Food oral processing is an essential procedure not only for the consumption and digestion of foods but also for the appreciation and pleasure of food texture and food flavour. The consumption of a ...food inside mouth involves various oral operations, including first bite, chewing and mastication, transportation, bolus formation, swallowing, etc. Exact mechanisms and governing principles of these oral operations are still not fully understood, despite of continuous efforts made by scientists from food, psychology, physiology, dental and clinical studies, and other disciplines. This article reviews recent progresses and literature findings about food processing and transformation in mouth, with particular attention on the physiology and rheology aspects of oral operations. The physiological behaviour of human's oral device is discussed in terms of biting capability, tongue movement, saliva production and incorporation, and swallowing. The complexity of oral processing is analysed in relation to the rheology and mechanical properties of foods. The swallowing and oral clearing process is also examined for its criteria, triggering mechanism, bolus deformation, and the rheology of swallowing.
Saliva is a complex fluid with multifunctional roles in the oral cavity. Even though its importance on oral health maintenance has long been recognized, the critical functions of saliva on food oral ...processing and perception have only been acknowledged recently.
This review will present saliva as an unavoidable ingredient that has a profound impact on our eating experience. We aim to emphasize that what is perceived in-mouth is a food-saliva mixture rather than the food on the plate. The mechanisms through which saliva interacts with food components will be discussed in detail together with the implications of food-saliva interactions to food oral processing and perception.
At the structural level, saliva facilitates the breakdown of food structures, contributes to the formation of a cohesive bolus and increases the degree of lubrication for a safe swallow. At the molecular level, saliva interacts with food components, leading to the formation of new compounds, complexes and microstructures. The mechanisms underlying food-saliva interactions include surface coating and clustering, colloidal interactions, complexation, enzymatic breakdown and binding of aroma compounds.
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•Saliva is an unavoidable ingredient in food oral processing.•Saliva influences greatly our eating experience, oral strategy and sensory perception.•What is perceived in-mouth is a food-saliva mixture rather than the food on the plate.•Saliva should not be neglected when trying to understand oral sensations/perception.•Saliva plays a role in the variability of eating behavior, perception and preference.
Edible insects are considered a new alternative sustainable source of proteins that exhibits higher feed-conversion efficiency and has a less negative environmental impact, compared to conventional ...animal-derived protein sources. Highly nutritional edible insects may help solve issues of global malnutrition and food insecurity, while byproducts have the potential for practical application in the food industry, agriculture, and medicine. Despite these numerous benefits, negative attitudes toward insects as food exist in societies where it is not part of their culture to consume insects, raising barriers to the wider introduction of edible insects in the diet on a regular basis.
In this review, we discuss the sensory characteristics, such as flavor and texture, of edible insect and insect-based foods, their contribution to consumers’ attitudes toward edible insects, and approaches to alter the quality of sensory attributes—from insect farming and processing to novel product formulation and taste education.
Sensory and visual characteristics of edible insects, and availability of information on their origin and safety, are important factors in consumer appeal and their willingness to try eating insects in the future. Flavor and texture of edible insects depend largely on the insect species, its development stage, and the way it is processed. Recent findings on insect production, processing, and formulation of insect-based foods, as well as ways to increase familiarity with edible insects, demonstrate the potential to enhance the acceptability of insects as a novel food.
•Edible insects could be a new alternative sustainable source of protein.•Sensory characteristics of edible insects affect consumer appeal.•Flavor and texture vary among insect species.•Insect processing and product formulation alter sensory attributes.•Taste education may enhance perception of edible insects.
As the very first step of food consumption, food oral processing is not only of great importance to food intake and the following digestion and adsorption, but also provides the necessary sensory ...attributes that please the consumer. Starting from the first bite, to oral manipulation including mastication and transportation, until bolus formation and swallowing, food products undergo a variety of physical and biochemical changes over a wide range of time and length scales. A number of efforts had been made to uncover the mechanisms in each oral processing step; some of which are still poorly understood. This review covers some of the most recent progress made in the area of food oral processing, with an emphasis on eating and swallowing difficulties in the elderly and the corresponding model food development. It also includes the oral surface coating and lubrication and the dynamic textural perception during food oral processing. The authors hope that this will facilitate food scientists, psychologists, dentists and other clinical researchers to further understand and reveal the detailed controlling mechanisms and governing principles of food oral processing.
