Effect of cross-cultural differences on thickness, firmness and sweetness sensitivity.

Sensitivity of the somatosensory system may be influenced by multiple physiological parameters. Variations in oral physiology can arise from cross-cultural differences which may potentially affect sensory sensitivity. The aim of this case study was to quantify texture and taste sensitivity in Dutch (Caucasian) and Chinese (Asian) adults living in the Netherlands. Eighty-five healthy subjects were recruited including 44 Dutch (Caucasian) adults (29 females, 22.8 ± 2.3 yrs) and 41 Chinese (Asian) adults (30 females, 24.5 ± 2.1 yrs) living in the Netherlands for less than 1 year. Three sets of stimuli were used to quantify sensitivity of thickness (maltodextrin solutions differing in viscosity), firmness (agar gels differing in fracture stress) and sweetness (sucrose solutions differing in concentration). The 2-Alternative Forced Choice (2-AFC) ascending staircase method was used to determine texture and taste sensitivity. Unstimulated and stimulated saliva flow rate, fungiform papillae density (FPD), lingual tactile threshold and PROP taster status were determined and are referred to as physiological and sensory consumer characteristics. No significant differences were observed between Chinese and Dutch adults for thickness (Dutch 2.60 mPas, Chinese 2.19 mPas), firmness (Dutch 10.5 kPa, Chinese 10.3 kPa) and sweetness sensitivity (Dutch 0.012 g/mL, Chinese 0.017 g/mL). No significant differences were observed between Chinese and Dutch adults for saliva flow rate, lingual tactile threshold and PROP taster status. The relationships between the three sensory sensitivities (thickness, firmness, sweetness) and five physiological and sensory consumer characteristics (unstimulated and stimulated saliva flow rate, FPD, lingual tactile threshold, PROP taster status) were analyzed. Only one out of 15 relationships, firmness sensitivity and FPD, was significantly and weakly related suggesting that inter-individual variation in these consumer characteristics is almost unrelated to sensory sensitivity. We conclude that in this case study thickness, firmness and sweetness sensitivities do not differ between Dutch and Chinese adults living in the Netherlands. Saliva flow rate, fungiform papillae density, lingual tactile threshold and PROP taster status do not explain inter-individual variation in sensory sensitivity between these consumers.

Comparison of and relationships between oral physiology, anatomy and food oral processing behavior of Chinese (Asian) and Dutch (Caucasian) consumers differing in age.

The aims of the study were (1) to compare oral physiology, anatomy and food oral processing behavior of consumers by age (Chinese young adults vs Chinese older adults) and by ethnicity (Chinese (Asian) vs. Dutch (Caucasian)) and (2) to explore relationships between oral physiology, anatomy and food oral processing behavior of Chinese consumers. Oral physiology (mastication performance, saliva flow rate and dental status) and anatomy (volume of oral cavity, tongue dimensions, facial anthropometry, height and weight) were determined in Chinese (Asian) young adults (n = 32; 18-30 yrs) and Chinese (Asian) older adults (n = 32; 60-85 yrs) and compared to previously determined oral physiology and anatomy of Dutch (Caucasian) young adults (n = 32; 18-30 yrs) and Dutch (Caucasian) older adults (n = 32; 65-85 yrs). Oral processing behavior (consumption time, chews per bite, bite size, eating rate) of solid foods (cooked carrot, sausage and tofu-gan) was quantified using video recordings. Regarding the effect of age on physiology, anatomy and food oral processing behavior, Chinese (Asian) older adults consumed all foods with lower eating rates compared to Chinese (Asian) young adults probably due to changes in oral physiology and anatomy. Regarding the effect of ethnicity on oral physiology, anatomy and food oral processing behavior, Chinese (Asians) had lower percentages of normal occlusion, slightly wider and shorter tongues, lower head height:width ratio and lower BMI compared to Dutch (Caucasians). Overall, Chinese adults displayed similar food oral processing behavior compared to Dutch adults. Consumption time, chews per bite and bite size did not differ between Chinese and Dutch adults. Only a small difference in eating rate were observed between these groups. Body weight and number of teeth were the physiological and anatomical parameters that related the strongest with oral processing behavior of solid foods. We conclude that age and ethnicity impact oral physiology, anatomy and oral processing behavior of solid foods. Oral physiology and anatomy only partially explain the variation in oral processing behavior of solid foods in consumer groups differing in ethnicity and age. Other factors such as culture and consumption habits are suggested to have a stronger influence on oral processing behavior.

Relating oral physiology and anatomy of consumers varying in age, gender and ethnicity to food oral processing behavior.

