The effect of bolus size on masticatory parameters at swallowing threshold in children using a hard, solid, artificial test food

Creating similar food boluses as that in vivo using a novel in vitro bio-inspired oral mastication simulator (iBOMS-Ⅲ): The cases with cooked rice and roasted peanuts

Food bolus is the major outcome of oral processing of foods. Its structure and properties are crucial for safe swallowing and subsequent gastric digestion. However, collecting the ready-to-swallow bolus for further analysis in either normal or deficient human subjects is difficult, regulatorily or practically. Here, a novel in vitro bio-inspired oral mastication simulator (iBOMS-Ⅲ) was developed to be capable of replicating food boluses comparable to those in vivo. Cooked rice and roasted peanuts were used as the model foods (soft and hard) respectively. Particle size distribution, moisture content and rheology of the food boluses produced in the iBOMS-Ⅲ were assessed. A conventional food blender was also employed as a non-consequential comparation. Eighteen healthy young volunteers of the ages from 20-30 years (10 male and 8 female) were invited to provide the in vivo data. For cooked rice boluses produced by the iBOMS-Ⅲ with 10, 12, 14, and 20 chewing number of cycles, the moisture content exhibited minimal variation (68.3-68.8 wt%), aligning closely with values obtained from the average value of the human subjects (67.5 wt%). Similarly, the boluses from roasted peanut displayed similar moisture contents across masticatory number of cycles (36, 40, and 44 number of cycles), averaging at 35.3 %, mirroring the average in vivo results (33.8 wt%). Furthermore, the shear viscosity of both cooked rice and roasted peanut boluses exhibited minimal variations with iBOMS-Ⅲ chewing number of cycles. The particle size distributions of the boluses produced with 14 and 44 chewing number of cycles matched well with the in vivo data for cooked rice and roasted peanuts, with median particle size (d50) being 1.07 and 0.78 mm, respectively. The physical properties of the food boluses collected from the food blender, with varying grinding times, differed significantly. This study demonstrates the value of the iBOMS-Ⅲ in achieving realistic boluses with two very different food textures.

A breakage index for characterizing in vitro nut fragmentation and predicting human oral fragmentation

Breakage of food influences eating experience and sensory perception. The aims of the study were to identify an appropriate breakage index and to develop an in vitro method for predicting the ease of oral breakage of nuts. Kernels of five types of nuts were fragmented in vitro using a texture analyzer and 12 subjects therefore performed molar bites. In addition, peanuts were differently roasted (over 0, 15, 25, and 35 min) to vary texture within the same nut type. Projected particle areas were determined using imaging. Two Breakage Indices were compared (1) BI-I, the difference, after and before fragmentation, in square root values of ratios between total projected area and volume [Agrawal et al., 1997, Archives of Oral Biology, 42(1), 1-9], and (2) BI-II, the ratio of the total projected area after and before fragmentation. BI-II gives a stronger linear regression than BI-I between in vivo and in vitro index values for different types of nuts; Pearson's r = 0.834 versus 0.499 (12 subjects with all data pooled). Using BI-II, a subject's regression result in fragmentation tests with differently roasted peanuts was as strong as when testing different nut types: Pearson's r = 0.984 versus 0.964. Since the range of the in vitro BI-II values was 5.5 times smaller in the peanut tests, the finding of a similarly strong regression indicates a high sensitivity of BI-II to detect differences in food texture. BI-II is useful for food industry to determine how easily solid foods break down and thereby compare the potential of flavor release between foods during chewing.

Effect of food portion on masticatory parameters in 8- to 10-year-old children

The objective of this study was to explore differences in bite size and the amount of intraoral processing of four different foods between a reference and a double portion in 8- to 10-year-old children and, also to explore if there were differences depending on the child's weight status. The study was undertaken in 8- to 10-year-old children (n = 89). Body mass index was determined, and weight status was established based on Centers for Disease Control and Prevention(CDC) guidelines. A reference (half a banana, half a large peeled carrot, a slice of loaf cake, and half a salami stick), and a double portion of each food were offered to children in a randomized order in two different sessions. Three consecutive bites were taken and averaged. Variables in this study were bite size (g), number of cycles until swallowing, sequence duration as well as cycles/g. Comparisons were performed with Mann-Whitney, Kruskal-Wallis, and Wilcoxon tests, regressions and correlations were run. Bite size was ≈13% larger with the double portion (p ≤ .05 for salami, banana, and loaf cake). Cycles/g decreased for all foods with the double portion, although only significantly for banana and loaf cake. Normal and obese children had larger bite sizes (p ≤ .05) of banana than overweight children, while only obese had larger bites of loaf cake with the double portion. In conclusion, the bite size of foods in 8- to 10-year-old children increases (13%) when the portion size is doubled and the larger bite size leads to fewer cycles/g (8%). These effects differ among foods. These parameters do not depend on weight status.