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•A specific review emphasis on the eating and swallowing issues and their solutions for the elderly population•A summary of most recent development of model foods for food oral processing research and weight control clinical purpose•Food-saliva interactions during food oral processing and the dynamic sensory perception evaluations
Soy protein isolate (SPI) was modified by ultrasound pretreatment (200 W, 400 W, 600 W) and controlled papain hydrolysis, and the emulsifying properties of SPIH (SPI hydrolysates) and USPIH ...(ultrasound pretreated SPIH) were investigated. Analysis of mean droplet sizes and creaming indices of emulsions formed by SPIH and USPIH showed that some USPIH had markedly improved emulsifying capability and emulsion stabilization against creaming during quiescent storage. Compared with control SPI and SPIH-0.58% degree of hydrolysis (DH), USPIH-400W-1.25% (USPIH pretreated under 400W sonication and hydrolyzed to 1.25% DH) was capable of forming a stable fine emulsion (d 43 = 1.79 μm) at a lower concentration (3.0% w/v). A variety of physicochemical and interfacial properties of USPIH-400W products have been investigated in relation to DH and emulsifying properties. SDS−PAGE showed that ultrasound pretreatment could significantly improve the accessibility of some subunits (α-7S and A-11S) in soy proteins to papain hydrolysis, resulting in changes in DH, protein solubility (PS), surface hydrophobicity (H 0), and secondary structure for USPIH-400W. Compared with control SPI and SPIH-0.58%, USPIH-400W-1.25% had a higher protein adsorption fraction (F ads) and a lower saturation surface load (Γsat), which is mainly due to its higher PS and random coil content, and may explain its markedly improved emulsifying capability. This study demonstrated that combined ultrasound pretreatment and controlled enzymatic hydrolysis could be an effective method for the functionality modification of globular proteins.
Oral processing of food is a dynamic process involving a range of deformation processes. The mechanical properties and the rheology of food have been widely used to understand and predict in mouth ...flow properties and to discover relationships with sensory perception. However, only limited success has been realised using such approaches to characterise and to interpret food texture. Tribology is emerging as a contributing discipline for understanding oral processing of food as well as texture and mouthfeel, since it encompasses both the fluid’s (lubricant’s) rheological properties as well as the surface properties of the interacting substrates in relative motion.
► Two very different physical principles for the oral perception of food texture. ► “Oral” rheology dominates texture sensation at the early stage of eating. ► “Oral” tribology dominates texture sensation at the later stage of eating. ► Transition of food rheology to tribology reflected in TDS profile analysis. ► Texture features could be grouped as related to rheology or tribology or both.
In this work, peanut protein isolate (PPI) was grafted with maltodextrin (MD) through the ultrasound-assisted Maillard reaction. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) ...analysis showed a link between PPI and MD. The substantially increased accessibility of the major subunits (conarachin, acidic subunit of arachin, and basic subunit of arachin) in PPI under high-intensity ultrasound treatment led to changes in the degree of graft (DG), zeta-potential, protein solubility, and surface hydrophobicity of conjugates. Emulsion systems (20% v/v oil, 2.0% w/v PPI equivalent, pH 3.8) formed by untreated PPI, PPI-MDC (PPI-MD conjugates obtained with wet-heating alone), and UPPI-MDC (PPI-MD conjugates obtained with ultrasound-assisted wet heating) were characterized using a light-scatter particle size analyzer and confocal laser scanning microscope. Results showed that emulsions of untreated PPI and PPI-MDC were not stable due to immediate bridging flocculation and coalescence of droplets, whereas that formed by UPPI-MDC with 32.4% DG was stable with a smaller mean droplet size. It was believed that high-intensity ultrasound promoted production of glycated PPI, which was soluble and surface active at pH 3.8 and thus improved emulsification properties for UPPI-MDC. This study shows that glycated PPI by ultrasound-assisted Maillard reaction is an effective emulsifying agent for low pH applications.
