Bolus quality and food comfortability of model cheeses for the elderly as influenced by their texture

Organoleptic properties and neuroimaging response on the perception of edible gels

The rapidly increasing number of elderly people in the world highlights the need for the development of innovative foods with modified textures that do not expose the elderly to the risks associated with food consumption (risk of aspiration, suffocation, and chocking). Providing specific food such as edible gel for the elderly population and the study of their properties is a challenge for the scientific community. There are some available gels in the supermarkets destined for the sports population, with specific texture and technological properties that could be used and extrapolated for senior people. To explore this potential, five types of sport commercial gels purchased from a local Slovak market were characterized in order to evaluate their technological properties and to know if these types of gels are suitable for the senior population. The energy gels were evaluated using acceptance testing, involving 75 seniors who evaluated important organoleptic attributes by a combination of hedonic and intensity scales. The same consumer panel then profiled the gels using the Temporal Dominance of Sensations (TDS) technique. The prevalence of food neophobia was measured with the Food Neophobia Scale (FNS) and also using neuroimaging and biometric methods. The results suggest that there are significant differences in the perception of edible gels, as confirmed by measurements via electroencephalography (EEG) and Facereading. We conclude by suggesting the potential of specific foods such as edible gels for the elderly population as our findings also confirm that the composition of these specific and sustainable foods may elicit different perceptions. This highlights the need to use biometric and neuroimaging methods in food research in order to create more optimal formulations for specific populations.

Bolus rheology of texture adjusted food-Effect of age

Swallowing disorders, or dysphagia, affect a large part of the population due to factors such as degenerative diseases, medication side effects or simply age-related impairment of physiological oropharyngeal function. The management of dysphagia is mainly handles through texture-modified foods of progressively softer, smoother, moister textures, depending on the severity of the disorder. Rheological and physiological-related properties of boluses were determined for a group of five older persons (average age, 74) for a set of texture-modified foods: bread, cheese and tomato and the combination into a sandwich. The softest class was gel food, after which came a smooth timbale; both were compared to boluses of regular food. The subjects chewed until ready to swallow, at which point the bolus was expectorated and measured regarding saliva content, linear viscoelasticity and shear viscosity. The results were compared to those of a previously studied younger group (average age, 38). The general physiological status of the subjects was determined by hand and tongue strength, diadochokinesis and one-legged standing and showed that all subjects were as healthy and fit as the younger group. Age-related properties such as one-legged standing with closed eyes and salivary flow plus bolus saliva content were lower for the older group, but the average chews-until-swallow was surprisingly also lower. Consequently, bolus modulus and viscosity were higher than for the younger group. Overall, the intended texture modification was reflected in bolus rheological and physiological-related properties. Bolus modulus, viscosity, saliva content and chews-until-swallowed all decreased from regular food to timbale food to gel food.

Influence of food oral processing, bolus characteristics, and digestive conditions on the protein digestibility of turkey cold meat and fresh cheese

During mastication, foods are progressively transformed to achieve swallowable boluses and their characteristics are crucial for the subsequent digestion events. The main goal of this work was to evaluate the impact of food oral processing, bolus properties, and different digestive conditions on the protein digestibility of turkey cold meat and fresh cheese. In vivo normal and deficient masticated food boluses were prepared by a young volunteer. Besides, three digestion models were used to simulate the different physiological conditions frequently observed in adults and the elderly, presenting good or poor oral health: i) Normal Masticated-Normal Digested model; ii) Deficient Masticated-Normal Digested model; and iii) Deficient Masticated-Elderly Digested model. The oral processing behaviour (number of chews, chewing time, chewing rate, and saliva uptake), bolus particle size, textural and viscoelastic properties of boluses, and protein digestibility of samples were determined. Results showed that deficient masticated boluses exhibited lower amounts of saliva uptake and greater particle sizes, hardness, stiffness, and rigidity, notably in deficient masticated turkey cold meat boluses. Moreover, the worst digestive scenario (Deficient Masticated-Elderly Digested model) negatively impacted on the proteolysis extend of samples, especially for total soluble proteins and soluble peptides contents. The current study demonstrates that the oral processing behaviour and degree of food fragmentation impacted on the granulometric, texture, and viscoelastic properties of both food boluses, whereas the worst digestive scenario commonly observed in the elderly reduced the proteolysis extend of the products evaluated.

