Tongue pressure modulation for initial gel consistency in a different oral strategy

Antimicrobial adhesive self-healing hydrogels for efficient dental biofilm removal from periodontal tissue

OBJECTIVES

Oral biofilms, including pathogens such as Porphyromonas gingivalis, are involved in the initiation and progression of various periodontal diseases. However, the treatment of these diseases is hindered by the limited efficacy of many antimicrobial materials in removing biofilms under the harsh conditions of the oral cavity. Our objective is to develop a gel-type antimicrobial agent with optimal physicochemical properties, strong tissue adhesion, prolonged antimicrobial activity, and biocompatibility to serve as an adjunctive treatment for periodontal diseases.

METHODS

Phenylboronic acid-conjugated alginate (Alg-PBA) was synthesized using a carbodiimide coupling agent. Alg-PBA was then combined with tannic acid (TA) to create an Alg-PBA/TA hydrogel. The composition of the hydrogel was optimized to enhance its mechanical strength and tissue adhesiveness. Additionally, the hydrogel's self-healing ability, erosion and release profile, biocompatibility, and antimicrobial activity against P. gingivalis were thoroughly characterized.

RESULTS

The Alg-PBA/TA hydrogels, with a final concentration of 5 wt% TA, exhibited both mechanical properties comparable to conventional Minocycline gel and strong tissue adhesiveness. In contrast, the Minocycline gel demonstrated negligible tissue adhesion. The Alg-PBA/TA hydrogel also retained its rheological properties under repeated 5 kPa stress owing to its self-healing capability, whereas the Minocycline gel showed irreversible changes in rheology after just one stress cycle. Additionally, Alg-PBA/TA hydrogels displayed a sustained erosion and TA release profile with minimal impact on the surrounding pH. Additionally, the hydrogels exhibited potent antimicrobial activity against P. gingivalis, effectively eliminating its biofilm without compromising the viability of MG-63 cells.

SIGNIFICANCE

The Alg-PBA/TA hydrogel demonstrates an optimal combination of mechanical strength, self-healing ability, tissue adhesiveness, excellent biocompatibility, and sustained antimicrobial activity against P. gingivalis. These attributes make it superior to conventional Minocycline gel. Thus, the Alg-PBA/TA hydrogel is a promising antiseptic candidate for adjunctive treatment of various periodontal diseases.

Development and Characterization of a Novel Composite Hydrogel Biomaterial for Improved Mucoperiosteal Wound Repair

Mucoperiosteal wound healing, as it occurs after pediatric cleft palate surgery, can be challenging due to the limitations of current treatments such as tissue flaps secured with sutures and fibrin glue. In this study, we characterized the in vitro performance of a novel composite hydrogel biomaterial designed to be employed as an in situ wound filler and enhance mucoperiosteal wound healing. We evaluated a range of photopolymerizable formulations containing methacrylated gelatin (GelMA), glycol chitosan, and bioglass microparticles. Our aim was to identify one or more formulations with an appropriate balance of properties against a set of functional requirements that we established for this application. To test the formulations against these criteria, we measured photopolymerization kinetics, mechanical properties, degradation rate, in vitro biocompatibility, and ex vivo tissue adhesion. All formulations polymerized in less than 90 s using violet light. In addition, we found that GelMA-based hydrogels were more adhesive to mucoperiosteal tissue than clinical standard fibrin glue. Inclusion of small amounts of bioglass in the formulation increased mechanical compatibility with mucoperiosteal tissue, enhanced cytoconductivity, and promoted cell proliferation. Taken together, our results support the suitability of these photopolymerized composite hydrogels as in situ mucoperiosteal wound fillers. Overall, this study lays the groundwork for investigating the in vivo, pre-clinical effectiveness of these composite hydrogels in improving mucoperiosteal wound healing outcomes.

Merkel cells and keratinocytes in oral mucosa are activated by mechanical stimulation

The detection of mechanical qualities of foodstuffs is essential for nutrient acquisition, evaluation of food freshness, and bolus formation during mastication. However, the mechanisms through which mechanosensitive cells in the oral cavity transmit mechanical information from the periphery to the brain are not well defined. We hypothesized Merkel cells, which are epithelial mechanoreceptors and important for pressure and texture sensing in the skin, can be mechanically activated in the oral cavity. Using live-cell calcium imaging, we recorded Merkel cell activity in ex vivo gingival and palatal preparations from mice in response to mechanical stimulation. Merkel cells responded with distinct temporal patterns and activation thresholds in a region-specific manner, with Merkel cells in the hard palate having a higher mean activation threshold than those in the gingiva. Unexpectedly, we found that oral keratinocytes were also activated by mechanical stimulation, even in the absence of Merkel cells. This indicates that mechanical stimulation of oral mucosa independently activates at least two subpopulations of epithelial cells. Finally, we found that oral Merkel cells contribute to preference for consuming oily emulsion. To our knowledge, these data represent the first functional study of Merkel-cell physiology and its role in flavor detection in the oral cavity.

