Association between chewing efficiency and mastication patterns for meat, and influence on tenderness perception

The aim of this study was to investigate whether individuals' chewing patterns were related to their chewing efficiency, and influenced their perceptions of meat tenderness. Chewing efficiency was measured using two methods. Subjects continuously assessed the tenderness of a range of samples throughout the chewing sequence using Time Intensity. At the same time electromyographs (EMGs) were recorded from their masticatory muscles.

Subjects were subdivided into four groups with respect to their chewing efficiencies with the two methods. These subgroups differed significantly in the number of chews, total chewing time and chew work, both for the initial chews and the complete chewing sequence, for the meat samples. No significant difference was found in the dentition between the groups. Significant differences were found between the groups in their temporal perceptions of tenderness.     

Comparison of electromyographic pattern of sensory experts and untrained subjects during chewing of Mahon cheese

Use of electromyography (EMG) to monitor mastication is a relatively new concept in assessing food physical and sensory properties. Although expert assessment of cheese characteristics is widely used, the effect of training in sensory analysis on mastication patterns, as assessed using EMG is not well known. Nine samples of the same Mahon cheese (60 days ripening) were given to 24 subjects (8 experts, 16 untrained) and EMG recorded for each chewing sequence. Three samples were tested in a single session by each subject, and three sessions carried out on different days. EMG was recorded from four masticatory muscles for each subject. From EMG records the following was extracted: number of chews, chewing time, mean and maximum voltage of EMG bursts (i.e. chews) across chewing sequence, chewing work and chewing rate. No gender bias was found for the EMG parameters considered, therefore, as regards gender, each group was considered to be homogeneous. Variability within-subjects across samples was greater for experts than untrained subjects. Significant differences in chewing time, chewing work and chewing rate were found between the expert and untrained groups. Data analysis of the three sessions showed an influence of cognitive constructs, mediating states, on the chewing process. The experts were found to be goal driven as to their mastication process. Experts showed no significant differences between sessions, untrained subjects were found to vary their EMG output in successive sessions for number of chews, chewing time, mean voltage, and chewing work.     

Individuality of understanding and assessment of sensory attributes of foods, in particular, tenderness of meat

This study examines the extent to which variations in consumers' sensory assessments of food arise from the inability to report accurately sensory perceptions, from confusion regarding the criteria by which to assess samples, or from differences in their oral breakdown of the products.

Twenty consumers assessed the tenderness of a range of 8 hot, freshly roasted meat samples using Time Intensity (TI). Overall a significant correlation was found between the maximum recorded intensity (Imax) of their TI curves and single sensory scores given by a trained panel. Correlation was significant for only 42% of the consumers individually. Significant correlations were found between the amount of masticatory muscle activity undertaken during chewing (measured using electromyography) and Imax for all but 2 of the consumers. Thus subjects' perceptions were accurately described by their chewing work, suggesting between subject differences in perception arose from differences in the way chewing work was applied to break down the samples. The sensory input from the masticatory muscles may represent the major determinant of perceived tenderness of meat.     

CHEWING PATTERNS OF VARIOUS TEXTURE FOODS STUDIED BY ELECTROMYOGRAPHY IN YOUNG AND ELDERLY POPULATIONS

The effects of food texture on the chewing patterns of elderly and young people, masticatory recordings using electromyography (EMG) were carried out. Fourteen French adults (mean 29.4 years) and 23 elderly (mean 67.7 years) participated. Six food products (rice, beef, cheese, crispy bread, apple and peanuts) were tested. The chewing pattern of elderly subjects was characterized by a significant increase of number of chews and chewing duration for all foods except rice. Whatever the food type, muscle activity per chew (mean amplitude × burst duration) was lower for elderly than for young subjects. Single chews appeared less effective for food reduction in elderly than in young subjects. This can be partly compensated for by increasing the chewing duration and number of chews. No significant difference was found between both groups of subject for the total amount of EMG activity required prior to swallow whatever the food chewed.     

USE OF COMBINED ELECTROMYOGRAPHY AND KINESTHESIOLOGY DURING MASTICATION TO CHART THE ORAL BREAKDOWN OF FOODSTUFFS: RELEVANCE TO MEASUREMENT OF FOOD TEXTURE

This paper describes a method for obtaining detailed information about the velocities, directions and relative forces involved in mastication, and how these change throughout the chewing sequence, from combined electromyograph and kinematic records in human subjects. Differences in the temporal breakdown patterns of apple, carrot and biscuit are highlighted. Mastication of apple and carrot relied on vertical compression for each chew, with decreasing effort applied over the course of the chewing sequence. Differences between these products were related principally to the chewing effort exerted. For biscuit, compression was the predominant mechanism of breakdown in early chews but this was transferred to a shear action over the course of the sequence.     

