Relating oral physiology and anatomy of consumers varying in age, gender and ethnicity to food oral processing behavior

Creating similar food boluses as that in vivo using a novel in vitro bio-inspired oral mastication simulator (iBOMS-Ⅲ): The cases with cooked rice and roasted peanuts

Food bolus is the major outcome of oral processing of foods. Its structure and properties are crucial for safe swallowing and subsequent gastric digestion. However, collecting the ready-to-swallow bolus for further analysis in either normal or deficient human subjects is difficult, regulatorily or practically. Here, a novel in vitro bio-inspired oral mastication simulator (iBOMS-Ⅲ) was developed to be capable of replicating food boluses comparable to those in vivo. Cooked rice and roasted peanuts were used as the model foods (soft and hard) respectively. Particle size distribution, moisture content and rheology of the food boluses produced in the iBOMS-Ⅲ were assessed. A conventional food blender was also employed as a non-consequential comparation. Eighteen healthy young volunteers of the ages from 20-30 years (10 male and 8 female) were invited to provide the in vivo data. For cooked rice boluses produced by the iBOMS-Ⅲ with 10, 12, 14, and 20 chewing number of cycles, the moisture content exhibited minimal variation (68.3-68.8 wt%), aligning closely with values obtained from the average value of the human subjects (67.5 wt%). Similarly, the boluses from roasted peanut displayed similar moisture contents across masticatory number of cycles (36, 40, and 44 number of cycles), averaging at 35.3 %, mirroring the average in vivo results (33.8 wt%). Furthermore, the shear viscosity of both cooked rice and roasted peanut boluses exhibited minimal variations with iBOMS-Ⅲ chewing number of cycles. The particle size distributions of the boluses produced with 14 and 44 chewing number of cycles matched well with the in vivo data for cooked rice and roasted peanuts, with median particle size (d50) being 1.07 and 0.78 mm, respectively. The physical properties of the food boluses collected from the food blender, with varying grinding times, differed significantly. This study demonstrates the value of the iBOMS-Ⅲ in achieving realistic boluses with two very different food textures.

Food-Oral Processing: Current Progress, Future Directions, and Challenges

Oral processing refers to the series of physical, chemical, and biological processes inside the oral cavity when we consume food. This process affects the taste, quality, and nutrient absorption of the body. In the human diet, oral processing plays a crucial role because it impacts not only the food flavor and texture but also the absorption and utilization of nutrients. With the progress of science and technology and the increasing demand for food, the study of oral processing has become increasingly important. This paper reviews the history and definition of oral processing, its current state of research, and its applications in food science and technology, focusing on personalized taste customization, protein structure modification, food intake and nutrition, and bionic devices. It also analyzes the impact of oral processing on different types of food products and explores its potential in the food industry and science research.

Impact of gut microbiota and associated mechanisms on postprandial glucose levels in patients with diabetes

Diabetes and its complications are serious medical and global burdens, often manifesting as postprandial hyperglycemia. In recent years, considerable research attention has focused on relationships between the gut microbiota and circulating postprandial glucose (PPG). Different population studies have suggested that PPG is closely related to the gut microbiota which may impact PPG via short-chain fatty acids (SCFAs), bile acids (BAs) and trimethylamine N-oxide (TMAO). Studies now show that gut microbiota models can predict PPG, with individualized nutrition intervention strategies used to regulate gut microbiota and improve glucose metabolism to facilitate the precision treatment of diabetes. However, few studies have been conducted in patients with diabetes. Therefore, little is known about the relationships between the gut microbiota and PPG in this cohort. Thus, more research is required to identify key gut microbiota and associated metabolites and pathways impacting PPG to provide potential therapeutic targets for PPG.

