Food oral processing and eating behavior from infancy to childhood: evidence on the role of food texture in the development of healthy eating behavior.

Eating behaviors develop in early life and refine during childhood, shaping long-term food choice and dietary habits, which underpin optimum growth and health. The development of Food Oral Processing (FOP) is of major importance in the establishment of eating behaviors at two scale levels: for the initial acceptance of food texture and for the longer-term development of eating behaviors associated to food intake. To date, both processes have been studied as independent topics and the current review proposes a parallel vision on their development from the onset of complementary feeding to later childhood. Individual factors affecting these FOP-related behaviors as they relate to food texture acceptance are discussed, alongside examples of interventions aiming at modifying them. Opportunity to better consider food textures when designing foods for children is addressed. Altogether, the review demonstrates the critical role of food texture in the development of a child's FOP skills, eating habits, and dietary patterns. These scientific knowledges need to be considered for the development of healthier eating behavior. We identify research gaps that need to be addressed and highlight the need to design foods that can support the development of healthy oral processing and eating behaviors among infants and children.

Paediatric solid oral dosage forms for combination products: Improving in vitro swallowability of minitablets using binary mixtures with pellets.

There is a growing interest in enhancing the acceptability of paediatric pharmaceutical formulations. Solid oral dosage forms (SODF), especially multiparticulates, are being considered as an alternative to liquid formulations, but they may compromise palatability when large volumes are required for dosing. We hypothesised that a binary mixture of multiparticulates for paediatric use, designed to increase the formulation maximum packing fraction, could reduce the viscosity of the mixture in soft food and facilitate swallowing. Using the Paediatric Soft Robotic Tongue (PSRT) - an in vitro device inspired by the anatomy and physiology of 2-year-old children - we investigated the oral phase of swallowing for multi-particulate formulations, i.e., pellets (350 and 700 µm particles), minitablets (MTs, 1.8 mm), and their binary mixtures (BM), by evaluating oral swallowing time, the percentage of particles swallowed, and post-swallow residues. We also conducted a systematic analysis of the effect of the administration method, bolus volume, carrier type, particle size, and particle volume fraction on pellets swallowability. The results demonstrated that the introduction of pellets affected the flowing ability of the carriers, increasing shear viscosity. The size of the pellets did not appear to influence particle swallowability but raising the particle volume fraction (v.f.) above 10% resulted in a decrease in the percentage of particles swallowed. At v.f. 0.4, pellets were easier to swallow (+ 13.1%) than MTs, being the administration method used highly dependent on the characteristics of the multi-particulate formulation under consideration. Finally, mixing MTs with only 24% of pellets improved particle swallowability, achieving swallowing levels similar to those of pellets alone. Thus, combining SODF, i.e., MTs and pellets, improves MT swallowability, and offers new possibilities for adjusting product palatability, being particularly attractive for combination products.

A novel soft robotic pediatric in vitro swallowing device to gain insights into the swallowability of mini-tablets.

Soft robotics could help providing a better understanding of the mechanisms underpinning the swallowability of solid oral dosage forms (SODF), especially by vulnerable populations such as the elderly or children. In this study a novel soft robotic in vitro device is presented, the Pediatric Soft Robotic Tongue (PSRT), inspired by the literature data on the anatomy and physiology of a 2-year-old child. Multi-particulate oral formulations (i.e., mini-tablets (MT)) were considered, including different scenarios such as SODF carrier (i.e., soft-food, liquid), administration methods, SODF size and volume fraction. In vitro results showed that semi-solid foods like yoghurt and apple puree (shear viscosity above âˆ¼ 150 mPa.s at γ̇ = 50 s-1, and its yield stress up to âˆ¼ 5 Pa) may be considered more suitable than thin liquids (i.e., xanthan gum 0.25 %) for swallowing MT. However, the reduction of MT size did not bring any benefit in terms of swallowability in the range studied. Regarding the administration method, spreading MT on top of a teaspoon full of carrier should be preferred over mixing MT with the carrier or placing MT on the tongue first to favour their swallowability. Finally, and under the in vitro conditions studied using yoghurt as carrier, it would be possible to increase the volume fraction of SODF up to 0.20 without influencing swallowability according to the three parameters evaluated (% of MT swallowed, bolus velocity, and post-swallow residues). These results should help to design more focused sensory and/or clinical tests to improve product formulation and patient acceptability.

Description of oral behavior during the oral processing of heterogeneous apple purees: An application of the temporal check-all-that-apply method.

