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Chewing is a sensorimotor activity that aims to prepare food for swallowing, in which saliva intervenes, moistening food particles, assisting in bolus formation, enzymatic digestion, and swallowing. This study investigated the effect of chewing carrots of different shapes on salivary secretion and protein profiles using 2-DE gel electrophoresis. Fifteen participants chewed sliced or grated carrots, or parafilm (non-food control), in a crossover design, with saliva samples collected before and after mastication. The results showed significant differences in salivation and saliva composition when chewing carrots vs. the control, with sliced carrots inducing greater changes: 37 protein spots, including amylase and immunoglobulin spots, 9 protein spots, and 1 protein spot were significantly altered after chewing sliced carrots, grated carrots, and parafilm, respectively. Mastication combined with the sensory properties of food had a greater effect on saliva secretion and salivary protein levels than mastication alone. Among carrot shapes, the results suggest that harder food textures, which require more chewing effort, lead to more pronounced changes in salivary protein profiles. These findings contribute to the understanding of how food shape and texture influence salivation and salivary proteome dynamics, with potential implications for oral digestion, food-related sensory experiences, and the personalisation of diets for individuals with a compromised chewing capacity. [ABSTRACT FROM AUTHOR]

Abstract With a growing global population and ageing demographics, the food industry stands at a pivotal crossroads, necessitating bespoke solutions and groundbreaking innovations. In vitro experiments can help understanding food oral processing and formulating products meeting the specific needs of different populations. However, current in vitro models do not reproduce well human oral anatomy and tongue biomechanics, essential for assessing the behaviour of novel and texturized foods under physiologically relevant oral conditions. In response, we unveil a novel 3D biomimetic artificial mouth, showcasing a pneumatic multi-degree-of-freedom artificial tongue meticulously crafted to mirror the mechanical properties and wettability of the human tongue. This cutting-edge technology, featuring tongue surface papillae, is capable of performing lifelike movements. The comparison with in vivo data demonstrates that it accurately reproduces oral processing of three, vastly different, soft foods. Textural characteristics (firmness, adhesive and cohesive properties) and shear viscosities—measured at oral and oropharyngeal-relevant shear rates—of in vitro food boli closely mirrored those observed in vivo. This in vitro device presents unprecedented opportunities for studying the dynamics of food transformation in the mouth, to adapt texture towards food that can be swallowed with ease and to improve food palatability, accommodating specific health needs critical for older adults (e.g., reduced salivary secretion, tongue weakness or poor coordination).

Abstract Preferred mouth behavior studies have mostly focused on Western populations using the JBMB tool to determine how food is manipulated in the mouth. The objective of this study was to determine the relationship between preferred mouth behavior and eating behavior among the diverse group of 209 Malaysians participants. A series of Analysis of Variances and an unsupervised machine learning technique known as Latent Class Clustering were utilized to determine individual's oral behavior. The Adult Eating Behavior Questionnaire was later modeled using causal networks, specifically Partial Least Squares‐Confirmatory Factor Analysis, to uncover relationship between appetitive qualities. The results from this study showed that cultural context and appropriateness play an essential role when classifying preferred mouth behavior using behavioral questionnaires and models. Furthermore, this study also determined the relationship between eating behavior and preferred mouth behavior, as well as unique differences in eating behavior observed among the mouth behavior groups.

Eating behaviors develop in early life and refine during childhood, shaping long-term food choice and dietary habits, which underpin optimum growth and health. The development of Food Oral Processing (FOP) is of major importance in the establishment of eating behaviors at two scale levels: for the initial acceptance of food texture and for the longer-term development of eating behaviors associated to food intake. To date, both processes have been studied as independent topics and the current review proposes a parallel vision on their development from the onset of complementary feeding to later childhood. Individual factors affecting these FOP-related behaviors as they relate to food texture acceptance are discussed, alongside examples of interventions aiming at modifying them. Opportunity to better consider food textures when designing foods for children is addressed. Altogether, the review demonstrates the critical role of food texture in the development of a child's FOP skills, eating habits, and dietary patterns. These scientific knowledges need to be considered for the development of healthier eating behavior. We identify research gaps that need to be addressed and highlight the need to design foods that can support the development of healthy oral processing and eating behaviors among infants and children. [ABSTRACT FROM AUTHOR]

With a growing global population and ageing demographics, the food industry stands at a pivotal crossroads, necessitating bespoke solutions and groundbreaking innovations. In vitro experiments can help understanding food oral processing and formulating products meeting the specific needs of different populations. However, current in vitro models do not reproduce well human oral anatomy and tongue biomechanics, essential for assessing the behaviour of novel and texturized foods under physiologically relevant oral conditions. In response, we unveil a novel 3D biomimetic artificial mouth, showcasing a pneumatic multi-degree-of-freedom artificial tongue meticulously crafted to mirror the mechanical properties and wettability of the human tongue. This cutting-edge technology, featuring tongue surface papillae, is capable of performing lifelike movements. The comparison with in vivo data demonstrates that it accurately reproduces oral processing of three, vastly different, soft foods. Textural characteristics (firmness, adhesive and cohesive properties) and shear viscosities—measured at oral and oropharyngeal-relevant shear rates—of in vitro food boli closely mirrored those observed in vivo. This in vitro device presents unprecedented opportunities for studying the dynamics of food transformation in the mouth, to adapt texture towards food that can be swallowed with ease and to improve food palatability, accommodating specific health needs critical for older adults (e.g., reduced salivary secretion, tongue weakness or poor coordination). [ABSTRACT FROM AUTHOR]