Anticipating food structure of meat products from mastication physics applying machine learning

Alternatives to animal-based products are becoming more relevant. Most of those products rely at some stage on a structuring process; hence researchers are developing techniques to measure the goodness of the structured material. Conventionally, a typical sensory study or texture analysis by measuring deformation forces would be applied to test the produced material for its texture. However, meat alternatives and meat differ in more points than just the texture, making it hard to extract the isolated texture impression. To objectively obtain qualitative and quantitative differences between different food structures, evaluation of oral processing features is an upcoming technology which qualifies as promising addon to existing technologies. The kinematic data of the jaw and exerted forces regarding muscle activities are recorded during mastication. Resulting datasets are high in dimensionality, covering thousands of individual chews described by often more than ten features. Evaluating such a dataset could benefit from applying computational evaluation strategies designed for large datasets, such as machine learning and neural networks. The aim of this work was to assess the performance of machine learning algorithms such as Support Vector Machines and Artificial Neural Networks or ensemble learning algorithms like Extra Trees Classifier or Extreme Gradient Boosting. We evaluated different pre-processing techniques and various machine algorithms for learning models with regard to their performance measured with established benchmark values (Accuracy, Area under Receiver-Operating Curve score, F1 score, precision-recall Curve, Matthews Correlation Coefficient (MCC)). Results show remarkable performance of classification of each single chew between isotropic and anisotropic material (MCC up to 0.966). According to the feature importance, the lateral jaw movement was the most important feature for classification; however, all features were necessary for an optimal learning process.

Oral processing, rheology, and mechanical response: Relations in a two-phase food model with anisotropic compounds

Food-material poses a challenging matrix for objective material scientific description that matches the consumers' perception. With eyes on the emerging structured food materials from alternative protein sources, objectively describing perceived texture characteristics became a topic of interest to the food industry. This work made use of the well-known methodologies of jaw tracking and electromyography from the field of "food oral processing" and compared outcomes with mechanical responses to the deformation of model food systems to meat alternatives. To enable transferability to meat alternative products, an anisotropic structuring ingredient for alternative products, high-moisture texturized vegetable protein (HM-TVP), was embedded in an isotropic hydrocolloid gel. Data of the jaw movement and muscle activities exerted during mastication were modeled in a linear mixed model and set in relation to characteristic values obtained from small- and large-strain deformation. For improvement of the model fit, this work makes use of two new data-processing strategies in the field of oral processing: (i) Muscle activity data were set in relation to true forces and (ii) measured data were standardized and subjected to dimensional reduction. Based on that, model terms showed decreased p-values on various oral processing features. As a key outcome, it could be shown that an anisotropic structured phase induces more lateral jaw movement than isotropic samples, as was shown in meat model systems.

Factors associated with eating rate: a systematic review and narrative synthesis informed by socio-ecological model

Accumulating evidence shows associations between rapid eating and overweight. Modifying eating rate might be a potential weight management strategy without imposing additional dietary restrictions. A comprehensive understanding of factors associated with eating speed will help with designing effective interventions. The aim of this review was to synthesise the current state of knowledge on the factors associated with eating rate. The socio-ecological model (SEM) was utilised to scaffold the identified factors. A comprehensive literature search of eleven databases was conducted to identify factors associated with eating rate. The 104 studies that met the inclusion criteria were heterogeneous in design and methods of eating rate measurement. We identified thirty-nine factors that were independently linked to eating speed and mapped them onto the individual, social and environmental levels of the SEM. The majority of the reported factors pertained to the individual characteristics (n = 20) including demographics, cognitive/psychological factors and habitual food oral processing behaviours. Social factors (n = 11) included eating companions, social and cultural norms, and family structure. Environmental factors (n = 8) included food texture and presentation, methods of consumption or background sounds. Measures of body weight, food form and characteristics, food oral processing behaviours and gender, age and ethnicity were the most researched and consistent factors associated with eating rate. A number of other novel and underresearched factors emerged, but these require replication and further research. We highlight directions for further research in this space and potential evidence-based candidates for interventions targeting eating rate.

Portion-control tableware differentially impacts eating behaviour in women with and without overweight