A secret of salivary secretions: Multimodal effect of saliva in sensory perception of food

Saliva plays multifunctional roles in oral cavity. Even though its importance for the maintenance of oral health has long been established, the role of saliva in food perception has attracted increasing attention in recent years. We encourage researchers to discover the peculiarity of this biological fluid and aim to combine the data concerning all aspects of the saliva influence on the sensory perception of food. This review presents saliva as a unique material, which modulates food perception due to constant presence of saliva in the mouth and thanks to its composition. Therefore, we highlight the salivary components that contribute to these effects. Moreover, this review is an attempt to structure the effects of saliva on perception of different food categories, where the mechanisms of salivary impact in perception of liquid, semi-solid, and solid foods are revealed. Finally, we emphasize that the large inter-individual variability in salivary composition and secretion appear to contribute to the fact that everyone experiences food in their own way. Therefore, the design of the sensory studies should consider the properties of volunteers' saliva and also carefully monitor the experimental conditions that affect salivary composition and flow rate.

Relationship among oral health status, bolus formation and food comfortability during consumption of model cheeses in elderly

The aim of this study was to investigate the impact of oral impairment on chewing behaviour, food bolus properties and food comfortability during elderly consumption of model cheeses. Seventy-two elderly persons (aged 66 to 88) was recruited and classified into two groups according to dental status (poor vs. satisfactory). They showed a wide range of salivary flow rates whatever their dental status (stimulated: 0.2-3.8 mL min^-1, resting: 0.1-0.8 mL min^-1). Standardized bites of four model cheeses with an identical composition but different textures (soft, hard, processed and whipped) were tested. The time and number of chewing cycles required to form a bolus were measured. The rheological properties of the bolus were studied, as was saliva moistening. Food comfortability was assessed by means of a questionnaire composed of 5 sections (1-oral comfort, 2-bolus formation, 3-pain, 4-texture and 5-flavour perception). The chewing parameters measured were not modified by the oral health. However, elderly with poor dentition formed harder boluses than elderly with satisfactory dentition. Moreover, for elderly with poor dentition, the quantity of saliva incorporated into the bolus was correlated with the stimulated salivary flow rate, which was not the case for elderly with satisfactory dentition. General oral comfort and its different attributes were poorly associated with the oral health of the elderly. A multifactorial analysis performed on an average cheese showed that food comfortability is independent of changes in the hardness and moistening of the bolus, regardless of dental status. In particular, poor dental status increases the hardness of the bolus without modifying its comfortability.

Food-related oral discomfort: A cross-sectional survey assessing the sensory dimension of oral discomfort in French independently living adults

BACKGROUND

Discomfort encountered during oral processing may cause food avoidance and increase the risk of malnutrition in older adults. The aim of the present survey was to explore the relationships between oral health and the oral discomfort experienced while eating in senior people.

MATERIALS AND METHODS

In a cross-sectional study, oral discomfort was assessed in a sample of 119 independently living participants aged between 35 and 81 years. Statistical analyses were used to identify categorical variables associated with food-related oral discomfort, including age, oral health-related quality of life (OHQoL), saliva secretion, occluding support, oral diseases and denture use.

RESULTS

Food-related oral discomfort concerned 28.5% of the participants. Within the sample study, the risk of experiencing food-related oral discomfort was increased for participants perceiving average (OR = 7.968, CI 95% = 2.603-24.381, p = .000) or poor OHQoL (OR = 17.109, CI 95% = 4.398-66.552, p = .000) and presenting strictly fewer than 7 occlusal functional units (OFUs) (OR = 3.396, CI 95% = 1.206-9.561, p = .020). Textured foods including fibrous (66.6%), heterogenous (60.6%) and grainy foods (42.4%) were mostly cited as food-related oral discomfort trigger factors. Within the 66-80 years group, participants having 0-6 OFUs were four times more likely to experience oral discomfort related to fibrous foods than participants having more than 7 OFUs (OR = 4.812, CI 95% = 1.192-19.415, p = .024). Within this group, participants having their teeth replaced by denture were also four times more likely to develop oral discomfort related to foods with heterogeneous textures (OR = 4.714, CI 95% = 1.030-21.562, p = .045) and grainy foods (OR = 7.285, CI 95% = 1.308-40.568, p = .023) than non-denture wearers.

CONCLUSION

Poor oral health conditions may generate oral discomfort with foods in the elderly especially with fibrous, heterogenous and grainy textures, and thus affect mealtime experience.

