Abstract
The aim of the present study was to determine the relationship between the flow rate of saliva and characteristics of the food. Therefore, we determined the rate of saliva secretion in 16 healthy subjects in rest and while chewing natural and artificial foods (toast with and without margarine, three sizes of breakfast cake, and Parafilm). We also determined the chewing rate, number of chewing cycles until swallowing, and time until swallowing. The physical characteristics of the foods were quantified from force-deformation experiments. The results showed that the average at which mechanical failure occurred (yield force) was 1.86 ± 0.24 N for the breakfast cake and 16.3 ± 1.3 N for the melba toast. The flow rates obtained without stimulation and with Parafilm were significantly lower (P < 0.001) than the flow rates obtained from chewing food. No differences in flow rate occurred between the natural foods. The flow rates of the saliva as obtained without stimulation, with Parafilm stimulation, and with chewing on the various foods were significantly correlated (P < 0.05). There were no significant differences in chewing rate among the foods. The number of chewing cycles and the time until swallowing significantly depended on the type or volume of the food.
Highlights
Saliva is implicated in a wide variety of physiological and biological processes that are crucial to the initial digestion in the upper parts of the gastrointestinal (GI) tract including lubrication, cleansing, enzymatic digestion and maintenance of dental and mucosal integrity[16].Reduction of particle size, reduction of resistance against food deformation and the formation of a coherent bolus that can be swallowed are the main goals of the chewing process
Many studies report on the flow rate of saliva in response to gustatory stimulation with acid[25], to mechanical stimulation from chewing inert materials[8,10], or to chewing natural foods[10,15,18,24]
Saliva was obtained by chewing on several natural foods: toast (Melba toast; Buitoni, Italy, www.buitoni.com; 2.7 g, 7.9 cm3) without and with margarine (Linera – Unilever; the Netherlands, www.unilever.nl; 2.0 g) and three portions of breakfast cake (Right, Peijnenburg, the Netherlands, www.right.nl), which were cut in rectangular blocks of 17x18x30 mm (9.2 cm3, 5.6g), 26x18x30 mm (14 cm3, 8.6g), and 37x18x30 mm (20.0 cm3, 13.2g), respectively
Summary
Saliva is implicated in a wide variety of physiological and biological processes that are crucial to the initial digestion in the upper parts of the gastrointestinal (GI) tract including lubrication, cleansing, enzymatic digestion and maintenance of dental and mucosal integrity[16].Reduction of particle size, reduction of resistance against food deformation and the formation of a coherent bolus that can be swallowed are the main goals of the chewing process. The whole saliva is derived predominantly from three paired major salivary glands, i.e. the parotid, submandibular and sublingual glands (together accounting for about 90% of the fluid production) as well as from the minor salivary glands in the oral mucosa[16]. Many studies report on the flow rate of saliva in response to gustatory stimulation with acid[25], to mechanical stimulation from chewing inert materials[8,10], or to chewing natural foods[10,15,18,24]. The salivary flow rate, while chewing food, is elicited by gustatory and mechanical stimulation and the gustatory stimulation of natural food in producing the flow of saliva appeared to be much more important than the mechanical stimulation from chewing[24]. The consistency of food can be quantified by the deformation of a food sample under mechanical force[14]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