The cellular basis of mechanosensation in mammalian tongue

Mechanosensory neurons that innervate the tongue provide essential information to guide feeding, speech, and social grooming. We use in vivo calcium imaging of mouse trigeminal ganglion neurons to identify functional groups of mechanosensory neurons innervating the anterior tongue. These sensory neurons respond to thermal and mechanical stimulation. Analysis of neuronal activity patterns reveal that most mechanosensory trigeminal neurons are tuned to detect moving stimuli across the tongue. Using an unbiased, multilayer hierarchical clustering approach to classify pressure-evoked activity based on temporal response dynamics, we identify five functional classes of mechanosensory neurons with distinct force-response relations and adaptation profiles. These populations are tuned to detect different features of touch. Molecular markers of functionally distinct clusters are identified by analyzing cluster representation in genetically marked neuronal subsets. Collectively, these studies provide a platform for defining the contributions of functionally distinct mechanosensory neurons to oral behaviors crucial for survival in mammals.

Effects of Food and Liquid Properties on Swallowing Physiology and Function in Adults

Foods and liquids have properties that are often modified as part of clinical dysphagia management to promote safe and efficient swallowing. However, recent studies have questioned whether this practice is supported by the evidence. To address this, a scoping review was conducted to answer the question: "Can properties of food and liquids modify swallowing physiology and function in adults?" Online search in six databases yielded a set of 4235 non-duplicate articles. Using COVIDENCE software, two independent reviewers screened the articles by title and abstract, and 229 full-text articles were selected for full-text review. One-hundred eleven studies met the inclusion criteria for qualitative synthesis and assessment of risk of bias. Three randomized controlled trials and 108 non-randomized studies were analyzed. Large amounts of variability in instrumental assessment, properties of food and liquids, and swallowing measures were found across studies. Sour, sweet, and salty taste, odor, carbonation, capsaicin, viscosity, hardness, adhesiveness, and cohesiveness were reported to modify the oral and pharyngeal phase of swallowing in both healthy participants and patients with dysphagia. Main swallow measures modified by properties of food and liquids were penetration/aspiration, oral transit time, lingual pressures, submental muscle contraction, oral and pharyngeal residue, hyoid and laryngeal movement, pharyngeal and upper esophageal sphincter pressures, and total swallow duration. The evidence pooled in this review supports the clinical practice of food texture and liquid consistency modification in the management of dysphagia with the caveat that all clinical endeavors must be undertaken with a clear rationale and patient-specific evidence that modifying food or liquid benefits swallow safety and efficiency while maintaining quality of life.

Application of a balloon-type pressure sensor in texture evaluation of tongue-crushable foods

A relationship has recent been suggested to exist between tongue pressure measured using balloon-type sensors and the tongue-crushable food range of individuals. This study was conducted to investigate the applicability of a balloon-type pressure sensor for texture evaluation of tongue-crushable soft foods. Six gellan gum gels were used as a soft food model. The fracture force and strain of gels were controlled at two and three levels by changing the gum concentration and acyl-group content, respectively. The pressure sensor was inserted between a food sample and texture analyzer probe, and pressure values during compression of gels was measured. During the compression test, both the food and tongue-pressure sensor were deformed, eventually leading to fracture of food gels. Using the tongue-pressure sensor, the food gels fractured at lower force because of the shape of the sensor but showed longer displacement as the sensor deformed compared to without the sensor. Gels with low fracture force in the conventional test without the sensor exhibited lower fracture force, work, gradient, and true stress than those with high fracture force in the sensor test. Displacement, clearance or distance from the bottom plate, and true stress at fracture were appropriate parameters for expressing the fracture characteristics. Both the true fracture stress and fracture pressure in the sensor test decreased with the fracture strain of gels in a conventional test. These results suggest that by using a larger balloon and faster sampling, the sensor can be used to determine the fracture behavior of tongue-crushable foods.

