Investigating oral somatosensory perception and oral symptoms of head and neck cancer patients: insights on eating behaviour

PURPOSE

Sensory alterations and oral manifestations are prevalent among head and neck cancer (HNC) patients. While taste and smell alterations have been thoroughly investigated, studies on their oral somatosensory perception remain limited. Building upon our previous publication that primarily focused on objective somatosensory measurements, the present work examined self-reported sensory perception, including somatosensation and oral symptoms, in HNC patients and evaluated their link with eating behaviour.

METHODS

A cross-sectional study was conducted using self-reported questionnaires on sensory perception, oral symptoms, sensory-related food preference, and eating behaviour among HNC patients (n = 30). Hierarchical clustering analysis was performed to categorise patients based on their sensory perception. Correlations between oral symptoms score, sensory perception, sensory-related food preference, and eating behaviour were explored.

RESULTS

Two distinct sensory profiles of patients were identified: no alteration (n = 14) and alteration (n = 16) group. The alteration group showed decreased preference towards several sensory modalities, especially the somatosensory. Concerning eating behaviour, more patients in the alteration group agreed to negatively connotated statements (e.g. having food aversion and eating smaller portions), demonstrating greater eating difficulties. In addition, several oral symptoms related to salivary dysfunction were reported. These oral symptoms were correlated with sensory perception, sensory-related food preference, and eating behaviour.

CONCLUSION

This study presented evidence demonstrating that sensory alterations in HNC patients are not limited to taste and smell but cover somatosensory perception and are linked to various aspects of eating. Moreover, patients reported experiencing several oral symptoms. Those with sensory alterations and oral symptoms experienced more eating difficulties.

Carbohydrate Oral Rinsing, Cycling Performance and Individual Complex Carbohydrate Taste Sensitivity

The aim of this pilot study was to determine the effect of individual complex carbohydrate taste sensitivity on cycling performance with complex carbohydrate oral rinsing. Ten male participants completed five cycling time trials in a fasted state with a seven-day washout period between each trial. Participants completed a fixed amount of work (738.45 ± 150.74 kJ) as fast as possible on a cycle ergometer while rinsing with an oral rinse for 10 s every 12.5% of the trial. An oral rinse (maltodextrin, oligofructose, glucose, sucralose or water control) was given per visit in a randomised, crossover, blinded design. Afterwards, participants had their taste assessed with three stimuli, complex carbohydrate (maltodextrin), sweet (glucose) and sour (citric acid), using taste assessment protocol to determine individual taste sensitivity status. Participants were subsequently grouped according to their complex carbohydrate taste sensitivity and complex carbohydrate taste intensity. There were no significant effects of the oral rinses on cycling performance time (p = 0.173). Participants who did not have improvements in exercise performance with the maltodextrin rinse experienced a stronger taste intensity with complex carbohydrate stimuli at baseline (p = 0.047) and overall (p = 0.047) than those who did have improvements in performance. Overall, a carbohydrate oral rinse was ineffective in significantly improving cycling performance in comparison with a water control. However, when participants were grouped according to complex carbohydrate taste intensity, differences in exercise performance suggest that individual sensitivity status to complex carbohydrates could impact the efficacy of a carbohydrate-based oral rinse.

Solid-State Fermented Plant Foods as New Protein Sources

The current animal-based production of protein-rich foods is unsustainable, especially in light of continued population growth. New alternative proteinaceous foods are therefore required. Solid-state fermented plant foods from Africa and Asia include several mold- and Bacillus-fermented foods such as tempeh, sufu, and natto. These fermentations improve the protein digestibility of the plant food materials while also creating unique textures, flavors, and taste sensations. Understanding the nature of these transformations is of crucial interest to inspire the development of new plant-protein foods. In this review, we describe the conversions taking place in the plant food matrix as a result of these solid-state fermentations. We also summarize how these (nonlactic) plant food fermentations can lead to desirable flavor properties, such as kokumi and umami sensations, and improve the protein quality by removing antinutritional factors and producing additional essential amino acids in these foods. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 15 is April 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Oral somatosensory alterations and salivary dysfunction in head and neck cancer patients

PURPOSE

Patients with head and neck cancer (HNC) are at high risk of malnutrition due to eating difficulties partly mediated by sensory alterations and salivary dysfunction. Clinical studies have mostly focused on taste and smell alterations, while changes in oral somatosensory perception are largely understudied. The study aimed to investigate oral somatosensory (tactile, texture, chemesthetic, and thermal) responses and salivary functions of HNC patients in comparison to healthy controls.

METHODS

A cross-sectional study was conducted using psychophysical tests in HNC patients (n = 30) and in age- and gender-matched control subjects (n = 30). The tests included measurements of point-pressure tactile sensitivity, whole-mouth chemesthetic stimulation, food texture discrimination, and temperature discrimination. Salivary functions, including hydration, saliva consistency, pH, volume, and buffering capacity, were also evaluated.

RESULTS

HNC patients demonstrated significantly lower chemesthetic sensitivity (for medium and high concentrations, p < 0.05), thermal sensitivity (p = 0.038), and salivary functions (p = 0.001). There were indications of lower tactile sensitivity in the patient group (p = 0.101). Patients were also less sensitive to differences in food roughness (p = 0.003) and firmness (p = 0.025).

CONCLUSION

This study provided evidence that sensory alterations in HNC patients extend beyond their taste and smell. The measurements demonstrated lower somatosensory responses, in part associated with their reduced salivary function. Oral somatosensory alterations and salivary dysfunction may consequently impart the eating experience of HNC patients. Thus, further investigations on food adjustments for this patient group seem warranted.

Layered food designs to create appetizing desserts: A proof-of-concept study

Creating layers in foods is a culinary technique commonly used to diversify sensory experiences, but it has not been reported scientifically on its effect on hedonic and appetitive responses. This study aimed to investigate the use of dynamic sensory contrasts in layered foods to stimulate liking and appetite, using lemon mousse as a model. A sensory panel evaluated the perceived sour taste intensity of lemon mousses acidified by various amounts of citric acid. Bilayer lemon mousses with unequal distribution of citric acid across the layers to deliver higher levels of intraoral sensory contrast were developed and evaluated. A consumer panel evaluated the liking and desire to eat lemon mousses (n = 66), and a selection of samples was further investigated in an ad libitum food intake setting (n = 30). In the consumer study, bilayer lemon mousses with a layer of low acidity (0.35% citric acid w/w) on top and higher acidity (1.58 or 2.8% citric acid w/w) at the bottom showed consistently higher liking and desire scores than their corresponding counterparts with identical acid levels equally distributed in a monolayer. In the ad libitum setting, the bilayer mousse (top: 0.35; bottom: 1.58% citric acid w/w) had a significant 13% increase in intake compared to its monolayer counterpart. Modulating sensory properties across food layers with different configurations and layer compositions can be further explored as a tool to design appetizing foods for consumers at risk of undernutrition.

Health versus environmental benefits: Does additional information influence consumer acceptance of pulse-based spreads?

