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2.
Appetite ; 180: 106313, 2023 01 01.
Article in English | MEDLINE | ID: mdl-36122622

ABSTRACT

Since COVID-19 outbreak, States adopted different combinations of measures to restrain its spread that affected individual behaviors and the already fragile local and global food systems. The aim of this research is to contribute to the scientific debate around food systems sustainability through the analysis of behavioral shifts in household food waste drivers, specifically occurring during the recent global pandemic. A survey was developed based on an extended version of the Motivation-Opportunity-Ability (MOA) approach. A representative sample of 3000 respondents in Italy and in the Netherlands (1500 per country) completed this survey in May 2020, while lockdown to mitigate the first wave of COVID-19 outbreak was active in both countries. A cluster analysis based on individual food-waste- related behaviors identified four homogenous groups of consumers in the Italian sample and five in the Dutch sample. The comparative analysis of these groups led to the identification of several communalities in behavioral patterns, both within and between the two countries. Results suggest that in both countries, self-reported quantities of household food waste actually decreased, with a stronger reduction reported by Italian consumers. The MOA approach allowed to explain this perceived reduction as largely depending on the increase of opportunity to dedicate more time - to food-related activities as compared to the pre-COVID-19 period, with positive consequences on food management ability. These findings assist in drafting recommendations for tailored interventions to reduce the amount of domestic food waste and preserve positive behaviors emerged during lockdown, that could be continued in the absence of crisis.


Subject(s)
COVID-19 , Refuse Disposal , Humans , Food , COVID-19/epidemiology , Communicable Disease Control , Italy/epidemiology
3.
Front Immunol ; 13: 915366, 2022.
Article in English | MEDLINE | ID: mdl-35874769

ABSTRACT

γ9δ2T cells fill a distinct niche in human immunity due to the unique physiology of the phosphoantigen-reactive γ9δ2TCR. Here, we highlight reproducible TCRδ complementarity-determining region 3 (CDR3δ) repertoire patterns associated with γ9δ2T cell proliferation and phenotype, thus providing evidence for the role of the CDR3δ in modulating in vivo T-cell responses. Features that determine γ9δ2TCR binding affinity and reactivity to the phosphoantigen-induced ligand in vitro appear to similarly underpin in vivo clonotypic expansion and differentiation. Likewise, we identify a CDR3δ bias in the γ9δ2T cell natural killer receptor (NKR) landscape. While expression of the inhibitory receptor CD94/NKG2A is skewed toward cells bearing putative high-affinity TCRs, the activating receptor NKG2D is expressed independently of the phosphoantigen-sensing determinants, suggesting a higher net NKR activating signal in T cells with TCRs of low affinity. This study establishes consistent repertoire-phenotype associations and justifies stratification for the T-cell phenotype in future research on γ9δ2TCR repertoire dynamics.


Subject(s)
Complementarity Determining Regions , T-Lymphocytes , Adult , Cell Proliferation , Complementarity Determining Regions/genetics , Humans , Phenotype
4.
Viruses ; 14(1)2022 01 10.
Article in English | MEDLINE | ID: mdl-35062321

ABSTRACT

In the complex interplay between inflammation and graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (allo-HSCT), viral reactivations are often observed and cause substantial morbidity and mortality. As toxicity after allo-HSCT within the context of viral reactivations is mainly driven by αß T cells, we describe that by delaying αß T cell reconstitution through defined transplantation techniques, we can harvest the full potential of early reconstituting γδ T cells to control viral reactivations. We summarize evidence of how the γδ T cell repertoire is shaped by CMV and EBV reactivations after allo-HSCT, and their potential role in controlling the most important, but not all, viral reactivations. As most γδ T cells recognize their targets in an MHC-independent manner, γδ T cells not only have the potential to control viral reactivations but also to impact the underlying hematological malignancies. We also highlight the recently re-discovered ability to recognize classical HLA-molecules through a γδ T cell receptor, which also surprisingly do not associate with GVHD. Finally, we discuss the therapeutic potential of γδ T cells and their receptors within and outside the context of allo-HSCT, as well as the opportunities and challenges for developers and for payers.


