Discrimination of cucumber cultivars using a multiple‐point sheet sensor to measure biting force

To define the textural differences among three cucumber cultivars, we combined two different mechanical measurements: a direct measurement of mastication force using a multiple‐point sheet sensor (MSS), and a uniaxial compression test. For mastication force measurement, subjects bit a sample placed on the sheet sensor with their upper and lower incisors. During a single bite, masticatory force was measured using a computerised MSS device called the ISCAN system with a TSCAN sheet sensor. Values of maximum bite force, the time at which maximum bite force appeared, area under the force–time curve, contact area and maximum pressure point for one cultivar were significantly higher than those for the other two. For all the parameters, lower values corresponded to crispness and higher values to toughness. Overall tendencies were the same in the compression test, though the compression test tends to yield smaller standard deviations. The MSS masticatory test is suitable for analysing masticatory properties with respect to each individual, while the instrument test is suitable for analysing physical properties inherent in each sample. Combination of the actual mastication test performed in the human oral cavity and conventional mechanical tests provides the most reliable objective analysis of food texture. Copyright © 2003 Society of Chemical Industry     

THE USE OF INTRAORAL LOAD CELLS IN THE STUDY OF TEXTURE PERCEPTION

A new method to study texture perception is described. Miniaturized load cells were placed in the oral cavity to record the time course of the bite force. The bites were made, during psychophysical tests on hardness comparison, into products (silicone elastomers) exhibiting simple rheological behaviour. The silicone samples were placed on either side of the load cell. The control measurements proved that the recordings under these conditions were stable and reproducible. An analysis of the time course of the curves revealed differences in perception strategy between the subjects. The use of load cells together with standardized products allows a better understanding of the relationship between the rheological measurements of a product and the motor activity of the chewing apparatus when the texture of a solid food product is perceived.     

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.     

Dynamics of food breakdown during eating in relation to perceptions of texture and preference: a study on biscuits

Combined recording of masticatory muscle activity and jaw movement patterns during eating was used to examine the process of food breakdown in the mouth for a series of “Rich Tea”-type biscuits in 19 ordinary consumers. These data indicated an initial increase in chewing work from the masticatory muscles over the first 5–10 chews followed by a decline over the remainder of the chewing sequence. The work was concentrated in vertical closing of the jaw during the early chews but as this declined over the later chews there was an increase in the amount of work occurring with the teeth in near occlusion. The relative amount of work input into the chewing sequence, the duration of the sequence, and the degree of work undertaken at occlusion, differed among groups of the consumers who were classified according to their chewing efficiency (CE). Subjects from different CE groups appeared to have different understandings of the textural characteristics of the samples which they assessed as “hardness”, “crunchiness” and “crumbliness”. Differences in the oral breakdown patterns for different CE groups may provide an understanding of differences in consumer preferences for the samples. ©     

ORAL PHYSIOLOGY AND TEXTURE PERCEPTION OF SEMISOLIDS

ABSTRACT

In the oral cavity, the food is subjected to several mechanical and chemical processes. It is fractured by the teeth, diluted and broken down by saliva, heated or cooled by the ambient temperature of the mouth, formed into a bolus and finally swallowed. Numerous receptors in the oral cavity and nose respond to the initially ingested food and monitor the changes during processing. This leads to central perceptions of taste, odor, irritation and texture of the food. Most sensations associated with food texture occur only when the food is manipulated, deformed or moved across the oral receptors. In addition, people assessing the same stimulus differ in their ratings of that stimulus and their oral physiological parameters also exhibit inter‐individual variations. This paper is based on the PhD thesis of one of the authors. It gives an overview of this study and includes related work of other authors. The aim of our research was to improve the understanding of oral texture perception, in particular to examine the role of oral physiological processes in oral texture perception of semisolids and to investigate whether individual differences in perception could be attributed to differences in oral physiology among subjects. The results of our study demonstrate that oral physiological parameters such as oral sensitivity, tongue movements, temperature and saliva composition are of importance for texture perception of semisolids. Many parameters of oral physiology correlate with various perceived texture attributes. This implies that intra‐individual differences in texture perception could be attributed to variations in oral physiology. Oral physiology thus plays a role in texture perception of semisolids and should be taken into account in future texture research.