Despite the known health benefits and the potential for substituting less environmentally sustainable consumed foods such as meat, the current intake of pulses in developed countries remains less than recommended. Barriers are related to sensory characteristics and lack of knowledge about preparation, while drivers of environmental benefits are intangible. The aim of this study was to investigate the effect of additional information about health or environmental benefits of pulses on the acceptance of novel pulse-based products from chickpeas, black beans, and faba beans. Perceptions of these pulse-based spreads in a blind and informed stage were assessed with 202 consumers in urban and suburban areas of Denmark. In general, the familiar chickpea spread followed by the relatively most unfamiliar black bean spread was liked the most. Only for these two products, additional information increased hedonic perception, regardless of the context (health or environmental benefits). If consumers did not like the spread, as found for the faba bean spread, providing additional information did not significantly alter this perception. Participants' preferences and willingness to pay (WTP) in a discrete choice experiment corresponded to hedonic scores, whereas providing additional information increased the WTP. These findings suggest that extrinsic cues such as health or environmental benefits may only be useful in products with an acceptable baseline taste profile. Moreover, black beans might be investigated as a promising source for further product development due to their acceptance by consumers besides being the comparably most unfamiliar pulse type.

A review on children's oral texture perception and preferences in foods

Texture properties of foods are particular drivers for food acceptance and rejection in children. The texture preferences follow the developmental progression of the child and these changes modulate the present and future food habits. This paper reviews the development and factors influencing texture preferences in children and the methods in food texture research with children. The child's acceptance of more complex food textures is age-dependent. The progression is indorsed by the development of oral processing skills at an early age and bolstered by repeated exposures to foods with varying textures. Children generally reject foods containing pieces or bits (i.e., geometrical textural properties); however, the impact of mechanical textural properties on food acceptance is less clear. Child characteristics such as food neophobia, picky eating, and tactile over-responsivity, negatively affect the acceptance of more diverse food textures. Depending on the child's age, the prevailing methods of characterizing food texture preferences in children include observational techniques and self-reported questionnaires. Despite knowledge of children's development of masticatory skills, learning, and cognitive abilities, the relationships of these changes to food texture acceptance and the recommended test methodology for evaluating product texture acceptance in this period of life are still limited.

Effect of processing and microstructural properties of chickpea-flours on in vitro digestion and appetite sensations

Nowadays, pulse flours are ingredients that are more and more used as substitutes in traditional staples (i.e., pasta, bread). In this study, cellular chickpea-flour was used as an ingredient to replace conventional raw-milled chickpea-flour in suspensions and semi-solid purees. The contribution of cellular integrity on in vitro macronutrient digestion and the subsequent effect on in vivo appetite sensations were investigated. Alternating the flour preparation sequence by interchanging hydrothermal treatment and mechanical disintegration (thermo-mechanical treatment) resulted in three chickpea-flours with distinct levels of cellular integrity, and thus nutrient accessibility. The study showed that cellular integrity in chickpea-flours was preserved upon secondary hydrothermal treatment and led to significant attenuation of in vitro macronutrient digestion as compared to conventional chickpea-flour. In a randomized crossover design, significant increase of mean in vivo subjective appetite sensations satiety and fullness along with decreases in hunger, desire to eat, and prospective food consumption were achieved when cellular integrity was kept without an effect on palatability and appearance of the purees (n = 22). In vitro digestion along with microstructural assessment confirmed the importance of cellular integrity for attenuating macronutrient digestion and thereby contributing to enhanced subjective satiety and fullness in pulses. Overall, this study highlights the promising potential of altarenating the flour preparation sequence resulting in macronutrient and energy-matched flours with different nutrient encapsulation which lead to different in vitro digestion kinetics and in vivo appetite sensations.

Maltodextrin-Based Carbohydrate Oral Rinsing and Exercise Performance: Systematic Review and Meta-Analysis

Background

Carbohydrates are an important fuel for optimal exercise performance during moderate- and high-intensity exercise; however, carbohydrate ingestion during high-intensity exercise may cause gastrointestinal upset. A carbohydrate oral rinse is an alternative method to improve exercise performance in moderate- to high-intensity exercise with a duration of 30–75 min. This is the first systematic review and meta-analysis to comprehensively examine the isolated effect of maltodextrin-based rinsing on exercise performance.

Objective

The objective of this review was to establish the effect of a maltodextrin-based carbohydrate oral rinse on exercise performance across various modes of exercise. Furthermore, a secondary objective was to determine the effects of moderators [(1) participant characteristics; (2) oral rinse protocols; (3) exercise protocol (i.e. cycling, running etc.) and (4) fasting] on exercise performance while using a maltodextrin-based, carbohydrate oral rinse.

Methods

Five databases (MEDLINE, PsycINFO, Embase, SPORTDiscus and Global Health) were systematically searched for articles up to March 2021 and screened using Covidence (a systematic review management tool). A random effects robust meta-analysis and subgroup analyses were performed using Stata Statistical Software: Release 16.

Results

Thirty-five articles met the inclusion criteria and were included in the systematic review; 34 of these articles were included in the meta-analysis. When using a conventional meta-analytic approach, overall, a carbohydrate oral rinse improved exercise performance in comparison with a placebo (SMD = 0.15, 95% CI 0.04, 0.27; p = 0.01). Furthermore, when implementing an adjusted, conservative, random effects meta-regression model using robust variance estimation, overall, compared with placebo, a carbohydrate oral rinse demonstrated evidence of improving exercise performance with a small effect size (SMD = 0.17, 95% CI − 0.01, 0.34; p = 0.051).

Conclusion

This systematic review and meta-analysis demonstrates that a maltodextrin-based carbohydrate oral rinse can improve exercise performance. When comparing the two meta-analytic approaches, although non-significant, the more robust, adjusted, random effects meta-regression model demonstrated some evidence of a maltodextrin-based carbohydrate oral rinse improving exercise performance overall.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40279-022-01658-3.

Perceptions and Attitudes about Eating with the Fingers-An Explorative Study among Older Adults with Motoric Eating Difficulties, Relatives and Professional Caregivers

Difficulties of managing cutlery, manipulating food on the plate and transporting food to the mouth may negatively influence the ability for self-provision and nutritional status among older adults with motoric eating difficulties. The purpose was to explore perceptions and attitudes about eating with the fingers among older adults with motoric eating difficulties, and relatives and professional caregivers of older adults with motoric eating difficulties. Qualitative data was collected through individual interviews with older adults >65 years (N = 14) with motoric eating difficulties and focus groups with relatives (N = 15) and professional caregivers (N = 15). Data was analyzed using deductive and inductive content analysis. Although the older adults had normative ideas about proper eating and culinary rules, they regularly consumed several foods with their fingers without previously reflecting upon this. Using bread to grip or wrap foods and inserting skewers into foods may increase the acceptability of eating with the fingers. However, the importance of the disease causing the eating difficulties, how it was perceived, and its severity were crucial in understanding how eating with the fingers was perceived. Finger foods may be suitable for older adults with major eating difficulties because they have developed a self-acceptance in relation to their condition over time.