Subject(s)
Hematopoietic Stem Cell Transplantation/adverse effects , Intraepithelial Lymphocytes/immunology , Virus Diseases/complications , Virus Diseases/prevention & control , Cytomegalovirus , Cytomegalovirus Infections/prevention & control , Epstein-Barr Virus Infections/prevention & control , Graft vs Host Disease/etiology , Hematologic Neoplasms , Herpesvirus 4, Human , Receptors, Antigen, T-Cell, gamma-delta/immunology
5.
Elife ; 102021 02 04.
Article in English | MEDLINE | ID: mdl-33538246

ABSTRACT

Lymphocyte numbers need to be quite tightly regulated. It is generally assumed that lymphocyte production and lifespan increase homeostatically when lymphocyte numbers are low and, vice versa, return to normal once cell numbers have normalized. This widely accepted concept is largely based on experiments in mice, but is hardly investigated in vivo in humans. Here we quantified lymphocyte production and loss rates in vivo in patients 0.5-1 year after their autologous hematopoietic stem cell transplantation (autoHSCT). We indeed found that the production rates of most T- and B-cell subsets in autoHSCT-patients were two to eight times higher than in healthy controls, but went hand in hand with a threefold to ninefold increase in cell loss rates. Both rates also did not normalize when cell numbers did. This shows that increased lymphocyte production and loss rates occur even long after autoHSCT and can persist in the face of apparently normal cell numbers.


Subject(s)
Hematopoietic Stem Cell Transplantation/statistics & numerical data , Lymphocyte Count , Lymphocytes/physiology , Transplantation, Autologous/statistics & numerical data , Adult , Female , Humans , Male , Middle Aged
6.
Blood Adv ; 5(1): 240-249, 2021 01 12.
Article in English | MEDLINE | ID: mdl-33570642

ABSTRACT

We conducted a multicenter prospective single-arm phase 1/2 study that assesses the outcome of αß T-cell depleted allogeneic hematopoietic stem cell transplantation (allo-HSCT) of peripheral blood derived stem cells from matched related, or unrelated donors (10/10 and 9/10) in adults, with the incidence of acute graft-versus-host disease (aGVHD) as the primary end point at day 100. Thirty-five adults (median age, 59; range, 19-69 years) were enrolled. Conditioning consisted of antithymocyte globulin, busulfan, and fludarabine, followed by 28 days of mycophenolic acid after allo-HSCT. The minimal follow-up time was 24 months. The median number of infused CD34+ cells and αß T cells were 6.1 × 106 and 16.3 × 103 cells per kg, respectively. The cumulative incidence (CI) of aGVHD grades 2-4 and 3-4 at day 100 was 26% and 14%. One secondary graft failure was observed. A prophylactic donor lymphocyte infusion (DLI) (1 × 105 CD3+ T cells per kg) was administered to 54% of the subjects, resulting in a CI of aGVHD grades 2-4 and 3-4 to 37% and 17% at 2 years. Immune monitoring revealed an early reconstitution of natural killer (NK) and γδ T cells. Cytomegalovirus reactivation associated with expansion of memory-like NK cells. The CI of relapse was 29%, and the nonrelapse mortality 32% at 2 years. The 2-year CI of chronic GVHD (cGVHD) was 23%, of which 17% was moderate. We conclude that only 26% of patients developed aGVHD 2-4 after αß T-cell-depleted allo-HSCT within 100 days and was associated with a low incidence of cGVHD after 2 years. This trial was registered at www.trialregister.nl as #NL4767.


