scholarly journals WPI Gel Microstructure and Mechanical Behaviour and Their Influence on the Rate of In Vitro Digestion

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1066
Author(s):  
Stephen Homer ◽  
Roderick Williams ◽  
Allison Williams ◽  
Amy Logan
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
In Vitro Digestion ◽  
Protein Isolate ◽  
In Vitro Digestibility ◽  
Gastric Digestion ◽  
Intestinal Phase ◽  
Ph Values ◽  
Oral Processing

The influence of microstructure and mechanical properties on the in vitro digestibility of 15% whey protein isolate (WPI) gels was investigated. Gels were prepared via heat set gelation at three pH values (pH 3, 5 and 7), which produced gels with distinct microstructures and mechanical properties. The gels were minced to simulate an oral/chewing phase, which led to the formation particles of various sizes and textures. The minced gels were passed through either an Infogest (pre-set pH of 3) or Glass stomach (dynamic pH) protocol. Gels were digested in the gastric phase for up to 120 min, at which point the extent of digestion was measured by the amount of filterable nitrogen passing through a sieve. The digesta from both gastric methods were passed through an in vitro simulated intestinal phase. A strong link was found between the elasticity of the initial gel and the gel particle size following simulated oral processing, which significantly (p < 0.01) affected the rate of digestion in the gastric phase. A weaker correlation was also found between the pH of the gels and the extent of gastric digestion. This work highlights the differences in the rate of gastric digestion, arising from oral processing, which can be attributed to the material properties of the substrate.

scholarly journals Impact of Oral Mastication on the in vitro Digestibility of Pigmented and Non-Pigmented Rice Varieties

2021 ◽  
Vol 12 (1) ◽  
pp. 1148-1160
Keyword(s):  
Amylose Content ◽  
Starch Content ◽  
In Vitro Digestion ◽  
In Vitro Digestibility ◽  
Rice Varieties ◽  
Pigmented Rice ◽  
Rice Samples ◽  
Oral Processing

The extent of starch hydrolysis and glycemic index (GI) of foods depends on how it is orally processed, but many in vitro digestion studies failed to consider the oral phase of digestion. This research aimed to understand the relationship between oral mastication and GI of rice. For this study, different rice varieties (pigmented and non-pigmented) were selected and analyzed for their physicochemical properties. The amylose content for all rice varieties was higher than 25%, with the starch content of 68.68 ± 0.70% - 81.60 ± 1.78%. Temporal dominance of sensation was determined for rice samples to understand the consumers' sensory preferences towards the pigmented rice varieties. In vivo oral mastication studies were also performed for the rice varieties, in which significant differences were observed amongst pigmented and non-pigmented rice samples. The particle size for pigmented rice varieties after in vivo oral mastication was significantly larger (50% particles greater than 2 mm; due to its intact morphology) than non-pigmented rice. The significant impact of oral processing on the GI of rice irrespective of the varieties was also observed in this study. Thus, this research sheds light on the need for oral processing for in vitro digestion studies.

Cytocompatibility and Material Properties of Poly-carbonate Urethane/Carbon Nanofiber Composites for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Material Properties ◽  
Carbon Nanofiber ◽  
Scar Tissue ◽  
Tissue Response ◽  
Positive Interactions ◽  
Weight Percentage ◽  
Poly Carbonate

AbstractCarbon nanofibers possess excellent conductivity properties, which may be beneficial in the design of more effective neural prostheses, however, limited evidence on their cytocompatibility properties exists. The objective of the present in vitro study was to determine cytocompatibility and material properties of formulations containing carbon nanofibers to predict the gliotic scar tissue response. Poly-carbonate urethane was combined with carbon nanofibers in varying weight percentages to provide a supportive matrix with beneficial bulk electrical and mechanical properties. The substrates were tested for mechanical properties and conductivity. Astrocytes (glial scar tissue-forming cells) were seeded onto the substrates for adhesion. Results provided the first evidence that astrocytes preferentially adhered to the composite material that contained the lowest weight percentage of carbon nanofibers. Positive interactions with neurons, and, at the same time, limited astrocyte functions leading to decreased gliotic scar tissue formation are essential for increased neuronal implant efficacy.

scholarly journals Physicochemical and Microstructural Characterization of Whey Protein Films Formed with Oxidized Ferulic/Tannic Acids

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1599
Author(s):  
Yaosong Wang ◽  
Youling L. Xiong
Keyword(s):  
Whey Protein ◽  
Microstructural Characterization ◽  
Protein Isolate ◽  
Light Transmittance ◽  
In Vitro Digestibility ◽  
Protein Films ◽  
Film Forming ◽  
Protein Sulfhydryl ◽  
Reduced Light