Flavor Characterization of Animal Hydrolysates and Potential of Glucosamine in Flavor Modulation

Bovine (meat and heart) and porcine (hemoglobin and plasma) raw materials were hydrolyzed by Protease A (both endo- and exopeptidase activity), with or without glucosamine added during the enzyme inactivation step. Hydrolysates were characterized via peptide analysis (yield, UV- and fluorescence scanning spectroscopy, and peptide size distribution via size exclusion chromatography), sensory evaluation, and volatile compound analysis via gas chromatography mass-spectrometry (GC-MS) to determine if glucosamine-induced Maillard reaction improved taste and flavor. Porcine hemoglobin produced the most flavor-neutral hydrolysate, and could expectedly have the broadest application in food products. Both bovine meat and -heart hydrolysates were high in umami, and thereby good candidates for savory applications. Porcine plasma hydrolysate was high in liver flavor and would be suitable for addition to certain meat products where liver flavor is desirable. All hydrolysates had low perceived bitterness. Glucosamine-induced Maillard reaction had just a minor influence on the sensory profile via an increased perception of sweet taste (p = 0.038), umami taste (p = 0.042), and yolk flavor (p = 0.038) in the hydrolysates, irrespective of raw material. Glucosamine addition had a statistically significant effect on 13 of 69 volatiles detected in the hydrolysates, but the effect was minor and raw material-specific.

Flavour stability of sterilised chickpeas stored in pouches

The increasing need for sustainable food choices places a demand on developing palatable foods from lower impact production and with a suitable shelf-life. In this context, knowledge of the sensory properties of whole sterilised chickpeas is required to be able to make them more attractive to the consumers. The sensory quality of chickpeas is largely dependent on the aroma and flavour, which can be influenced by storage conditions. In this study, sterilised chickpeas in two different packaging materials with different oxygen permeabilities, stored up to 52 weeks at ambient temperature (20 °C) were investigated using both descriptive sensory profiling and gas chromatography – mass spectrometry – olfactometry analysis (GC-MS-O). During storage, intense, sulphury and meat-like aromas decreased in intensity, while with longer storage time hay-like, green-like and potato-like flavours and aromas became more apparent. A total of 40 odour-active volatiles were detected, of which some had properties reminiscent of the chickpea flavour profiles. However, no clear relationships could be established between these odorants and the sensory changes observed during storage by descriptive sensory analysis. It was concluded that, significant changes in the sensory attributes of sterilised chickpeas occurred during 52 weeks of storage, but that packaging material does not seem to largely influence the sensory attributes during storage.

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Significant sensory changes occur in sterilised chickpeas during 52 weeks storage.

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40 odour-active volatiles are detected in the sterilised chickpeas.

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Sulphur compounds formed during sterilisation change during storage.

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Hay and green attributes are perceived more intense with increased storage time.

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Oxygen permeability of packaging does not impact the sensory quality during storage.

Does FGF21 Mediate the Potential Decrease in Sweet Food Intake and Preference Following Bariatric Surgery?

The liver-derived hormone fibroblast growth factor 21 (FGF21) has recently been linked to preference for sweet-tasting food. We hypothesized, that surgery-induced changes in FGF21 could mediate the reduction in sweet food intake and preference following bariatric surgery. Forty participants (35 females) with severe obesity (BMI ≥ 35 kg/m²) scheduled for roux-en-y gastric bypass (n = 30) or sleeve gastrectomy (n = 10) were included. Pre- and postprandial responses of intact plasma FGF21 as well as intake of sweet-tasting food assessed at a buffet meal test, the hedonic evaluation of sweet taste assessed using an apple juice with added sucrose and visual analog scales, and sweet taste sensitivity were assessed before and 6 months after bariatric surgery. In a cross-sectional analysis pre-surgery, pre- and postprandial intact FGF21 levels were negatively associated with the hedonic evaluation of a high-sucrose juice sample (p = 0.03 and p = 0.02). However, no changes in pre- (p = 0.24) or postprandial intact FGF21 levels were found 6 months after surgery (p = 0.11), and individual pre- to postoperative changes in pre- and postprandial intact FGF21 levels were not found to be associated with changes in intake of sweet foods, the hedonic evaluation of sweet taste or sweet taste sensitivity (all p ≥ 0.10). In conclusion, we were not able to show an effect of bariatric surgery on circulating FGF21, and individual postoperative changes in FGF21 were not found to mediate an effect of surgery on sweet food intake and preference.

3D printing of a high protein yoghurt-based gel: Effect of protein enrichment and gelatine on physical and sensory properties

The potential application of 3D printing technology in creating protein-rich desserts with multisensory design was investigated. Yoghurt-gel inks were formulated by varying the concentration of gelatine and whey protein isolate (WPI). Assessment of rheological and textural properties prior to printing, showed that an increase of gelatine concentration from 7.5 to 12.5% w/w increased the yield stress, storage modulus, loss modulus, firmness, and resilience of yoghurt gels. Addition of 12% WPI reduced these effects; creating softer gels with reduced resilience. However, these gels showed stable shape after printing, especially in formulations with higher gelatine concentrations. The changes in textural properties caused by the extrusion process need to be considered when designing yoghurt gels, as a significant reduction in firmness and resilience and an increase in adhesiveness were observed after 3D printing. The more stable and well-shaped 3D printed yoghurt gels were obtained by the combined effect of WPI and gelatine which provided a good balance of appearance, taste, flavour, and mouthfeel attributes evaluated by a trained sensory panel. A consumer study performed with thirty healthy adults showed the potential to improve sensory acceptance through the creation of multisensory layered design.

Taste alterations and oral discomfort in patients receiving chemotherapy

PURPOSE

Taste alterations (TA) and oral discomfort in cancer patients are neglected side effects of the disease and treatments. They contribute to poor appetite, decrease food intake and affect quality of life, leading to adverse outcomes such as malnutrition and depression. The study aimed to explore TAs in relation to other oral conditions causing discomfort in cancer patients. Additionally, the correlation between patients' acidity of saliva and experienced TAs and oral discomfort was evaluated.

METHODS

A case study including 100 patients diagnosed with cancer receiving chemotherapy or immunotherapy. Data were collected using two questionnaire forms: the Chemotherapy-induced Taste Alteration Scale (CiTAS) and an additional information questionnaire. Saliva samples were collected for each patient and measured with a pocket pH meter. Data were analysed using descriptive statistics, and comparisons were performed using the Kruskal-Wallis H test, Mann-Whitney U test and Fisher's exact test.

RESULTS

The prevalence of reported TAs was 93%. Patient age, oral discomfort and swallowing difficulty were found to be significant factors for experienced TAs (p < 0.05). No correlation between patients' acidity of saliva and reported TAs and oral discomfort was found.

CONCLUSION

CiTAS proved to be a convenient tool to collect information about TAs in cancer patients. Using the CiTAS tool, a high prevalence (93%) of reported TAs in cancer patients receiving chemo- or immunotherapy was found. CiTAS provides a fast and cheap recognition of symptoms and causes of TAs that can be addressed.