Portion control tableware has been described as a potentially effective approach for weight management, however the mechanisms by which these tools work remain unknown. We explored the processes by which a portion control (calibrated) plate with visual stimuli for starch, protein and vegetable amounts modulates food intake, satiety and meal eating behaviour. Sixty-five women (34 with overweight/obesity) participated in a counterbalanced cross-over trial in the laboratory, where they self-served and ate a hot meal including rice, meatballs and vegetables, once with a calibrated plate and once with a conventional (control) plate. A sub-sample of 31 women provided blood samples to measure the cephalic phase response to the meal. Effects of plate type were tested through linear mixed-effect models. Meal portion sizes (mean ± SD) were smaller for the calibrated compared with the control plate (served: 296 ± 69 vs 317 ± 78 g; consumed: 287 ± 71 vs 309 ± 79 g respectively), especially consumed rice (69 ± 24 vs 88 ± 30 g) (p < 0.05 for all comparisons). The calibrated plate significantly reduced bite size (3.4 ± 1.0 vs 3.7 ± 1.0 g; p < 0.01) in all women and eating rate (32.9 ± 9.5 vs 33.7 ± 9.2 g/min; p < 0.05), in lean women. Despite this, some women compensated for the reduced intake over the 8 h following the meal. Pancreatic polypeptide and ghrelin levels increased post-prandially with the calibrated plate but changes were not robust. Plate type had no influence on insulin, glucose levels, or memory for portion size. Meal size was reduced by a portion-control plate with visual stimuli for appropriate amounts of starch, protein and vegetables, potentially because of the reduced self-served portion size and the resulting reduced bite size. Sustained effects may require the continued use of the plate for long-term impact.

Average thickness of the bones of the human neurocranium: development of reference measurements to assist with blunt force trauma interpretations

The accurate interpretation of a blunt force head injury relies on an understanding of the case circumstances (extrinsic variables) and anatomical details of the individual (intrinsic variables). Whilst it is often possible to account for many of these variables, the intrinsic variable of neurocranial thickness is difficult to account for as data for what constitutes 'normal' thickness is limited. The aim of this study was to investigate the effects of age, sex and ancestry on neurocranial thickness, and develop reference ranges for average neurocranial thickness in the context of those biological variables. Thickness (mm) was measured at 20 points across the frontal, left and right parietals, left and right temporals and occipital bones. Measurements were taken from post-mortem computed tomography scans of 604 individuals. Inferential statistics assessed how age, sex and ancestry affected thickness and descriptive statistics established thickness means. Mean thickness ranged from 2.11 mm (temporal squama) to 19.19 mm (petrous portion). Significant differences were noted in thickness of the frontal and temporal bones when age was considered, all bones when sex was considered and the, right parietal, left and right temporal and occipital bones when ancestry was considered. Furthermore, significant interactions in thickness were seen between age and sex in the frontal bone, ancestry and age in the temporal bone, ancestry and sex in the temporal bone, and age, sex and ancestry in the occipital bone. Given the assorted influence of the biological variables, reference measurement ranges for average thickness incorporated these variables. Such reference measurements allow forensic practitioners to identify when a neurocranial bone is of normal, or abnormal, thickness.

Gastric emptying rate of a solid meal in patients with anterior open bite malocclusion: A preliminary study

Objectives:

The objective of the study was to investigate the relationship between anterior open bite (AOB) malocclusion and digestion by evaluating mastication and gastric emptying (GE) of a solid meal.

Material and Methods:

We recruited 26 female participants and divided them into two groups according to their occlusion status: The control group with normal occlusion (n = 11; age: 25.2 ± 2.8 years; and body mass index [BMI]: 21.1 ± 1.9 kg/m2) and the AOB group with AOB malocclusion (n = 15; age: 23.2 ± 5.5 years; BMI: 21.0 ± 1.6 kg/m2). GE, chewing, and occlusion were assessed simultaneously. A food questionnaire survey was also administered on the same day.

Results:

A significant positive correlation was noted between open bite and the occlusal analysis findings. Negative correlations were found between the food questionnaire score and both the open bite and occlusal analysis findings, which confirmed that AOB affects mastication. However, no significant difference in the GE rate parameters was observed between the two groups.

Conclusion:

Adaptive mechanisms may have a compensatory effect on the GE rate. However, the lack of tooth contact in the anterior occlusal region resulted in reduced masticatory ability. Orthodontic treatment should thus be considered, regardless of the presence of digestive problems, to improve mastication.

