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

Factors associated with eating rate: a systematic review and narrative synthesis informed by socio-ecological model

Accumulating evidence shows associations between rapid eating and overweight. Modifying eating rate might be a potential weight management strategy without imposing additional dietary restrictions. A comprehensive understanding of factors associated with eating speed will help with designing effective interventions. The aim of this review was to synthesise the current state of knowledge on the factors associated with eating rate. The socio-ecological model (SEM) was utilised to scaffold the identified factors. A comprehensive literature search of eleven databases was conducted to identify factors associated with eating rate. The 104 studies that met the inclusion criteria were heterogeneous in design and methods of eating rate measurement. We identified thirty-nine factors that were independently linked to eating speed and mapped them onto the individual, social and environmental levels of the SEM. The majority of the reported factors pertained to the individual characteristics (n = 20) including demographics, cognitive/psychological factors and habitual food oral processing behaviours. Social factors (n = 11) included eating companions, social and cultural norms, and family structure. Environmental factors (n = 8) included food texture and presentation, methods of consumption or background sounds. Measures of body weight, food form and characteristics, food oral processing behaviours and gender, age and ethnicity were the most researched and consistent factors associated with eating rate. A number of other novel and underresearched factors emerged, but these require replication and further research. We highlight directions for further research in this space and potential evidence-based candidates for interventions targeting eating rate.

Impact of aging on the digestive system related to protein digestion in vivo

For the current aging population, protein is an important macronutrient to counteract the development of sarcopenia. Protein digestion is influenced by the capacity of the digestive system. The current evidence is reviewed about the impact of aging on the human digestive system and related to protein digestion in vivo. Aging changes the digestive organs which impacts protein digestion. Dentition decreases and mastication changes, potentially affecting particle size reduction. Stomach gastric acidity is unchanged, gastric emptying is delayed, while total transit time remains unchanged. Production of enzymes by the pancreas is decreased, but any changes in the small intestine remain unresolved. Animal studies showed decreased fecal protein digestion in older compared to young animals. Human studies showed decreased postprandial peripheral plasma appearance of ingested amino acids and increased splanchnic extraction. The findings suggest that the deteriorating digestive system with aging results in decreased protein digestion. Interpretation of the results should be taken with caution because of interindividual differences in the aging process, and because studies on protein digestion in aging humans are scarce. More information is needed on healthy aging and its relation to the digestive tract and protein digestion, several methods including in vitro experiments are valuable in this perspective.

Oral processing behavior and dental caries; an insight into a new relationship

INTRODUCTION

Previous evidence suggests an individual variation in the preferred oral processing behavior. Individuals can be classified as firm processing(FPL) or soft processing likers(SPL). FPL(crunchers and chewers) prefer using their teeth while SPL(smooshers and suckers) prefer using the tongue and the palate when processing different food items. Variation in the preferred oral processing behavior has been associated with differences in food texture preference and eating time. Time is one of the factors directly related to the development of dental caries(tooth decay). Oral retention and eating times are associated with greater caries experience. This study aims to explore if a relationship exists between the preferred oral processing behavior and the individual's caries experience.

MATERIALS AND METHODS

This was a cross-sectional, dental center-based study conducted at Jordan University of Science and Technology. Five hundred participants consented to fill out the preferred oral processing behavior(POPB) questionnaire. Anthropometric measurements (including weight, height, and waist circumference) were recorded. A single trained and calibrated dentist registered each participant's caries experience and plaque levels using the DMFS index and plaque index of Silness and Loe.

RESULTS

A total of 351(70.2%) and 149(29.8%) participants were typed as FPL and SPL, respectively. SPL demonstrated higher levels of dental caries experience compared to FPL. The mean DMFS score for SPL was 28.8(±25.43) while for FPL was 18.71(± 18.34). This difference remained significant after adjustment for confounders(P<0.001). SPL exhibited a significantly higher mean score for the "M" component(P <0.001) while no significant difference in the mean score of the "D"(P = 0.076) and "F"(P = 0.272) components was observed when compared to FPL.