Factors Associated with Favorable Changes in Food Preferences After Bariatric Surgery

PURPOSE

Bariatric surgery may shift food preferences towards less energy-dense foods. Eating behavior is multifactorial, and the mechanisms driving changes in food preferences could be a combination of a physiological response to surgery and social and psychological factors. This exploratory study aimed to identify potential factors explaining the variation in changes in food preferences after bariatric surgery.

MATERIALS AND METHODS

Physiological, social, and psychological data were collected before, 6 weeks or 6 months after surgery. All variables were analyzed in combination using LASSO regression to explain the variation in changes in energy density at an ad libitum buffet meal 6 months after bariatric surgery (n=39).

RESULTS

The following factors explained 69% of the variation in changes in food preferences after surgery and were associated with more favorable changes in food preferences (i.e., a larger decrease in energy density): female gender, increased secretion of glicentin, a larger decrease in the hedonic rating of sweet and fat and a fatty cocoa drink, a lower number of recent life crises, a low degree of social eating pressure, fulfilling the diagnostic criteria for binge eating disorder, less effort needed to obtain preoperative weight loss, a smaller household composition, a lower degree of self-efficacy and a higher degree of depression, nutritional regime competence, and psychosocial risk level.

CONCLUSION

Factors explaining the variation in altered food preferences after bariatric surgery not only include a physiological response to surgery but also social and psychological factors.

Formulation of Heat-Induced Whey Protein Gels for Extrusion-Based 3D Printing

This study investigated the extrusion-based 3D printability of heat-induced whey protein gels as protein rich food inks. In particular, the effects of ionic strength by the addition of NaCl (0-250 mM), protein content (10%, 15%, 20%), fat content (0%, 10%), and partial substitution of whey protein isolate (WPI) with microparticulated whey protein (MWP) or micellar casein isolate (MCI) on printability were assessed. Texture analysis, specifically Young's modulus, rheological measurements including yield stress, and creep-recovery behavior were used to characterize the gels. Modifications of the formulation in terms of ionic strength, increased protein content, and the formation of emulsion gels were insufficient to maintain a continuous extrusion process or shape stability after printing. However, the substitution of WPI with MWP created more viscoeleastic gels with improved printability and shape retention of the 3D cube structure after deposition. The partial replacement of WPI with MCI led to phase separation and 3D-printed cubes that collapsed after deposition. A narrow range of rheological material properties make WPI and MWP emulsion gels promising food inks for extrusion-based 3D printing.

Stabilization of directly acidified protein drinks by single and mixed hydrocolloids-combining particle size, rheology, tribology, and sensory data

BACKGROUND

High methoxyl pectin and carboxymethylcellulose (CMC) can be used as a stabilizer for directly acidified protein drinks (DAPDs). Use of pectin or CMC together with other polysaccharides and their impacts on product's rheological properties and tribological behavior are still largely unknown. This project investigated the impact of pectin and CMC, alone or in combination with guar gum, locust bean gum (LBG), and gellan gum when preparing DAPDs. The particle size distributions, rheological properties, tribological properties, and sensory properties were determined.

RESULTS

Pectin and CMC were dominating in the mixed system with other stabilizers. Increasing the concentration of hydrocolloids resulted in higher viscosity and better lubrication (lower friction coefficient). The sensory viscosity, smoothness, coating, and stickiness intensified as the concentration of hydrocolloids increased. The type and amount of hydrocolloids had a strong effect on the sensorial texture perception, but the flavor perception was only slightly affected.

CONCLUSION

Use of combined stabilizers may contribute to providing an effective viscosity enhancement without affecting the flavor in acidified milk beverages.

Production of Taste Enhancers from Protein Hydrolysates of Porcine Hemoglobin and Meat Using Bacillus amyloliquefaciens γ-Glutamyltranspeptidase

To improve the flavor of hydrolysates from porcine hemoglobin and meat, γ-glutamyltranspeptidase (GGT) from Bacillus amyloliquefaciens was added to catalyze the formation of kokumi γ-glutamyl peptides via a γ-glutamyl transfer reaction. Quantitation of free amino acids and γ-glutamyl dipeptides was carried out in combination with sensory analysis. Sensory perception, especially the thick, complex, continuous, and overall kokumi sensation of both hemoglobin and meat hydrolysates, was greatly enhanced by γ-glutamylation. Due to the higher amount of glutamine present in meat hydrolysates, γ-glutamylated hydrolysates from meat contained higher concentrations of γ-glutamyl dipeptides and showed stronger kokumi sensation than the hemoglobin counterpart without the addition of glutamine. For hydrolysates from both raw materials, extra addition of glutamine (10 and 20 mM) was beneficial for obtaining higher concentrations of γ-glutamyl dipeptides but contributed little to the kokumi sensation. This study revealed that the kokumi sensation of protein hydrolysates could be intensified by a γ-glutamyl transfer reaction, and the enhanced kokumi sensation could be related to the generation of γ-glutamyl peptides.

Bariatric Surgery Leads to Short-Term Effects on Sweet Taste Sensitivity and Hedonic Evaluation of Fatty Food Stimuli

OBJECTIVE

The aim of this study was to investigate the effect of bariatric surgery on sweet taste sensitivity and the hedonic evaluation of sweet, savory, and fatty food stimuli as well as associations with weight loss and food preferences assessed at a buffet meal test.

METHODS

The detection and recognition threshold for sweet taste and the hedonic rating of sweet, savory, and fatty food stimuli were assessed before and after a preoperative diet-induced weight loss and 6 weeks, 6 months, and 18 months after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) (n = 29).

RESULTS

The detection threshold for sweet taste decreased after the diet-induced weight loss and 6 weeks after RYGB (both P ≤ 0.03). The hedonic rating of high-fat food stimuli decreased 6 weeks after RYGB and SG (all P ≤ 0.02). Changes in the hedonic rating of high-fat food stimuli were associated with increased preferences for high-fat foods at the buffet meal (P = 0.03) and tended to be associated with weight loss (P = 0.05). No changes were detected for sweet and savory food stimuli.

CONCLUSIONS

RYGB increased sweet taste sensitivity; however, this effect was already seen after the diet-induced weight-loss. RYGB and SG decreased the hedonic evaluation of high-fat food stimuli, but this effect did not translate into decreased preferences for high-fat food.

Protein hydrolysates of porcine hemoglobin and blood: Peptide characteristics in relation to taste attributes and formation of volatile compounds

The objective of this study was to investigate the impact of endo- and exo-peptidase treatment on certain structural characteristics of peptides and volatile compounds of porcine hemoglobin and whole blood hydrolysates. Porcine hemoglobin and whole blood were hydrolyzed by endo- and exo-peptidases. The presence of exopeptidases reduced the bitterness and altered the volatile profiles of protein hydrolysates. Exopeptidase treatment can release terminal amino acids from peptides, which in turn may contribute to formation of volatile compounds by Maillard reactions. In contrast, endopeptidases conferred a slightly bitter taste and different volatile profiles. For hemoglobin hydrolysates, principal component analysis revealed that proteases were categorized into three groups based on endo- or exo-peptidase activity. Whole blood is a more complex raw material, yet the proteases were still categorized in a similar fashion. This work contributes to understanding structural characteristics responsible for taste and volatile profiles of protein hydrolysates.