Ethnicity impact on oral processing behaviour and glycemic response to noodles: Chinese (Asian) vs. New Zealander (Caucasian)

There is an increasing awareness of the link between food breakdown during chewing and its nutrient release and absorption in the gastrointestinal tract. However, how oral processing behaviour varies among different ethnic groups, and how such difference further impacts on bolus characteristics and consequently glycemic response (GR) are not well understood. In this study, we recruited a group of Asian (Chinese) subjects in China (n = 32) and a group of Caucasian subjects in New Zealand (n = 30), both aged between 18 and 30 years, and compared their blood glucose level (BGL) over 120 min following consumption of a glucose drink and cooked white noodles. We also assessed their chewing behaviour, unstimulated saliva flow rate, and ready-to-swallow bolus characteristics to determine whether these measures explain the ethnic differences in postprandial glycaemia. Compared to New Zealand subjects, the Chinese subjects showed 35% slower saliva flow rate but around 2 times higher salivary α-amylase activity in the unstimulated state. During consumption of noodles, Chinese subjects on average took a larger mouthful size, chewed each mouthful for longer and swallowed a larger number of particles with a smaller particle size area. Total GR measured by area under the curve (IAUC) was higher among the Chinese subjects. They also experienced higher BGL at 15 min, as well as higher peak BGL. There were strong correlations observed between oral processing and GR parameters. Results of this study confirmed the significance of oral processing in determining food digestion, and will provide new insights on the role of ethnicity in influencing people's physiological response to food.

Current Perspectives on Food Oral Processing

Food oral processing (FOP) is a fast-emerging research area in the food science discipline. Since its first introduction about a decade ago, a large amount of literature has been published in this area, forming new frontiers and leading to new research opportunities. This review aims to summarize FOP research progress from current perspectives. Food texture, food flavor (aroma and taste), bolus swallowing, and eating behavior are covered in this review. The discussion of each topic is organized into three parts: a short background introduction, reflections on current research findings and achievements, and future directions and implications on food design. Physical, physiological, and psychological principles are the main concerns of discussion for each topic. The last part of the review shares views on the research challenges and outlooks of future FOP research. It is hoped that the review not only helps readers comprehend what has been achieved in the past decade but also, more importantly, identify where the knowledge gaps are and in which direction the FOP research will go.

Physical Frailty and Oral Frailty Associated with Late-Life Depression in Community-Dwelling Older Adults

Late-life depression is a major mental health problem and constitutes a heavy public health burden. Frailty, an aging-related syndrome, is reciprocally related to depressive symptoms. This study investigated the associations of physical frailty and oral frailty with depression in older adults. This large-scale cross-sectional study included 1100 community-dwelling older adults in Taiwan. The participants completed a dental examination and questionnaires answered during personal interviews. The 15-item Geriatric Depression Scale was used to assess depression, and information on physical conditions and oral conditions was collected. Multivariable logistical regression analysis was conducted to examine associations of interest. Significant factors associated with depression were pre-physical frailty (adjusted odds ratio (aOR) = 3.61), physical frailty (aOR = 53.74), sarcopenia (aOR = 4.25), insomnia (aOR = 2.56), pre-oral frailty (aOR = 2.56), oral frailty (aOR = 4.89), dysphagia (aOR = 2.85), and xerostomia (aOR = 1.10). Depression exerted a combined effect on physical frailty and oral frailty (aOR = 36.81). Physical frailty and oral frailty were significantly associated with late-life depression in community-dwelling older adults in a dose–response manner. Developing physical and oral function interventions to prevent depression among older adults is essential.

Effect of cross-cultural differences on thickness, firmness and sweetness sensitivity

Sensitivity of the somatosensory system may be influenced by multiple physiological parameters. Variations in oral physiology can arise from cross-cultural differences which may potentially affect sensory sensitivity. The aim of this case study was to quantify texture and taste sensitivity in Dutch (Caucasian) and Chinese (Asian) adults living in the Netherlands. Eighty-five healthy subjects were recruited including 44 Dutch (Caucasian) adults (29 females, 22.8 ± 2.3 yrs) and 41 Chinese (Asian) adults (30 females, 24.5 ± 2.1 yrs) living in the Netherlands for less than 1 year. Three sets of stimuli were used to quantify sensitivity of thickness (maltodextrin solutions differing in viscosity), firmness (agar gels differing in fracture stress) and sweetness (sucrose solutions differing in concentration). The 2-Alternative Forced Choice (2-AFC) ascending staircase method was used to determine texture and taste sensitivity. Unstimulated and stimulated saliva flow rate, fungiform papillae density (FPD), lingual tactile threshold and PROP taster status were determined and are referred to as physiological and sensory consumer characteristics. No significant differences were observed between Chinese and Dutch adults for thickness (Dutch 2.60 mPas, Chinese 2.19 mPas), firmness (Dutch 10.5 kPa, Chinese 10.3 kPa) and sweetness sensitivity (Dutch 0.012 g/mL, Chinese 0.017 g/mL). No significant differences were observed between Chinese and Dutch adults for saliva flow rate, lingual tactile threshold and PROP taster status. The relationships between the three sensory sensitivities (thickness, firmness, sweetness) and five physiological and sensory consumer characteristics (unstimulated and stimulated saliva flow rate, FPD, lingual tactile threshold, PROP taster status) were analyzed. Only one out of 15 relationships, firmness sensitivity and FPD, was significantly and weakly related suggesting that inter-individual variation in these consumer characteristics is almost unrelated to sensory sensitivity. We conclude that in this case study thickness, firmness and sweetness sensitivities do not differ between Dutch and Chinese adults living in the Netherlands. Saliva flow rate, fungiform papillae density, lingual tactile threshold and PROP taster status do not explain inter-individual variation in sensory sensitivity between these consumers.

