A Sensory Method to Evaluate Food Texture for Oropharyngeal Dysphagia by Emulating Oral Tasks

ABSTRACT

Dysphagia involves impairments in chewing and swallowing, requiring foods with controlled textural properties to ensure safe and efficient oral processing. Despite standardized frameworks like the International Dysphagia Diet Standardisation Initiative (IDDSI), reproducible sensory evaluation tools are limited. This study proposes a methodological framework for the sensory evaluation of texture‐modified foods (TMFs) designed to mimic the oral processing patterns of individuals with oropharyngeal dysphagia (OD). A multidisciplinary expert panel developed a structured sensory protocol incorporating emulated oral tasks representative of typical oral behaviors in OD patients. Thirty‐two commercial TMFs were analyzed, identifying key sensory attributes—hardness, fracturability, adhesiveness, flowability, residue and intraoral variability—linked to swallowing safety and acceptability. Oral tasks included holding the food in the mouth, moving it with the tongue, pressing it against and removing it from the palate, assessing consistency changes, and swallowing. Each attribute was mapped to specific oral tasks. Results revealed substantial variability in the sensorial attributes of foods intended for OD people. This approach bridges clinical dysphagia care with sensory science, enabling better evaluation and development of safer, more acceptable foods for individuals with OD. Further validation is warranted to confirm its diagnostic and practical applicability.

Oropharyngeal dysphagia (OD) impairs chewing and swallowing, requiring adapted food textures. This study presents a sensory evaluation method for texture‐modified foods based on emulating oral tasks performed by people with OD. Specific oral tasks were linked to key attributes such as hardness, adhesiveness, and residue. Findings reveal substantial variability among products, providing a framework to develop safer, more acceptable foods for people with OD.

1. Introduction

1.1. Background

Sensory analysis of food is an essential tool for establishing relationships between consumers' sensory perceptions and the physicochemical and functional properties of products (Ray 2021; Ruiz‐Capillas and Herrero 2021). During oral processing, food is transformed into a bolus suitable for swallowing through the action of sensory receptors and their interaction with factors such as saliva, temperature, and oral mucosa (Engelen and van der Bilt 2008). From this perspective, the sensory analysis of texture provides a valuable framework for developing cognitive tasks focused on oral processing and facilitates understanding of how the physical and chemical properties of food affect the consumer's perceptual experience. Although oral processing is an implicit component of sensory analysis in individuals without swallowing disorders, it becomes a critical consideration for those with difficulty in chewing and/or swallowing.

The term dysphagia refers to difficulty in processing, moving, and swallowing food from the oral cavity through the pharynx and esophagus (Logemann 1998). A specific condition, oropharyngeal dysphagia (OD), involves impairments in the oral and pharyngeal phases of swallowing, which compromise the safety and efficiency of the process (Clavé and Shaker 2015). Given its functional impact, dysphagia is a common symptom across various populations, including older adults, individuals with neurological disorders or cancer, critically ill patients, and those undergoing long‐term hospitalization (Baijens et al. 2016). Each group exhibits a distinct dysphagia phenotype, with differing swallowing deficits that require foods with adapted textures to ensure safe and effective intake.

The textural adaptation of foods for individuals with OD is supported by robust scientific evidence proving its effectiveness in reducing swallowing complications and enhancing quality of life (García‐Segovia et al. 2020; Hadde 2022; Sukkar et al. 2018; Wu et al. 2021). Longitudinal studies have shown that this approach improves caloric and protein intake, reducing the risk of malnutrition and sarcopenia, which are common in people with OD. Adapting textures per standardized protocols also lowers the risk of respiratory infections, including pneumonia resulting from bronchoaspiration (Cichero et al. 2017). However, clinical implementation faces challenges stemming from the lack of international consensus on terminology and classification of OD‐oriented food textures. Subjectivity and variability in assessment practices hinder diet standardization and the alignment between professional recommendations and the patient's actual intake. More than 50 terms have been identified to describe food textures, highlighting the urgent need for unified criteria (Cichero et al. 2017; Yli‐Hukka et al. 2022).

In the sensory analysis of OD‐oriented foods, studies focus on evaluating attributes such as viscosity, graininess, stickiness, smell, and taste, based on procedures derived from general sensory analysis (Chambers et al. 2017). This analysis is critical for validating the acceptance and safety of texture‐modified foods (TMFs) by identifying attributes that optimize swallowing (Matta et al. 2006; Merino et al. 2021). The sensory experience of people with OD and their caregivers plays a key role in food validation, and alignment with clinical recommendations is crucial to ensure safe and adequate nutrition (Cheng et al. 2025). However, the lack of alignment between clinical guidance and the food industry limits TMFs' availability. A paucity of knowledge, an absence of consensus, and fear of complications such as choking or malnutrition generate uncertainty among patients and their caregivers, affecting adherence to the recommended dietary adaptations (Kalkers et al. 2022). As a result, diets are often restricted to pureed foods, limiting opportunities to explore other options that could be equally safe but more appealing. Research on TMFs for people with OD remains limited, partly due to ongoing barriers to accessing products such as thickening and texturizing agents. These challenges emphasize the need for further exploration and new approaches aimed at analyzing the sensory aspects of oral feeding (Dhamodharan et al. 2025).