Characterization of Roselle calyx from different geographical origins

Roselle (Hibiscus sabdariffa L.) is considered an underexploited food crop with nutritional and large scale processing potential. Roselle can be utilized as a functional food, mainly due to being rich in vitamin C, anthocyanins, other phytochemicals, and natural color. Although Roselle has been widely planted and consumed, little is known about the composition of aroma profiles. In this study, seventeen samples of dried Roselle calyx were collected from eight countries and the aroma profiles were determined by dynamic headspace sampling and GC-MS and GC-olfactometry. Furthermore, total soluble solids, pH, and color L* a* b* were determined, and sugars and acids were measured using ion chromatography. There were significant (p < 0.05) differences in all measured variables in physicochemical properties and non-volatile compounds. A total of 135 volatiles were identified mainly terpenes, aldehydes, esters, furans, and ketones. Thirty-seven odorants were reported as potentially important aroma compounds based on GC-olfactometry. This study provides valuable information for future commercial utilization of Roselle in the food industry.

Sensory-Driven Development of Protein-Enriched Rye Bread and Cream Cheese for the Nutritional Demands of Older Adults

To promote healthy aging and minimize age-related loss of muscle mass and strength, adequate protein intake throughout the day is needed. Developing and commercializing protein-enriched foods holds great potential to help fulfill the nutritional demands of older consumers. However, innovation of appealing protein-enriched products is a challenging task since protein-enrichment often leads to reduced food palatability. In this study, rye bread and cream cheese prototypes fortified by whey protein hydrolysate (WPH), whey protein isolate (WPI), and/or soy protein isolate (SPI) were developed. Both sensory properties and consumer liking of prototypes were evaluated. Results showed that different proteins had various effects on the sensory characters of rye bread and cream cheese. The taste and texture modification strategies had positive effects in counteracting negative sensory changes caused by protein-enrichment. Consumers preferred 7% WPH and 4% WPH + 4% SPI-enriched breads with taste and texture modified. Sour taste and dry texture had considerable effects on consumer liking of rye bread. Addition of WPI and butter enhanced the flavor of cream cheese and increased consumer acceptance. Protein-enrichment doubled the protein content in the most liked prototypes, which have the potential to be incorporated into older consumers' diets and improve their protein intake substantially.

Patient profiling for success after weight loss surgery (GO Bypass study): An interdisciplinary study protocol

Despite substantial research efforts, the mechanisms proposed to explain weight loss after gastric bypass (RYGB) and sleeve gastrectomy (SL) do not explain the large individual variation seen after these treatments. A complex set of factors are involved in the onset and development of obesity and these may also be relevant for the understanding of why success with treatments vary considerably between individuals. This calls for explanatory models that take into account not only biological determinants but also behavioral, affective and contextual factors. In this prospective study, we recruited 47 women and 8 men, aged 25–56 years old, with a BMI of 45.8 ± 7.1 kg/m² from the waiting list for RYGB and SL at Køge hospital, Denmark. Pre-surgery and 1.5, 6 and 18 months after surgery we assessed various endpoints spanning multiple domains. Endpoints were selected on basis of previous studies and include: physiological measures: anthropometrics, vital signs, biochemical measures and appetite hormones, genetics, gut microbiota, appetite sensation, food and taste preferences, neural sensitivity, sensory perception and movement behaviors; psychological measures: general psychiatric symptom-load, depression, eating disorders, ADHD, personality disorder, impulsivity, emotion regulation, attachment pattern, general self-efficacy, alexithymia, internalization of weight bias, addiction, quality of life and trauma; and sociological and anthropological measures: sociodemographic measures, eating behavior, weight control practices and psycho-social factors.

Joining these many endpoints and methodologies from different scientific disciplines and creating a multi-dimensional predictive model has not previously been attempted. Data on the primary endpoint are expected to be published in 2018.

Trial registration

Clinicaltrials. gov ID NCT02070081.

Comparison of rapid descriptive sensory methodologies: Free-Choice Profiling, Flash Profile and modified Flash Profile

Rapid sensory methods have been developed as alternatives to traditional sensory descriptive analysis methods. Among them, Free-Choice Profiling (FCP) and Flash Profile (FP) are two that have been known for many years. The objectives of this work were to compare the rating-based FCP and ranking-based FP method; to evaluate the impact of adding adjustments to FP approach; to investigate the influence of the number of assessors on the outcome of modified FP. To achieve these aims, a conventional descriptive analysis (DA), FCP, FP and a modified version of FP were carried out. Red wines made by different grape maturity and ethanol concentration were used for sensory testing. This study showed that DA provided a more detailed and accurate information on products through a quantitative measure of the intensity of sensory attributes than FCP and FP. However, the panel hours for conducting DA were higher than that for rapid methods, and FP was even able to separate the samples to a higher degree than DA. When comparing FCP and FP, this study showed that the ranking-based FP provided a clearer separation of samples than rating-based FCP, but the latter was an easier task for most assessors. When restricting assessors on their use of attributes in FP, the sample space became clearer and the ranking task was simplified. The FP protocol with restricted attribute sets seems to be a promising approach for efficient screening of sensory properties in wine. When increasing the number of assessors from 10 to 20 for conducting the modified FP, the outcome tended to be slightly more stable, however, one should consider the degree of panel training when deciding the optimal number of assessors for conducting FP.

A Systematic Review of Behavioural Interventions Promoting Healthy Eating among Older People

Because eating habits are inseparably linked with people's physical health, effective behaviour interventions are highly demanded to promote healthy eating among older people. The aim of this systematic review was to identify effective diet interventions for older people and provide useful evidence and direction for further research. Three electronic bibliographic databases-PubMed, Scopus and Web of Science Core Collection were used to conduct a systematic literature search based on fixed inclusion and exclusion criteria. English language peer-reviewed journal articles published between 2011 and 2016 were selected for data extraction and quality assessment. Finally, a total of 16 studies were identified. The studies' duration ranged from three weeks to seven years. The majority of studies were carried out in European countries. Seven studies had a moderate quality while the remaining studies were at a less than moderate level. Three dietary educational interventions and all meal service related interventions reported improvements in older people's dietary variety, nutrition status, or other health-related eating behaviours. Multicomponent dietary interventions mainly contributed to the reduction of risk of chronic disease. The results supported that older people could achieve a better dietary quality if they make diet-related changes by receiving either dietary education or healthier meal service. Further high-quality studies are required to promote healthy eating among older people by taking regional diet patterns, advanced information technology, and nudging strategies into account.

Green Tea Polyphenols Decrease Strecker Aldehydes and Bind to Proteins in Lactose-Hydrolyzed UHT Milk

The effect of epigallocatechin gallate enriched green tea extract (GTE) on flavor, Maillard reactions and protein modifications in lactose-hydrolyzed (LH) ultrahigh temperature (UHT) processed milk was examined during storage at 40 °C for up to 42 days. Addition of GTE inhibited the formation of Strecker aldehydes by up to 95% compared to control milk, and the effect was similar when GTE was added either before or after UHT treatment. Release of free amino acids, caused by proteolysis, during storage was also decreased in GTE-added milk either before or after UHT treatment compared to control milk. Binding of polyphenols to milk proteins was observed in both fresh and stored milk samples. The inhibition of Strecker aldehyde formation by GTE may be explained by two different mechanisms; inhibition of proteolysis during storage by GTE or binding of amino acids and proteins to the GTE polyphenols.