PRACTICAL APPLICATIONS

By understanding the processes in the mouth while eating, a better understanding of the sensations and the perceptions of the food can be gained. Taking for each food the relevant physiological parameter into consideration when performing and designing rheological/instrumental measurements grants more natural conditions and better predictions of sensory perception. This could save time and money on time‐consuming and expensive sensory panels in the earlier steps of product development and renovation. Knowing how physiological processes highlight specific flavor/texture sensations may be useful for product development or quality control where one typically wants to focus on certain sensations and ignores others. In addition, a future application could be to tailor products for personalized nutrition, individual choices or clinical nutrition based on physiological groups.     

Food oral processing—A review

Food oral processing is an essential procedure not only for the consumption and digestion of foods but also for the appreciation and pleasure of food texture and food flavour. The consumption of a food inside mouth involves various oral operations, including first bite, chewing and mastication, transportation, bolus formation, swallowing, etc. Exact mechanisms and governing principles of these oral operations are still not fully understood, despite of continuous efforts made by scientists from food, psychology, physiology, dental and clinical studies, and other disciplines. This article reviews recent progresses and literature findings about food processing and transformation in mouth, with particular attention on the physiology and rheology aspects of oral operations. The physiological behaviour of human's oral device is discussed in terms of biting capability, tongue movement, saliva production and incorporation, and swallowing. The complexity of oral processing is analysed in relation to the rheology and mechanical properties of foods. The swallowing and oral clearing process is also examined for its criteria, triggering mechanism, bolus deformation, and the rheology of swallowing.     

CONSUMER TEXTURE PREFERENCES: EFFECT OF AGE, GENDER AND PREVIOUS EXPERIENCE

Four different strawberry candies with varying thickening agents (pectin, gelatin, starch, and gelatin + starch) were rated by three consumer age groups: teenagers (13–14 years), young adults (19–23 years) and the middle-aged (40–63 years) (n = 60 in each group). Age, gender, use frequencies and hedonic ratings often commercial candy types were collected as background information. Four preference groups were found by using preference mapping. The most important factor predicting preference of a sample were hedonic evaluations of commercial candies whose texture was similar to that of the test sample. If the consumers gave high hedonic ratings to one sample they also tended to report liking for the commercial candy with a similar texture. Age and gender also affected hedonic evaluations in most cases. For example, the middle-aged consumers were more clearly segmented into different preference groups than were the two younger groups. Use frequencies of commercial candies had no statistically significant effect on sample preference. We conclude that, in the case of candy, consumers' preferences can be explained by the liking of commercial candies with similar texture. Also, age and gender may have significant effects.     

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.     

Development of model mouth for food oral processing studies: Present challenges and scopes

Food oral processing research covers the study of mastication, role of tongue, teeth, and palate, food-saliva interaction, bolus formation, texture and flavor perceptions, etc. Over the preceding decades, instrumental approaches were advanced to evaluate texture, flavor, and other physicochemical changes by simulating some form of oral functionalities and environments. However, a comprehensive assessment of food products under actual oral processing is still an open topic of research, and has many persisting challenges. Present experimental methods utilize a number of different instruments and feedbacks from trained human panel in order to draw some form of correlations between physicochemical properties of the food composition and its sensorial properties. Major shortfalls of these existing instruments are their justifiable limitation to become a true representation of actual oral conditions and mechanisms. It therefore leads to contemplate on an ambitious objective to develop a device closely resembling the processes and mechanisms of human mouth.This paper proposes a review of the development of artificial mouth and masticatory devices designed specifically for food oral processing studies. The devices which have been exclusively built for other purposes such as dental treatment, speech therapy, jaw simulation, etc. are judicially excluded from this review. The article further covered a state of the art on engineering interpretation of oral features. Following on, sincere attempts have been made to identify and classify the challenges and research gaps including the interdisciplinary nature of the field. This review has been summarized with guidelines for follow-up research and development in the direction of advance instrumentalization of food oral processing covering the research interests from both academics and food industries.     