The International Dysphagia Diet Standardization Initiative (IDDSI) framework provides a globally recognized tool for classifying and adapting food textures, promoting accessible and safe options (Cichero et al. 2017). However, its implementation in the food industry faces significant challenges, including the lack of standardized methods to ensure the consistency and safety of TMFs. The oral cavity's remarkable ability to discriminate complex textural attributes represents a potentially valuable, yet largely unexplored, advantage in the field of OD (Vance Civille and Seltsam 2014). Caregivers and clinicians typically test foods to validate their suitability, but the procedure lacks standardized protocols to ensure objective, reproducible, and safe results. The theoretical framework for food adaptation proposed by IDDSI recommends that people with OD verify the texture of their food through visual techniques such as the drip test for liquids (spilled from a spoon) or the pressure test with a cutlery (mashed with a fork), as well as observing adhesiveness, similar to the tests performed in an instrumental texture profile analysis (TPA), among others. This underscores that the evaluator's experience, skill, and knowledge are essential to ensure food safety and acceptability. Assessments should also be aligned with the recommendations of the clinical professional responsible for the individual with OD.

At present, a consensus among professionals is lacking, resulting in confusion and potential risks for people with OD (Cheng et al. 2025). Consequently, the development of objective and reproducible sensory tools is critical to assess the acceptability and safety of adapted foods, facilitating their application by clinical professionals, caregivers, and the food industry.

1.2. Theoretical Framework for Evaluating Texture Modification in Dysphagia

In the field of food sensory analysis, standardization of terminology is key to ensure consistency in communication among the different stakeholders involved. For example, (ISO 5492:2008) establishes a specific vocabulary for the scientific field and provides a common framework that integrates the multisensory dimension of analysis, including visual, olfactory, gustatory, tactile, and auditory aspects, as well as factors that may influence evaluation, such as sensory fatigue or the evaluator's prior expectations (ISO 5492: 2008). Another relevant standard is ISO 11036:2020, which relates to the texture profile method. Both standards support the development of reproducible and rigorous sensory evaluation tools (ISO 11036: 2020). However, since ISO standards were created for evaluation by normotypical individuals, applying them to foods formulated for dysphagic populations needs methodological adjustments.

Oral feeding is a fundamental means by which humans interact with their environment. This connection transcends the basic functions of nutrition and hydration by enabling active participation in daily life, promoting social relationships, and reinforcing individual identity. During daily life, people have access to a wide variety of foods, the contact, selection, and handling of which are part of a preliminary phase that directly influences oral processing (Shune et al. 2016). This prior contact with food triggers anticipatory responses that benefit oral processing and swallowing. Before ingestion, humans validate food through a multisensory assessment, mainly visual and olfactory, which allows them to anticipate the effort and chewing and swallowing strategies required. Although this process is often implicit, it is often overlooked when offering food to people with OD. In practice, these patients often receive food that is unpalatable, unattractive in appearance, and of unclear origin, which could lead to atypical oral processing patterns even in people without swallowing difficulties. Therefore, it is essential to consider food sensory and textural attributes from this initial stage in order to anticipate the oral processing required (Álvarez et al. 2020). Once in the oral cavity, food undergoes processing through mechanical and chemical actions that constitute the first stage of digestion. The efficiency of this processing depends on the physical nature of the food, differing between liquids, semisolids, and solids, each involving specific phases (Matsuo and Fujishima 2020; Vance Civille and Seltsam 2014).

According to Matsuo and Fujishima (2020), during the oral processing of solid foods, the transport stage is divided into different sub‐phases. These include the transformation of food into a cohesive bolus, which involves crushing, kneading, and cohesion, until a structure suitable for effective and safe swallowing is obtained. Devezeaux de Lavergne et al. (2017) provides an overview of oral processing focused on food attributes during oral processing, identifying two key moments: the initial phase, in which the food undergoes transformations that modify its original characteristics, and the development phase, in which attributes influencing the mechanics of oral processing emerge and intensify. The final outcome of these actions is the formation of a bolus, which involves a series of coordinated oral actions aimed at achieving specific physical and mechanical properties to ensure effective and safe swallowing. Various studies have established that the bolus must meet certain basic requirements of moderate cohesiveness, low adhesiveness, particle size less than 3–4 mm (Gray‐Stuart 2016), and optimal moisture conditions, reaching approximately 30% saliva content (Hosotsubo et al. 2016). These characteristics help food to acquire a cohesive and safe structure, allowing efficient transport through the pharynx and esophagus while minimizing the risk of choking, aspiration, or ineffective swallowing. During oral processing, the larynx prepares to execute a triple closure mechanism to protect the airway during bolus transit through the pharynx. This involves the descent of the epiglottis, the approximation of the true and false vocal cords, and the closure of the laryngeal vestibule. Immediately after, the upper esophageal sphincter opens, allowing the bolus to pass from the pharynx into the esophagus. This step is facilitated by the constriction exerted by the pharyngeal muscles and the back of the tongue. Once the bolus enters the esophagus, the upper esophageal sphincter closes again and the laryngeal vestibule reopens, thus restoring normal respiratory function (Shaw and Martino 2013).