Self-Powered and Flexible Triboelectric Sensors with Oblique Morphology towards Smart Swallowing Rehabilitation Monitoring System

With aging, disability of the body can easily occur because the function of the body is degraded. Especially, swallowing disorder is regarded as a crucial issue because patients cannot obtain the nutrients from food by swallowing it. Hence, the rehabilitation of swallowing disorder is urgently required. However, the conventional device for swallowing rehabilitation has shown some limitations due to its external power source and internal circuit. Herein, a self-powered triboelectric nanogenerator for swallowing rehabilitation (TSR) is proposed. To increase the electrical output and pressure sensitivity of the TSR, the tilted reactive ion etching is conducted and the electrical output and pressure sensitivity are increased by 206% and 370%, respectively. The effect of the tilted reactive ion etching into the electrical output generated from the TSR is systematically analyzed. When the tongue is pressing, licking, and holding the TSR, each motion is successfully detected through the proposed TSR. Based on these results, the smart swallowing rehabilitation monitoring system (SSRMS) is implemented as the application and the SSRMS could successfully detect the pressing by the tongue. Considering these results, the SSRMS can be expected to be utilized as a promising smart swallowing rehabilitation monitoring system in near future.

Relationship between Food Crushing and Oral Function in Older Adults Requiring Nursing Home Care: A Pilot Study

We investigated how jelly is crushed and examined the relationship between tongue pressure and tongue food crushing ability among older adults requiring nursing home care. Seventy-two participants were instructed to freely crush the test foods soft jelly (SJ) and hard jelly (HJ). We visually evaluated the crushability of the test food and identified the intraoral tissues (active sites) used to crush the test food. The active sites were consistent for all participants for both SJ and HJ, and they included the maxillary and mandibular teeth in 41 participants, teeth and residual ridges in 15 participants, maxillary and mandibular residual ridges in 10 participants, and tongue and palate in six participants. Two participants failed to crush the SJ; the active sites in both participants were the tongue and palate. No participant using the tongue and palate as active sites could crush the HJ. Furthermore, 64 participants could crush the SJ and 23 could crush the HJ using the tongue and palate. The cutoff value of the tongue pressure for crushability of the HJ was 22.0 kPa. Assessing tongue pressure and intraoral active sites involved in food crushing could help determine an appropriate diet for older adults requiring nursing home care.

Effect of fracture properties of gels on tongue pressure during different phases of squeezing and swallowing

To provide appropriate foods for elderly people with eating difficulties, it is necessary to take account of the ability of compensatory mastication such as tongue squeezing. However, the biomechanics of tongue squeezing is still unclear. The aim of present study is to investigate the effect of the initial mechanical properties of gels on the change in tongue pressure production during squeezing and swallowing. As test sample, nine kinds of gels with three fracture force and three fracture strain were prepared. Tongue pressure during squeezing and swallowing gels was measured by using an ultra-thin tongue pressure sensor with five measuring points attached on the hard palate in seven healthy participants, and analyzed at four phases; Initial squeeze, Middle squeeze, Last squeeze, and Swallowing. The maximal magnitude of tongue pressure was increased for gels with higher fracture force at most measuring points and was decreased for gels with higher fracture strain at some measuring points on the median line during Initial and Middle squeezing. However, no influence by fracture force and strain was found in magnitude during Last squeezing and Swallowing. The duration of tongue pressure increased for gels with higher force at most measuring points during Middle squeezing, although no influence by strain was found during each phase. The results clearly show how the initial fracture properties of gels influence on tongue pressure production during each phase of food oral processing, which clarified one aspect of squeezing with tongue, as the compensatory mastication.

Update and review of the gerodontology prospective for 2020's: Linking the interactions of oral (hypo)-functions to health vs. systemic diseases

New lines of evidence suggest that the oral-systemic medical links and oral hypo-function are progressively transcending beyond the traditional clinical signs and symptoms of oral diseases. Research into the dysbiotic microbiome, host immune/inflammatory regulations and patho-physiologic changes and subsequent adaptations through the oral-systemic measures under ageism points to pathways leading to mastication deficiency, dysphagia, signature brain activities for (neuro)-cognition circuitries, dementia and certain cancers of the digestive system as well. Therefore, the coming era of oral health-linked systemic disorders will likely reshape the future of diagnostics in oral geriatrics, treatment modalities and professional therapies in clinical disciplines. In parallel to these highlights, a recent international symposium was jointly held by the International Association of Gerontology and Geriatrics (IAGG), Japanese Society of Gerodontology (JSG), the representative of USA and Taiwan Academy of Geriatric Dentistry (TAGD) on Oct 25th, 2019. Herein, specific notes are briefly addressed and updated for a summative prospective from this symposium and the recent literature.