Long-Term Visuo-Gustatory Appetitive and Aversive Conditioning Potentiate Human Visual Evoked Potentials

Human recognition of foods and beverages are often based on visual cues associated with flavors. The dynamics of neurophysiological plasticity related to acquisition of such long-term associations has only recently become the target of investigation. In the present work, the effects of appetitive and aversive visuo-gustatory conditioning were studied with high density EEG-recordings focusing on late components in the visual evoked potentials (VEPs), specifically the N2-P3 waves. Unfamiliar images were paired with either a pleasant or an unpleasant juice and VEPs evoked by the images were compared before and 1 day after the pairings. In electrodes located over posterior visual cortex areas, the following changes were observed after conditioning: the amplitude from the N2-peak to the P3-peak increased and the N2 peak delay was reduced. The percentage increase of N2-to-P3 amplitudes was asymmetrically distributed over the posterior hemispheres despite the fact that the images were bilaterally symmetrical across the two visual hemifields. The percentage increases of N2-to-P3 amplitudes in each experimental subject correlated with the subject's evaluation of positive or negative hedonic valences of the two juices. The results from 118 scalp electrodes gave surface maps of theta power distributions showing increased power over posterior visual areas after the pairings. Source current distributions calculated from swLORETA revealed that visual evoked currents rose as a result of conditioning in five cortical regions-from primary visual areas and into the inferior temporal gyrus (ITG). These learning-induced changes were seen after both appetitive and aversive training while a sham trained control group showed no changes. It is concluded that long-term visuo-gustatory conditioning potentiated the N2-P3 complex, and it is suggested that the changes are regulated by the perceived hedonic valence of the US.

FGF21 Is a Sugar-Induced Hormone Associated with Sweet Intake and Preference in Humans

The liking and selective ingestion of palatable foods-including sweets-is biologically controlled, and dysfunction of this regulation may promote unhealthy eating, obesity, and disease. The hepatokine fibroblast growth factor 21 (FGF21) reduces sweet consumption in rodents and primates, whereas knockout of Fgf21 increases sugar consumption in mice. To investigate the relevance of these findings in humans, we genotyped variants in the FGF21 locus in participants from the Danish Inter99 cohort (n = 6,514) and examined their relationship with a detailed range of food and ingestive behaviors. This revealed statistically significant associations between FGF21 rs838133 and increased consumption of candy, as well as nominal associations with increased alcohol intake and daily smoking. Moreover, in a separate clinical study, plasma FGF21 levels increased acutely after oral sucrose ingestion and were elevated in fasted sweet-disliking individuals. These data suggest the liver may secrete hormones that influence eating behavior.

The influence of feeding crimped kernel maize silage on broiler production, nutrient digestibility and meat quality

Two experiments were carried out in parallel with male Ross 308 broilers over 37 d. An experiment with a total of 736 broilers was performed to study the effect of dietary inclusion of crimped kernel maize silage (CKMS) on broiler production and meat quality. Another study with 32 broilers was carried out from 21 to 25 d to investigate the inclusion of CKMS on nutrient digestibility. In both trials, 4 dietary treatments were used: wheat-based feed (WBF), maize-based feed (MBF), maize-based feed supplemented with 15% CKMS (CKMS-15) and maize-based feed supplemented with 30% CKMS (CKMS-30). Compared with MBF, the dry matter (DM) intakes of broilers receiving CKMS-15 and CKMS-30, respectively, were numerically 7.5 and 6.2% higher and feed conversion ratio 6 and 12% poorer (significant for 30% CKMS), although there were no significant differences in AME content between the three diets. At 37 d, the body weight of birds receiving 15% CKMS was similar to birds fed with MBF. However, the inclusion of 30% CKMS decreased broiler growth. Dietary supplementation with CKMS significantly reduced the apparent digestibility of phosphorus. The fat digestibility was significantly lower for CKMS-30 than for the other three diets. Broiler mortality decreased significantly when CKMS was added to the diet. The consumption of drinking water was significantly lower in all maize-based diets as compared to WBF and was lowest in broilers fed with CKMS-30. An improved litter quality in terms of DM content and a lower frequency of foot pad lesions was observed with broilers supplemented with both dietary levels of CKMS. The addition of CKMS to maize-based diets increased juiciness, tenderness and crumbliness of the meat. In conclusion, the dietary supplementation of 15% CKMS had no negative effect on broiler growth and positively influenced bird welfare in terms of mortality and foot pad health. Therefore, the addition of 15% CKMS to maize-based diets is considered an advantageous feeding strategy in broiler production.

Influence of serving temperature on flavour perception and release of Bourbon Caturra coffee

The present study aimed to investigate coffee flavour perception and release as function of serving temperature to support standardisation in the specialty coffee branch. The coffee cultivar Bourbon Caturra was evaluated at six serving temperatures ranging from 31°C to 62°C. Coffee samples were analysed by dynamic headspace sampling gas chromatography-mass spectrometry and descriptive analyses using sip-and-spit tasting. The release of volatiles followed mostly the van't Hoff principle and was exuberated at temperatures above 40°C. Aliphatic ketones, alkylpyrazines, some furans and pyridines increased most notably at temperatures ⩾50°C. The changes in volatile release profiles could explain some of the sensory differences observed. The flavour notes of 'sour', 'tobacco' and 'sweet' were mostly associated with the coffees served at 31-44°C, whereas coffees served between 50°C and 62°C exhibited stronger 'overall intensity', 'roasted' flavour and 'bitter' notes.

Sensory quality of drinking water produced by reverse osmosis membrane filtration followed by remineralisation

Membrane filtration of ground, surface, or sea water by reverse osmosis results in permeate, which is almost free from minerals. Minerals may be added afterwards, not only to comply with (legal) standards and to enhance chemical stability, but also to improve the taste of drinking water made from permeate. Both the nature and the concentrations of added minerals affect the taste of the water and in turn its acceptance by consumers. The aim of this study was to examine differences in taste between various remineralised drinking waters. Samples selected varied in mineral composition, i.e. tap water, permeate, and permeate with added minerals (40 or 120 mg Ca/L, added as CaCO3, and 4 or 24 mg Mg/L added as MgCl2), as well as commercially available bottled drinking waters, to span a relevant product space in which the remineralised samples could be compared. All samples were analysed with respect to their physical-chemical properties. Sensory profiling was done by descriptive analysis using a trained panel. Significant attributes included taste intensity, the tastes bitter, sweet, salt, metal, fresh and dry mouthfeel, bitter and metal aftertaste, and rough afterfeel. Total dissolved solids (TDS) was a major determinant of the taste perception of water. In general, lowering mineral content in drinking water in the range examined (from <5 to 440 mg/L) shifted the sensory perception of water from fresh towards bitter, dry, and rough sensations. In addition, perceived freshness of the waters correlated positively with calcium concentration. The greatest fresh taste was found for water with a TDS between 190 and 350 mg/L. Remineralisation of water after reverse osmosis can improve drinking quality significantly.