Another key conceptual foundation for the present methodological proposal is the typical pathophysiological profile of people with OD. The inherent difficulties in oral processing and swallowing lead to various compensations and adaptations of normal mechanics, which in turn influence the rheology and tribology behavior of the food. Recognizing the feeding phenotype of an individual with dysphagia enables them to be considered as consumers with specific needs, thereby guiding the design of appropriate solutions. Individuals with dysphagia often exhibit a variety of oral behaviors that make them unique to consumers, as oral processing can modify the properties of the bolus. These behaviors include:

• Attempts at lingual propulsion with reduced force levels, which alter the mechanical properties of the bolus through shearing effects.

• Chewing compensation by pressing the tongue against the palate, used to mitigate deficits in mastication.

• Prolonged oral processing time, resulting in extended food residence in the oral cavity.

• Delayed swallowing onset, due to reduced efficiency in laryngeal vestibule closure or upper esophageal sphincter opening, potentially compromises safe bolus transit.

• Increased oral secretions resulting from impaired clearance. This condition can cause the bolus to mix with greater quantities of thicker saliva.

• Decreased oral secretions in cases of xerostomia, which negatively impacts bolus lubrication and cohesion.

• Gums‐based mastication, often due to tooth loss, compromises proper food fragmentation.

• Heightened alertness during oral processing, reflecting increased muscle fatigue caused by voluntary motor compensations that override normal automatic control.

• An active residue phase, marked by double or repeated swallowing attempts to ensure tract cleansing, often accompanied by changes in saliva properties (e.g., increased volume and/or density) after swallowing certain foods.

In addition, it is needed to distinguish between different phenotypes of dysphagia according to the underlying etiology (Table 1), as these variations determine the need to adapt the physical characteristics of food to optimize both oral processing and swallowing performance.

TABLE 1.

Phenotypes of dysphagia and their characteristics.

Phenotype	Characteristics	References
Presbyphagia	The person does not necessarily experience difficulty swallowing, and it is common for them to normalize the condition. Tooth loss makes it difficult to handle hard foods. Food passage through the pharynx may be less effective, and some residue may remain after swallowing certain foods (attention should be paid to fracturability and residue). Sporadic episodes of choking may occur with very fluid foods (attention should be paid to the flowability variable).	Chen et al. (2021), Yang et al. (2022)
Sarcopenic dysphagia	The person has less swallowing strength (consider the variable of adhesiveness) and may have difficulty coordinating swallowing and breathing with liquids (consider the variable of flowability). Loss of strength will probably make it difficult to handle solid foods (consider the hardness variable), which will generate more heterogeneous boluses that may produce post‐swallowing residue (consider fracturability and residue).	Chen et al. (2021), Yang et al. (2022)
Neurogenic dysphagia	There is a high probability of difficulty handling liquid foods and loss of sensitivity in the laryngeal vestibule, leading to increased post‐swallowing residue (pay attention to fracturability and residue). Loss of muscle strength makes it quite difficult to propel the bolus (pay attention to adhesiveness). The person needs more time to activate swallowing reflexes, so food remains in the oral cavity for longer. The person is likely to have decreased strength, making it difficult to chew food (pay attention to hardness).	Warnecke et al. (2021)
Cognitive dysphagia	The person does not necessarily have difficulties with swallowing biomechanics, which may coexist with presbyphagia, sarcopenic dysphagia, or neurogenic dysphagia. The person tends to become distracted during meals, stops swallowing when food is in their mouth, or tends to talk with food in their mouth, which poses a safety risk. In advanced stages of the disease, some people with oropharyngeal dysphagia may experience a progressive disconnection from the act of eating, which can lead to food refusal and, in many cases, refusal to eat, especially in end‐of‐life contexts. Given the insecurity caused by oral feeding, there is a tendency to select foods that are easy to process orally (considering hardness, fracturability, adhesiveness, and residue) and to avoid foods that cause problems in the oral cavity.	Dehaghani et al. (2021)
Esophageal dysphagia	Retrosternal retention is common (the person reports food getting stuck at the sternum) to occur, as esophageal peristalsis is insufficient to transport the bolus. Foods that cause difficulty in peristalsis (due to their stickiness) will cause more problems. Although this condition should not pose a safety risk and is exclusively an efficacy problem, it is possible that the obstruction at the esophageal level may begin to collapse that pathway, posing a risk of food or secretions entering the airway. Therefore, foods that involve greater compaction of the bolus (considering fracturability and residue) would be appropriate.	Richmond et al. (2024)
Mechanical dysphagia	There is a higher likelihood of alterations in swallowing efficiency, although the risk of compromised safety is lower. The individual is highly likely to experience difficulties during the oral processing of food, particularly related to its hardness and fracturability. Inefficient bolus transport is also expected, associated with properties such as adhesiveness and the presence of residue. In some cases, previous medical interventions may have affected the functionality of the laryngeal region, potentially hindering the management of foods with higher flowability.	Kuhn et al. (2023)