Interrelations among physical characteristics,sensory perception and oral processing of protein-based soft-solid structures

Oral processing is essential in breaking down the physicochemical structure of the food and thus important to the sensory perception of food in the mouth. To have an understanding of protein-based, soft-solid texture perception, a multidisciplinary approach was applied that combined studies of food microstructure with mechanical properties, sensory evaluation, and oral physiology. Model foods were developed by combining ion-induced micro-phase separation and protein-polysaccharide phase separation and inversion. Activities of masseter, anterior temporalis and anterior digastric muscles during oral processing were recorded by electromyography (EMG), while jaw movement amplitudes, durations, and velocities were simultaneously collected by a three-dimensional jaw tracking system (JT-3D). Changes in the microstructure of mixed gels significantly altered the characteristics of the chewing sequence, including the muscle activities, number of chews, chewing duration and chewing frequency. Mechanical attributes related to structural breakdown and sensory perception of firmness were highly correlated with the amount of muscle activity required to transform the initial structure into a bolus ready for swallowing. Chewing frequency was linked to mechanical properties such as recoverable energy, fracture strain and water holding capacity of the gels. Increased adhesiveness and moisture release also resulted in slower chewing frequency. Evaluation of oral processing parameters at various stages (i.e., first cycle, first 5 cycles, and last 3 cycles) was found to be a useful method to investigate the dynamic nature of sensory perception at first bite, during chewing and after swallowing. The study showed that muscle activity and jaw movement can be used to understand the links between physical properties of foods and sensory texture.     

INFLUENCE OF CHEWING AND SWALLOWING BEHAVIOR ON VOLATILE RELEASE IN TWO CONFECTIONERY SYSTEMS

Electromyography, electroglottography and turbine airflow technology were used to characterize the chewing, swallowing and breath flow profiles of 35 subjects during the consumption of two different (a gum Arabic‐ and carrageenan‐based) confectionery chews. Simultaneous volatile release measurements were obtained using atmospheric pressure chemical ionization mass spectrometry. Subgroups of subjects displaying different eating characteristics were identified for both products. Parameters accounting for the maximum variance (product 1, 42% and product 2, 52%) between the subgroups were chewing force, chewing rate, proportion of work and total number of chews. Volatile release measurements were significantly different between the subgroups from product 1. The impact of the different eating characteristics on volatile release from product 2 was less defined, and postulated to be a result of the contrasting textural properties. Manipulating in vivo breakdown of chewy confectionery products, by texture modification, may influence consumer's volatile release and subsequent flavor perception.     

Can we understand food oral processing using Kano model? Case study with confectionery products

This study had two objectives, to determine oral processing parameters and its correlation with mechanical properties of selected confectionery products and to categorize oral processing and sensory attributes based on a Kano model. Thirteen panelists analyzed five confectionery products in the oral processing part of the study. In parallel, 327 interviews participated in a field survey to enable analyzing responses to food quality and oral processing attributes. It has been confirmed that oral processing parameters are interrelated with most of the mechanical properties of confectionery products. Average number of bites is correlated with consumption time per bite, chewing rate, and bite size. Consumption time and chewing rate were negatively correlated for Brownie cake. Satiation was associated with eating rate and calorie intake rate for Jelly Candy and Waffle. All food quality requirements were categorized as “attractive” and “one-dimensional.” Oral processing parameters—food breakdown and eating rate are aligned to “attractive” category, bite size was identified as a “must-be” category, and number of chews is outlined as a “reverse” category. The Kano model results show that oral processing parameters have a strong influence on consumer satisfaction in parallel with well-known sensorial characteristics associated with food quality.     

Training and Sensory Judgment Effects on Mastication as Studied by Electromyography

Electromyography recordings (EMG) were performed on 10 naive and 10 trained subjects during mastication of different samples of beef. For each group of subjects, ordinary mastication was compared to mastication accompanied by tenderness assessment of the chewed sample. Trained subjects showed a larger variation in muscle work than a naive group when chewing. Sensory assessment modified more the mastication profiles of trained subjects than those of naive ones and these variations occurred at the beginning of the masticatory sequence. EMG was useful for comparing mastication of different groups of panelists and appeared to be an interesting alternative for information about texture perception of naive subjects.     