Psyllium: a useful functional ingredient in food systems

Psyllium gum is a hydrocolloid found in the husk of seeds from Plantago ovata. Psyllium husk has been used in traditional medicine in areas of India and China. Its consumption has been shown to provide nutritional benefits, such as the capacity to reduce the glycaemic index, to minimize the risk of cardiovascular diseases, to decrease cholesterol and constipation problems and others. Thus, interest in the incorporation of psyllium in food products is twofold. First, it can be a natural alternative to the use of other gums and hydrocolloids considered additives. Second, it can be used to improve the nutritional properties of products in which it is incorporated. However, for this purpose, it is necessary to add great quantities of psyllium. This review analyses the potential use of psyllium in distinct food products, considering its advantages and inconveniences as well as possible solutions for undesired effects. Among the analyzed products there are bakery products and, in particular, gluten-free breads where psyllium has been used as a gluten substitute. The incorporation of psyllium into dairy products such as yogurts and those derived from fruits, among others, is also addressed.

Compression test of soft gellan gels using a soft machine equipped with a transparent artificial tongue

A soft machine system (texture analyzer equipped with an artificial tongue) was developed to analyze the occurrence of fractures in soft food gels compressed between the tongue and hard palate. Artificial tongues were newly designed with a modulus similar to that of a somewhat tense human tongue, using transparent urethane gels. A model of soft foods that are easy or difficult to crush with the tongue was prepared using gellan gums at different concentrations. A piece of gellan gum gel was uniaxially compressed on an artificial tongue with the flat probe of a texture analyzer. The food gel and artificial tongue were deformed, leading to the fracturing of food gels alone. During compression-induced fracture, the softer food gels exhibited a lower force, lower displacement, and lower true stress than the harder gels on all artificial tongues. The fracture probability of gellan gels was lower for the combination of harder food gels and softer artificial tongues, as softer materials can deform to a larger extent. Fracture displacement of food gels was increased as the modulus of the artificial tongue decreased; however, the fracture force did not differ significantly. These results suggest that an artificial tongue with elastic modulus values similar to those of the actual human tongue is suitable for determining the fracture behavior of foods during compression between the tongue and hard palate.

Coordination of tongue pressure production, hyoid movement, and suprahyoid muscle activity during squeezing of gels

OBJECTIVE

The aim of this study was to evaluate tongue movement and its biomechanical effects during squeezing, one of the oral strategies for processing soft foods, by tongue pressure sensors, videofluorography, and surface electromyography.

DESIGN

Fifteen healthy men (mean age, 31.0 ± 4.1 years) without dysphagia were recruited. A 0.1-mm-thick pressure sensor sheet with five measuring points, videofluorography, and surface electromyography were used for synchronous measurements of tongue pressure, hyoid movement, and suprahyoid muscles activity, respectively, while squeezing 5 mL of gels. Amplitude, duration, area, and their sequential order during initial squeezing were analyzed. Differences in hyoid position at the onset, peak, and offset of hyoid movement were also analyzed.

RESULTS

At the beginning of initial squeezing, tongue pressure at the middle area of the hard palate, hyoid movement, and suprahyoid muscle activity appeared simultaneously, followed by tongue pressure at the anterior area and then at the posterior area. When the hyoid was in an elevated position, the amplitude of suprahyoid muscle activity and tongue pressure peaked. At the end of initial squeezing, the hyoid position at the offset of hyoid excursion was superior to that at the onset. All evaluation items of tongue pressure, hyoid movement, and suprahyoid muscle activity were modulated according to the texture of gels.

CONCLUSIONS

During initial squeezing, tongue pressure, hyoid movement, and suprahyoid muscle activity were coordinated while being modulated by the food texture. At the end of initial squeezing, the hyoid was maintained in an elevated position, which might be beneficial for subsequent squeezing.