Merino et al. (2021) developed a targeted sensory methodology for evaluating TMFs designed for people with OD secondary to cerebral palsy. Their approach involved training a panel of professional tasters, including speech and language therapists, to identify and assess key sensory attributes that could serve as selection criteria for appropriate TMFs. The selected attributes were firmness, cohesiveness, adhesiveness, flowability, and residue. The study emphasized the importance of training expert panels in sensory attributes recognition to improve the selection and tailoring of TMFs and, consequently, enhance the quality of life of people with dysphagia. The methodology proposed by these authors provides an effective framework for the sensory evaluation of TMFs, offering a scientifically grounded basis for the development of safer and more acceptable foods for people with OD.

Delaney et al. (2025) adopted a multidisciplinary expert panel to establish food categories based on textural properties. Although the study focused on a pediatric population without swallowing disorders, it aligns with the present study by emphasizing the gradual and controlled introduction of foods into the oral feeding routine, a common practice for patients with OD. The expert panel found moisture, flowability, firmness, particle size, and fragment distribution as the most relevant characteristics in sensory analysis. While cohesiveness was considered in the classification of foods, adhesiveness was excluded, as the target population generally did not present swallowing impairment, unlike people with OD. This study provided a novel perspective by incorporating the expected oral abilities of the target population into the sensory analysis.

The central hypothesis of this study is that a sensory evaluation method tailored to the phenotypic profiles of individuals with dysphagia will not only serve as a reliable tool for assessing the texture of TMFs but will support more informed decision‐making in the selection of foods that are both safe and effective for this population.

The main objective of this study was to propose a sensory evaluation methodology for TMFs tailored to feeding phenotypic profiles of people with OD. This approach enables caregivers and clinicians to assess and determine food acceptability. The method was based on the typical oral tasks performed by people with OD during the oral processing and swallowing of TMFs. Incorporating these oral tasks as a means of obtaining information on textural attributes that condition oral processing and swallowing in people with OD may enhance the effectiveness of the proposed evaluation method (Delaney et al. 2025).

2. Materials and Methods

2.1. Samples

Thirty‐two foodstuffs considered suitable for consumption by people with OD were purchased. Of these, 24 (75%) were foods specifically marketed for these individuals (creams, pureed dishes, purées, jellies, thickened beverages). These TMFs were selected because their labels indicated that they were intended for people with swallowing and/or chewing difficulties. In contrast, 8 (25%) were regular products, such as yogurts (n = 2), smoothies (n = 2), mousse (n = 1), flan (n = 1), hummus (n = 1), and custard (n = 1). Thus, commercial foods were considered potentially suitable for consumption by patients with OD according to their swallowing phenotype. This selection allowed us to prioritize the characterization of TMFs adapted to dysphagia, ensuring the identification and validation of relevant oral attributes and tasks. Conversely, samples intended for normotypical individuals provided a frame of reference for comparing textures and oral behaviors.

Each product was prepared and presented strictly according to the manufacturer's instructions, ensuring consistent and reproducible conditions for sensory evaluation. The service was carried out using previously standardized neutral materials. Products intended to be consumed cold were evaluated at a controlled temperature of 5 C; those meant to be consumed at room temperature were assessed at that temperature, and products intended to be consumed hot were tested at 40°C, ensuring standardized service conditions during sensory evaluation.

2.2. Sensory Testing Room

The evaluation of products for the development of the TMF sensory protocol method in the context of OD was carried out in the sensory analysis laboratory of the Public University of Navarra, in compliance with ISO 8589:2007. The sessions aimed at defining attributes and oral tasks were held in a tasting room with capacity for 25 participants, equipped with a central area for discussion and comparison of results. As this was a proof of concept, the procedure strictly adhered to the principles of sensory methodology, maintaining a controlled experimental design.

2.3. Evaluation Method

2.3.1. Formation of the Focus Group

This group was assembled to ensure a multidisciplinary perspective and included nine professionals: five experts in sensory analysis of food, three specialists in product development for people with dysphagia, and one speech therapist with clinical experience in dysphagia. A targeted strategy was used to generate sensory descriptors and explore their relationship to oral tasks associated with OD. Each session was moderated by a trained speech and language therapist, while another researcher systematically recorded all comments and sensory attributes identified during the discussion. Panelists received initial training to familiarize themselves with the oral tasks associated with dysphagia, which were reviewed at the start of each session to ensure methodological consistency. The study was conducted in accordance with ethical and legal standards governing research involving human participants, complying with regulations on the protection of personal data. All participants were verbally informed and provided with their consent to take part in the sessions.

2.3.2. Temporality and Sensory Analysis

The analysis was carried out over 9 days, with two test sessions held each day. Each session lasted 90 min, and four products were evaluated per session. A 1‐h break was scheduled between sessions to allow for sensory recovery and prevent cognitive fatigue. After evaluating each sample, participants rinsed with water to minimize residual effects and ensure consistency in sensory perceptions.