Dynamic release and perception of key odorants in grilled eel during chewing

The release mechanism of odorants in the oral cavity during consumption directly affects sensory attributes, consumers' preferences, and ultimately purchase intent. Targets was set to monitor in real-time the key odorants released from grilled eel during mastication via an atmospheric pressure chemical ionization mass spectrometry (APCI-MS) connected with a nose interface. The release and perception of odorants during mastication were divided into three distinct phases. Dimethyl sulfide was the main odorant in the first stage. The release and perception of fishy aromas were predominant in the middle and last stages of mastication contributed by trimethylamine, 1-penten-3-ol, and 2-methyl-1-butanol. Chewing behavior experiments suggested that extending the chewing period to >20 s and having a chewing frequency of 2 cycles/s could enhance the aroma delivery of grilled eel and optimize the consumer experience. Consequently, the results explained the relationship between aroma release and the optimal chewing behavior for grilled eel consumption.

Influence of Age and Individual Differences on Mouthfeel Perception of Whey Protein-Fortified Products: A Review

Protein needs are considered to increase with age, with protein consumption being associated with many positive outcomes. Protein-fortified products are often used to improve nutritional status and prevent age-related muscle mass loss in older adults. Accordingly, older adults are commonly provided with products fortified with whey protein; however, such products can cause mouthdrying, limiting consumption and product enjoyment. Currently, the extent to which age and individual differences (e.g., saliva, oral health, food oral processing) influence the perception of whey protein-derived mouthdrying is relatively unclear. Previous research in this area has mainly focused on investigating mouthdrying, without taking into account individual differences that could influence this perception within the target population. Therefore, the main focus of this review is to provide an overview of the relevant individual differences likely to influence mouthfeel perception (specifically mouthdrying) from whey protein-fortified products, thereby enabling the future design of such products to incorporate better the needs of older adults and improve their nutritional status. This review concludes that age and individual differences are likely to influence mouthdrying sensations from whey protein-fortified products. Future research should focus more on the target population and individual differences to maximise the benefits from whey protein fortification.

Food Oral Processing-An Industry Perspective

We illustrate how scientific understanding of Food Oral Processing enables food product development with specific benefits for several target populations. in vivo, in vitro, and in silico approaches are discussed in the context of their ability to quantify oral processing from the molecular to the macroscopic scale. Based on this understanding, food structures with enhanced performance in terms of hedonic and nutritional properties as well as appropriateness for age and certain medical conditions can be developed. We also discuss current gaps and highlight development opportunities from an industry perspective.

Relationship between age and sex and the numbers of ingestions and swallows for foods of different textures among healthy adults

BACKGROUND

The number of swallows needed per single ingestion of food is an important index when assisting a patient with dysphagia in eating. While providing meal assistance, the caregiver may assume that one ingestion is completed with one swallow and then may administer the next ingestion even if the individual's mouth still has remaining food from the previous ingestions, increasing the risk for aspiration and choking.

OBJECTIVE

The objective of this pilot study was to clarify the differences in foods ingested and swallowed because of influencing factors such as age and gender among healthy adults.