Bolus rheology of texture-modified food: Effect of degree of modification

Swallowing disorders, or dysphagia, require an intake of texture-modified foods progressively softer, smoother, and moister depending on the severity of the disorder. Bolus rheology was determined for five healthy subjects for a set of such solid foods regularly given to dysphagia patients. The softest class was gel food, then a smooth timbale which both were compared to the corresponding regular, un-modified food. The foods investigated were bread, cheese, tomato, and the combination as a sandwich, all for the respective texture class: gel, timbale, and regular food. The subjects chewed until ready to swallow and the expectorated bolus was immediately measured for complex shear modulus and viscosity, and moisture and saliva content were determined. Rheology show that texture-modification influenced bolus rheology with decreased viscosity and modulus for increased degree of modification. Also saliva content as well as chews-to-swallow decreased with degree of modification. Overall, the bolus saliva content was lower for the combination (sandwich) than for the individual components. Saliva content was fairly constant irrespective of food moisture content. The phase angle for all boluses was also relatively constant, indicating a similar bolus structure. All boluses of the texture-modified foods showed high extensional viscosity, which is important for bolus cohesiveness. Bolus rheology rather than food texture determines if a food is safe to swallow and the results show that the intended texture-modification is reflected in the flow properties of the respective boluses.

Physical properties of a model set of solid, texture-modified foods

Those suffering from swallowing disorders, or dysphagia, require texture-modified foods for safe swallowing. The texture is modified according to the severity of the disorder, as maintained by the guidelines outlining classes of texture-modified foods, ranging from viscous soups to soft, solid foods. As a basis for studies of bolus rheology and oral response of solid texture-modified foods, a set of well-defined, solid foods has been identified and characterized regarding texture and physical properties. Gelled food is compared to both the firmer timbale class and to the corresponding regular food. Foods eaten at room temperature were chosen to avoid temperature effects: bread, cheese, tomato, and the combination into a sandwich. All foods were tested as gel, timbale, and regular food. The texture was determined by compression and penetration tests, thereby showing a decrease in strength (compression stress), stiffness (modulus), and penetration force for increased degree of modification. The moisture content increased with increased degree of modification. The structural change from room to oral temperature was monitored by the complex shear modulus that showed a decrease with increasing temperature. Cheese and the gelatine-based tomato gel showed a distinct melting when the temperature was increased to 37°C. The texture-modified foods were softer and moister in all aspects as compared to the regular foods, which follows the intended modification. The classes for the texture-modified foods were qualitatively comparable to other national classification systems with regard to solid foods, but there is a lack of objective, physics-based classification of texture, especially for solid, texture-modified foods.

Texture and texture assessment of thickened fluids and texture-modified food for dysphagia management

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.

Formulating protein-based beverages for the dysphagia diets of the elderly: viscosity, protein quality, in vitro digestion, and consumers acceptability

BACKGROUND

Dysphagia is defined as a disorder of the swallowing mechanism. The most common management of dysphagia is diet modification by thickening food and beverages. This study aimed to obtain protein-based beverages for the dysphagia diets of the elderly, corresponding to the 'honey' (III) level of dysphagia fluids according to the National Dysphagia Diet classifications, and containing 100 g kg^-1 of good-quality proteins with a high rate of hydrolysis during digestion.

RESULTS

Four protein formulations made from pea proteins, milk proteins, a mixture of milk and pea proteins, and milk proteins with added konjac glucomannan, were evaluated on the basis of rheological characterization and proteolysis kinetics during in vitro digestion. The mixture of milk proteins and pea proteins, and the mixture of milk proteins with added konjac glucomannan, showed typical yielding pseudoplastic fluid behavior with similar apparent viscosity but different structural characteristics. These differences were the reason for the differences in proteolysis kinetics during digestion. The mixture of milk and pea proteins showed viscous liquid behavior and was more rapidly hydrolyzed under gastrointestinal conditions than mixtures containing milk proteins and konjac glucomannan acting as a weak gel system.

CONCLUSION

We presume that geriatric consumers with swallowing difficulties may benefit from 'honey'-level viscosity, protein-based beverages containing pea and milk proteins through faster proteolysis and better bioaccessibility of amino acids during digestion. © 2020 Society of Chemical Industry.

Considerations for the Development of Innovative Foods to Improve Nutrition in Older Adults

The population of older adults is growing globally. This increase has led to an accumulation of chronic illnesses, so-called age-related diseases. Diet and nutrition are considered the main drivers of the global burden of diseases, and this situation applies especially to this population segment. It relates directly to the development of coronary heart disease, hypertension, some types of cancer, and type 2 diabetes, among other diseases, while age-associated changes in body composition (bone and muscle mass, fat, sarcopenia) constitute risk factors for functional limitations affecting health status and the quality of life. Older adults present eating and swallowing problems, dry mouth, taste loss, and anorexia among other problems causing “anorexia of aging” that affects their nutritional status. The strategies to overcome these situations are described in this study. The impact of oral food processing on nutrition is discussed, as well as approaches to improve food acceptance through the design of innovative foods. These foods should supply a growing demand as this group represents an increasing segment of the consumer market globally, whose needs must be fulfilled.