Each sample was evaluated independently using a structured form that included texture attributes. The intensity of each attribute was rated on unstructured 15 cm scales. Following the individual evaluations, a group discussion was held to reach consensus on the identified attributes, their intensity, and the oral strategies used in processing the TMFs.

2.3.3. Selection of Attributes to Establish the Texture Profile Adapted to OD

According to Merino et al. (2021), the mechanical attributes of firmness, cohesiveness, adhesiveness, flowability, and residue were initially selected as key variables for the evaluation of food products intended for people with dysphagia. Subsequently, a discussion phase was carried out among the different members of the working group with the aim of reaching a consensus and precisely defining the meaning and scope of each term. This was done to ensure a shared understanding among experts, evaluate the relevance of each attribute in the swallowing process of people with OD, and assess the potential inclusion of new attributes. For this purpose, a wide variety of TMFs specifically formulated for people with dysphagia were used. The sensory attributes of these products were evaluated to identify and select those most representative of the target population. This process led to the following refinements:

• Firmness was redefined as hardness to encompass products with different levels of textural adaptation, from crushed to easy‐to‐chew.

• Fracturability was included due to its close relationship with hardness and its relationship with safe particle size.

• Cohesiveness was removed after practical experience, as it was considered redundant due to its conceptual overlap with other attributes. In particular, fracturability is inversely related, since cohesive foods tend to fragment less, while adhesiveness partially overlaps, since it contributes to keeping the bolus cohesive within the oral cavity.

• The concept of intraoral variability was incorporated.

Given that people with OD exhibit oral behaviors that differ from the typical biomechanics of oral processing and swallowing, it was appropriate to identify situations in which the food modifies its own attributes in the oral cavity due to factors such as temperature or salivation. This intraoral variability is particularly evident in products such as commercial jellies or certain yogurts. For example, a jelly that softens with oral heat or a yogurt that changes its viscosity when mixed with saliva. These foods represent cases of intraoral variability that can complicate the safe handling of the bolus in patients with OD. The proposal was to focus the expert panelists on detecting this characteristic in order to avoid foods that cause significant changes in the oral cavity and that may hinder oral processing, which require precise control and compensation.

2.3.4. Definition of Attributes and Their Relationship to the Pathophysiology of OD

Each of the proposed attributes has a direct impact on oral processing and may represent a functional limitation within the usual pathophysiology of people with OD. Table 2 lists the selected attributes, a definition of each, and the possible limitations that each attribute could imply for a person with OD.

TABLE 2.

List of textural attributes, definitions, and their pathophysiological limitations in an individual with OD (based on Buschang et al. 1997; Devezeaux de Lavergne et al. 2017; Matsuo and Fujishima 2020; Nakamura et al. 2020; Nishinari, Fang, et al. 2019; Nishinari, Turcanu, et al. 2019).

Attribute	Definition	Pathophysiology (situations where this factor may act as a limitation)
Oral variability	A condition in which the food's textural properties are altered during manipulation within the oral cavity, leading to a significant impact on oral processing and its coordination with swallowing.	–Lip seal deficit –Glossopalatine seal deficit –Laryngeal vestibule closure deficit
Fracturability	A property related to the level of hardness that can affect bolus cohesiveness. Fragment sizes must be safe for swallowing while allowing proper detection and cohesion to form a homogeneous bolus.	–Reduced tongue mobility –Impaired oral seal –Glossopalatine seal deficit
Hardness	A property involving the application of the necessary force to break down food and reduce it to a safe particle size, allowing proper formation of the bolus.	–Weak chewing strength –Reduced tongue mobility –Impaired oral seal –Glossopalatine seal deficit
Adhesiveness	A property requiring the application of biomechanical forces necessary to detach food from the mucosa, either during bolus formation or lingual–pharyngeal propulsion.	–Limited tongue mobility –Lingual strength deficit –Pharyngeal constrictor weakness
Flowability	A property influencing the speed at which food travels through the pharyngeal tract.	–Glossopharyngeal seal deficit –Delayed laryngeal vestibule closure –Velopharyngeal seal deficit
Residue	A condition in which food accumulates in the pharyngeal region after swallowing. This may be caused by retention of the bolus itself or changes in oral secretions generated during processing.	–Pharyngeal weakness –Oral propulsion deficit –Inadequate laryngeal elevation –Defective laryngeal vestibule closure –Deficit in upper esophageal sphincter opening

2.3.5. Sensory Evaluation Scale

To quantify the sensory perceptions associated with each attribute, the Visual Analog Scale (VAS) was selected due to its sensitivity in capturing the subjective intensity of the evaluated sensory characteristics. This scale consisted of a continuous 15 cm line, with its endpoints being the extreme values of the attribute evaluated. Panelists were asked to indicate their perception by marking a point on the line, which allows a subjective response to be transformed into quantifiable numerical data. The choice of this scale responds to the need to obtain accurate and nuanced measurements adapted to the specificity of the sensory profile associated with people with dysphagia.