A masticatory simulator is a mechanical device that mimics the physiological structures of the human oral cavity, chewing movement system, and functions. The advantage of this device lies in real‐time tracking and analysis of food boluses within a sealed oral space, offering a direct validation platform for food experiments without constraints related to time, space, and individual variations. The degree to which the masticatory simulator simulates physiological structures reflects its efficacy in replicating oral physiological processes. This review mainly discusses the physiological structures of the oral cavity, the simulation of biomimetic components, and the development, feasibility assessment, applications, and prospects of masticatory simulators in food. The highlight of this review is the analogy of biomimetic component designs in masticatory simulators over the past 15 years. It summarizes the limitations of masticatory simulators and their biomimetic components, proposing potential directions for future development. The purpose of this review is to assist readers in understanding the research progress and latest literature findings on masticatory simulators while also offering insights into the design and innovation of masticatory simulators. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the impact of food texture, oral processing, bolus characteristics, and in vitro digestive conditions on the starch and protein digestibility of al dente and soft-cooked commercial red lentil pasta. For that, samples were cooked as suggested by the provider and their texture properties were promptly analysed. Then, normal and deficient masticated pasta boluses were produced by four healthy subjects, characterised in terms of their oral processing, bolus granulometry, texture and viscoelastic properties, and finally subjected to static in vitro digestion, according to the INFOGEST consensus for both adults and the older adult population. Normal masticated boluses exhibited greater saliva impregnation and lower proportions of large particles, hardness, and stiffness than deficient masticated boluses. Likewise, insufficiently masticated al dente–cooked pasta boluses caused a delay in oral starch digestion owing to the larger particles attained during food oral processing, while reduced intestinal conditions in the elderly only interfere with the release of total soluble proteins in all samples. This work evidences the importance of considering the initial texture of products, oral capabilities, processing behaviour, and physical and mechanical properties of food boluses in digestion studies, opening new prospects in designing pulse-based foods that meet the nutritional requirements of the world's population. [ABSTRACT FROM AUTHOR]

This article outlines the outputs from a series of our research activities on food texture studies. This includes mechanical and physiological approaches to texture quantification and their applications to product design, which aims to meet the increased demand for foods/beverages that are palatable as well as safe for consumption. As a result of tremendous efforts and supports, we have published approx. 40 research papers, including original papers and reviews, since 2011. This can contribute to novel academic insights into the mechanism and behavior of food oral processing in humans and serve as a practical tool for industry to facilitate inter-company and international collaborations to produce qualified and standardized products. [ABSTRACT FROM AUTHOR]

Chewing is a sensorimotor activity that aims to prepare food for swallowing, in which saliva intervenes, moistening food particles, assisting in bolus formation, enzymatic digestion, and swallowing. This study investigated the effect of chewing carrots of different shapes on salivary secretion and protein profiles using 2-DE gel electrophoresis. Fifteen participants chewed sliced or grated carrots, or parafilm (non-food control), in a crossover design, with saliva samples collected before and after mastication. The results showed significant differences in salivation and saliva composition when chewing carrots vs. the control, with sliced carrots inducing greater changes: 37 protein spots, including amylase and immunoglobulin spots, 9 protein spots, and 1 protein spot were significantly altered after chewing sliced carrots, grated carrots, and parafilm, respectively. Mastication combined with the sensory properties of food had a greater effect on saliva secretion and salivary protein levels than mastication alone. Among carrot shapes, the results suggest that harder food textures, which require more chewing effort, lead to more pronounced changes in salivary protein profiles. These findings contribute to the understanding of how food shape and texture influence salivation and salivary proteome dynamics, with potential implications for oral digestion, food-related sensory experiences, and the personalisation of diets for individuals with a compromised chewing capacity.

