16 research outputs found
Demographics of Protoplanetary Disks: A Simulated Population of Edge-on Systems
The structure of protoplanetary disks plays an essential role in planet
formation. Disks that are highly inclined, or ''edge-on'', are of particular
interest since their geometry provides a unique opportunity to study the disk's
vertical structure and radial extent. Candidate edge-on protoplanetary disks
are typically identified via their unique spectral energy distribution and
subsequently confirmed through high-resolution imaging. However, this selection
process is likely biased toward the largest, most massive disks, and the
resulting sample may not accurately represent the underlying disk population.
To investigate this, we generated a grid of protoplanetary disk models using
radiative transfer simulations and determined which sets of disk parameters
produce edge-on systems that could be recovered by aforementioned detection
techniques--i.e., identified by their spectral energy distribution and
confirmed through follow-up imaging with HST. In doing so, we adopt a
quantitative working definition of "edge-on disks" that is observation-driven
and agnostic about the disk inclination or other properties. Folding in
empirical disk demographics, we predict an occurrence rate of 6.2% for edge-on
disks and quantify biases towards highly inclined, massive disks. We also find
that edge-on disks are under-represented in samples of Spitzer-studied young
stellar objects, particularly for disks with M 0.5 .
Overall, our analysis suggests that several dozen edge-on disks remain
undiscovered in nearby star-forming regions, and provides a universal selection
process to identify edge-on disks for consistent, population-level demographic
studies.Comment: 20 pages, 6 figure
Transport of food digesta and model particles in the small intestinal mucus
The last boundary between ingested food and the gastrointestinal (GI) tract mucosa is the mucus layer. This highly complex viscoelastic medium has evolved to provide a robust barrier that traps and immobilises potentially hazardous particulates such as bacteria but still allows the passage of nutrients to the epithelial surfaces. However, the rules governing this selective barrier function, particularly in relation to transport of particulates, remain unknown. Recent studies suggest that surface properties of model nanoparticles can impact on colloidal transport in intestinal mucus (1). In particular, adsorption of bile salts (BS) to particles proved to significantly enhance their diffusion in the small intestinal mucus in vitro (2). The concentration of BS in the human small intestinal lumen can, however, vary greatly between the fasted and the fed states. There is also a significant difference in the overall concentration of BS between different age groups (e.g. infant vs. adult humans). In this study we used quantitative confocal microscopy to look at the transport characteristics in the porcine ex vivo (detached from the tissue) intestinal mucus of post-digestion food particulates such as yogurt digesta as well as lipid droplets that derived from in vitro digestion of sodium caseinate stabilised emulsions. Moreover, we used multiple-particle tracking technique to investigate the extent to which the concentration of BS can impact on the permeability of the mucus to model, sub-micron size particles such as latex beads, and their transport in this secretion. Finally, we investigated how the permeability and microstructure of the intact small intestinal mucus (i.e. attached to the mucosal tissue) may vary between specific locations on the tissue. Such insights will help support efforts to both engineer fabricated foods with enhanced nutritional quality required to fight the obesity epidemic, and to overcome the failure of many pharmaceutical and nutraceutical preparations to provide effective oral delivery of active compounds
Transport of food digesta and model particles in the small intestinal mucus
The last boundary between ingested food and the gastrointestinal (GI) tract mucosa is the mucus layer. This highly complex viscoelastic medium has evolved to provide a robust barrier that traps and immobilises potentially hazardous particulates such as bacteria but still allows the passage of nutrients to the epithelial surfaces. However, the rules governing this selective barrier function, particularly in relation to transport of particulates, remain unknown. Recent studies suggest that surface properties of model nanoparticles can impact on colloidal transport in intestinal mucus (1). In particular, adsorption of bile salts (BS) to particles proved to significantly enhance their diffusion in the small intestinal mucus in vitro (2). The concentration of BS in the human small intestinal lumen can, however, vary greatly between the fasted and the fed states. There is also a significant difference in the overall concentration of BS between different age groups (e.g. infant vs. adult humans). In this study we used quantitative confocal microscopy to look at the transport characteristics in the porcine ex vivo (detached from the tissue) intestinal mucus of post-digestion food particulates such as yogurt digesta as well as lipid droplets that derived from in vitro digestion of sodium caseinate stabilised emulsions. Moreover, we used multiple-particle tracking technique to investigate the extent to which the concentration of BS can impact on the permeability of the mucus to model, sub-micron size particles such as latex beads, and their transport in this secretion. Finally, we investigated how the permeability and microstructure of the intact small intestinal mucus (i.e. attached to the mucosal tissue) may vary between specific locations on the tissue. Such insights will help support efforts to both engineer fabricated foods with enhanced nutritional quality required to fight the obesity epidemic, and to overcome the failure of many pharmaceutical and nutraceutical preparations to provide effective oral delivery of active compounds