ANALYSIS OF FOOD CRUSHING SOUNDS DURING MASTICATION: TOTAL SOUND LEVEL STUDIES 1

The total sound level of airborne noise was measured continuously during consecutive chews of fresh and stale samples of potato chips and tortilla chips. Sensory estimations of crispness were also made. Samples were evaluated using both an open mouth and a closed mouth procedure. Analysis showed that the total sound level decreased as chewing progressed. Significant differences were observed between open mouth and closed mouth chewing, with the former displaying higher sound levels. However, there were no statistical differences in the sound levels between fresh and stale samples. Sensory assessments ofcrispness showed decreasing crispness as chewing progressed. Statistical differences were observed in the sensory evaluations between fresh and stale samples. Openmouth sensory evaluations were significantly different from closed-mouth evaluations for potato chips but not for tortilla chips. Good correlations were observed between the acoustic measurements and the sensory estimations, in agreement with the work of other investigators.     

Static vs. dynamic liking in chewing gum: A new approach using a background task and a natural setting

Chewing gum is a particular product, consumed during long periods of time and usually while doing something else. Therefore, traditional hedonic tests might not provide sufficient information. The aim of the present work was to compare the liking scores resulting from asking consumers whether they liked the product only once (static liking, SL) to those obtained when asking repeatedly during consumption (dynamic liking, DL). For this purpose, three different mint chewing gums were evaluated by two groups of 50 consumers. In both cases, consumers evaluated the samples at home using an Internet application specifically designed for the experiment. In the SL, consumers were prompted to rate their liking only after 5 min of chewing. During this time, consumers were presented with a series of curious facts (“Did you know…?”) which they would read from the screen as a background task. For the DL, consumers were asked to rate the samples every 45 s during a period of 10 min while performing the same background task, having a maximum of 10 s to answer.Comparing the results obtained by both techniques at the same moment of consumption (5 min), ratings were found to be significantly higher with the SL for all samples. This could indicate that, when asked once, consumers gave their overall liking score and not their liking at precisely 5 min. Nonetheless, at that moment, the sample ranking was the same for both methods. Moreover, DL showed that when taking into account preference throughout consumption time, a significant product ranking inversion could be found, revealing that preference was time dependent and also that this change was different among products.     

The effect of oral tactile sensitivity on texture perception and mastication behavior

Mastication is a notable source of interindividual variation in texture perception and could be linked to oral tactile sensitivity. To better understand the influence of oral tactile sensitivity on mastication behavior, this study measured masticatory behavior and texture discrimination in participants of high (n = 20) and low (n = 21) oral tactile sensitivity. Overall, there was no significant difference between high and low sensitivity participants in their ability to distinguish texture changes (p = .486). However, there were significant differences found between the groups based on their masticatory behaviors including chewing pattern and overall number of chewing cycles. Additionally, those in the high sensitivity group used more stochastic chewing movements, while those in the low sensitivity group were found to use crescent‐shaped chewing cycles. It was also noted that in the high sensitivity group, the jaw moved further distances in all phases and moved at a higher velocity when opening but not when closing, when compared to the low sensitivity group. These results show what particular aspects of mastication are most influenced by oral tactile feedback. Chewing patterns have been shown to influence texture and flavor perception, as well as energy intake. However, much of the person‐to‐person variability in chewing patters comes from unknown sources. This study shows which chewing behaviors are different between a group of individuals with high oral tactile sensitivity and another with low oral tactile sensitivity. These findings highlight the manner in which tactile feedback from the mouth influences chewing.     

COMPRESSION RATES IN THE MOUTH

The mte of compression of solid foods in the mouth varies widely. The rate of movement of the jaws is not linear but follows an approximate sine curve pattern. The first few chews on a piece of food are frequehtly slower than subsequent chews. Other factors that affect the mte of compression are: differences in chewing mtes between individuals, how wide the jaw is opened, the placement of teeth with respect to the temperomandibular joint and the type of food. More studies are needed on compression mtes between the teeth in order to establish the mnge of compression speeds that would be preferred for use in objective texture measurements.     

INFLUENCE OF CHEWING EFFICIENCY ON TEXTURE AND FLAVOUR PERCEPTIONS OF FOOD

This study examined the effect of differences in chewing efficiency on selected panellists' perceptions of the stickiness and flavour of cooked pasta. Chewing efficiency was measured by the degree of breakdown of an almond, and weight loss of chewing gum after predetermined numbers of chews. Pasta was cooked for various lengths of time in tomato juice to provide a series of samples varying in texture and flavour. The attributes considered in this study were clearly understood and detected in all of the samples by all the subjects. Nevertheless the subjects differed in the time intensity representations of their perceptions of these attributes. Differences in the efficiencies with which subjects break down food in the mouth may account for the abilities of subjects to distinguish between samples in terms of texture and flavour.     