The objective of this study was to assess the potential of the temporal check-all-that-apply (TCATA) method to describe oral behavior from the introduction of products into the mouth until swallowing. In particular, we wanted to test the feasibility of the task, the ability to show differences between composite products, and the possibility of segmenting the panel based on the data collected. Terms referring to actions performed during food oral processing (FOP) were used instead of classical sensory descriptors. The evaluation consisted, for a panel of 54 subjects, of checking the boxes corresponding to the actions in progress throughout the consumption of the products. The five products studied were an apple puree and four heterogeneous mixtures that were obtained by adding gel pieces varying in size (two sizes) and firmness (two levels of firmness). The participants did not encounter any particular difficulty in describing in real time the actions in progress during the consumption of the products. Data collected made it possible to describe the sequences of actions carried out during the FOP and to determine the influence of the presence of pieces of gels, their size and their firmness. We highlighted two groups of subjects presenting different behaviors. The subjects in the first one exhibited little difference in processing between the four samples containing the gel pieces, while the subjects in the second group adapted their behavior according to the firmness of the gel pieces. Overall, this exploratory study suggests the ability of TCATA in describing oral behavior during FOP. Future studies should aim at validating it with objective measurements of FOP.

Effects of Apple Form on Energy Intake During a Mid-Afternoon Snack: A Preload Paradigm Study in School-Aged Children.

Consuming foods with a form or a texture that requires longer oral processing is a way to decrease food intake. Although this approach is promising for leveraging healthier eating patterns in adults, it has never been explored in children. This study evaluated whether starting a mid-afternoon snack by eating either apple segments or applesauce would modify hunger and subsequent food intake during this meal. Forty-four children (8-10 years old) participated in two videotaped mid-afternoon snacks, during which they received one of the two forms of apple as a food preload followed 10 min later by ad libitum consumption of sweetened cottage cheese. They self-reported their level of hunger throughout consumption, and the weight of cottage cheese consumed was determined at the end of the snack. Children's chewing capabilities and eating traits were parent-reported. Eating a raw apple increased oral exposure time and decreased bite size compared to eating applesauce. However, neither the reported hunger nor consecutive food intake were modified. Regardless of the meal, children eating fast had a higher ad libitum energy intake. The individual eating rate for the cottage cheese was correlated with the eating rate observed for applesauce but not for apple segments, the latter being associated with children's chewing difficulties. This study suggests that the form of a fruit offered at the start of a mid-afternoon snack does not impact food intake; the findings clearly call for more exploration of satiation mechanisms related to food texture properties among children and indicate the need to consider children's oral processing skills.

Perspectives on Astringency Sensation: An Alternative Hypothesis on the Molecular Origin of Astringency.

Flavor is one of the main drivers of food consumption and acceptability. It is associated with pleasure feels during eating. Flavor is a multimodal perception corresponding to the functional integration of information from the chemical senses: olfaction, gustation, and nasal and oral somatosensory inputs. As a result, astringency, as a sensation mediated by the trigeminal nerves, influences food flavor. Despite the importance of astringency in food consumer acceptance, the exact chemosensory mechanism of its detection and the nature of the receptors activated remain unknown. Herein, after reviewing the current hypotheses on the molecular origin of astringency, we proposed a ground-breaking hypothesis on the molecular mechanisms underpinning this sensation as a perspective for future research.

Longitudinal analysis of the salivary metabolome of breast-fed and formula-fed infants over the first year of life.

INTRODUCTION: The salivary metabolome has been increasingly studied over the past ten years due to the potential of saliva as a non-invasive source of biomarkers. However, although saliva has been studied in relation to various diseases, its dynamic evolution during life is not known. This is particularly true for the first months of life. Infancy is indeed a critical period during which numerous behavioural and physiological events occur, such as dietary transitions and tooth eruption, which can lead to important biological modifications in the oral cavity. OBJECTIVES: The aim of this work was therefore to study the evolution of the salivary metabolome during the first months of life by 1H NMR. METHODS: Saliva of 32 infants with different milk feeding histories (breast vs formula) was collected at 6 stages, including 3 months old, 15 days before the onset of complementary feeding (CF), approximately 15 days after the onset of CF, approximately 21 days after the onset of CF and at approximately 11 and 15 months, and analysed. RESULTS: The longitudinal analysis showed a significant modification of the profiles of 18 metabolites over time; 14 presented an increase in abundance whereas 4 presented a decrease. These modifications seemed to be linked, for the most part, to an increase in oral microbial metabolism. Milk feeding history during the first months of life had no effect on metabolites. CONCLUSION: This work shows that the salivary metabolome should be considered when studying the changes occurring during infancy.

Factors Associated With Food Texture Acceptance in 4- to 36-Month-Old French Children: Findings From a Survey Study.