In vitro digestion evidence of how plant proteins modulate infant formulas digestibility
Infant formulas (IF) are the key nutritional source for infants who cannot be breastfed. There is currently a growing interest for these sensitive products, in order to control their quality and to design their composition with regard to nutritional balance and sustainable development concerns.This work aimed to study how plant proteins influence the digestibility of IF.Five infant formulas were developed with identical composition except that the protein source were whey proteins in the “reference IF”, pea, faba bean, rice or potato proteins in the four “plant IF” tested. The five IF were first evaluated using an in vitro static gastrointestinal model simulating infant conditions. Protein hydrolysis rate (PHR) and amino acid bioaccessibility (AAB) were measured using free amino group and free amino acid analyses, respectively. The pea and faba bean IF were then submitted to an in vitro dynamic digestion model closer to the physiological conditions, and compared to the reference IF. Protein digestibility (PHR and AAB) as well as the digesta microstructure were followed.Results showed that both PHR and AAB were very similar between the reference IF and pea and faba bean IF, but significantly lower for rice and potato IF. In dynamic conditions, the structure disintegration and the PHR showed differences among the reference, pea and faba bean IF. These differences were more pronounced during the gastric phase compared to the end of the intestinal digestion. This could result from the structure of proteins obtained from the processing steps that is known to influence the protein hydrolysis.This study provides new insights on the impact of protein source on the digestibility of IF. It especially showed that some plant proteins could be appropriate candidates for the composition of IF from a nutritional point of view
In vitro digestion evidence of how plant proteins modulate infant formulas digestibility
Infant formulas (IF) are the key nutritional source for infants who cannot be breastfed. There is currently a growing interest for these sensitive products, in order to control their quality and to design their composition with regard to nutritional balance and sustainable development concerns.This work aimed to study how plant proteins influence the digestibility of IF.Five infant formulas were developed with identical composition except that the protein source were whey proteins in the “reference IF”, pea, faba bean, rice or potato proteins in the four “plant IF” tested. The five IF were first evaluated using an in vitro static gastrointestinal model simulating infant conditions. Protein hydrolysis rate (PHR) and amino acid bioaccessibility (AAB) were measured using free amino group and free amino acid analyses, respectively. The pea and faba bean IF were then submitted to an in vitro dynamic digestion model closer to the physiological conditions, and compared to the reference IF. Protein digestibility (PHR and AAB) as well as the digesta microstructure were followed.Results showed that both PHR and AAB were very similar between the reference IF and pea and faba bean IF, but significantly lower for rice and potato IF. In dynamic conditions, the structure disintegration and the PHR showed differences among the reference, pea and faba bean IF. These differences were more pronounced during the gastric phase compared to the end of the intestinal digestion. This could result from the structure of proteins obtained from the processing steps that is known to influence the protein hydrolysis.This study provides new insights on the impact of protein source on the digestibility of IF. It especially showed that some plant proteins could be appropriate candidates for the composition of IF from a nutritional point of view
Influence of protein source on the functionality and the digestibility of infant formulas
International audienceInfant formulas (IF) are the only source of nutrition for infants who cannot be breastfed from their mothers. There is currently a growing interest for these sensitive products, in order to control more carefully their quality and design their composition with regard to sustainable development concern. The aim of this work was to study how a partial substitution of dairy proteins by plant proteins influenced the functionality and the digestibility of IF. Three IF were developed with identical composition, except that 50% of the proteins were whey proteins in the “reference IF”, and pea or faba bean proteins in the “plant IF”. Homogenization and drying steps parameters were investigated at a semi-industrial scale (IF flow rate around 100 kg.h-1). The process influence was assessed through the IF microstructure using confocal microscopy, and the protein digestibility using a dynamic in vitro digestion model. The results showed that the emulsion structure differed depending on the protein type source that did not lead to the same stabilization of the fat droplets. It simultaneously affected the viscosity of the IF and consequently the drying parameters. Last, differences in terms of protein hydrolysis rate were observed mainly during the gastric phase compared to the end of the digestion. This study provides new insights on the impact of the substitution of protein source in IF. It showed that plant protein sources could be good candidates for dairy proteins substitution in IF, both from a processing and nutritional point of view
In vitro digestion evidence of how plant proteins modulate infant formulas digestibility