Protein-based biodegradable packaging films are of environmental significance. The effect of oxidized ferulic acid (OFA)/tannic acid (OTA) on the crosslinking and film-forming properties of whey protein isolate (WPI) was investigated. Both of the oxidized acids induced protein oxidation and promoted WPI crosslinking through the actions of quinone carbonyl and protein sulfhydryl, and amino groups. OTA enhanced the tensile strength (from 4.5 MPa to max 6.7 MPa) and stiffness (from 215 MPa to max 376 MPa) of the WPI film, whereas OFA significantly increased the elongation at break. The water absorption capability and heat resistance of the films were greatly improved by the addition of OTA. Due to the original color of OTA, the incorporation of OTA significantly reduced light transmittance of the WPI film (λ 200–600 nm) as well as the transparency, whereas no significant changes were induced by the OFA treatment. Higher concentrations of OTA reduced the in vitro digestibility of the WPI film, while the addition of OFA had no significant effect. Overall, these two oxidized polyphenols promoted the crosslinking of WPI and modified the film properties, with OTA showing an overall stronger efficacy than OFA due to more functional groups available.

scholarly journals Impact of the Simulated Gastric Digestion Methodology on the In Vitro Intestinal Proteolysis and Lipolysis of Emulsion Gels

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 321
Author(s):  
Camila Mella ◽  
Michelle Quilaqueo ◽  
Rommy N. Zúñiga ◽  
Elizabeth Troncoso
Keyword(s):  
Heat Treatment ◽  
Protein Isolate ◽  
Gastric Digestion ◽  
Human Gastrointestinal Tract ◽  
Gel Structure ◽  
Intestinal Digestion ◽  
Food Digestion ◽  
The Impact ◽  
Digestion Methods

The aim of this work was to study the impact of the methodology of in vitro gastric digestion (i.e., in terms of motility exerted and presence of gastric emptying) and gel structure on the degree of intestinal proteolysis and lipolysis of emulsion gels stabilized by whey protein isolate. Emulsions were prepared at pH 4.0 and 7.0 using two homogenization pressures (500 and 1000 bar) and then the emulsions were gelled by heat treatment. These gels were characterized in terms of texture analysis, and then were subjected to one of the following gastric digestion methods: in vitro mechanical gastric system (IMGS) or in vitro gastric digestion in a stirred beaker (SBg). After gastric digestion, the samples were subjected to in vitro intestinal digestion in a stirred beaker (SBi). Hardness, cohesiveness, and chewiness were significantly higher in gels at pH 7.0. The degree of proteolysis was higher in samples digested by IMGS–SBi (7–21%) than SBg–SBi (3–5%), regardless of the gel’s pH. For SBg–SBi, the degree of proteolysis was not affected by pH, but when operating the IMGS, higher hydrolysis values were obtained for gels at pH 7.0 (15–21%) than pH 4.0 (7–13%). Additionally, the percentage of free fatty acids (%FFA) released was reduced by 47.9% in samples digested in the IMGS–SBi. For the methodology SBg–SBi, the %FFA was not affected by the pH, but in the IMGS, higher values were obtained for gels at pH 4.0 (28–30%) than pH 7.0 (15–19%). Our findings demonstrate the importance of choosing representative methods to simulate food digestion in the human gastrointestinal tract and their subsequent impact on nutrient bioaccessibility.

scholarly journals 127 Porcine in vitro digestibility of whole stillage predigested with multi-enzyme during different time periods

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 49-50
Author(s):  
Kevin S Jerez Bogota ◽  
Tofuko A Woyengo
Keyword(s):  
Dry Matter ◽  
In Vitro Digestion ◽  
Enzyme Treatment ◽  
Optimal Time ◽  
In Vitro Digestibility ◽  
Percentage Points ◽  
Whole Stillage ◽  
Freeze Dried ◽  
Different Sources

Abstract A study was conducted to determine the effects of the period of predigesting whole stillage (WS; slurry material that is dried into DDGS) with multi-enzyme and composition of the multi-enzyme on porcine in vitro digestibility of dry matter (IVDDM) of the WS. Four samples of whole stillage from 4 different sources were freeze-dried and divided into 13 subsamples to give 52 sub-samples. Thirteen treatments were applied to the 48 sub-samples within source. The treatments were undigested WS (control); or pre-digested with 1 of 3 multi-enzymes (MTE1, MTE2, and MTE3) at 55 °C for 6, 12, 18 or 24 h in 3 × 4 factorial arrangement. The MTE1 contained xylanase, β-glucanase, cellulase, mannanase, protease, and amylase; MTE2 contained xylanase, α-galactosidase, and cellulase; and MTE3 contained xylanase, cellulase, β-glucanase, and mannanase. The 52 subsamples were subjected to porcine in vitro digestion. The IVDDM of untreated WS was 73.3%. The IVDDM increased (P&lt; 0.05) with an increase in the predigestion period. However, a rise in the predigestion period from 0 to 12 h resulted in greater (P&lt; 0.05) response in mean IVDDM than an increment in the predigestion period from 12 to 24 h (11 vs. 0.83 percentage points). Predigestion period and multi-enzyme type interacted on IVDDM such that the improvement in IVDDM between 0 and 12 hours of predigestion differed (P&lt; 0.05) among the 3 multi-enzyme types (13.3, 11.1, and 8.5 percentage points for MTE3, MTE2, and MTE1, respectively). The LS means by multi-enzyme treatment were modeled and resulted in unparallel curves (P&lt; 0.05). The estimated maximum response of IVDDM for MTE1, MTE2 and MTE 3 were 82.4%, 84.7% and 87.1% at 15.8, 13 and 13.1 hours, respectively. In conclusion, the optimal time of predigestion of WS with multi-enzymes (with regard to improvement in its IVDDM) was approximately 14 h.

