitum meal. This study was a randomized cross-over trial with 38 subjects. The results clearly showed that food with greater textural complexity led to significantly lower food intake overall. The first course of the meal and total food intake was significantly reduced (p<0.05) although food intake at the second course did not differ between groups. Despite the differing total intake, all subjects rated to have the same sense of satiety after three hours post-trial and the time taken to the next eating occasion did not differ between different preload conditions. Increased textural complexity in food enhances satiation and may potentially impact on satiety however this needs to be further confirmed in future studies. The findings suggest that foods with more complex textures can be a helpful tool in reducing the short-term food intake and enhancing the satiation response.

Quantification of pizza baking properties of different cheeses, and their correlation with cheese functionality.

The aim of this study is to quantify the pizza baking properties and performance of different cheeses, including the browning and blistering, and to investigate the correlation to cheese properties (rheology, free oil, transition temperature, and water activity). The color, and color uniformity, of different cheeses (Mozzarella, Cheddar, Colby, Edam, Emmental, Gruyere, and Provolone) were quantified, using a machine vision system and image analysis techniques. The correlations between cheese appearance and attributes were also evaluated, to find that cheese properties including elasticity, free oil, and transition temperature influence the color uniformity of cheeses.

Multi-layered plasma-polymerized chips for SPR-based detection.

The surface functionalization of a noble metal is crucial in a surface plasmon resonance-based biomolecular detection system because the interfacial coating must retain the activity of immobilized biomolecules while enhancing the optimal loading. We present here a one-step, room-temperature, high-speed, gas-phase plasma polymerization process for functionalizing gold substrates using siloxane as an adhesion layer and acrylic acid as a functional layer. Siloxane- and thiol-based coatings were compared for their performance as adhesion and the interfacial layer for subsequent functionalization. An in situ sequential deposition of siloxane and acrylic acid resulted in a 7-fold increase in carboxylic functionality surfacial content compared to films deposited with thiol-containing precursors. Grading of the layer composition achieved as a consequence of ion-induced mixing on the surface coating under the application of the plasma is confirmed through secondary ion mass spectroscopic studies. DNA hybridization assays were demonstrated on gold/glass substrates using surface plasmon enhanced ellipsometry and the applicability of this coating for protein immunoassays were demonstrated with plasma functionalized gold/plastic substrates in Biacore 3000 SPR instrument.

Plasma functionalization of AFM tips for measurement of chemical interactions.

In this paper, a new, fast, reproducible technique for atomic force microscopy (AFM) tips functionalization used for chemical interaction measurements is described. Precisely, the deposition of an aminated precursor is performed through plasma-enhanced chemical vapor deposition (PECVD) in order to create amine functional groups on the AFM tip and cantilever. The advantages of the precursor, aminopropyltriethoxysilane (APTES), were recently demonstrated for amine layer formation through PECVD deposition on polymeric surfaces. We extended this procedure to functionalize AFM probes. Titration force spectroscopy highlights the successful functionalization of AFM tips as well as their stability and use under different environmental conditions.

Functionalization of cycloolefin polymer surfaces by plasma-enhanced chemical vapour deposition: comprehensive characterization and analysis of the contact surface and the bulk of aminosiloxane coatings.

The surface science of bioassay devices is of great importance in the development of modern diagnostic platforms. The quality of surface is one of the most important elements of the device, often governing the background response, hence controlling the sensitivity of an assay. Detailed surface characterization and analysis are imperative for the preparation of reproducible coatings with desired properties. We performed a comprehensive characterization of 3-aminopropyl-triethoxysilane films prepared under two different deposition conditions on COP slides. Two sets of slides were prepared, by exposing them to plasma reaction for 30 seconds (A30 slide) and 4 minutes (A4 slide). While the variations in the deposition conditions seemed very subtle, the use of several powerful analytical tools helped us to reveal some fundamental differences between the studied films in terms of binding capacity, swelling and adhesion. Overall, the A30 films, with a thickness of 5.12 nm, showed up to 40% higher binding capacity and 25% better adhesion than the thicker A4 coatings (28.15 nm). Upon contact with aqueous media, a significant change was observed in terms of surface roughness. The A30 slides outperformed A4 slides, resulting in smoother surface, which is an important parameter for biomolecule immobilisation. The use of the techniques described in this article is aimed to set new standards for the characterization and analysis of the substrate surface of the future diagnostic devices.

Combining nutrition, food science and engineering in developing solutions to Inflammatory bowel diseases--omega-3 polyunsaturated fatty acids as an example.

The Inflammatory bowel diseases, Crohn's disease and ulcerative colitis, are debilitating conditions, characterised by lifelong sensitivity to certain foods, and often a need for surgery and life-long medication. The anti-inflammatory effects of long chain omega-3 polyunsaturated acids justify their inclusion in enteral nutrition formulas that have been associated with disease remission. However, there have been variable data in clinical trials to test supplementary omega-3 polyunsaturated fatty acids in inducing or maintaining remission in these diseases. Although variability in trial design has been suggested as a major factor, we suggest that variability in processing and presentation of the products may be equally or more important. The nature of the source, and rapidity of getting the fish or other food source to processing or to market, will affect the percentage of the various fatty acids, possible presence of heavy metal contaminants and oxidation status of the various fatty acids. For dietary supplements or fortified foods, whether the product is encapsulated or not, whether storage is under nitrogen or not, and length of time between harvest, processing and marketing will again profoundly affect the properties of the final product. Clinical trials to test efficacy of these products in IBD to date have utilised the relevant skills of pharmacology and gastroenterology. We suggest that knowledge from food science, nutrition and engineering will be essential to establish the true role of this important group of compounds in these diseases.

Determination of a representative volume element based on the variability of mechanical properties with sample size in bread.

Quantitative analysis of food structure is commonly obtained by image analysis of a small portion of the material that may not be the representative of the whole sample. In order to quantify structural parameters (air cells) of 2 types of bread (bread and bagel) the concept of representative volume element (RVE) was employed. The RVE for bread, bagel, and gelatin-gel (used as control) was obtained from the relationship between sample size and the coefficient of variation, calculated from the apparent Young's modulus measured on 25 replicates. The RVE was obtained when the coefficient of variation for different sample sizes converged to a constant value. In the 2 types of bread tested, the tendency of the coefficient of variation was to decrease as the sample size increased, while in the homogeneous gelatin-gel, it remained always constant around 2.3% to 2.4%. The RVE resulted to be cubes with sides of 45 mm for bread, 20 mm for bagels, and 10 mm for gelatin-gel (smallest sample tested). The quantitative image analysis as well as visual observation demonstrated that bread presented the largest dispersion of air-cell sizes. Moreover, both the ratio of maximum air-cell area/image area and maximum air-cell height/image height were greater for bread (values of 0.05 and 0.30, respectively) than for bagels (0.03 and 0.20, respectively). Therefore, the size and the size variation of air cells present in the structure determined the size of the RVE. It was concluded that RVE is highly dependent on the heterogeneity of the structure of the types of baked products.