Characterization of oral tactile sensitivity and masticatory performance across adulthood

Texture perception is one of the most important factors in food acceptance, yet population-wide differences in texture sensations are not well understood. The variation in texture perception across populations is thought to depend on oral tactile sensitivity and masticatory performance. To address this hypothesis, we aimed to measure tactile acuity with a battery of tests and quantitate the relationship to masticatory performance. The study was performed on 98 participants, in three age groups (20-25, 35-45, or over 62). Two main measures of oral sensitivity were performed: to assess bite force, subjects were asked to discriminate between foam samples of varying hardness. Second, to assess lingual sensitivity the subjects were asked to identify 3D printed shapes using their tongue, as well as identify confectionary letters. Additionally, masticatory performance was measured through assessing each participants ability to mix two-colored chewing gum. In general, we found that sensitivity and masticatory performance in the younger age groups was superior to that of older adults. We also found a positive linear trend between bite force sensitivity and masticatory performance with younger participants, a trend not found in older participants. We found no significant relationship between age groups for bite force sensitivity and masticatory performance, suggesting that age-related declines in bite force sensitivity are not a significant cause of altered masticatory performance. This study represents a valuable first step in showing that bite force sensitivity does not depend on age, and the minimal influence of factors such as oral sensitivity on masticatory performance. PRACTICAL APPLICATIONS: In a society that is rapidly aging, it is important to understand the subtle changes in physiology and eating behavior that are associated with aging. This study used a variety of tests oral sensitivity to better understand which aspects of oral physiology are integral for effective chewing. The information gained helps shed light on to the factors that create an effective chewing cycle. Besides moving knowledge forward, this study may help in designing food and rehabilitation programs for those with trouble chewing and swallowing, increasing their overall quality of life.

Association of feeding behavior with jaw bone metabolism and tongue pressure

In recent decades, the eating habits of children and adolescents have undergone many changes due to the diversification of lifestyles worldwide. Reduced masticatory function in growing animals results in changes in the mandible, including a decrease in bone mass. However, the influence of different eating behaviors on jaw bone metabolism (e.g., the palatal palate) during the growth period is not fully understood. In addition, recent clinical studies reported that masticatory performance is positively related to tongue pressure in adults, but no consensus has been reached regarding whether tongue pressure is related to masticatory performance in children. This review summarizes current findings related to these issues, focusing on the influence of different feeding behaviors on jaw bone metabolism, including the development of tongue pressure. Consumption of a soft diet had a negative impact on jaw bone metabolism in the maxilla and mandible of rats; however, mastication of a hard diet recovered the collapsed equilibrium of bone turnover caused by a soft diet during growth. Tongue pressure is closely associated with an increase in masticatory performance in children. Peak maximum tongue pressure is reached earlier in women than in men. Before reaching adulthood, women require intervention to increase their peak tongue pressure.

Sagittal Plane Kinematics of the Jaw and Hyolingual Apparatus During Swallowing in Macaca mulatta

Studies of mechanisms of feeding behavior are important in a society where aging- and disease-related feeding disorders are increasingly prevalent. It is important to evaluate the clinical relevance of animal models of the disease and the control. Our present study quantifies macaque hyolingual and jaw kinematics around swallowing cycles to determine the extent to which macaque swallowing resembles that of humans. One female and one male adult Macaca mulatta were trained to feed in a primate chair. Videofluoroscopy was used to record kinematics in a sagittal view during natural feeding on solid food, and the kinematics of the hyoid bone, thyroid cartilage, mandibular jaw, and anterior-, middle-, and posterior-tongue. Jaw gape cycles were defined by consecutive maximum gapes, and the kinematics of the swallow cycles were compared with those of the two consecutive non-swallow cycles preceding and succeeding the swallow cycles. Although there are size differences between macaques and humans, and macaques have shorter durations of jaw gape cycles and hyoid and thyroid upward movements, there are several important similarities between our macaque data and human data reported in the literature: (1) The durations of jaw gape cycles during swallow cycles are longer than those of non-swallow cycles as a result of an increased duration of the jaw-opening phase; (2) Hyoid and thyroid upward movement is linked with a posterior tongue movement and is faster during swallow than non-swallow cycles; (3) Tongue elevation propagates from anterior to posterior during swallow and non-swallow cycles. These findings suggest that macaques can be a useful experimental model for human swallowing studies.

Influence of bruxism and splint therapy on tongue pressure against teeth

OBJECTIVES

This study estimated the maximum tongue pressure (MTP) against teeth in bruxers, and verified the effect of a stabilization splint.

METHOD

Forty subjects (mean age: 26.57 years) were assigned to two groups (n520): bruxers and nonbruxers. Sleep bruxism was diagnosed by self-report, presence of tooth wear and tongue indentation, and by using a BiteStrip2 device. Maximum tongue pressure was measured by intraoral appliances containing pressure sensors. After baseline evaluation, bruxers received a stabilization splint and non-bruxers received a palatal splint, both for nocturnal use. Maximum tongue pressure was reassessed after 30 and 60 days. Data were submitted to repeated-measures ANOVA and Tukey test (Pv0.05).