Subject(s)
Graft vs Host Disease , Hematologic Neoplasms , Hematopoietic Stem Cell Transplantation , Adult , Graft vs Host Disease/etiology , Hematologic Neoplasms/therapy , Hematopoietic Stem Cell Transplantation/adverse effects , Humans , Middle Aged , Neoplasm Recurrence, Local , Prospective Studies , T-Lymphocytes
7.
J Clin Invest ; 130(9): 4637-4651, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32484803

ABSTRACT

γ9δ2T cells play a major role in cancer immune surveillance, yet the clinical translation of their in vitro promise remains challenging. To address limitations of previous clinical attempts using expanded γ9δ2T cells, we explored the clonal diversity of γ9δ2T cell repertoires and characterized their target. We demonstrated that only a fraction of expanded γ9δ2T cells was active against cancer cells and that activity of the parental clone, or functional avidity of selected γ9δ2 T cell receptors (γ9δ2TCRs), was not associated with clonal frequency. Furthermore, we analyzed the target-receptor interface and provided a 2-receptor, 3-ligand model. We found that activation was initiated by binding of the γ9δ2TCR to BTN2A1 through the regions between CDR2 and CDR3 of the TCR γ chain and modulated by the affinity of the CDR3 region of the TCRδ chain, which was phosphoantigen independent (pAg independent) and did not depend on CD277. CD277 was secondary, serving as a mandatory coactivating ligand. We found that binding of CD277 to its putative ligand did not depend on the presence of γ9δ2TCR, did depend on usage of the intracellular CD277, created pAg-dependent proximity to BTN2A1, enhanced cell-cell conjugate formation, and stabilized the immunological synapse (IS). This process critically depended on the affinity of the γ9δ2TCR and required membrane flexibility of the γ9δ2TCR and CD277, facilitating their polarization and high-density recruitment during IS formation.


Subject(s)
Cell Proliferation , Lymphocyte Activation , Models, Immunological , Neoplasms/immunology , Receptors, Antigen, T-Cell, gamma-delta/immunology , T-Lymphocytes/immunology , Antigens, Neoplasm/immunology , Butyrophilins/immunology , Humans , Jurkat Cells , Neoplasm Proteins/immunology , Neoplasms/pathology , T-Lymphocytes/pathology
9.
Cancer Immunol Res ; 8(4): 530-543, 2020 04.
Article in English | MEDLINE | ID: mdl-32019779

ABSTRACT

γδ T cells in human solid tumors remain poorly defined. Here, we describe molecular and functional analyses of T-cell receptors (TCR) from tumor-infiltrating γδ T lymphocytes (γδ TIL) that were in direct contact with tumor cells in breast cancer lesions from archival material. We observed that the majority of γδ TILs harbored a proinflammatory phenotype and only a minority associated with the expression of IL17. We characterized TCRγ or TCRδ chains of γδ TILs and observed a higher proportion of Vδ2+ T cells compared with other tumor types. By reconstructing matched Vδ2- TCRγ and TCRδ pairs derived from single-cell sequencing, our data suggest that γδ TILs could be active against breast cancer and other tumor types. The reactivity pattern against tumor cells depended on both the TCRγ and TCRδ chains and was independent of additional costimulation through other innate immune receptors. We conclude that γδ TILs can mediate tumor reactivity through their individual γδ TCR pairs and that engineered T cells expressing TCRγ and δ chains derived from γδ TILs display potent antitumor reactivity against different cancer cell types and, thus, may be a valuable tool for engineering immune cells for adoptive cell therapies.


Subject(s)
Immunotherapy, Adoptive/methods , Leukocytes, Mononuclear/immunology , Lymphocytes, Tumor-Infiltrating/immunology , Receptors, Antigen, T-Cell, gamma-delta/immunology , T-Lymphocyte Subsets/immunology , Triple Negative Breast Neoplasms/immunology , Adult , Aged , Aged, 80 and over , Case-Control Studies , Cell Line, Tumor , Coculture Techniques , Female , Healthy Volunteers , High-Throughput Nucleotide Sequencing/methods , Humans , Middle Aged , Receptors, Antigen, T-Cell, gamma-delta/genetics , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/pathology , Triple Negative Breast Neoplasms/therapy
10.
Mol Ther ; 28(2): 561-571, 2020 02 05.
Article in English | MEDLINE | ID: mdl-31882320