Feasibility of using a protein gel for masticatory assessment of older people

Masticatory function plays a crucial role in the breakdown of food for bolus formation and safe swallowing. Chewable silicone gel particles (Optosil) were used for assessing masticatory performance by dentists but such particles were found not suitable for older people due to its hard and dry texture and unfavored flavor. Therefore, with fast growing number of older people who have eating and swallowing difficulties, seeking a suitable model food for masticatory performance assessment becomes an important issue. This study was to develop a glucose-containing model food system for reliable evaluation of the masticatory performance. Three formulas with different amount of gelatin were used to prepare the gels and their textural properties were analyzed. A glucometer was used to measure glucose concentration in saliva. Both young adults (23.5 ± 1.1 years) and older subjects (72.9 ± 5.4 years) were asked to perform mastication tests to verify the reliability of the method. Results showed that the Gel-15% sample gave the best performance and was selected as the test food. Reliability of the current method was proved by the classical standard of Optosil method. Moreover, our findings indicated that masticatory performance was significantly positively correlated with bite force in both young and older adults (young subjects: r = 0.874, p < 0.01; older subjects: r = 0.638, p < 0.01). In conclusions, this study suggested that the newly method could accurately and efficiently measure the masticatory performance of older people.     

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.     

Liking of food textures and its relationship with oral physiological parameters and mouth-behavior groups

Researchers have categorized people into four “mouth-behavior” groups based on their oral processing preferences, and claimed that members of those mouth-behavior groups differ in their food texture preferences. If people could be classified into groups based on their liking of different textures, food products could be targeted to specific subgroups, potentially enhancing consumer acceptability. In the first part of our study, we grouped people based on their liking ratings of a wide variety of food textures by asking 288 participants to rate their liking of 106 food texture attributes in an online survey. In the second part of our study, we further examined relationships among individuals' food texture liking ratings, mouth-behavior group membership, and measurements of four oral physiological parameters (saliva flow rate, chewing efficiency, biting force, and particle size sensitivity). One-hundred participants completed the online survey on food texture liking, classified themselves into one of four mouth-behavior groups (Chewers, Crunchers, Smooshers, and Suckers), and were measured for four oral physiological parameters. We refuted the idea that large texture-liking subgroups exist. Although our participants self-categorized themselves into the four mouth-behavior groups similarly to previous researchers, our texture liking measurements did not support the presumed preferences of those mouth-behavior groups. Clustering of participants on their oral physiological measurements produced a “low particle-size sensitivity” cluster, a “high biting force” cluster, a “high saliva flow rate” cluster, and a “low saliva flow and low chewing efficiency” cluster. Neither our texture liking nor our oral physiological measurements predicted membership in the four mouth-behavior groups.     

CONSUMER AWARENESS OF AND ATTITUDES TO FOOD TEXTURE II. Children and Teenagers

A discussion of children’s and teenagers’ attitudes to food texture is presented based on published data relative to growth and development and on information obtained from original consumer interviews. It is pointed out that, in this population group, physiological factors appear to be dominant in shaping attitudes to texture. These are modified by psychological, social, cultural, and other factors in the adult consumer. With both children and teenagers, texture is an important attribute of foods influencing their likes and dislikes. In the young child, attitudes to food texture follow the developmental sequence of oral functions, and textures are rejected which are difficult to manipulate in the mouth at a particular stage of physical development. The high degree of texture awareness of teenagers may possibly surpass that of adults. Teenagers also appear to have a better understanding of the concept of texture suggesting that this attribute may assume greater importance with the oncoming generation of adult consumers.     

