Rheosfood Inc.

South Korea

Rheosfood Inc.

South Korea
SEARCH FILTERS
Time filter
Source Type

Hong S.-R.,Dongguk University | Sun D.-S.,Dongguk University | Yoo W.,Rheosfood Inc. | Yoo B.,Dongguk University
International Journal of Food Engineering | Year: 2012

Gum-based food thickeners are widely used to care for patients with dysphagia in Korea. In this study, the flow properties of commercially available gum-based food thickeners marketed in Korea were determined as a function of temperature. The flow properties of thickeners were determined based on the rheological parameters of the power law and Casson models. Changes in shear stress with the rate of shear (1-100 s-1) at different temperatures (5, 20, 35, and 50 oC) were independent of the type of thickener. All thickeners had high shear-thinning behavior (n=0.08-0.18) with yield stress at the different temperatures tested. In general, apparent viscosity (na,50) values progressively decreased with an increase in temperature. In addition, the consistency index (K) and Casson yield stress (soc) values did not change much upon an increase in temperature from 5 to 35 oC, except for sample B. In the temperature range of 5-50 oC, the thickeners followed an Arrhenius temperature relationship with a high determination coefficient (R2=0.93-0.97): activation energies (Ea) for the flow of thickeners were in the range of 2.44 - 10.7 kJ/mol. Rheological parameters demonstrated considerable differences in flow behavior between the different gum-based food thickeners, indicating that their flow properties are related to the type of thickener and the flow properties of gum. © 2012 De Gruyter.


Cho H.-M.,Dongguk University | Yoo W.,Rheosfood Inc. | Yoo B.,Dongguk University
Food Science and Biotechnology | Year: 2012

Thickened beverages prepared with commercial food thickeners are widely used to promote safer and more successful swallowing in patients with dysphagia. In this study, the rheological properties of cold thickened beverages (bottled water, orange juice, apple juice, and whole milk) prepared with a commercially available gum-based food thickener (xanthan-guar gum mixture) marketed in Korea were investigated at 3 different thickener concentrations (2, 3, and 4%, w/w). Thickened beverages showed high shearthinning (n=0. 12-0. 21) behavior with Casson yield stress at all concentrations. Their apparent viscosity (ηa,50), consistency index (K), Casson yield stress (σoc), storage modulus (G′), and loss modulus (G″) increased with an increase in thickener concentration. Steady and dynamic rheological parameters also demonstrated greater differences in rheological behaviors between thickened beverages with different thickener concentrations. These results suggest that rheological properties of thickened beverages are strongly affected by thickener concentration and the type of beverage prepared. © 2012 The Korean Society of Food Science and Technology and Springer Science+Business Media Dordrecht.


Cho H.-M.,Dongguk University | Yoo W.,Rheosfood Inc. | Yoo B.,Dongguk University
Preventive Nutrition and Food Science | Year: 2015

Rheological properties of thickened fluids used for consumption by people with dysphagia (swallowing difficulty) are very sensitive to several factors, such as thickener type, temperature, pH, sugar, protein, and NaCl. In this study, steady and dynamic rheological properties of thickened water samples mixed with five commercial xanthan gum-based food thickeners (A∼E) were studied in the presence of NaCl at different concentrations (0.3%, 0.6%, 0.9%, and 1.2%). The magnitudes of apparent viscosity (ηa,50), consistency index (K), yield stress (σoc), and dynamic moduli (G′ and G″) showed significant differences in rheological behaviors between thickened samples with various NaCl concentrations. Dynamic moduli values of all thickened samples, except for samples with thickener C, were much higher than those of the control (0% NaCl). All rheological parameter values (K, G′, and G″) in a thickener A were much higher than those in other thickeners. These results suggest that rheological properties of thickened samples containing NaCl are strongly affected by xanthan gum-NaCl interaction and depended on the type of thickener. Copyright © 2015 by The Korean Society of Food Science and Nutrition. All rights reserved.