ABSTRACT

Despite extensive usage of gene therapy medicinal products (GTMPs) in clinical studies and recent approval of chimeric antigen receptor (CAR) T cell therapy, little information has been made available on the precise molecular characterization and possible variations in terms of insert integrity and vector copy numbers of different GTMPs during the complete production chain. Within this context, we characterize αßT cells engineered to express a defined γδT cell engineered to express a defined γδT receptor (TEG) currently used in a first-in-human clinical study (NTR6541). Utilizing targeted locus amplification in combination with next generation sequencing for the vector producer clone and TEG001 products, we report on five single-nucleotide variants and nine intact vector copies integrated in the producer clone. The vector copy number in TEG001 cells was on average a factor 0.72 (SD 0.11) below that of the producer cell clone. All nucleotide variants were transferred to TEG001 without having an effect on cellular proliferation during extensive in vitro culture. Based on an environmental risk assessment of the five nucleotide variants present in the non-coding viral region of the TEG001 insert, there was no altered environmental impact of TEG001 cells. We conclude that TEG001 cells do not have an increased risk for malignant transformation in vivo.


Subject(s)
Genetic Engineering , Genetic Therapy , Genetic Vectors/genetics , Immunotherapy, Adoptive , T-Lymphocytes/immunology , Genetic Therapy/methods , Humans , Immunotherapy, Adoptive/methods , Mutagenesis, Insertional , Mutation , Phenotype , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/metabolism , T-Lymphocytes/metabolism , Transgenes , Untranslated Regions , Virus Integration
11.
Waste Manag ; 67: 298-307, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28511926

ABSTRACT

In Europe, it is estimated that more than 50% of total food waste - of which most is avoidable - is generated at household level. Little attention has been paid to the impact on food waste generation of consuming food products that differ in their method of food preservation. This exploratory study surveyed product-specific possible impacts of different methods of food preservation on food waste generation in Dutch households. To this end, a food waste index was calculated to enable relative comparisons of the amounts of food waste from the same type of foods with different preservation methods on an annual basis. The results show that, for the majority of frozen food equivalents, smaller amounts were wasted compared to their fresh or ambient equivalents. The waste index (WI) proposed in the current paper confirms the hypothesis that it may be possible to reduce the amount of food waste at household level by encouraging Dutch consumers to use (certain) foods more frequently in a frozen form (instead of fresh or ambient). However, before this approach can be scaled to population level, a more detailed understanding of the underlying behavioural causes with regard to food provisioning and handling and possible interactions is required.


Subject(s)
Family Characteristics , Food , Solid Waste , Europe , Frozen Foods , Netherlands
12.
J Acad Nutr Diet ; 115(10): 1614-25, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25769746

ABSTRACT

BACKGROUND: Processed foods are major contributors to excessive sodium intake in Western populations. We investigated the effect of food reformulation on daily dietary sodium intake. OBJECTIVE: To determine whether uninformed consumers accept reduced-sodium lunches and to determine the effect of consuming reduced-sodium lunches on 24-hour urinary sodium excretion. DESIGN: A single-blind randomized controlled pretest-posttest design with two parallel treatment groups was used. PARTICIPANTS/SETTING: Participants chose foods in an experimental real-life canteen setting at the Restaurant of the Future in Wageningen, the Netherlands, from May 16 until July 1, 2011. INTERVENTION: After a run-in period with regular foods for both groups, the intervention group (n=36) consumed foods with 29% to 61% sodium reduction (some were partially flavor compensated). The control group (n=38) continued consuming regular foods. MAIN OUTCOME MEASURES: Outcomes for assessment of acceptance were the amount of foods consumed, energy and sodium intake, remembered food liking, and intensity of sensory aspects. Influence on daily dietary sodium intake was assessed by 24-hour urinary sodium excretion. STATISTICAL ANALYSES PERFORMED: Between and within-subject comparisons were assessed by analysis of covariance. RESULTS: Energy intake and amount consumed of each food category per lunch remained similar for both groups. Compared with the control group, the intervention group's sodium intake per lunch was significantly reduced by -1,093 mg (adjusted difference) (95% CI -1,285 to -901), equivalent to 43 mmol sodium. Remembered food liking, taste intensity, and saltiness were scored similarly for almost all of the reduced-sodium foods compared with the regular foods. After consuming reduced-sodium lunches, compared with the control group, intervention participants' 24-hour urinary sodium excretion was significantly lower by -40 mEq (adjusted difference) (95% CI -63 to -16) than after consuming regular lunches, and this reflects a decreased daily sodium intake of 1 g. CONCLUSIONS: Comparing the two treatment groups, consumption of reduced-sodium foods over a 3-week period was well accepted by the uninformed participants in an experimental real-life canteen setting. The reduced-sodium foods did not trigger compensation behavior during the remainder of the day in the intervention group compared with the control group, as reflected by 24-hour urinary sodium excretion. Therefore, offering reduced-sodium foods without explicitly informing consumers of the sodium reduction can contribute to daily sodium intake reduction.