基于口腔咀嚼原理的咀嚼模拟器研究进展

咀嚼模拟器是指模仿人类口腔生理结构、咀嚼运动系统以及咀嚼功能的机械装置.该类型设备因不受伦理、时间、环境的影响,能够为揭示食物的口腔破碎、食团重组及风味成分释放的动力学过程提供直接的实验验证.本文主要对口腔生理及其模拟方法做出简单介绍,为咀嚼模拟器的构建提供有效的科学依据和参考因素.同时在口腔咀嚼原理基础上对应用于各领...     

The oral management of food: the bases of oral success and for understanding the sensations that drive us to eat

Everyone understands the verbs—to chew, to smell and to swallow. Most people subconsciously take eating for granted. As consumers, we enjoy eating without much need to understand how we succeed. But we do not all succeed equally, adapting as best we can with the teeth we have managed not to lose. Impaired dentitions lead to changes in food selection, style of cooking and other food preparation. The physiology of mastication is briefly reviewed. This process necessarily involves ingestion past the lips where temperature is monitored. Incision provides extremely sensitive detection of internal texture whilst the lips and tip of tongue detect external texture. Videofluorography (VFG) has provided the essential basis for visualizing and analyzing the processes by which food is moved to the cheek teeth and is subsequently manipulated. Data on the process of crushing food between the teeth explains the release of vapor and the sensation of food texture, which change progressively as the mouthful is chewed. Salivary flow rates and salivary proteins are critical for the developing coherence of the food bolus and its adhesion to the tongue prior to swallowing. The movement of odors from the mouth to the olfactory nerves in the roof of the nasal cavity involves the dynamic combination of tongue movement, continuing respiration and, late in the chewing sequence, the adhesion of the bolus to the moving tongue, which can be seen graphically on VFG. These coordinated interactive processes together provide the basis of oral success.     

Effect of time and temperature of storage after cooking on the sensory quality of Bintje potatoes.

Seventeen trained judges used a scoring technique with nine-point scales to evaluate sensory attributes of cooked potatoes (variety: Bintje) that had been kept hot after cooking for different lengths of time at different temperatures. Maximal storage times before the potatoes were considered unacceptable were determined for each temperature. In addition, comparisons were made with preference data obtained for 55 untrained consumers. For all sensory attributes significant differences in average scores were obtained among samples stored for different periods of time (0, 1, 2, 3 and 4 h) and different temperatures (60, 75 and 90°C), as well as significant interactions between time and temperature. In general the effect of time was largest at the highest temperature. The differences were largest for flavour and smallest for appearance. The maximum times the potatoes could be kept at 60, 75 and 90°C before becoming unacceptable in flavour were 2.9, 2.2 and 1.3 h, respectively. The corresponding values for texture and appearance were higher. Generally potatoes that had been kept hot were described as ‘dark, greyish or brownish, and dry on the surface', and having a 'strong and musty odour; musty, old and bitter flavour, and watery, soggy, and spongy texture ’For 55 untrained consumers, (highly) significant differences were obtained in preference frequencies for appearance, flavour, and texture for pairs of samples stored after cooking at 75°C for different periods of time. The differences were largest for flavour, and smallest for appearance. Generally, the freshly prepared sample was preferred, and the difference in preference increased with increased storage time. The results from the untrained consumers are in close agreement with the results obtained by the trained panel. It was concluded that consumers in general also consider the sensory changes of keeping potatoes hot after cooking as deleterious, and that the unacceptability limits determined by the trained panel were not unreasonably small.     

基于多连杆结构的二维仿生咬合力测量装置

目的:研制一种用于咬合模拟试验的多连杆结构的咬合模拟装置。方法:分析了运用多连杆结构复刻人类口腔咬合轨迹的可行性,基于多连杆结构对咬合模拟装置进行机构设计,用Solidworks软件对装置的运动轨迹进行模拟仿真,并通过试验验证咬合模拟装置的有效性。结果:咬合模拟装置最大开口距离为50 mm,所选食材中胡萝卜咬合力最大为65.77 N,最小值为豆腐的2.05 N;咬合模拟试验与感官评价试验结果呈正相关,验证了咬合模拟装置的有效性。结论:咬合模拟装置可以有效地进行体外咬合模拟试验,其测力结果可以用于食品质地等研究。