Kim S.-G.,Dongguk University | Yoo W.,Rheosfood Inc. | Yoo B.,Dongguk University
Preventive Nutrition and Food Science | Year: 2014

The flow behaviors of three thickened fruit juices (orange, apple, and grape juice) prepared with a commercial instant xanthan gum (XG)-based thickener that is marketed in Korea were investigated at different thickener concentrations (1.0%, 1.5%, 2.0%, 2.5%, 3.0%, and 3.5%) and setting times (5 and 30 min) using a rheometer and a line-spread measurement method. The flow distance values measured by the line-spread test (LST) were compared with the apparent viscosity (νa,50) values measured with a sophisticated computer-controlled rheometer. The νa,50 values of the juices increased as thickener concentration increased, whereas their flow distances decreased. The νa,50 values at the 30-min setting time were much higher than those at the 5-min setting time, indicating that the setting time before serving or consuming thickened juices can affect viscosity values. Plots comparing νa,50 values to LST flow distances revealed strong exponential relationships between the two measures (R2=0.989 and R2=0.987 for the 5- and 30-min setting times, respectively). These results indicate that the LST can be a suitable instrument for evaluating the viscosity of thickened fruit juices prepared with different XG-based thickener concentrations and setting times for the dysphagia diet. Copyright © 2014 by The Korean Society of Food Science and Nutrition. All rights Reserved.


Kim S.-G.,Dongguk University | Yoo W.,Rheosfood Inc. | Yoo B.,Dongguk University
Preventive Nutrition and Food Science | Year: 2014

Flow and dynamic rheological properties of hot thickened soups for consumption by the elderly people with swallowing difficulty (dysphagia) were investigated at a serving temperature of 60°C. In this study, sea mustard soup (SMS) and dried pollock soup (DPS), which have been widely known as favorable hot soups provided in a domestic hospitals and nursing homes for dysphagic patients, were thickened with four commercial xanthan gum (XG)-based food thickeners (coded A-D) marketed in Korea. Thickened soups prepared with different thickeners showed high shear-thinning flow behaviors (n=0.15-0.21). Apparent viscosity (ηa,50), consistency index (K), storage modulus (G′), and loss modulus (G″) demonstrated differences in rheological behaviors between the XG-based thickeners. The magnitudes of G′ were much higher than those of G″ over the entire range of frequency (ω) with the high dependence on ω, showing the rheological behavior similar to a weak gel. In general, all rheological parameter values of thickened DPS samples were higher when compared to the thickened SMS samples. These results indicate that flow and dynamic rheological properties of hot thickened soups containing commercial XG-based thickeners are strongly dependent on the type of thickener and soup. Copyright © 2014 by The Korean Society of Food Science and Nutrition. All rights Reserved.


PubMed | Dongguk University and Rheosfood Inc.
Type: Journal Article | Journal: Preventive nutrition and food science | Year: 2014

The flow behaviors of three thickened fruit juices (orange, apple, and grape juice) prepared with a commercial instant xanthan gum (XG)-based thickener that is marketed in Korea were investigated at different thickener concentrations (1.0%, 1.5%, 2.0%, 2.5%, 3.0%, and 3.5%) and setting times (5 and 30 min) using a rheometer and a line-spread measurement method. The flow distance values measured by the line-spread test (LST) were compared with the apparent viscosity (a,50) values measured with a sophisticated computer-controlled rheometer. The a,50 values of the juices increased as thickener concentration increased, whereas their flow distances decreased. The a,50 values at the 30-min setting time were much higher than those at the 5-min setting time, indicating that the setting time before serving or consuming thickened juices can affect viscosity values. Plots comparing a,50 values to LST flow distances revealed strong exponential relationships between the two measures (R(2)=0.989 and R(2)=0.987 for the 5- and 30-min setting times, respectively). These results indicate that the LST can be a suitable instrument for evaluating the viscosity of thickened fruit juices prepared with different XG-based thickener concentrations and setting times for the dysphagia diet.


PubMed | Dongguk University and Rheosfood Inc.
Type: Journal Article | Journal: Clinical nutrition research | Year: 2016

The effect of human saliva on the flow properties of pudding-like thickened water prepared with commercial food thickeners was investigated, and their viscosity differences were also compared as a function of salivary reaction time (0-60 min after the addition of saliva). Food thickeners used in this study were starch-based (SB), gum-containing starch-based (GSB), and gumbased (GB) commercial thickeners marketed in Korea. GB showed no significant reduction in viscosity upon contact with human saliva during the salivary reaction. In contrast, SB almost completely lost its viscosity shortly after the addition of saliva, and GSB significantly reduced its viscosity after 20 min of reaction time but retained its viscosity. The results of this study indicate that GB can enhance the swallowing safety of dysphagic patients by retaining a stable viscosity level without the reduction of viscosity during consumption of thickened fluids, whereas SB may increase the possibility of aspiration owing to a rapid decrease of viscosity upon contact with human saliva.

Loading Rheosfood Inc. collaborators
Loading Rheosfood Inc. collaborators