Thickened fluids and texture‐modified foods are commonly used in the medical management of individuals who suffer from swallowing difficulty (known as dysphagia). However, how to reliably assess ...texture properties of such food systems is still a big challenge both to industry and to academic researchers. This article aims to identify key physical parameters that are important for objective assessment of such properties by reviewing the significance of rheological or textural properties of thickened fluids and texture‐modified foods for swallowing. Literature reviews have identified that dominating textural properties in relation to swallowing could be very different for thickened fluids and for texture‐modified foods. Important parameters of thickened fluids are generally related with the flow of the bolus in the pharyngeal stage, while important parameters of texture‐modified foods are generally related with the bolus preparation in the oral stage as well as the bolus flow in the pharyngeal stage. This review helps to identify key textural parameters of thickened fluids and texture‐modified foods in relation to eating and swallowing and to develop objective measuring techniques for quality control of thickened fluids and texture‐modified foods for dysphagia management.
Food oral processing research covers the study of mastication, role of tongue, teeth, and palate, food-saliva interaction, bolus formation, texture and flavor perceptions, etc. Over the preceding ...decades, instrumental approaches were advanced to evaluate texture, flavor, and other physicochemical changes by simulating some form of oral functionalities and environments. However, a comprehensive assessment of food products under actual oral processing is still an open topic of research, and has many persisting challenges. Present experimental methods utilize a number of different instruments and feedbacks from trained human panel in order to draw some form of correlations between physicochemical properties of the food composition and its sensorial properties. Major shortfalls of these existing instruments are their justifiable limitation to become a true representation of actual oral conditions and mechanisms. It therefore leads to contemplate on an ambitious objective to develop a device closely resembling the processes and mechanisms of human mouth.
This paper proposes a review of the development of artificial mouth and masticatory devices designed specifically for food oral processing studies. The devices which have been exclusively built for other purposes such as dental treatment, speech therapy, jaw simulation, etc. are judicially excluded from this review. The article further covered a state of the art on engineering interpretation of oral features. Following on, sincere attempts have been made to identify and classify the challenges and research gaps including the interdisciplinary nature of the field. This review has been summarized with guidelines for follow-up research and development in the direction of advance instrumentalization of food oral processing covering the research interests from both academics and food industries.
•Engineering details of the anatomical and physiological features of human mouth in relation to food oral processing.•Succinct review on artificial masticatory devices currently available for food oral processing research.•Organization and categorization of the challenges, research gaps, and scopes for the future artificial oral systems.
Swallowing is the final stage of an eating process. Even though individuals know exactly when and how to swallow, the controlling mechanisms and the determining criteria of bolus swallowing are still ...not yet clear. One hypothesis is that bolus rheology, i.e. its flow-ability and stretch-ability, determines the triggering of a swallowing and the main aim of this work was to test this hypothesis. A wide range of fluid foods, including 18 commercial products and 10 lab-constituted foods, were examined for easiness of swallowing by a panel of 19 subjects. Oral residence time, defined as the time from the ingestion till the completion of swallowing, was determined for each eating process. It was observed that the oral residence time had a linear relationship with the sensed difficulty of swallowing. That is a food sensed difficult-to-swallow tends to stay longer in the oral cavity. Rheological properties (both shear and stretching flow) of these foods and their simulated boluses (mixture of food and simulated saliva) have also been determined at body temperature. The apparent shear viscosity showed a positive correlation with the sensed difficult of swallowing. However, the stretching behaviour of a fluid food, characterised by the maximum stretching force and the work of stretching showed much improved correlation to the sensory perceived easiness of swallowing. It was concluded that bolus rheology, in particular its extensional stretch-ability, had the most important influence on the ease of swallowing.
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