2.3.6. Emulated Oral Tasks for Sensory Evaluation

Given that the texture evaluation form was developed for the sensory analysis of products intended for people with OD, it was agreed that the oral tasks should emulate the oral processing patterns typically performed by this population. These tasks were based on characteristic oral behaviors, such as prolonged oral retention of food, compensatory tongue activity in place of mastication, conscious control over the act of swallowing, and intentional managing of the residue phase (Solomon 2006; Cichero and Lam 2014; Soares et al. 2015; Ashiga et al. 2019; Sungsinchai et al. 2019). Table 3 outlines the proposed oral tasks along with the corresponding attributes used to set up the texture profile.

TABLE 3.

Proposed tasks for the oral processing of texture‐modified foods, emulating an individual with oropharyngeal dysphagia, and their relationship with sensory attributes (based on Barewal et al. 2021; Colevas et al. 2022; Matsuo and Fujishima 2020; Sungsinchai et al. 2019).

Oral task	Assessment focus	Associated attribute
Hold the food in the mouth statically for 10 s	Detect whether the bolus changes shape prematurely or if any discomfort arises that hinders oral processing.	Intraoral variability
Move the bolus with the tongue from left to right along the anterior part of the mouth, rolling and gathering it	Assess how easy or difficult it is to move the bolus without pieces separating or being lost in the process. The surface area generated by the food during this movement can indicate whether it clumps together or disperses.	Adhesiveness, fracturability
Gently press the food against the palate with the tongue	Assess the force exerted to change the shape of the bolus or to break it.	Hardness
	Assess the presence of microfragments distributed throughout the oral surface.	Fracturability
Raise the food forcefully toward the palate with the tongue/chew the food	Assess the food's ability to stick to the palate. Chewing can help to perceive adhesiveness through the food's adhesion to the teeth.	Adhesiveness
Detach the food from the palate using the tongue	Assess the force applied by the tongue to detach the food from the oral cavity—not only from the palate and oral mucosa, but also from the pharyngeal region during bolus transport at the time of swallowing.	Adhesiveness
Swallow food	Assess how easily the bolus moves around in the mouth and the effort required to prepare it before swallowing.	Flowability
	Find whether there have been any changes in saliva (becoming thicker or thinner, or an increase in volume that causes discomfort), abnormal oral sensations (excessive dryness or stinging), or the appearance of food debris. Need to swallow more frequently.	Residue
Assess food variability	Decide whether the manipulation and retention of the food in the mouth significantly interfere with the detection of textural attributes, or if these attributes undergo meaningful changes during the analysis.	Intraoral variability

2.3.7. Intended Users According to Professional Profile

In the management of dysphagia, two types of professional profiles can be distinguished: trained personnel and specialized professionals. Trained personnel receive specific training to care for people with dysphagia, without necessarily being specialized in this field, as their usual duties include other responsibilities in addition to this care. Specialized professionals have the professional knowledge and skills to evaluate, diagnose, and/or design therapeutic intervention procedures for people with dysphagia. The assessment form proposed in this study, supplemented with instructions for performing oral tasks (Table 3), is designed to be used by both profiles. Likewise, it is considered that caregivers, who are also part of these groups, can benefit from the use of this assessment form to establish the suitability of TMFs for people with OD.

3. Results

3.1. Structure of the Sensory Evaluation Questionnaire

A standardized tool for the sensory evaluation of texture in food products intended for people with OD is presented (Data S1). The purpose of the proposed form is to provide a reproducible and structured protocol that allows the characterization of key textural attributes, thereby promoting comparability across studies and their integration with instrumental analyses.

The evaluation form includes six main attributes: intraoral variability (applicable to liquids and semisolids), fracturability (applicable to solids), hardness, adhesiveness, flowability, and residue. Each attribute is assessed both in binary terms (present/absent) and quantitatively using a VAS, where “Very little” stands for the minimum intensity, and “A lot” represents the maximum. To assist with interpretation, the scale line is subdivided into five zones.

The evaluators received the coded sample along with the evaluation form, in which the date and identification details were recorded. The protocol also includes the selection of “unsuitable” attributes, which allows undesirable sensory characteristics to be distinguished depending on the context of use or regulatory requirements.

3.2. Protocol for Application and Conditions for Evaluation in OD Contexts

This protocol describes a standardized method for sensory evaluation of TMFs texture even when evaluators do not have OD. To this end, ingestion patterns typical of people with this condition were emulated. This emulation allowed for a more realistic assessment of the suitability of products intended for this population, while maintaining controlled and safe conditions during the session. The operating procedure for sensory evaluation was carried out in four stages:

3.2.1. Stage 1: Self‐Regulated Portioning Procedure

Each panelist was instructed to place a “self‐selected” amount of food in their oral cavity. The amount was freely determined according to the participant's own comfort for safety limitations, ensuring adequate manipulation of the product within the mouth. This self‐regulated approach allowed participants to handle the sample naturally and safely, avoiding forced or unrealistic oral conditions. The rationale for this process lies in preserving individual variability in oral handling capacity, which is particularly relevant when evaluating TMFs designed for populations with swallowing difficulties, such as people with OD.