A comparative study of beef quality after ageing longissimus muscle using a dry ageing bag, traditional dry ageing or vacuum package ageing

The objective of this study was to investigate beef quality of longissimus muscle after ageing in dry ageing bags, traditional dry ageing or vacuum for 8 or 19 days. Lower ageing weight loss, odour score and microbial growth were found in meat aged in dry ageing bags than after traditional dry ageing. The sensory panel detected no differences for most of the sensory attributes between samples using the two dry ageing methods, except for the odour of the cutting surface. The dry-aged steaks had more umami and butter fried meat taste compared with vacuum-aged steaks. Ageing time affected most of the sensory traits in this study, which improved as ageing time increased from 8 to 19 days. In a consumer test, meat aged for 21 days in dry ageing bags was preferred than the samples aged in vacuum. This may be due to the higher tenderness and juiciness obtained during storage in dry ageing bags than meat aged in vacuum.

Quinine sensitivity influences the acceptance of sea-buckthorn and grapefruit juices in 9- to 11-year-old children

The acceptance of novel foods by children is related to a number of factors, and differences in taste sensitivity may form some specific challenges. High sensitivity might be a barrier to the acceptance of sour/bitter products by children. This study investigated the effect of sensitivity to bitter, sour, sweet, and salty tastes on the acceptance of Nordic juices in 9- to 11-year-old children. A total of 328 children were subjected to two taste sensitivity tests for quinine, citric acid, sucrose, and NaCl. Their acceptance of six juices (carrot, rosehip, sea-buckthorn, lingonberry, grapefruit, and aronia) was measured. Bitter sensitivity was found to be significantly correlated to the intake of the sweet sea-buckthorn and lingonberry juices; the most bitter-sensitive children exhibited the highest intake of these juices. The opposite relationship was found for bitter sensitivity and the intake of the bitter grapefruit juice. Sour, sweet, and salt sensitivities did not affect the intake of any of the juices. Liking scores were not affected by sensitivity. In conclusion, bitter sensitivity appears to influence food intake in children to a greater extent than sour, sweet, or salt sensitivity. Bitter-sensitive children exhibited a reduced intake of grapefruit juice and a higher intake of sucrose-sweetened juices. Thus, bitter sensitivity might be a challenge in the acceptance of certain bitter foods.

Physicochemical and sensory characterization of Cheddar cheese with variable NaCl levels and equal moisture content

The present study investigated the effect of salt (NaCl) on the flavor and texture of Cheddar cheese with the particular aim to elucidate consequences of, and strategies for, reducing the salt concentration. Descriptive sensory analysis and physicochemical mapping of 9-mo-old Cheddar cheeses containing 0.9, 1.3, 1.7, and 2.3% salt and an equal level of moisture (37.6 ± 0.1%) were undertaken. Moisture regulation during manufacture resulted in slightly higher calcium retention (158 to 169 mmol/kg) with decreasing NaCl concentration. Lactose was depleted only at 0.9 and 1.3% salt, resulting in concomitantly higher levels of lactate. Lower levels of casein components and free amino acids were observed with decreasing NaCl concentration, whereas levels of pH 4.6-soluble peptides were higher. Key taste-active compounds, including small hydrophobic peptides, lactose, lactate, and free amino acids, covaried positively with bitter, sweet, sour, and umami flavor intensities, respectively. An additional direct effect of salt due to taste-taste enhancement and suppression was noted. Sensory flavor profiles spanned a principal component dimension of palatability projecting true flavor compensation of salt into the space between cheeses containing 1.7 and 2.3% salt. This space was characterized by salt, umami, sweet, and a range of sapid flavors, and was contrasted by bitter and other off-flavors. Rheological and sensory measurements of texture were highly correlated. Cheeses made with 2.3% salt had a longer and slightly softer texture than cheeses containing 0.9, 1.3, and 1.7% salt, which all shared similar textural properties. Moisture regulation contributed to restoring the textural properties upon a 50% reduction in salt, but other factors were also important. On the other hand, significant flavor deterioration occurred inevitably. We discuss the potential of engineering a favorable basic taste profile to restore full palatability of Cheddar with a 50% reduction in salt.

Acceptance of Nordic snack bars in children aged 8-11 years

Background

A health promoting diet is suggested to be tailored to regional circumstances to preserve the cultural diversity in eating habits, as well as contribute to more environmentally friendly eating. It may influence consumer acceptance, however, if the components of the diet differs considerably from their habitual food.

Objective

This study aimed to investigate whether snack bars composed of Nordic ingredients were accepted by 8–11 year-old Danish (n=134) and Swedish (n=109) children.

Design

A seven-point hedonic scale was used to measure the children's acceptance of five snack bars that varied in their composition of whole grains, berries and nuts. A preference rank ordering of the five bars was also performed.

Results

The results showed that samples that were rated highest in liking and were most preferred in both countries were a kamut/pumpkin bar and an oat/cranberry bar. The sample with the lowest rating that was also least preferred was a pumpernickel/sea buckthorn bar. Flavour was the most important determinant of overall liking followed by texture, odour and appearance.

Conclusions

Children's acceptances and preferences were highly influenced by the sensory characteristics of the bars, mainly flavour. In agreement with earlier studies, the novel food ingredients seemed to influence children's preferences. The Nordic snack bars may have a potential to be a snack option for Danish and Swedish school children, but repeated exposures to the products are recommended to increase children's acceptance.

Effects of repeated exposure on acceptance of initially disliked and liked Nordic snack bars in 9-11 year-old children

BACKGROUND & AIMS

Children's food choices are guided by their preferences. It is established, however, that repeated exposure to a novel food increases children's acceptance. This study investigated how acceptance of an initially liked and disliked snack bar develops in 9-11 year-old children.

METHODS

315 children were randomised into three groups: A control group (n = 111) and two groups exposed to an initially liked kamut bar (n = 94) and an initially disliked sea buckthorn bar (n = 110). Acceptance of both bars was tested before and after the exposure period, and on the 9th exposure.

RESULTS

Intake of both bars increased significantly in the exposure groups. There was no difference in the control groups' intake or liking of the bars between pre and post-testing. Liking rose significantly for children exposed to the disliked sea buckthorn bar, while this was not observed in children exposed to the liked kamut bar. In a post-test children exposed to kamut bars had higher intake of that bar than non-exposed children. This was also observed for the sea buckthorn bar that was also given significantly higher liking scores by the exposure group.

CONCLUSIONS

The majority of children exposed to an initially disliked bar increase acceptance after nine exposures to the same level as an initially liked bar. Children repeatedly exposed to a liked bar show stable acceptance.