Breakage of food influences eating experience and sensory perception. The aims of the study were to identify an appropriate breakage index and to develop an in vitro method for predicting the ease of oral breakage of nuts. Kernels of five types of nuts were fragmented in vitro using a texture analyzer and 12 subjects therefore performed molar bites. In addition, peanuts were differently roasted (over 0, 15, 25, and 35 min) to vary texture within the same nut type. Projected particle areas were determined using imaging. Two Breakage Indices were compared (1) BI‐I, the difference, after and before fragmentation, in square root values of ratios between total projected area and volume [Agrawal et al., 1997, Archives of Oral Biology, 42(1), 1–9], and (2) BI‐II, the ratio of the total projected area after and before fragmentation. BI‐II gives a stronger linear regression than BI‐I between in vivo and in vitro index values for different types of nuts; Pearson's r = 0.834 versus 0.499 (12 subjects with all data pooled). Using BI‐II, a subject's regression result in fragmentation tests with differently roasted peanuts was as strong as when testing different nut types: Pearson's r = 0.984 versus 0.964. Since the range of the in vitro BI‐II values was 5.5 times smaller in the peanut tests, the finding of a similarly strong regression indicates a high sensitivity of BI‐II to detect differences in food texture. BI‐II is useful for food industry to determine how easily solid foods break down and thereby compare the potential of flavor release between foods during chewing. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the impact of food texture, oral processing, bolus characteristics, and in vitro digestive conditions on the starch and protein digestibility of al dente and soft-cooked commercial red lentil pasta. For that, samples were cooked as suggested by the provider and their texture properties were promptly analysed. Then, normal and deficient masticated pasta boluses were produced by four healthy subjects, characterised in terms of their oral processing, bolus granulometry, texture and viscoelastic properties, and finally subjected to static in vitro digestion, according to the INFOGEST consensus for both adults and the older adult population. Normal masticated boluses exhibited greater saliva impregnation and lower proportions of large particles, hardness, and stiffness than deficient masticated boluses. Likewise, insufficiently masticated al dente–cooked pasta boluses caused a delay in oral starch digestion owing to the larger particles attained during food oral processing, while reduced intestinal conditions in the elderly only interfere with the release of total soluble proteins in all samples. This work evidences the importance of considering the initial texture of products, oral capabilities, processing behaviour, and physical and mechanical properties of food boluses in digestion studies, opening new prospects in designing pulse-based foods that meet the nutritional requirements of the world’s population.

To reproduce the tactile perception of multiple contacts on the human tongue surface, it is necessary to use a pressure measurement device with high spatial resolution. However, reducing the size of the array sensing unit and optimizing the lead arrangement still pose challenges. This article describes a deconvolution neural network (DNN) for improving the resolution of tongue surface tactile imaging, which alleviates this tradeoff between tactile sensing performance and hardware simplicity. The model can work without high‐resolution tactile imaging data of tongue surface: First, in the compression test using artificial tongues, the tactile image matrix (7 × 7) with low resolution can be acquired by sensor array with a sparse electrode arrangement. Then, through finite element analysis modeling, combined with the distribution rule of additional stress on the two‐dimensional plane, the pressure data around the existing detection points are calculated, further expanding the tactile image matrix data amount. Finally, the DNN, based on its efficient nonlinear reconstruction attributes, uses the low‐resolution and high‐resolution tactile imaging matrix generated by compression test and finite element simulation, respectively, to train, and outputs high‐resolution tactile imaging information (13 × 13) closer to the tactile perception of the tongue surface. The results show that the overall accuracy of the tactile image matrix calculated by this model is above 88%. Then, we deduced the spatial difference graph of the resilience index of the three kinds of ham sausages through the high‐resolution tactile imaging matrix. [ABSTRACT FROM AUTHOR]

The rate of flavor release in the mouth from traditional dry-cured pork was evaluated in this study. It was hypothesized that a slow steady release of flavor would occur on chewing and hydration. To test this, high salt dry-cured pork was chewed and held in oral cavity without swallowing for 4 different chewing stages (B, NC30, C30, EC). Saliva and food bolus from 16 healthy subjects were collected during oral processing, and analyzed for saliva flow rate, total saliva protein content, saliva pH, conductivity, saliva and sodium, and taste components. Results show that oral processing behavior and salivary release have important effects on flavor release of dry-cured pork. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that oral processing has a certain effect on the protein composition and concentration in saliva. This study suggests that the interaction between food and saliva that accompanies chewing can lead to significant changes in sensory perception during oral processing.

Oral processing is a combination of various actions, the detailed description of which has always been the subject of relevant research. By means of imaging technology and sensory evaluation, more knowledge of oral processing have been accumulated. Presently, the advances in sensory technology have added quantitative parameters to the qualitative description of oral processing, which also enriched the specifics of each action. Previous studies have shown that oral processing includes lip closure, dental occlusion, masticatory muscles activity, tongue movement, and swallowing, whose processing contains rich information such as the movement of organ and the intensity of organ contacts. "Quantification" was taken in this review as the basic feature of in situ detection information, the relevant parameters and feasible methods for the quantitative description of each activity was recorded in detail. In addition, basic problems and feasible optimization schemes of the existing in situ detection device are also proposed in the hope of promoting the development of in situ detection device thus providing available information for the description of oral processing. [ABSTRACT FROM AUTHOR]

A bio-interface is a thin fluid boundary layer that separates and protects biological surfaces by offering multi-functionalities. Saliva forms a typical bio-interface inside oral cavity and plays a critically important role in food oral processing. During oral processing of food, wetting and mixing of food particles, formation of food bolus, colloidal and enzymatic interactions of food components, oral lubrication, and diffusion of flavor compounds are all closely related to properties of the saliva bio-interface. A saliva bio-interface consists of a multi-layered microstructure with each layer for different functional roles. This review presents information about the formations and structures of saliva films, and the underlying mechanisms of interactions occurring at interface. The review aims to provide solutions to following questions: how flavor compounds transport across, and how physical and chemical interactions are regulated at the saliva bio-interfaces. Important implications of saliva interfaces and their possible applications are also highlighted. Saliva film as an oral bio-interface can be seen as an indispensable component of food oral processing. It functions as an independent phase with its unique properties and behavior. For the point of view of either food oral manipulation or sensory perception, a proper understanding of functionalities of saliva film is essential. By analyzing saliva functions using five-layered model and at molecular level, it is hoped that this review can help to stimulate very different thinking and very different approaches to eating and sensory perception research. • Salivary film is treated as an independent phase inside the oral cavity. • The structures and functions of salivary bio-interfaces are revealed. • Interactions during oral processing are classified in five salivary sublayers. [ABSTRACT FROM AUTHOR]