Subject(s)
Diet , Food Preferences , Sodium, Dietary/administration & dosage , Sodium/urine , Taste , Adolescent , Adult , Choice Behavior , Energy Intake , Female , Humans , Lunch , Male , Netherlands , Single-Blind Method , Young Adult
13.
J Nutr ; 141(12): 2249-55, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22049293

ABSTRACT

Bread is a major contributor to sodium intake in many countries. Reducing the salt (NaCl) content in bread might be an effective way to reduce overall sodium intake. The objectives of this study were to examine the effects of gradually lowering the salt content in brown bread, with and without flavor compensation (KCl and yeast extract), on bread consumption and sodium intake compensation by choice of sandwich fillings. A total of 116 participants (age: 21 ± 3 y; BMI: 22 ± 2 kg/m²) consumed a buffet-style breakfast on weekdays for 4 wk. Participants received either regular bread (control group: n = 39), bread whose salt content was gradually lowered each week by 0, 31, 52, and 67% (reduced group: n = 38), or bread whose salt content was also gradually lowered each week but which was also flavor compensated (compensated group: n = 39). A reduction of up to 52% of salt in bread did not lead to lower consumption of bread compared to the control (P = 0.57), whereas less bread was consumed when salt was reduced by 67% (P = 0.006). When bread was flavor compensated, however, a reduction of 67% did not lead to lower consumption (P = 0.69). Salt reduction in bread (with and without flavor compensation) did not induce sodium intake compensation (P = 0.31). In conclusion, a salt reduction of up to 52% in bread or even up to 67% in flavor-compensated bread neither affected bread consumption nor choice of sandwich fillings.


Subject(s)
Bread/analysis , Choice Behavior , Sodium Chloride, Dietary/administration & dosage , Adolescent , Adult , Diet , Female , Humans , Male , Netherlands , Taste , Young Adult
14.
Eur J Haematol ; 87(5): 419-25, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21732981

ABSTRACT

OBJECTIVES: Invasive mold infections (IMI) are an important cause of morbidity and mortality in patients with hematological malignancies. Cumulative incidence numbers vary greatly, probably because local circumstances influence the incidence of IMI. Therefore, comparison of different patient groups at risk should be performed at one hospital. METHODS: We performed a single-center retrospective analysis examining both adult patients treated with chemotherapy for acute leukemia or MDS and patients undergoing allogeneic or autologous stem cell transplantation (SCT) between June 2007 and August 2009. IMI were classified according to the EORTC criteria. RESULTS: A total of 211 patients with 237 predefined risk episodes were analyzed. A total of 22 IMI were observed: three of them were classified as proven, 15 as probable, and four as possible. No IMI were observed in the autologous SCT group. The incidence of proven and probable IMI in the allogeneic SCT group was 7.2%, and in the chemotherapy group, 14.3%. Patients with IMI had a higher mortality risk. CONCLUSIONS: We demonstrate for the first time that patients receiving intensive chemotherapy for acute leukemia have the highest risk of developing IMI during their treatment compared to patients with allogeneic SCT.