Flavour development in pork. Influence of flavour precursor concentrations in longissimus dorsi from pigs with different raw meat qualities

Flavour development and overall eating quality of pan-fried pork chops of longissimus dorsi from eight different raw meat qualities aged for 4 and 15 days were assessed by a trained sensory panel. The raw meat qualities were obtained through combinations of strategic feeding/fasting (control vs. low glycogen concentration), slaughter live-weight (84kg vs. 110kg), and gender (female vs. castrate). The flavour development was investigated for possible correlation with the concentrations of selected individual flavour precursors present in the raw meat: monosaccharides, IMP and degradation products, fatty acids, lactate and thiamine. Differences in precursor concentrations between the raw meat qualities were observed with feeding/fasting and ageing as the main factors with the largest influence of all experimental factors. However, the concentrations of the precursors could not explain the differences in sensory perception of the pan-fried pork chops. Overall, the differences were small.

Differential transfer of dietary flavour compounds into human breast milk

Transfer of dietary flavour compounds into human milk is believed to constitute the infant's early flavour experiences. This study reports on the time-dependent transfer of flavour compounds from the mother's diet to her breast milk using a within-subject design. Eighteen lactating mothers completed three test days on which they provided a baseline milk sample prior to ingestion of capsules containing 100 mg d-carvone, l-menthol, 3-methylbutyl acetate and trans-anethole. Milk samples were collected 2, 4, 6 and 8 h post-ingestion and analysed by a dynamic headspace method and gas chromatography-mass spectroscopy. The recovery quantities were adjusted for variations in milk fat content. Concentration-time profiles for d-carvone and trans-anethole revealed a maximum around 2 h post-ingestion, whereas the profile for l-menthol showed a plateau pattern. The ester 3-methylbutyl acetate could not be detected in the milk, but a single determination showed traces (<0.4 ppb) in a 1 h milk collection. Flavour compounds appeared to be transmitted differentially from the mother's diet to her milk. The results imply that human milk provides a reservoir for time-dependent chemosensory experiences to the infant; however, volatiles from the diet are transferred selectively and in relatively low amounts.

Oxidative Stability of Milk Influenced by Fatty Acids, Antioxidants, and Copper Derived from Feed

Differences in the oxidative stability of milk from cows fed grass-clover silage or hay were examined in relation to fatty acid composition and contents of antioxidants and copper in the milk. The oxidation processes were induced by exposing the milk to fluorescent light. Protein oxidation was measured as an accumulation of dityrosine, whereas lipid oxidation was measured as an accumulation of lipid hydroperoxides as the primary oxidation product, and as the secondary oxidation products, pentanal, hexanal, and heptanal. No differences were found in the protein oxidation of the 2 types of milk measured as accumulation of dityrosine, but there was an increased accumulation of lipid hydroperoxides and hexanal in milk from cows fed grass-clover silage, compared with milk from cows fed hay. The higher degree of lipid oxidation in milk from cows fed grass-clover silage could not be explained from the concentration of alpha-tocopherol, carotenoids, uric acid, and copper in the milk. However, it was thought to be highly influenced by the significantly higher concentration of linolenic acid present in milk from cows fed grass-clover silage. A larger part of alpha-tocopherol and beta-carotene was transferred from the feed to the milk when cows were fed grass-clover silage than when cows were fed hay as roughage. The significantly higher concentration of polyunsaturated fatty acids in milk from cows fed grass-clover silage may be important for the better transfer of alpha-tocopherol from the feed to the milk. Other circumstances, as the different conditions in the rumen may also play a role, due to the different types of roughages and their digestibility, or be related to the mechanisms during milk production for the higher yielding cows fed grass-clover silage.

Flavor release measurement from gum model system

Flavor release from a mint-flavored chewing gum model system was measured by atmospheric pressure chemical ionization mass spectroscopy (APCI-MS) and sensory time-intensity (TI). A data analysis method for handling the individual curves from both methods is presented. The APCI-MS data are ratio-scaled using the signal from acetone in the breath of subjects. Next, APCI-MS and sensory TI curves are smoothed by low-pass filtering. Principal component analysis of the individual curves is used to display graphically the product differentiation by APCI-MS or TI signals. It is shown that differences in gum composition can be measured by both instrumental and sensory techniques, providing comparable information. The peppermint oil level (0.5-2% w/w) in the gum influenced both the retronasal concentration and the perceived peppermint flavor. The sweeteners' (sorbitol or xylitol) effect is less apparent. Sensory adaptation and sensitivity differences of human perception versus APCI-MS detection might explain the divergence between the two dynamic measurement methods.

Release of peppermint flavour compounds from chewing gum: effect of oral functions

During chewing, the oral cavity functions like a bellow, forcing volatile flavour compounds into the exhaling air to the nasal compartment. Accordingly, we hypothesised that flavour release from chewing gum is predominantly governed by chewing frequency (CF), although other oral functions, like masseter muscle activity (MMA), chewing force (CFO), and saliva flow rate (SFR), may also play a role. In 10 healthy young males, the retronasal expired air of menthol and menthone from peppermint-flavoured (2%) chewing gum was determined as functions of CF, SFR, MMA, and CFO. The experimental setup comprised three separate series of a 4-min chewing period. These series differed only with respect to CF, i.e., habitual frequency, and 60 and 88 strokes/min. Results showed that more than 50% of the released menthol and menthone could be retrieved in the expired air and saliva. After 2-min of chewing, the concentration of flavour compounds in the expired air depended primarily on MMA and CF, becoming higher with increased MMA and CF. The concentration of flavour compounds in saliva depended primarily on SFR and the duration of the chewing task, becoming lower with high SFR and prolonged chewing duration. An increased volume of saliva in the mouth seemed to keep more flavour compounds in the aqueous phase, thereby diminishing the release via the retronasal route. In conclusion, flavour release to the retronasal compartment was dependent on MMA and CF and influenced by the volume of saliva present in the mouth.

Flavor release measurement by atmospheric pressure chemical ionization ion trap mass spectrometry, construction of interface and mathematical modeling of release profiles

An instrumental on-line retronasal flavor analysis was developed to obtain information about the release of flavor compounds in expired air from humans during eating. The volatile flavor compounds were measured by ion trap mass spectrometry with an atmospheric pressure chemical ionization source (APCI). An interface was designed to sample the breath directly from the nose. The repeatability in vitro for seven different flavor compounds came out with relative standard derivation less than 10% in most cases, which is acceptable. In vitro quantification was carried out by a determination of the concentration in the gas phase over a flavor solution by GC/MS, followed by measurements of intensities by the APCI ion trap. Ion suppression by acetone in the breath was negligible at concentration levels relevant in these experiments. The instrumental limits of detection for menthone and menthol coincide with that of the flavor detection threshold. An application study on the release of menthone and menthol from chewing gum by a group of six test persons was performed. Flavored chewing gum was used as a model matrix because of the long chewing periods and the simplicity of the system. It is concluded that the interface and the method can be used to measure breath from the nose. A mathematical model of the data was developed to give a quantitative method for description and characterization of the release of flavor compounds. The release profiles consisted of two sequences, one for a chewing period, and one for a phasing out process. The proposed method for modeling provided a reasonable description of the release process. In addition to flavor compounds, this new interface and mathematical application could provide information on chemicals in the human breath, which could be interesting, for example, within medical diagnosis.