The sensory quality of plant-based meat analogues (PBMAs) limits wider consumer acceptance, particularly because of their lack of perceived juiciness. This study aimed to investigate the role of bolus properties at different moments of consumption in dynamic texture perception, especially juiciness, of PBMA and beef patties. Patties were cooked to three core temperatures (60, 70, 80 °C) to obtain specimens differing in juiciness. For PBMA and beef patties, juiciness citation proportions (Temporal-Check-All-That-Apply) peaked within the first third of mastication, then decreased strongly until swallowing. This temporal pattern closely aligned with the serum release during mastication as 75% of serum was released from patties during the first third of mastication. Additional structural breakdown of bolus occurred until the end of mastication accompanied by less than 25% additional serum release. With increasing mastication, PBMA and beef patties showed a significant increase in saliva uptake and number of bolus particles, while bolus particle size and hardness decreased, demonstrating a progressive oral structural breakdown. No significant differences in bolus properties were observed between PBMA patties differing in juiciness, while beef patties varying in juiciness differed significantly in bolus water content and liquid expelled from bolus, as a result of the structural changes of myofibrillar protein upon heating. We conclude that, for the patties used in this study, juiciness perception of PBMA patties is driven by serum release during early stages of mastication and not effected by additional oral structural breakdown, while juiciness of beef patties is affected by initial serum release and differences in bolus properties resulting from additional oral structural breakdown. [Display omitted] • Juiciness perception of PBMAs was driven by serum release during early stages of mastication • Additional oral structural breakdown of PBMAs did not increase serum release considerably • Juiciness of beef patties is determined by initial serum release and oral structural breakdown • Differences in temporal juiciness perception can be attributed to patties' structural differences [ABSTRACT FROM AUTHOR]

[Display omitted] • The current panorama of research involving Food Oral Processing (FOP) is presented. • FOP relates food's intrinsic factor, sensory perception, and physiological effects. • FOP relates to cross modal perception of sensory attributes of bakery products (BP). • FOP shows potential to assist design of BP to meet actual food nutrition policies. • FOP may be used on development of healthier BP for special dietary & ageing needs. Food oral processing (FOP) is an emerging research topic that allows a better comprehension of the relation between intrinsic food factors (physicochemical and sensory properties), and human physiology and eating behaviours. FOP can then help in the design of novel and healthier food to meet both quality requirements and consumer needs. In this context, this review presents the current state of knowledge and new insights for future research concerning FOP of bakery products. The application of FOP in bakery science is new, with different protocols and related evaluation being applied, as detailed in this review. The current knowledge shows that bread structure and texture, influenced by formulation and process conditions, as well as the crust and shortenings present, impact bread breakdown and bolus formation, sensory perception, and food physiological effects such as glycaemic response, satiation, and satiety. For a better comprehension of oral processing, cross-modal perception between sensory attributes is used to understand consumer perception and this is carried out using both in vivo, and in vitro methods. This review highlighted the great potential of FOP to assist researchers and producers to face the current challenges relating to i – salt, fat and sugar reduction in bakery products to fulfil current food nutrition policies, ii – the design of healthier bakery products, and iii – the development of bakery products for consumers with special dietary requirements and ageing needs. In conclusion, FOP shows great potential to assist in the development of novel and healthier foods to meet actual food nutrition policies and consumer needs and should be more explored in bakery science and production. [ABSTRACT FROM AUTHOR]

Shear and extensional rheology are the critical tools for developing food thickeners for dysphagia management. In this work, Tremella polysaccharide (TP) and commercially available thickeners, including xanthan gum (XG), guar gum (GG), sodium alginate (SA), sodium carboxymethylcellulose (CMC), and konjac gum (KGM) were selected to compare the thickening performance at IDDSI level 1–3 by shear rheology, extensional rheology and droplet aspect ratio. For each IDDSI level, the concentrations of samples in similar shear viscosity at shear rate of 50 s−1 were successfully found and used for study. The shear rheology results showed that XG, KGM, TP and GG existed more prominent shear thinning behaviors when compared to SA and CMC. The filament break-up time of TP and XG was relatively close at IDDSI level 2–3 and significantly longer than the others, exhibiting excellent extensional viscosities. Moreover, the syringe extrusion flow behavior test demonstrated that XG and TP had larger droplet aspect ratios than the other polysaccharides used in this study, showing a higher cohesiveness. In conclusion, the shear and extensional properties of TP were comprehensively explored and confirmed to have great potentials for application in developing formulations for dysphagia thickeners. [Display omitted] • It cost less to prepare thickening liquids with same IDDSI levels by using TP. • TP demonstrated higher shear thinning characteristics at the same IDDSI level. • TP exhibited better extensional rheology and cohesiveness compared to the others. • TP showed great potentials for applications in dysphagia products. [ABSTRACT FROM AUTHOR]