Subject(s)
Leukemia/drug therapy , Mycoses/epidemiology , Stem Cell Transplantation , Adolescent , Adult , Aged , Female , Humans , Leukemia/complications , Male , Middle Aged , Mycoses/complications , Retrospective Studies , Young Adult
15.
Physiol Behav ; 104(3): 423-8, 2011 Sep 01.
Article in English | MEDLINE | ID: mdl-21570419

ABSTRACT

Here we review the role of oral movements in the perception of food attributes, particularly for semi-solid and liquid foods ingested almost in ready-to-swallow form. An overview of a series of instrumental and sensory studies suggests clear links between the type of sensation and the time point of processing in the mouth. Some commonly-reported sensations, such as thickness, are relatively immediate and reflect the bulk properties of food bolus when the food is relatively intact. Others, such as fattiness and melting, reflect both bulk and surface properties and follow considerable oral processing when the food is relatively degraded. Yet others, such as fatty after-feel, are only fully developed after swallowing is complete. In addition, oral processing also plays an important role in the generation of aroma and taste sensations. Most of these in prior vivo studies have now been confirmed by in vitro work using a modified rheometer, dubbed the Structure Breakdown Cell (SBC), wherein the mechanical and enzymatic break-down of food can be monitored directly and related to sensory profiles generated by trained panelists.


Subject(s)
Food , Mouth , Movement/physiology , Perception/physiology , Sensation/physiology , Touch/physiology , Humans , Taste/physiology
16.
N Engl J Med ; 356(19): 1957-65, 2007 May 10.
Article in English | MEDLINE | ID: mdl-17494928

ABSTRACT

BACKGROUND: In 2002, an act regulating the ending of life by a physician at the request of a patient with unbearable suffering came into effect in the Netherlands. In 2005, we performed a follow-up study of euthanasia, physician-assisted suicide, and other end-of-life practices. METHODS: We mailed questionnaires to physicians attending 6860 deaths that were identified from death certificates. The response rate was 77.8%. RESULTS: In 2005, of all deaths in the Netherlands, 1.7% were the result of euthanasia and 0.1% were the result of physician-assisted suicide. These percentages were significantly lower than those in 2001, when 2.6% of all deaths resulted from euthanasia and 0.2% from assisted suicide. Of all deaths, 0.4% were the result of the ending of life without an explicit request by the patient. Continuous deep sedation was used in conjunction with possible hastening of death in 7.1% of all deaths in 2005, significantly increased from 5.6% in 2001. In 73.9% of all cases of euthanasia or assisted suicide in 2005, life was ended with the use of neuromuscular relaxants or barbiturates; opioids were used in 16.2% of cases. In 2005, 80.2% of all cases of euthanasia or assisted suicide were reported. Physicians were most likely to report their end-of-life practices if they considered them to be an act of euthanasia or assisted suicide, which was rarely true when opioids were used. CONCLUSIONS: The Dutch Euthanasia Act was followed by a modest decrease in the rates of euthanasia and physician-assisted suicide. The decrease may have resulted from the increased application of other end-of-life care interventions, such as palliative sedation.


Subject(s)
Euthanasia/trends , Suicide, Assisted/trends , Aged , Aged, 80 and over , Analgesics, Opioid/administration & dosage , Cause of Death , Euthanasia/legislation & jurisprudence , Euthanasia/statistics & numerical data , Female , Follow-Up Studies , Humans , Hypnotics and Sedatives/administration & dosage , Male , Middle Aged , Netherlands , Suicide, Assisted/legislation & jurisprudence , Suicide, Assisted/statistics & numerical data , Surveys and Questionnaires , Withholding Treatment/statistics & numerical data , Withholding Treatment/trends
17.
Med Law ; 24(3): 575-83, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16229392

ABSTRACT

In the last 25 years almost every West European country has enacted a transplantation law. During the preparation of these laws an important issue was whether to base the transplantation law on explicit or presumed consent regarding organ donation post-mortem. A common view of supporters of the presumed consent system is that it will result in more organ donors than the rule of explicit consent. In this article the difference between the different systems is further explored. For that purpose, the systems for post mortem donation in 10 West European countries will be discussed. Focus will be on the legal role of relatives within the consent process and finally on the role of relatives in practice. It will be argued that the difference between the two types of systems is less important than it seems to be at first sight.