Food texture plays an important role in food acceptance by young children, especially during the complementary feeding period. The factors driving infant acceptance of a variety of food textures are not well-known. This study summarizes maternal reports of children's ability to eat foods of different textures (here: acceptance) and associated factors. Mothers of 4- to 36-month-old children (n = 2,999) answered an online survey listing 188 food-texture combinations representing three texture levels: purees (T1), soft small pieces (T2), hard/large pieces, and double textures (T3). For each offered combination, they reported whether it was spat out or eaten with or without difficulty by the child. A global food texture acceptance score (TextAcc) was calculated for each child as an indicator of their ability to eat the offered textured foods. The results were computed by age class from 4-5 to 30-36 months. The ability to eat foods without difficulty increased with age and was ranked as follows: T1> T2 > T3 at all ages. TextAcc was positively associated with exposure to T2 (in the age classes between 6 and 18 months old) and T3 (6-29 months) and negatively associated with exposure to T1 (9-36 months). Children's developmental characteristics, as well as maternal feeding practices and feelings with regard to the introduction of solids, were associated with texture acceptance either directly or indirectly by modulating exposure. Children's ability to eat with their fingers, gagging frequency, and to a lesser extent, dentition as well as maternal feelings with regard to the introduction of solids were the major factors associated with acceptance. This survey provides a detailed description of the development of food texture acceptance over the complementary feeding period, confirms the importance of exposure to a variety of textures and identifies a number of additional person-related associated factors.

A new masticatory performance assessment method for infants: A feasibility study.

This study evaluated the feasibility of assessing masticatory performance in infants and toddlers. Four groups of healthy children (n = 97, 42 girls and 55 boys) participated in the study: two study groups (SG) followed at 6, 8, and 10 months old (MO) or at 12, 15, and 18 MO, and two control groups (CG) of respectively 10 and 18 MO children. Masticatory performance was determined from children's ability to comminute a model gel during videotaped lab measurements. The gel was inserted in a mesh feeder and offered to the child for a 60s oral processing duration, then gel particles were collected from the feeder and photographed. Resulting gel breakdown was assessed from the characterization of the area and number of formed particles. Children strategy to orally process the gel (sucking vs. biting/chewing) was evaluated from video recordings. Children's compliance (acceptance of the feeder in the mouth for the expected duration) was average (51%) overall. It decreased from 1 year of age and was higher in SG than in CG. The number and area of gel particles formed under oral processing increased significantly with age, demonstrating an increase in children masticatory performance as they grew up. Median particles area was positively associated with sucking behavior and negatively associated with biting/chewing. The association with teeth emergence was not significant. In conclusion, the proposed method is relevant for quantifying the development of early masticatory performance in children who accept to hold the feeder in their mouth. PRACTICAL APPLICATIONS: In this article, a method to easily quantify masticatory performance in young children aged 6-18 MO was evaluated. The method is based on a feeder and could be used for collecting boluses, as an alternative to the chew-and-spit method when it is unfeasible. Children's compliance to the method and the impact of previous study participation on compliance to the protocol are detailed, giving thus a rationale for an optimal application of this method in future experiments. Finally, the determination of masticatory performance as a function of age thanks to this method could contribute to the understanding of food oral processing and food texture acceptance in childhood in future studies.

Patterns and predictors of food texture introduction in French children aged 4-36 months.

The aims of this study were to describe which and when food textures are offered to children between 4 and 36 months in France and to identify the associated factors. An online cross-sectional survey was designed, including questions about 188 food texture combinations representing three texture levels: purées (T1), soft small pieces (T2) and hard/large pieces and double textures (T3). Mothers indicated which combinations they already offered to their child. A food texture exposure score (TextExp) was calculated for all of the texture levels combined and for each texture level separately. Associations between TextExp and maternal and child characteristics and feeding practices were explored by multiple linear regressions, per age class. Answers from 2999 mothers living in France, mostly educated and primiparous, were analysed. Over the first year, children were mainly exposed to purées. Soft and small pieces were slowly introduced between 6 and 22 months, whereas hard/large pieces were mainly introduced from 13 months onwards. TextExp was positively associated with children's number of teeth and ability to eat alone with their finger or a fork. For almost all age classes, TextExp was higher in children introduced to complementary feeding earlier, lower for children who were offered only commercial baby foods and higher for those who were offered only home-made/non-specific foods during the second year. Our study shows that until 12 months of age the majority of French children were exposed to pieces to a small extent. It provides new insights to further understand the development of texture acceptance during a key period for the development of eating habits.

Acceptance of added fat to first complementary feeding purees: An exploration of fat type, feeding history and saliva composition.