Masticatory simulator refers to a mechanical device that mimics the physiological structure of human oral cavity, chewing control and functions. A masticatory simulation device has advantages of not being affected by ethics, time, or environment, and is capable of providing direct experimental verification of the dynamics of food's oral breakdown, bolus reorganization, and the release of flavor compounds. This article mainly introduces oral physiology and its simulation methods, so as to provide effective scientific basis and reference factors for the construction of masticatory simulator. At the same time, based on the principle of oral chewing, this article introduces the design principle, ideas and instrument test methods of masticatory simulator equipment applied in various fields, and focuses on the preliminary classification of existing masticatory simulator devices based on the application of equipment. It is hoped to facilitate the selection and application of masticatory simulator for researchers in different research fields.

While accumulating evidence implied the involvement of retro-nasal sensation in the consumption of nonvolatile taste compounds, it is still unclear whether it was caused by the taste compounds themselves, and if so, how can they migrate from the oral to nasal cavity. At first, we proposed aerosol particles as an alternative oral–nasal mass transfer mechanism. The high-speed camera approved that aerosol particles could be generated by the typical oral and pharynx actions during food oral processing; while the narrow-band imaging of nasal cleft and mass spectrometry of nostril-exhaled air approved the migration of aerosol within the oral–nasal route. Then, the "smelling" of taste compounds within the aerosol particles was testified. The four-alternative forced choices (4AFC) approved that the potential volatile residues or contaminants within the headspace air of pure taste solution cannot arouse significant smell, while the taste compounds embedded in the in vitro prepared aerosol particles can be "smelled" via the ortho route. The "smell" of sucrose is very different from its taste and the "smell" of quinine, implying its actual olfaction. The sweetness intensity of sucrose solution was also reduced when the volunteers' noses were clipped, indicating the involvement of retro-nasal sensation during its drinking. At last, the efficiency of aerosol as a mechanism of oral–nasal mass transfer was demonstrated to be comparable with the volatile molecules under the experimental condition, giving it the potential to be a substantial and unique source of retro-nasal sensation during food oral processing. [ABSTRACT FROM AUTHOR]

Background: The state of food comminution caused by chewing is an important factor triggering the swallowing reflex. However, the impact of retronasal aroma released from comminuted food to the nose upon swallowing during food intake is poorly understood. Objective: The present study investigated the relationship between aroma concentration and swallowing threshold while chewing a standardised test food. Methods: Twenty healthy participants took part in this study. Concentration of retronasal aroma was measured over time through the nostrils using an odour sensor. The aroma concentration was measured while chewing an orange‐flavoured gummy jelly until swallowing, and the number of chewing strokes was measured to determine the swallowing threshold. Next, the aroma concentration was measured while chewing the gummy jelly for 30 strokes, and 100% and 200% of swallowing threshold without swallowing. The surface area increase in the expectorated gummy jelly pieces was calculated using image analysis and defined as masticatory performance at 30 strokes. Results: The average number of chewing strokes until the swallowing threshold was 45.1 ± 14.2. Higher masticatory performance was associated with a smaller number of chewing strokes at swallowing threshold, and a greater increase in surface area at the swallowing threshold. The number of chewing strokes and the aroma concentration were similar between the swallowing threshold and at the maximum aroma concentration while chewing at 200% of the swallowing threshold. Conclusion: The findings suggested that the swallowing threshold might be influenced by retronasal aroma concentration as well as the state of food comminution. [ABSTRACT FROM AUTHOR]

Food texture properties and consumer characteristics influence oral processing behaviors. Little is known about oral processing behavior of pungent spicy foods. In two experiments, we investigated how adding ground dried chilies to tomato soup or beef patties and curried rice altered oral processing behaviors. In Experiment One, tomato soups differing in concentration of added ground dried chilies (0.01, 0.03, 0.20 or 0.40% w/w) were consumed (n = 23). In Experiment Two, lunch meals that differed in added ground dried chilies consisting of beef patties (0.0, 0.6 or 1.2% w/w) and curried rice (0.0, 0.4 or 1.0% w/w) were consumed (n = 49). Sip/bite sizes were determined using hidden balances. Oral processing behavior was quantified using video recordings followed by post hoc annotations of specific behaviors. When eating tomato soup, increasing oral burn was associated with increasing number of water sips, water intake and total time between sips. For the solid meals (beef patties and curried rice), increasing oral burn was associated with increased time between bites and total sips of water; conversely, total oral exposure time, total number of chews and number of chews per bite all decreased with greater burn. Saliva content and rate of saliva incorporation into the solid food bolus increased with added ground dried chilies while oral exposure time decreased. We conclude consumers adapt their oral processing behaviors to oral burn of solid foods by reducing oro-sensory exposure time, chewing bites less, increasing time between bites, and consuming more water, potentially to mitigate the discomfort associated with the burn imparted by ground dried chilies.