RESULTS

Bruxers showed an increased MTP against teeth (Pv0.05). Splint therapy decreased MTP for bruxers and non-bruxers.

DISCUSSION

Bruxers present tongue indentations or ulcerations; however, there is no evidence on their MTP. Further research should focus on therapies to avoid tongue ulcerations in bruxers.

In vivo observations and in vitro experiments on the oral phase of swallowing of Newtonian and shear-thinning liquids

In this study, an in vitro device that mimics the oral phase of swallowing is calibrated using in vivo measurements. The oral flow behavior of different Newtonian and non-Newtonian solutions is then investigated in vitro, revealing that shear-thinning thickeners used in the treatment of dysphagia behave very similar to low-viscosity Newtonian liquids during active swallowing, but provide better control of the bolus before the swallow is initiated. A theoretical model is used to interpret the experimental results and enables the identification of two dynamical regimes for the flow of the bolus: first, an inertial regime of constant acceleration dependent on the applied force and system inertia, possibly followed by a viscous regime in which the viscosity governs the constant velocity of the bolus. This mechanistic understanding provides a plausible explanation for similarities and differences in swallowing performance of shear-thinning and Newtonian liquids. Finally, the physiological implications of the model and experimental results are discussed. In vitro and theoretical results suggest that individuals with poor tongue strength are more sensitive to overly thickened boluses. The model also suggests that while the effects of system inertia are significant, the density of the bolus itself plays a negligible role in its dynamics. This is confirmed by experiments on a high density contrast agent used for videofluoroscopy, revealing that rheologically matched contrast agents and thickener solutions flow very similarly. In vitro experiments and theoretical insights can help designing novel thickener formulations before clinical evaluations.

Electromyography of Swallowing with Fine Wire Intramuscular Electrodes in Healthy Human: Amplitude Difference of Selected Hyoid Muscles

Few studies have examined the intensity of muscle activity during swallowing in healthy humans. We examined selected hyoid muscles using fine wire intramuscular electromyography (EMG) during swallowing of four food consistencies. Thirteen healthy adults were studied using videofluorography and EMG of the anterior belly of digastric (ABD), geniohyoid (GH), sternohyoid (SH), and masseter (MA; surface electrodes) while ingesting thin liquid (three trials) and solid food of three consistencies (banana, tofu, and cookie, three trials each). After rectification, integration, and normalization, peak EMG amplitudes for each muscle in each trial were measured. Hyoid displacements were measured in two dimensions. Data were analyzed using repeated measures ANOVA with Bonferroni correction. GH had the highest adjusted amplitude for both solids and liquid. For MA and ABD, amplitude was highest with triturated cookie. For ABD, amplitude was lowest with liquid. There were no significant food consistency effects for GH or SH. Hyoid displacements were greatest for cookie and the lowest for liquid. EMG amplitude varied with initial food consistency. The high peak EMG amplitude of GH is consistent with its essential role in opening the upper esophageal sphincter. High MA amplitude with hard solid foods is likely due to the higher tongue-palate pressure with triturated solids. The higher ABD amplitude with solid food is associated with greater hyoid displacement. These findings support the existence of a central pattern generator that modifies the level of muscle activity during pharyngeal swallowing in response to input from mechanoreceptors in the oral cavity.

Texture Softening of Beef and Chicken by Enzyme Injection Process

This research focuses on a new softening technology for use with chicken breast and eye of round beef in order to assist elderly individuals who have difficulty with eating due to changes in their ability to chew (masticatory function) or swallow. We investigated the hardness of chicken breast and eye of round beef through use of a texture analyzer after injection of a commercial enzyme. Among 7 commercial enzymes, bromelain and collupulin exhibited a marked softening effect on the tested chicken breast and eye of round beef given a 1.00% enzyme concentration. The hardness of bromelain-treated chicken breast reached 1.4×10(4) N/m(2), of collupulin-treated chicken breast reached 3.0×10(4) N/m(2), and of bromelain-treated eye of round beef reached 3.2×10(4) N/m(2), respectively, while their original shapes did not change. To find the level of tissue degradation with specific enzyme concentrations, enzyme injections at 0.1%, 0.25%, 0.50%, and 1.00% concentration of bromelain and papain were also evaluated. The results of this research could be useful for softening chicken breast and eye of round beef and will contribute to the development of foods that can be more easily eaten as part of a balanced diet for elderly adults.