In adults, fat is a major determinant of food palatability. From the onset of complementary feeding (CF) adding fat to complementary foods is recommended to ensure an optimal growth and cognitive development. However, whether adding fat to complementary foods would impact acceptance (in terms of intake and liking) has been little investigated. This study sought 1) to evaluate acceptance of added fat (either vegetable oils or dairy fat) in a vegetable puree in weaning-age infants; 2) to determine whether early differential fat exposure through milk (breast milk and formula have different fat composition) and fat addition in complementary foods can influence acceptance and 3) to explore if fat acceptance can be related to inter-individual differences in salivary compounds potentially involved in fat perception. Twenty six infants with contrasted milk feeding history participated and were introduced with complementary foods at 4.8 months. During the 1st month of complementary feeding, acceptance of 3 broccoli purees (0% fat, 7% of vegetable oils, 7% of dairy fat) was determined through ad libitum intake and global liking, in the laboratory and at home. Saliva was collected: lipolytic activity and carbonic anhydrase 6 concentration were determined. Puree intakes were not impacted by fat addition, whatever the type of added fat. Moreover, the history of milk feeding (breast milk vs. vegetable oils based formulas) in the very first months did not explain acceptance for added fat. Finally, no links between intake and saliva composition were evidenced. Altogether, this study found that the addition of fat did not modify food acceptance by infants during early complementary feeding. Thus, future research should investigate the development of fat acceptance over experience in early infancy.

Chewing bread: impact on alpha-amylase secretion and oral digestion.

During chewing, saliva helps in preparing the food bolus by agglomerating the formed particles, and it initiates enzymatic food breakdown. However, limited information is actually available on the adaptation of saliva composition during the oral processing of complex foods, especially for foods that are sensitive to salivary enzymes. We addressed this question in the context of starch-based products and salivary alpha-amylase. The objectives were two-fold: (1) to determine if salivary alpha-amylase secretion can be modulated by the bread type and (2) to evaluate the contribution of the oral phase in bread enzymatic breakdown. Mouthfuls of three different wheat breads (industrial, artisan and whole-meal breads) were chewed by twelve subjects. Saliva samples were collected at rest and at different times corresponding to 33, 66 and 100% of the individual's chewing sequence. Alpha-amylase activity and total protein content were determined for all saliva samples that were collected. Additionally, the salivary maltose concentration was measured as a marker of bread enzymatic digestion. Boluses were collected at the swallowing time to evaluate the saliva uptake. Chewing industrial bread induced higher saliva uptake than the other breads despite a similar chewing duration. The evolution of salivary amylase activity tended to depend on the type of bread and was highly influenced by a large degree of inter- and intra-subject variability. The protein and maltose concentration steadily increased during chewing as a result of bread breakdown. The salivary protein concentration was mainly affected by the release of the water-soluble proteins of the bread. The salivary maltose concentration was found to be significantly lower for the whole-meal bread. When considering the weight of the mouthful, enzymatic breakdown was found to be most efficient for the breads ranking from industrial > artisan > whole-meal.

The impact of mastication, salivation and food bolus formation on salt release during bread consumption.

Health authorities recommend higher fibre and lower salt content in bread products. However, these basic ingredients of bread composition are multifunctional, and important changes in their content influence the texture, flavour and acceptability of the product. This study was designed to investigate the link between oral processing, bolus formation and sodium release during the consumption of four different breads that varied in composition and structure. Chewing behaviour was determined by surface electromyography, and salivation was quantified from the water content of the boluses collected. The kinetics of bread degradation during food bolus formation was characterised by measuring the bolus heterogeneity by texture image analysis, and sodium release into the saliva was quantified. Mastication and salivation varied between products and between subjects, thus highlighting different bolus formation strategies. In vivo salt release was mainly explained by mastication parameters. The initial slope of sodium release increased when the chewing muscles' activity increased, and the maximum sodium concentration was reached later when more masticatory cycles were required to reach the swallowing point.

Temporal contrast of salt delivery in mouth increases salt perception.

The impact of salt delivery in mouth on salt perception was investigated. It was hypothesized that fast concentration changes in the delivery to the receptor can reduce sensory adaptation, leading to an increased taste perception. Saltiness ratings were scored by a panel over time during various stimulation conditions involving relative changes in NaCl concentration of 20% and 38%. Changes in salt delivery profile had similar effect on saltiness perception when delivered either by a sipwise method or by a gustometer. The impact of concentration variations and frequency of concentration changes was further investigated with the gustometer method. Five second boosts and 2 s pulses were delivered during 3 sequential 10-s intervals, whereas the delivered total salt content was the same for all conditions. Two second pulses were found to increase saltiness perception, but only when the pulses were delivered during the first seconds of stimulation. Results suggest that the frequency, timing, and concentration differences of salt stimuli can affect saltiness. Specifically, a short and intense stimulus can increase salt perception, possibly through a reduction of adaptation.