Particle Size Distribution of Brown and White Rice during Gastric Digestion Measured by Image Analysis

Abstract

The particle size distribution of foods during gastric digestion indicates the amount of physical breakdown that occurred due to the peristaltic movement of the stomach walls in addition to the breakdown that initially occurred during oral processing. The objective of this study was to present an image analysis technique that was rapid, simple, and could distinguish between food components (that is, rice kernel and bran layer in brown rice). The technique was used to quantify particle breakdown of brown and white rice during gastric digestion in growing pigs (used as a model for an adult human) over 480 min of digestion. The particle area distributions were fit to a Rosin-Rammler distribution function. Brown and white rice exhibited considerable breakdown as the number of particles per image decreased over time. The median particle area (x(50)) increased during digestion, suggesting a gastric sieving phenomenon, where small particles were emptied and larger particles were retained for additional breakdown. Brown rice breakdown was further quantified by an examination of the bran layer fragments and rice grain pieces. The percentage of total particle area composed of bran layer fragments was greater in the distal stomach than the proximal stomach in the first 120 min of digestion. The results of this study showed that image analysis may be used to quantify particle breakdown of a soft food product during gastric digestion, discriminate between different food components, and help to clarify the role of food structure and processing in food breakdown during gastric digestion.

Acid Diffusion into Rice Boluses is Influenced by Rice Type, Variety, and Presence of α‐Amylase

“…The mastication procedure was completed as described. The particle size distribution of the rice after mastication was measured using image analysis as described by Bornhorst and others (). The particle area (mm 2 ) for each particle and total number of particles was determined for each masticated sample.…”

In vitro gastric digestion of cooked white and brown rice using a dynamic rat stomach model

“…Basically, the same kind of lighting and photo-taking conditions for all tested samples were ensured. The images were then masked using Matlab v8.0 (Mathworks Inc., Natick, Massachusetts, USA) to ensure that all the particles were adequately and accurately captured, followed by analyzed using Image J software (Image J, NIH, Maryland, USA) for the measurements of the particle size distribution (as expressed by cumulative percentage of projected area for the rice particulates with different particle sizes), as well as median particle area (x 50 , mm 2 ) (Bornhorst et al, 2013b). For comparison, the initial particle size distribution and x 50 of the white and brown rice samples before being transferred into the DIVRS model was also determined by the image analysis method.…”

Fatty acid bioaccessibility and structural breakdown fromin vitrodigestion of almond particles

“…54,55 Gastric sieving has been reported during in vivo digestion of almonds where the growing pig was used as a model for the adult human. 21,22 The results of the current study suggest that nut particles greater than 1 mm can be broken down by in vitro models which include simulated peristalsis to a sufficiently small size to resemble those that would be emptied from the human stomach. This data could help future researchers design in vitro models for testing hypotheses related to gastric emptying, bioaccessibility, or satiety.…”

“…This model has previously been used to describe the size of solid food particles as determined by image analysis. 9,22 Scanning electron microscopy. Scanning electron microscopy (SEM) was conducted on almond particles digested for 180 minutes in the HGS as well as undigested almond particles as a control.…”

“…Size reduction of almond particles during gastric digestion has been observed in studies using the growing pig as a model for the adult human, but was not directly linked to lipid bioaccessibility. [21][22][23] This points to the need for more data on the breakdown of almond particles during digestion to clarify the relationship between particle breakdown and lipid bioaccessibility. However, static in vitro models of human digestion do not reproduce the peristaltic motion of the stomach 24 and thus may not lead to particle breakdown as it occurs in vivo.…”