Physical-chemical properties and in vitro digestibility of phosphorylated and glycosylated soy protein isolate

LWT ◽  
2021 ◽  
Vol 152 ◽  
pp. 112380
Author(s):  
Jingyuan Liu ◽  
Yangling Wan ◽  
Liuyang Ren ◽  
Mengdi Li ◽  
Ying Lv ◽  
...  
Keyword(s):  
Soy Protein ◽  
Soy Protein Isolate ◽  
Chemical Properties ◽  
Protein Isolate ◽  
In Vitro Digestibility ◽  
Physical Chemical

Relationship between intake of silage and its chemical composition and in vitro digestibility

1972 ◽  
Vol 23 (1) ◽  
pp. 25 ◽  
Author(s):  
DC Brown ◽  
JC Radcliffe
Keyword(s):  
Dry Matter ◽  
In Vitro Digestion ◽  
Ammonia Nitrogen ◽  
Matter Content ◽  
In Vitro Digestibility ◽  
Dry Matter Content ◽  
Regression Analyses ◽  
Lactic Acids

Twenty experimental silages were made from seven pasture species at different stages of maturity. In vivo dry matter, organic matter, and energy ad libitum intakes and digestibilities of the silages were determined with standardized pairs of Merino wethers. The following chemical characteristics of the silages were measured: nitrogen, ammonia nitrogen, total titratable acids, acetic, propionic, butyric, and lactic acids, total volatiles lost during oven drying, lactic acid as a percentage of the total organic acids, pH, acid pepsin dry matter disappearance, dry matter content, and in vitro digestibility and rate of digestion. When all 20 silages were considered, energy intakes on a body weight basis were significantly related to silage pH (r = 0.55) and rate of in vitro digestion (r = 0.58). When the five legume silages were removed from the analysis and only the 15 grass-dominant silages were considered, dry matter intakes were significantly related to acetic (r = –0.57) and propionic acid (r = –0.55) concentrations. Multiple regression analyses did not significantly increase the accuracy of predicting intake. The results suggested that silage intake was negatively related to the degree of fermentation that occurred during the ensiling process.

Contribution of soybean polysaccharides in digestion of oil-in-water emulsion-based delivery system in an in vitro gastric environment

2020 ◽  
Vol 26 (5) ◽  
pp. 444-452
Author(s):  
Shengnan Wang ◽  
Guoqiang Shao ◽  
Jinjie Yang ◽  
Hekai Zhao ◽  
Danni Qu ◽  
...  
Keyword(s):  
Soy Protein ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Food Delivery ◽  
Simulated Gastric Fluid ◽  
Gastric Digestion ◽  
Water Emulsion ◽  
Soy Hull ◽  
Soluble Polysaccharide

This study aims to evaluate the effects of soy soluble polysaccharide and soy hull polysaccharide on stability and characteristics of emulsions stabilised by soy protein isolate in an in vitro gastric environment. Zeta potential and particle size were used to investigate the changes of physico-chemical and stability in the three emulsions during in vitro gastric digestion, following the order: soy protein isolate–stability emulsion < soy protein isolate–soy soluble polysaccharide –stability emulsion < soy protein isolate–soy hull polysaccharide–stability emulsion, confirming that coalescence in the soy protein isolate–stability emulsion occurred during in vitro gastric digestion. Optical microscopy and stability measurement (backscattering) also validate that addition of polysaccharide (soy soluble polysaccharide and soy hull polysaccharide) can reduce the effect of simulated gastric fluid (i.e., pH, ionic strength and pepsin) on emulsion stability, especially, soy protein isolate–soy hull polysaccharide–stability emulsion, compared with soy protein isolate–stability emulsion. This suggests that the flocculation behaviours of these emulsions in the stomach lead to a difference in the quantity of oil and the size and structure of the oil droplets, which play a significant role in emulsion digestion in the gastrointestinal tract. This work may indicate a potential application of soy hull polysaccharide for the construction of emulsion food delivery systems.

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