Preparation of double‐network tofu with mechanical and sensory toughness

In this study, sugar beet pectin and soy protein were used to prepare the double‐network (DN) modified‐tofu by sequential laccase and microbial transglutaminase treatments. The mechanical properties of modified‐tofu were analysed by uniaxial compression test and texture profile analysis. The DN modified‐tofu exhibited greater mechanical toughness than the corresponding single‐network modified‐tofu, while the ratio of soy glycinin to soy protein isolate reached and exceeded 50%. The enhancement of mechanical toughness may be mainly ascribed to the hierarchical microstructure which is observed in DN modified‐tofu by scanning electron microscopy. DN modified‐tofu provided a distinctive mechanical and sensory tough texture as compared to other tofu samples. In addition, the oral processing measurements indicated that DN modified‐tofu required higher jaw‐closing muscle activities, a greater number of chews and longer chewing duration to be processed. Furthermore, the chewing pattern of DN modified‐tofu was different from other tofu samples.     

Particle breakdown dynamics of heterogeneous foods during mastication: Peanuts embedded inside different food matrices

Heterogeneous foods are widely consumed but little is known about the dynamics of their breakdown during mastication. To investigate these dynamics the particle size and bolus mass at regular stages of the chewing sequence were investigated using a single subject, who was carefully selected according to strict mastication and dental criteria. A standardized volume of both a gelatine gel and chocolate matrix containing roasted peanuts was chewed and expectorated after a specified number of chews or at the point of swallowing. The mass of various components of the bolus was determined along with peanut particle parameters (d₅₀, broadness (b), and specific surface area) at each interval.Results showed that for this subject the type of matrix influenced the pathway that the peanut particles (embedded inside each matrix) were broken down. The d₅₀ of peanut particles within the bolus of the gelatine gel were greater than within the bolus of the chocolate throughout the chewing sequence until the point of swallowing. At the point of swallowing, the d₅₀ of peanut particles inside the bolus of the gelatine gel and chocolate were the same. The broadness value (b) and specific surface area of the peanut particles in the bolus of the chocolate were greater than those in the bolus of the gelatine gel throughout the chewing sequence. The matrices also induced different dynamic trends in the mass of bolus components during the chewing sequence.     

Use of healthier fats in biscuits (olive and sunflower oil): changing sensory features and their relation with consumers' liking

The aim of this study was to evaluate consumer acceptability of biscuits when saturated fat was replaced by olive or sunflower oil and to determine the sensory characteristics responsible for changes in acceptability. Ninety seven consumers evaluated the acceptability of six biscuit samples varying in the fat source (dairy shortening, olive oil and sunflower oil) and fat content (10.6% and 15.6%). Using a Check All That Apply question (CATA), consumers also evaluated sensory properties of biscuits. Results indicated that the replacement of saturated fat (dairy shortening) by vegetable oils had an effect on biscuit acceptability which depended on biscuit fat content. According to biscuits' acceptability data, three different clusters of consumers were identified. By using a multiple factor analysis, the relationship among sensory CATA data and acceptability of each cluster explained the different acceptability patterns of consumers. For most of consumers acceptability was related to attributes “crispy”, “easy to chew” and “biscuit flavour” which, for one group were perceived in shortening biscuits and, for another in both olive and shortening biscuits. However, for the third group of consumers, acceptability was only related to flavour attributes like “roasted flavour” or “biscuit flavour” that were perceived in vegetable oil biscuits which were the preferred biscuits while, shortening biscuits were disliked and perceived as having an “off flavour”.     

基于仿口腔平台的食品咀嚼效果评定方法研究

食品在口腔加工中的形变过程以及口腔加工能力与形成可吞咽食团的相互关系受到越来越广泛的关注,然而测试人员的食品口腔加工过程难以直接观察,咀嚼实验的相关数据难以获取;并且口腔加工能力不易重复量化,使得咀嚼效果难以评定。为解决这些问题,基于前期开发的仿口腔平台,以石蜡和花生作为试验样品,分别通过仿口腔平台和测试人员进行咀嚼实验,并将收集的食团进行咀嚼效果指数测定和比较。数据分析表明：体内和体外咀嚼实验与咀嚼次数间具有显著相关性,不同咀嚼次数下体内组和体外组的花生中值粒径d₅₀、石蜡咀嚼效果指数MEI存在显著性差异(P<0.05);且当咀嚼次数达到食团吞咽所需的次数时,体外实验得到的食团样品与测试者口腔中收集的样品咀嚼效果评定指标具有高度一致性。研究结果表明,基于模拟人类食品口腔加工并生成食团的仿口腔平台进行食品咀嚼实验来评定咀嚼效果,可有效替代实验人员,减少实验成本,增加实验可重复性。