METHODS

The study enrolled 110 healthy adults (47.4 ± 15.8 years; 57 males, 53 females). The numbers of ingestions and swallows were counted and evaluated by food type (pilaf, 100 g; yogurt 80 g; and sponge cake, 35 g) and participant age and sex and analyzed by least-squares multiple regression analysis.

RESULTS

The mean numbers of ingestion/swallows were pilaf, 12.5 ± 3.2/13.4 ± 4.2; yogurt, 8.8 ± 2.1/10.8 ± 2.1; and sponge cake, 5.8 ± 2.1/7.0 ± 2.1. The mean number of ingestions and swallows for all foods were higher for female participants compared with male participants. Statistical analysis identified sex as a significant influencing factor for the number of ingestion for all foods. For the number of swallows, the significant influencing factors were sex for sponge cake and age for pilaf and yogurt.

CONCLUSION

For the test foods of different textures, sex and age were significant influencing factors for the numbers of ingestions and swallows. Further research is needed to elucidate the problem areas in this pilot study.

Differences in oral processing behavior of consumers varying in age, gender and ethnicity lead to changes in bolus properties but only to small differences in dynamic texture perception of sausages

Consumer characteristics such as age, gender and ethnicity influence food oral processing behavior. The aim of this study was to determine the effect of age, gender and ethnicity on consumption time, bolus properties and dynamic sensory perception of sausages. Consumption time, bolus properties (saliva incorporation, particle size distribution and rheological properties) and dynamic texture perception (Temporal Dominance of Sensations, TDS) of sausages were compared between young Dutch, Caucasians (n = 21; 22 ± 2.8 years), young Chinese, Asians (n = 21; 23 ± 1.6 years), and elderly Dutch, Caucasians (n = 22; 70 ± 4.3 years). Elderly Dutch masticated the sausage 22% longer (25.6 s) than young Dutch consumers (21.0 s). Elderly Dutch produced sausage boli that were softer, more adhesive, less cohesive and contained more particles than those of young Dutch adults. Elderly females produced more adhesive and less cohesive sausage bolus than males. Young Chinese females had 75.6% longer consumption time (29.5 s) than young Dutch females (16.8 s). Young Chinese males masticated the sausages in less time (18.8 s) than young Chinese females (29.5 s). Young Chinese produced softer and less cohesive bolus with slightly smaller and more particles than young Dutch. Saliva incorporation and bolus particle size were not affected by age, gender and ethnicity. Mediation analysis revealed that the effect of consumer characteristics such as age, gender and ethnicity on bolus properties was mediated by consumption time. At the beginning and end of consumption time, dynamic texture perception of sausages was similar for all consumer groups and strongly correlated with bolus properties. Differences in dynamic texture perception between consumer groups were observed only during the middle stages of mastication with low dominance rates. We conclude that consumers differing in age, gender and ethnicity vary in oral processing time to produce bolus with textural properties optimized to their needs. Furthermore, consumption time is the underlying mechanism that explains the differences in bolus properties between the consumer groups. While variations in consumption time of sausages lead to considerable differences in bolus properties, it only leads to small differences in dynamic texture perception.

Does Masticatory Ability Contribute to Nutritional Status in Older Individuals?

Mastication plays a primary role in the process of eating. Hence, compromised masticatory ability may affect the nutrition and quality of life, which are particularly important concerns among older individuals. It remains unclear how is the masticatory ability assessed regarding the nutritional status. We examined the effect of various oral factors on three masticatory ability tests conducted among older individuals. A total of 100 older individuals were enrolled in this study. Body mass index (BMI) as an indicator of nutritional status; and age, sex, and the number of occlusal and molar occlusal supports as clinical attributes were recorded. Three masticatory ability tests (masticatory efficiency, masticatory score, and satisfaction with mastication) were conducted, and tongue pressure, cheek pressure, and occlusal force were assessed as oral functions. A significant but weak correlation was found between masticatory efficiency and the masticatory score, but not between masticatory efficiency and satisfaction score. Objective masticatory efficiency was strongly associated with objective oral factors, whereas subjective assessments of masticatory ability (masticatory score and satisfaction score) were not. Furthermore, BMI was significantly associated with subjective assessments of masticatory ability but not with objective masticatory efficiency. Both subjective and objective assessments of masticatory ability, along with considerations of nutritional formulations, are required for the maintenance and improvement of nutritional status in older individuals.