Infant formulas (IF) are the key nutritional source for infants who cannot be breastfed. There is currently a growing interest for these sensitive products, in order to control their quality and to design their composition with regard to nutritional balance and sustainable development concerns.This work aimed to study how plant proteins influence the digestibility of IF.Five infant formulas were developed with identical composition except that the protein source were whey proteins in the “reference IF”, pea, faba bean, rice or potato proteins in the four “plant IF” tested. The five IF were first evaluated using an in vitro static gastrointestinal model simulating infant conditions. Protein hydrolysis rate (PHR) and amino acid bioaccessibility (AAB) were measured using free amino group and free amino acid analyses, respectively. The pea and faba bean IF were then submitted to an in vitro dynamic digestion model closer to the physiological conditions, and compared to the reference IF. Protein digestibility (PHR and AAB) as well as the digesta microstructure were followed.Results showed that both PHR and AAB were very similar between the reference IF and pea and faba bean IF, but significantly lower for rice and potato IF. In dynamic conditions, the structure disintegration and the PHR showed differences among the reference, pea and faba bean IF. These differences were more pronounced during the gastric phase compared to the end of the intestinal digestion. This could result from the structure of proteins obtained from the processing steps that is known to influence the protein hydrolysis.This study provides new insights on the impact of protein source on the digestibility of IF. It especially showed that some plant proteins could be appropriate candidates for the composition of IF from a nutritional point of view
Influence of protein source on the functionality and the digestibility of infant formulas
International audienceInfant formulas (IF) are the only source of nutrition for infants who cannot be breastfed from their mothers. There is currently a growing interest for these sensitive products, in order to control more carefully their quality and design their composition with regard to sustainable development concern. The aim of this work was to study how a partial substitution of dairy proteins by plant proteins influenced the functionality and the digestibility of IF. Three IF were developed with identical composition, except that 50% of the proteins were whey proteins in the “reference IF”, and pea or faba bean proteins in the “plant IF”. Homogenization and drying steps parameters were investigated at a semi-industrial scale (IF flow rate around 100 kg.h-1). The process influence was assessed through the IF microstructure using confocal microscopy, and the protein digestibility using a dynamic in vitro digestion model. The results showed that the emulsion structure differed depending on the protein type source that did not lead to the same stabilization of the fat droplets. It simultaneously affected the viscosity of the IF and consequently the drying parameters. Last, differences in terms of protein hydrolysis rate were observed mainly during the gastric phase compared to the end of the digestion. This study provides new insights on the impact of the substitution of protein source in IF. It showed that plant protein sources could be good candidates for dairy proteins substitution in IF, both from a processing and nutritional point of view
Are Faba Bean and Pea Proteins Potential Whey Protein Substitutes in Infant Formulas? An In Vitro Dynamic Digestion Approach
Infant formulas (IFs) are used as substitutes for human milk and are mostly based on cow milk proteins. For sustainability reasons, animal protein alternatives in food are increasingly being considered, as plant proteins offer interesting nutritional and functional benefits for the development of innovative IFs. This study aimed to assess how a partial substitution (50%) of dairy proteins with faba bean and pea proteins influenced the digestibility of IFs under simulated dynamic in vitro digestion, which were set up to mimic infant digestion. Pea-and faba bean-based IFs (PIF and FIF, respectively) have led to a faster aggregation than the reference milk-based IF (RIF) in the gastric compartment; that did not affect the digesta microstructure at the end of digestion. The extent of proteolysis was estimated via the hydrolysis degree, which was the highest for FIF (73%) and the lowest for RIF (50%). Finally, it was apparent that in vitro protein digestibility and protein digestibility-corrected amino acid score (PDCAAS)-like scores were similar for RIF and FIF (90% digestibility; 75% PDCAAS), but lower for PIF (75%; 67%). Therefore, this study confirms that faba bean proteins could be a good candidate for partial substitution of whey proteins in IFs from a nutritional point of view, provided that these in vitro results are confirmed in vivo
Influence of protein source on the functionality and the digestibility of infant formulas
Infant formulas (IF) are the only source of nutrition for infants who cannot be breastfed from their mothers. There is currently a growing interest for these sensitive products, in order to control more carefully their quality and design their composition with regard to sustainable development concern.
The aim of this work was to study how a partial substitution of dairy proteins by plant proteins influenced the functionality and the digestibility of IF.
Three IF were developed with identical composition, except that 50% of the proteins were whey proteins in the “reference IF”, and pea or faba bean proteins in the “plant IF”. Homogenization and drying steps parameters were investigated at a semi-industrial scale (IF flow rate around 100 kg.h-1). The process influence was assessed through the IF microstructure using confocal microscopy, and the protein digestibility using a dynamic in vitro digestion model.
The results showed that the emulsion structure differed depending on the protein type source that did not lead to the same stabilization of the fat droplets. It simultaneously affected the viscosity of the IF and consequently the drying parameters. Last, differences in terms of protein hydrolysis rate were observed mainly during the gastric phase compared to the end of the digestion.
This study provides new insights on the impact of the substitution of protein source in IF. It showed that plant protein sources could be good candidates for dairy proteins substitution in IF, both from a processing and nutritional point of view