The aim of this study was to link parameters describing oral physiology and anatomy of consumers varying in age, gender and ethnicity to food oral processing behavior. Three groups of healthy consumers were compared: Dutch, Caucasian adults (18-30 yrs, n =32), Chinese, Asian adults (18-30 yrs, n =32) and Dutch, Caucasian older adults (65-85 yrs, n =32). Mastication performance, salivary flow rate (stimulated and unstimulated) and dental status were quantified to characterize oral physiology. Volume of oral cavity, tongue dimensions, facial anthropometry, height and weight were quantified to characterize anatomy. Oral processing behavior of three solid foods (carrot, cheese and sausage) was quantified by video recordings and eating rate (g/s), average consumption time (s), chews per bite (-) and average bite size (g) were determined. Dutch, Caucasian older adults had smaller volume of oral cavity, lower number of teeth and larger head width compared to Dutch, Caucasian adults. Chinese, Asian adults showed significantly higher mastication performance and larger head width compared to Dutch, Caucasian consumers, while dental status did not significantly differ between groups. Males had significantly larger volumes of oral cavity and larger head height and width compared to females. Dutch, Caucasian adults had a shorter average consumption time (s), less chews per bite and consumed the three foods with higher eating rate (g/s) compared to Dutch, Caucasian older adults. Chinese, Asian adults had a significantly longer average consumption time (s), more chews per bite, smaller average bite size (g) and lower eating rate (g/s) compared to Dutch, Caucasian adults. Twenty-one significant relationships were found between oral physiological and anatomical parameters and oral processing behavior. Body weight resulted in the largest ß-values, indicating to be the anatomical parameter of largest influence on oral processing behavior. We conclude that only few oral physiological and anatomical parameters related with food oral processing behavior. We suggest that other factors, including cultural factors contribute to variation in food oral processing behavior between different consumer groups more than saliva flow, volume of oral cavity, mastication performance and dental status.

Age, gender, ethnicity and eating capability influence oral processing behaviour of liquid, semi-solid and solid foods differently.

Food oral processing depends on food properties and consumer characteristics. The aim of this study was to determine the effect of age, gender, ethnicity and eating capability on oral processing behaviour of liquid, semi-solid and solid foods. Oral processing behaviour of 18 commercially available foods, ranging from liquids, semi-solids to solids, was compared between Dutch, Caucasian adults (18-30 yrs), Chinese, Asian adults (18-30 yrs), Dutch, Caucasian elderly (60-80 yrs), and consumers with mild swallowing problems and/or low mastication efficiency (18-80 yrs). Participants were video recorded during food consumption and six oral processing parameters extracted. Elderly consumed all foods with lower eating rates (g/s) than young adults by increasing consumption time (s). Females consumed solid foods with lower eating rates (g/s) than males by reducing bite size (g). Chinese, Asian consumers consumed liquid and solid foods with lower eating rates (g/s) than Dutch, Caucasian consumers by reducing bites size (g). Chinese, Asian consumers consumed semi-solid foods with lower eating rates (g/s) than Dutch, Caucasian consumers by reducing bite size (g) and increasing consumption time (s). Consumers with decreased mastication efficiency or mild swallowing problems showed similar oral processing behaviour than healthy consumers, probably because reduction in eating capability was limited in the group. This demonstrates that different consumer groups adapt eating rate (g/s) in different ways by modifying bite size (g), consumption time (s) or both. To conclude, age, gender and ethnicity influence oral processing behaviour of liquid, semi-solid and solid foods differently. Understanding differences in oral processing behaviour of specific consumer groups can assist in steering sensory perception, food choice and energy intake of specific consumer groups such as the elderly.

Posterior resting state EEG asymmetries are associated with hedonic valuation of food.

Research on the hedonic value of food has been important in understanding the motivational and emotional correlates of normal and abnormal eating behaviour. The aim of the present study was to explore associations between hemispheric asymmetries recorded during resting state electroencephalogram (EEG) and hedonic valuation of food. Healthy adult volunteers were recruited and four minutes of resting state EEG were recorded from the scalp. Hedonic food valuation and reward sensitivity were assessed with the hedonic attitude to food and behavioural activation scale. Results showed that parieto-occipital resting state EEG asymmetries in the alpha (8-12Hz) and beta (13-30Hz) frequency range correlate with the hedonic valuation of food. Our findings suggest that self-reported sensory-related attitude towards food is associated with interhemispheric asymmetries in resting state oscillatory activity. Our findings contribute to understanding the electrophysiological correlates of hedonic valuation, and may provide an opportunity to modulate the cortical imbalance by using non-invasive brain stimulation methods to change food consumption.