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The present article aimed to present a standardized protocol for the production of a chewable test material that has been used in masticatory efficiency and performance studies. This chewable material has advantages in respect to its physical properties when compared to other artificial and natural test foods. It is constituted by mixing condensation silicon (58.3% by weight), common plaster (10.2% by weight), alginate (12.5% by weight), solid vaseline (11.5% by weight), tooth paste (7.5% by weight), and catalyst paste (20.8 mg/g), adding also three drops of mint essence. The mixed material is then inserted into an acrylic mould with perforations of 12 mm in diameter and 5 mm in height to produce rounded tablets with those measures after polymerization. It was named "Optocal -Brazilian version". A volume of 3 cm³ is indicated for a chewing test, which corresponds to 12 tablets using the present methodology. The present protocol can make the production of this chewable material easier, helping in its standardization for studies on masticatory function.

Two-colour chewing gum and wax have been widely used as test foods to evaluate the ability to mix and knead a food bolus. The mixing of the colours has been assessed by computer analysis or by visual inspection. Reports contradict each other about whether computer analysis and visual assessment could equally well discriminate between the masticatory performances of groups of participants with different dental status. This study compares the results of computer analysis of digital images of chewed two-colour wax with the results of visual assessment of these images. Sixty healthy subjects participated and chewed on red-blue wax for 5, 10, 15 and 20 chewing strokes. The subjects were divided into three groups of 20, matched for age and gender, according to their dental status: natural dentition, full dentures and maxillary denture plus implant-supported mandibular overdenture. Mixing of the chewed wax was determined by computer analysis of images of the wax and by visual assessment of the images by five examiners. Both the computer method and the observers were able to distinguish the mixing abilities of the dentate subjects from the two denture wearer groups. Computer analysis could also discriminate the mixing abilities of the two denture groups. However, observers were not able to distinguish the mixing abilities of the two denture groups after 5, 10 and 15 chewing strokes. Only after 20 chewing strokes, they could detect a significant difference in mixing ability.

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When we chew crispy food, the jaw decelerates and accelerates as a result of resistance and breakage of food particles, and a characteristic sound of the breakage of the food particles is produced. Our aim was to investigate how physical responses, in the form of vibrations, change during chewing. This will give an impression of how food characteristics change during the chewing process. Force resistance and sound emission of three crispy foods (biscuits) and one noncrispy food (cake) were determined with a texture analyzer. We measured skull vibration, while the subjects chewed and swallowed the foods. Clear skull vibrations were observed while the subjects started to chew the biscuits. The skull vibrations gradually decreased upon further chewing down to the level of skull vibrations produced by chewing on noncrispy cake. Then, the biscuits were chewed long enough to form a well‐moistened food bolus that was ready for swallowing. PRACTICAL APPLICATIONS The crispy nature of food products is an important sensory characteristic on which consumers base their appreciation. Rheological measurements have often turned out not to be completely satisfactory in explaining the relationship between food structure and texture perception. This could be explained by the notion that this approach disregards the oral processing and physiology of the mouth. The measurement of skull vibration, produced by the breakage of crispy food during chewing, provides information on how food characteristics gradually change during chewing. This information may help to understand the relationship between food structure and texture perception.