Creaminess is a pleasant sensory attribute, generally associated with the fat components in food and closely related to the lubricating properties. Saliva plays a crucial role in oral lubrication. The interaction of salivary components with food compounds, especially fat/oil, could substantially influence creaminess. This review discusses the importance of saliva in food oral processing. The mechanisms of fat-producing creaminess perception in different types of food matrices have been discussed.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

More and more studies have being done on the deformation process of food and the formation of food bolus during chewing. However, it is hard to observe the food oral processing (FOP) of subjects and obtain related data directly. A bionic chewing robot based on a six‐axis parallel mechanism was proposed in this paper. The robot can not only simulate the movement of the lower jaw but also set a variety of oral processing parameters, such as the number and shape of teeth, oral temperature, saliva volume, chewing cycles, speed and force. Meanwhile, dental wax and peanuts were taken as food samples, and the chewing experiments were carried out by the bionic chewing robot and subjects, respectively. The results showed that the bionic chewing robot could be used to mimic human FOP and produce food bolus. Especially when the chewing cycles met the requirement of swallowing, the median particle size of the peanut bolus and the mixing effect index of the dental wax bolus in the two different experiments were highly consistent. In addition, the robot was proved to have the same food texture detection function as the texture analyzer. [ABSTRACT FROM AUTHOR]

Rheological approach has been widely applied to investigate the flow behavior of fluid food for the understanding as well as prediction of oral textural sensation of such products. However, since oral textural sensation is highly dynamic and influenced by multiple contributing factors (i.e. oral temperature, oral processing time, saliva mixing, and varied shear rate), conventional rheological measurements can hardly be precise in predicting oral textural sensation and mouthfeel. Here, we propose a very different rheology approach, which synchronizes four major dimensions/variables in one set of rheological measurements: the oral residence time, the bolus temperature, the saliva ratio, and the oral shear rate. Results indicated that the multiple dimensional rheology approach improved the predictive accuracy of the in-mouth thickness of low-temperature yogurt and provided a new measure for quantifying the mouth-melting of yogurt. It appeared that apparent viscosity at a temperature of 13 °C, a saliva ratio of 20 %, and a shear rate of 1 s−1 gave the most reliable prediction of the in-mouth thickness of yogurt. This novel approach provides a much-improved accuracy of texture prediction which requires a minimal number of rheology tests. We believe that, even though this experimental approach was initially designed for low-temperature yogurt drinks, it is also applicable to the texture and mouthfeel prediction of many other food products. [Display omitted] • A novel rheological approach synchronizes oral residence time, bolus temperature, saliva ratio, and oral shear rate in a single measurement. • Multiple dimensional rheology approach provides faster and more accurate rheological predictions for oral texture perception. • Measurements taken at approximately 40 % of oral processing time are optimal for predicting perceived thickness. • A faster change in apparent viscosity corresponds to a stronger sensory mouth-melting in yogurts. • Temperature of 13 °C, saliva ratio of 20 %, and shear rate of 1 s−1 appear to be the best combination for predicting texture sensation. [ABSTRACT FROM AUTHOR]

In this study, we hypothesize that flavor compounds, volatile as well as non-volatile, can be transferred from the oral cavity to the nasal cavity in the form of aerosol particles. To test the potential of aerosol as the carrier of flavor compounds during a drinking process, the aerosol particles of sweetener solutions (sucrose or rebaudioside A) have been quantified at both the in situ and simulated conditions, with or without saliva mixing. As observed by an optical particle counter, shaking or splashing of test samples can generate huge numbers (1000–10000) of aerosol particles with most of them smaller than 1 μm. It was further observed that addition of sucrose, rebaudioside A, saliva, thickener (konjac glucomannan) and defoamer (simethicone emulsion) can significantly alter the generated aerosol particles of water both in situ and in vitro. As estimated by the intensity of fluorescence, the amount of transferred mass within the in vitro prepared aerosol can be 4.9 μg/min. The shear viscosities, surface tension, extensional break time and relaxation time were found to correlate with the aerosol generation of test sample. These results suggest that aerosol particles have the potential in carrying substantial amount of flavor compounds during oral processing, and their generation can be sensitively affected by the presence of food components and saliva. [Display omitted] • Aerosol particles can be generated during oral processing. • Aerosol particles function as an independent mechanism of oral-nasal mass transfer. • Taste compounds can be transferred from the oral cavity to nasal cavity during oral processing. • Generation and particle size distribution of aerosol particles during oral processing influenced by a number of factors. [ABSTRACT FROM AUTHOR]