3.2.2. Stage 2: Sample Ingestion Method Adapted to Product Type

The administration of samples was designed so that evaluators without OD could reproduce ingestion patterns representative of individuals with swallowing disorders. For liquid products, panelists were instructed to take a sip corresponding to the volume they could comfortably and safely handle, adjusted spontaneously to emulate the swallowing limitations typically observed in dysphagia. For semisolid products, a standard teaspoon was used, which the panelist self‐administered into the oral cavity according to their ability and preference, thus replicating adapted oral behaviors. If this protocol is to be used with solid foods, appropriate utensils such as a teaspoon or fork should be used, selected according to the product's texture and consistency, prioritizing comfort and controlled handling during the simulated intake process.

3.2.3. Stage 3: Evaluation Procedure

Once the food is placed in the oral cavity, panelists performed the oral tasks specified in the instruction sheet, which include chewing movements, simulated swallowing, or other specific actions related to oral tactile perception designed to evaluate the food in the context of sensory analysis adapted to people with dysphagia. During each test, panelists simultaneously completed the sensory evaluation form, documenting perceived sensations and attribute intensities in accordance with the defined variables.

3.2.4. Stage 4: Repetition of the Evaluation Session and Monitoring the Sensory Fatigue

To increase the accuracy of the sensory evaluations and focus the participants' attention on relevant sensory attributes, a second trial with the same sample was permitted. Testing sessions were organized in sets of no more than three consecutive products, interspersed with rest periods, to minimize sensory fatigue in participants and maintain reliability. This structured repetition protocol helps preserve data consistency and participants' comfort throughout the sensory analysis of responses during sensory analysis.

Additional safety and comfort considerations are essential to ensure the validity and ethical integrity of sensory analysis. It is recommended that panelists be provided with water or another neutralizing liquid between samples to cleanse the oral cavity and avoid possible biases in sensory perception. Likewise, breaks between trials should be sufficient to minimize sensory fatigue and keep concentration during tasting. It is essential that the instructions given to participants emphasize safety and respect for the individual ability of each panelist, prioritizing their well‐being throughout the evaluation process.

Although a controlled and quiet environment is recommended for conducting this type of sensory assessment, its application can be extended to various settings. People with OD perform eating and swallowing activities in diverse everyday contexts, where multiple variables may influence oral processing and swallowing function. Therefore, the evaluation form was designed for use across different environments, ensuring individualized application to obtain representative results that accurately reflect real‐life conditions.

4. Discussion

Despite growing knowledge and awareness of dysphagia in clinical settings, access to TMFs adapted for this population remains limited. People with OD often face a restricted variety of products and limited gradation in texture adaptation, which constrains dietary personalization. The heterogeneity of dysphagia phenotypes—including neurogenic, sarcopenic, esophageal, and respiratory forms—means that the optimal combination of textural attributes varies according to the type and severity of impairment. This highlights the need to establish specific sensory thresholds and to prioritize relevant characteristics for each profile, in accordance with IDDSI recommendations. Although the food industry has shown interest in developing specialized products, commercial offerings still focus on pureed foods. Considering that there are different phenotypes of dysphagia, a broader range of texture‐adapted products is required. Sensory analysis of food represents a useful tool for both caregivers and the food industry, as it validates products designed for people with dysphagia by identifying sensory attributes that may interfere with safe oral processing.

This proof‐of‐concept study identified and systematized key sensory attributes of TMFs texture, emulating the oral tasks typically observed in OD. A unique feature of the proposed sensory evaluation form is that it is structured around a set of oral tasks that mimic the oral processing behaviors of individuals with OD, thereby enabling panelists to reflect on the implication of the food's characteristics on different swallowing phenotypes. In the review by Guénard‐Lampron et al. (2021) texture descriptors suitable for people with dysphagia were analyzed, and the authors concluded that trained sensory panels represent an effective resource for verifying whether products are suitable for dysphagia based on a set of relevant attributes. They proposed the creation of a glossary of specific descriptors for people with dysphagia and the development of methods based on typical human oral processing (Guénard‐Lampron et al. 2021). In this context, the present proposal aligns with their approach, as it is based on a series of descriptors that tend to interfere with oral processing in people with dysphagia and proposes oral tasks that consider the different phases of oral processing. The IDDSI framework currently serves as a standardized framework for adapting foods for people with dysphagia. It provides a set of testing methods that allow both individuals with OD and caregivers to verify whether TMFs are safe and appropriate for consumption. Its proposed evaluation methods are based on the detection of attributes that may be significant in different degrees of impairment. For example, IDDSI level 4 considers the attributes of adhesiveness and cohesiveness, while level 5 also considers particle size. The IDDSI group's proposal is considered pioneering and truly democratizes food for people with OD, as it proposes a simple and easily accessible methodology. However, sensory analysis can provide an ideal complement to the detailed analysis of TMF, as there may be difficulties in objectively applying the evaluation methods proposed by IDDSI.