CONCLUSION

The current findings provide new insight into a possible relationship between the preferred oral processing behavior and an individual's caries experience. A relationship in which the preferred oral processing behavior can potentially affect and/or be affected by the dental caries experience.

Ethnicity impact on oral processing behaviour and glycemic response to noodles: Chinese (Asian) vs. New Zealander (Caucasian)

There is an increasing awareness of the link between food breakdown during chewing and its nutrient release and absorption in the gastrointestinal tract. However, how oral processing behaviour varies among different ethnic groups, and how such difference further impacts on bolus characteristics and consequently glycemic response (GR) are not well understood. In this study, we recruited a group of Asian (Chinese) subjects in China (n = 32) and a group of Caucasian subjects in New Zealand (n = 30), both aged between 18 and 30 years, and compared their blood glucose level (BGL) over 120 min following consumption of a glucose drink and cooked white noodles. We also assessed their chewing behaviour, unstimulated saliva flow rate, and ready-to-swallow bolus characteristics to determine whether these measures explain the ethnic differences in postprandial glycaemia. Compared to New Zealand subjects, the Chinese subjects showed 35% slower saliva flow rate but around 2 times higher salivary α-amylase activity in the unstimulated state. During consumption of noodles, Chinese subjects on average took a larger mouthful size, chewed each mouthful for longer and swallowed a larger number of particles with a smaller particle size area. Total GR measured by area under the curve (IAUC) was higher among the Chinese subjects. They also experienced higher BGL at 15 min, as well as higher peak BGL. There were strong correlations observed between oral processing and GR parameters. Results of this study confirmed the significance of oral processing in determining food digestion, and will provide new insights on the role of ethnicity in influencing people's physiological response to food.

Current Perspectives on Food Oral Processing

Food oral processing (FOP) is a fast-emerging research area in the food science discipline. Since its first introduction about a decade ago, a large amount of literature has been published in this area, forming new frontiers and leading to new research opportunities. This review aims to summarize FOP research progress from current perspectives. Food texture, food flavor (aroma and taste), bolus swallowing, and eating behavior are covered in this review. The discussion of each topic is organized into three parts: a short background introduction, reflections on current research findings and achievements, and future directions and implications on food design. Physical, physiological, and psychological principles are the main concerns of discussion for each topic. The last part of the review shares views on the research challenges and outlooks of future FOP research. It is hoped that the review not only helps readers comprehend what has been achieved in the past decade but also, more importantly, identify where the knowledge gaps are and in which direction the FOP research will go.

Relationship among oral health status, bolus formation and food comfortability during consumption of model cheeses in elderly

The aim of this study was to investigate the impact of oral impairment on chewing behaviour, food bolus properties and food comfortability during elderly consumption of model cheeses. Seventy-two elderly persons (aged 66 to 88) was recruited and classified into two groups according to dental status (poor vs. satisfactory). They showed a wide range of salivary flow rates whatever their dental status (stimulated: 0.2-3.8 mL min^-1, resting: 0.1-0.8 mL min^-1). Standardized bites of four model cheeses with an identical composition but different textures (soft, hard, processed and whipped) were tested. The time and number of chewing cycles required to form a bolus were measured. The rheological properties of the bolus were studied, as was saliva moistening. Food comfortability was assessed by means of a questionnaire composed of 5 sections (1-oral comfort, 2-bolus formation, 3-pain, 4-texture and 5-flavour perception). The chewing parameters measured were not modified by the oral health. However, elderly with poor dentition formed harder boluses than elderly with satisfactory dentition. Moreover, for elderly with poor dentition, the quantity of saliva incorporated into the bolus was correlated with the stimulated salivary flow rate, which was not the case for elderly with satisfactory dentition. General oral comfort and its different attributes were poorly associated with the oral health of the elderly. A multifactorial analysis performed on an average cheese showed that food comfortability is independent of changes in the hardness and moistening of the bolus, regardless of dental status. In particular, poor dental status increases the hardness of the bolus without modifying its comfortability.