Xerostomia is closely associated with food avoidance and malnutrition among elderly populations and has become a burgeoning global concern. Artificial saliva consisting of thickening agents has been developed for xerostomia-relieving. However, current available artificial saliva can only provide a short-term relief. The main goal of this work was to evaluate the thickening, lubricating and wetting abilities of sodium hyaluronate (SH) of different molecular weights in comparison with commonly used thickening agents (xanthan gum and sodium carboxymethyl cellulose) in artificial saliva. In this study, tri-detector array gel permeation chromatography (TDA-GPC) was used to characterize the hydrodynamic parameters of three different SH samples. Their rheological, tribological, moistening as well as sensory properties were carefully assessed in parallel with thickening agents. TDA-GPC analysis showed that SH presented a flexible irregular nematic conformation in dilute solution, and the molecular weight affected the rigidity of SH molecular chains. SH solutions behaved clearly shear-thinning as well as viscoelastic. Lubricating properties and hydrophilicity of SH solutions were found to be prominent. Their wettability was also found to be better than xanthan gum. Moreover, the perceived smoothness of high molecular weight SH was higher than that of thickening agents at concentrations of 0.3% and 0.6%. Overall, this study demonstrated that SH was capable of providing efficient moistening and lubrication and could be an ideal structural component for the applications in high performance artificial saliva. [Display omitted] • SH presented a flexible irregular nematic conformation in dilute solution. • SH was demonstrated to be prominent in lubricating and moistening properties. • SH existed better sensory scores than those of commercial thickening agents. • SH has great potentials for applications in commercial artificial saliva products. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the potential of the temporal check‐all‐that‐apply (TCATA) method to describe oral behavior from the introduction of products into the mouth until swallowing. In particular, we wanted to test the feasibility of the task, the ability to show differences between composite products, and the possibility of segmenting the panel based on the data collected. Terms referring to actions performed during food oral processing (FOP) were used instead of classical sensory descriptors. The evaluation consisted, for a panel of 54 subjects, of checking the boxes corresponding to the actions in progress throughout the consumption of the products. The five products studied were an apple puree and four heterogeneous mixtures that were obtained by adding gel pieces varying in size (two sizes) and firmness (two levels of firmness). The participants did not encounter any particular difficulty in describing in real time the actions in progress during the consumption of the products. Data collected made it possible to describe the sequences of actions carried out during the FOP and to determine the influence of the presence of pieces of gels, their size and their firmness. We highlighted two groups of subjects presenting different behaviors. The subjects in the first one exhibited little difference in processing between the four samples containing the gel pieces, while the subjects in the second group adapted their behavior according to the firmness of the gel pieces. Overall, this exploratory study suggests the ability of TCATA in describing oral behavior during FOP. Future studies should aim at validating it with objective measurements of FOP. [ABSTRACT FROM AUTHOR]

The perception of some food attributes is related to mechanical stimulation and friction experienced in the tongue-palate contact during mastication. This paper reports a new bench test to measure friction in the simulated tongue-palate contact. The test consists of a flat PDMS disk, representing the tongue loaded and reciprocating against a stationary lower glass surface representing the palate. The test was applied to molten chocolate samples with and without artificial saliva. Friction was measured over the first few rubbing cycles, simulating mechanical degradation of chocolate in the tongue-palate region. The effects of chocolate composition (cocoa solids content ranging between 28 ​wt% and 85 ​wt%) and structure (micro-aeration/non-aeration 0–15 ​vol%) were studied. The bench test clearly differentiates between the various chocolate samples. The coefficient of friction increases with cocoa solids percentage and decreases with increasing micro-aeration level. The presence of artificial saliva in the contact reduced the friction for all chocolate samples, however the relative ranking remained the same.

BACKGROUND: The human tongue is important in the oral processing of food and in sensory perception. Tongue topography could influence delicate differences in sensory perception. It is hypothesized that tongue surface roughness could alter oral lubrication status and affect perception of smoothness. Fifteen participants with varying levels of tongue surface roughness were recruited and tested. Participants' in situ oral lubrication status without and after consumption of fluid food (milk with varying fat content and maltodextrin solutions with different shear viscosities) was measured. Participants' smoothness sensory scores were also recorded. RESULTS: The in situ friction coefficient (0.299–1.505) was significantly positively correlated with tongue‐surface roughness (54.6–140.0 μm) in all types of test fluid samples across participants. Oral lubrication was significantly decreased when participants consumed the test fluid samples compared with no liquid food consumption, for all test fluid sample types (P < 0.05). No significant differences in in situ friction coefficient were found after participants consumed different test fluid samples, and this was mainly attributed to the limited quantities of fluid residuals in the oral cavity after expectoration. Participants whose tongue surface roughness differed did not exhibit significant differences in smoothness perception with different test fluid samples. CONCLUSION: Tongue surface roughness has a strong impact on in situ oral lubrication, and fluid food intake reduces in situ oral lubrication significantly. Saliva film and tongue surface roughness might play greater roles in oral lubrication and smoothness sensory perception if fluid is expectorated after consumption. The association between oral physiology and texture perception still needs further elucidation. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive design approach for an electro-mechanical system for food oral processing research. The bespoke design and prototype of the proposed device is a standalone and compact table top model and can be operated using a customized software interface. The design considered a bi-directional chewing motion to enable nearly similar mandible movement pattern as in human. Food texture profile can be estimated using a load cell with capacity up to 300 N. This design included a section of real shaped teeth assembly consisting of three teeth; and a controlled supply line for multi-point saliva injections. The device is fitted with easily replaceable sensors for in situ measurements of conductivity, pH, and temperature. Operating volume of the device can be kept in equivalence with the volume of human oral and nasal space. The device chamber can be hermetically sealed and temperature controlled. A duct system is fitted to connect the device with external analytical systems, such as electronic nose, for measuring gaseous substance release during experimentation. The system also enables easy retrieval of the processed sample so as to use the masticated samples and processed saliva for subsequent analysis by analytical instruments, such as electronic tongue, to identify released soluble compounds and taste profiles. Moreover, the design emphasized on easy cleaning and maintainability. Based on the proposed design, two working prototypes are developed. It is envisaged that the device will be a novel contribution to the progress in the field of food science, new product development, training to future professionals, and strengthening industry-academic collaborations in foreseeable future. • Detailed engineering and design features for a novel electro-mechanical chewing system. • Experimental validation of the prototypes. • Review on the potential of the novel system in food oral processing research and food product assessment. [ABSTRACT FROM AUTHOR]