There are specific tests for chewing efficiency that enable analysis of the suitability of a subject's oral processing. The Test of Masticating and Swallowing Solids (TOMASS) was developed to assess the efficiency of oral processing in people with Parkinson's disease (Athukorala et al. 2014). Although normative values have been established for the healthy population (Huckabee et al. 2018), no standardized scales currently exist to classify the different phenotypes of dysphagia. Some authors, such as Cichero et al. (2017) have proposed a qualitative interpretation of the TOMASS test to establish a relationship between oral processing efficiency and IDDSI levels. However, this interpretation depends largely on the clinician's experience and expertise. It is therefore likely that the clinician also relies on sensory analysis of the food consumed by the patients. Consequently, a standardized sensory‐based product assessment would serve as an ideal complementary tool (TOMASS). Surface electromyography (sEMG) is a noninvasive technique that allows for the analysis of masticatory effort, muscle activation times, and compensations in oral behaviors during altered swallowing, such as DOF (Alfonsi et al. 2023). sEMG has been used to evaluate chewing and swallowing behaviors in both spontaneous and guided swallowing (Saito et al. 2024). Furthermore, sEMG has even been applied in the clinical setting to validate TOMASS in populations without DOF (Huckabee et al. 2018) and with DOF (Todaro et al. 2021). On the other hand, sEMG also allows oral behavior during swallowing to be related to the type of TMF aimed at people with DOF. In fact, sEMG has been used to evaluate products covering IDDSI levels 0–2 (Sodhi et al. 2023, 2024) and 4–7 (Dhillon et al. 2023; Ko et al. 2021; Saito et al. 2024; Sharma et al. 2026). With the exception of the study by Sharma et al. (2026), which applied a quantitative descriptive sensory test, and Saito et al. (2024), which did not perform a sensory evaluation of the products, the sensory tests were hedonic (acceptance) tests. These studies established positive associations between IDDSI levels and electrophysiological response. However, the perceived intensity of the textural attributes of TMFs has not yet been related to the response obtained using sEMG.

Most studies analyzing TMFs for people with OD rely on objective methods or on approaches proposed within the IDDSI framework, without addressing the identification of relevant attributes through sensory methods. Considering the human oral sensory capacity and the benefits of using trained panelists, the application of sensory analysis methods enhances the effectiveness of current approaches in selecting appropriate products for people with OD.

5. Study Limitations and Future Directions

While this study provides a novel methodological framework for the sensory evaluation of TMFs for individuals with OD, several limitations should be acknowledged. These include the small expert panel (n = 9), the use of non‐dysphagic individuals emulating oral behaviors, and the absence of direct physiological or clinical swallowing assessments, which constrain the generalizability and functional validation of the findings. Future research should involve patients with OD to verify the relationship between sensory attributes and swallowing safety, expand panels to include caregivers, speech therapists with expertise in OD, and other relevant professionals, and integrate instrumental or clinical measures such as videofluoroscopy, sEMG, or TOMASS. Additionally, the methodology could guide the development of innovative TMFs tailored to different dysphagia phenotypes and explore multisensory interactions, including taste, aroma, and temperature, to optimize both safety and acceptability.

6. Conclusions

This study presents a sensory evaluation methodology specifically designed to emulate oral behaviors of individuals with OD, integrating TMFs with typical oral processing patterns. Key sensory attributes—including hardness, fracturability, adhesiveness, flowability, residue, and intraoral variability—were identified as critical for safe and effective swallowing. By incorporating emulated oral tasks into the sensory analysis assessment, the methodology allows a realistic and functional evaluation of TMFs, reflecting challenges faced by dysphagic people. A standardized sensory evaluation sheet was developed, allowing for an objective assessment of food texture across diverse settings, including home, care facilities, and hospital. The protocol complements existing frameworks such as IDDSI by providing qualitative and quantitative insights into food characteristics. Overall, this approach enhances the evaluation and development of TMFs, promoting safer, more acceptable, and varied dietary options, and has potential for integration into clinical practice and industrial product development.

Author Contributions

Jaime Paniagua: conceptualization, writing – original draft, writing – review and editing, supervision. María Teresa Murillo‐Arbizu: conceptualization, writing and reviewing, formal analysis, data curation, methodology, funding acquisition, project administration. Kizkitza Insausti: review and editing, writing and reviewing. Leyre Urtasun del Castillo: review and editing, writing, reviewing and funding acquisition. Marta Uriarte Ajona: review, writing and reviewing. María José Beriain: review and editing, writing and reviewing. Francisco C. Ibañez: conceptualization, writing and reviewing, formal analysis and data curation.

Funding

This work was supported by Gobierno de Navarra, PC056‐057.

Ethics Statement

This study was conducted in compliance with Spanish legislation (Organic Act n. 3/2018 of December 5 on Personal Data Protection and Guarantee of Digital Rights).

Consent

Written informed consent was obtained from all study participants.

Conflicts of Interest

The authors declare no conflicts of interest.

Supporting information

Data S1: jtxs70071‐sup‐0001‐Supinfo.docx.

Data Availability Statement

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.