Subject(s)
Presumed Consent , Third-Party Consent , Tissue and Organ Procurement/legislation & jurisprudence , Death , Europe , Family , Humans , Transplants
18.
Physiol Behav ; 86(1-2): 111-7, 2005 Sep 15.
Article in English | MEDLINE | ID: mdl-16112152

ABSTRACT

Practically all foods contain particles. It has been suggested that the presence of particles in food may affect the perception of sensory attributes. In the present study we investigated the effect of size and type (hardness and shape) of particles added to a CMC based vanilla custard dessert. The two types of particles included in the study were silica dioxide and polystyrene spheres, varying in size from 2 to 230 microm. Eighteen trained adults participated in the study. They rated the sensation of 17 sensory flavour and texture attributes on a 100-point visual analogue scale (VAS). The results indicate that the addition of particles increased the sensation of roughness attributes and decreased the ratings of a number of presumably favorable texture attributes (smoothness, creamy, fatty and slippery) significantly. These effects increased with increasing particle size up to 80 microm. Roughness ratings deceased for larger particles sizes. Surprisingly, even particles of 2 microm had significant effects: they increased perceived rough lip-tooth feel, and decreased slippery lip-tooth feel and smoothness of the product. The affected attributes had previously been related to lubricative properties of foods. Particles added to semi-solid foods with relatively low levels of fat seem to counteract the lubricating effects of the fat resulting in increased oral friction. In a separate study on size perception the silica dioxide particles were used. By sampling the stimuli between the tongue and palate, subjects rated the size of the particles on a 100-point scale in comparison to anchor stimuli containing no particles and particles of 250 microm. The perceived particle size significantly increased for larger particles. Furthermore, perceived particle size was negatively correlated with roughness ratings. Thus, subjects who were sensitive and perceived the particles as being relatively large reported the same stimuli to have less rough after-feel. In conclusion, particles added to a product induce large effects on texture sensations, and texture sensation is related to individual size perception.


Subject(s)
Sensation/physiology , Size Perception/physiology , Stereognosis/physiology , Taste/physiology , Adult , Female , Humans , Male , Odorants , Pain Measurement , Particle Size , Polystyrenes , Silicon Dioxide , Statistics as Topic
20.
Appetite ; 41(3): 273-81, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14637326

ABSTRACT

This study examined the effect of oral and product temperature on the perception of texture and flavor attributes. A trained panel assessed 21 texture and flavor attributes in one high-fat and one low-fat product of two semi-solids: custard dessert and mayonnaise. The products were evaluated at 10, 22 or 35 degrees C in combination with oral temperatures of 27, 35 and 43 degrees C. Results showed that modulation of product and oral temperature had significant effects on a number of attributes. Flavor intensities, melting mouth feel, and fat after feel increased, while subjective thickness decreased with increasing product temperature. Neither product- nor oral temperature had an effect on over-all creaminess. Oral temperature affected a number of mouth feel attributes: melting, heterogeneous and smooth. Furthermore, large differences existed in ratings between the high- and low-fat products of custard and mayonnaise, and they were more prominent in mayonnaise. We conclude that the effect of oral temperature on the perception of sensory attributes in semi-solids was small, but present, while the product temperatures influenced the ratings greatly.


Subject(s)
Food Technology , Mouth/physiology , Stereognosis/physiology , Taste , Thermosensing/physiology , Adolescent , Adult , Body Temperature/physiology , Dietary Fats , Female , Humans , Male , Temperature , Viscosity
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