• Sweetener solutions and water have different aerosol generating capabilities. • Presence of sweeteners in aerosol particles can be ortho -nasally discriminated. • Retronasal sensation contribute to the discrimination between sucrose and sucralose. • Retronasal sensation contribute to the bitter and metallic perception of sweeteners. In our previous study, sucrose was shown to be able to transfer in the form of aerosol particles from oral cavity to nasal cavity and deposit onto the olfactory cleft and then be "smelled" during oral consumption. To further elucidate the important roles of aerosol particles in olfactory sensation of sweetness, further sensory tests were designed in this study for sucrose, sucralose, rebaudioside A, and sucrose + quinine solutions. In first sensory test, subjects could discriminate all samples (water, sucralose, rebaudioside A, and sucrose + quinine) from sucrose (p < 0.05) via the ortho -nasal sensation of their aerosol particles, whereas water and sucralose were favored over sucrose (p < 0.05). In second sensory test, drinking experiences of sucrose and sucralose were more similar when their noses were clipped. In third sensory test, nose-clip could reduce sucrose's sweet intensity, sucrose + quinine's bitter intensity, and rebaudioside A's metallic intensity (p < 0.05). Aerosol particles generated in-situ and in-vitro were visualized by a high-speed camera and numbers were counted by an optical particle counter. These observations extend our understating of the role of retro -nasal sensation in the flavor perception of food and beverages, and provide food industry alternative strategies of sugar-reduction in the design of healthy food and beverages. [ABSTRACT FROM AUTHOR]

Xersotomia is associated with food avoidance and low nutritional assessment. This review seeks to document whether products called "saliva substitutes" or "artificial saliva" can really replace saliva in food oral processing. Pubmed and Science Direct were searched for articles using the keywords "saliva substitutes" and "artificial saliva." An advanced search was applied using the terms "xerostomia" and/or "food oral processing" and/or "eating" and/or "mastication" and/or "chewing" and/or "swallowing." The analysis methods and the inclusion criteria were documented in a protocol published in the International prospective register of systematic reviews (PROSPERO with the registration number CRD42019124585). The search included 43 articles, published between 1979 and 2017. Among the included studies, 17 were observational studies, 5 were pilot studies, 21 were crossover studies, and 14 of these studies were blinded. The Strobe score for the included articles varied from 7.5 to 20. The possible effects of the use of saliva substitutes on the ingestion function were poorly investigated. No evidence was based on physiological studies. It is unknown whether using a saliva substitute has an effect on the composition and rheological properties of the food bolus, on the lubrication of the oral and laryngeal mucosa or on both phenomena. Moreover, saliva substitutes were not formulated to improve food oral processing and most of them are flavored. New saliva substitutes and artificial saliva should be designed and formulated to improve food oral processing. [ABSTRACT FROM AUTHOR]

A large number of methodological procedures and experimental conditions are reported to describe the masticatory process. However, similar terms are sometimes employed to describe different methodologies. Standardisation of terms is essential to allow comparisons among different studies. This article was aimed to provide a consensus concerning the terms, definitions and technical methods generally reported when evaluating masticatory function objectively and subjectively. The consensus is based on the results from discussions and consultations among world‐leading researchers in the related research areas. Advantages, limitations and relevance of each method are also discussed. The present consensus provides a revised framework of standardised terms to improve the consistent use of masticatory terminology and facilitate further investigations on masticatory function analysis. In addition, this article also outlines various methods used to evaluate the masticatory process and their advantages and disadvantages in order to help researchers to design their experiments. [ABSTRACT FROM AUTHOR]

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Consuming foods with a form or a texture that requires longer oral processing is a way to decrease food intake. Although this approach is promising for leveraging healthier eating patterns in adults, it has never been explored in children. This study evaluated whether starting a mid-afternoon snack by eating either apple segments or applesauce would modify hunger and subsequent food intake during this meal. Forty-four children (8–10 years old) participated in two videotaped mid-afternoon snacks, during which they received one of the two forms of apple as a food preload followed 10 min later by ad libitum consumption of sweetened cottage cheese. They self-reported their level of hunger throughout consumption, and the weight of cottage cheese consumed was determined at the end of the snack. Children's chewing capabilities and eating traits were parent-reported. Eating a raw apple increased oral exposure time and decreased bite size compared to eating applesauce. However, neither the reported hunger nor consecutive food intake were modified. Regardless of the meal, children eating fast had a higher ad libitum energy intake. The individual eating rate for the cottage cheese was correlated with the eating rate observed for applesauce but not for apple segments, the latter being associated with children's chewing difficulties. This study suggests that the form of a fruit offered at the start of a mid-afternoon snack does not impact food intake; the findings clearly call for more exploration of satiation mechanisms related to food texture properties among children and indicate the need to consider children's oral processing skills.

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.