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Richard Ipsen - One of the best experts on this subject based on the ideXlab platform.
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Effects of added whey protein aggregates on textural and microstructural properties of Acidified Milk model systems
International Dairy Journal, 2016Co-Authors: Guanchen Liu, Patrizia Buldo, Marie T. Greve, Søren B. Nielsen, Jacob Holm Nielsen, Richard IpsenAbstract:Abstract Non-fat Milk model systems containing 5% total protein were investigated with addition of micro- or nanoparticulated whey protein at two levels of casein (2.5% and 3.5%, w/w). The systems were subjected to homogenisation (20 MPa), heat treatment (90 °C for 5 min) and chemical (glucono-delta-lactone) acidification to pH 4.6 and characterised in terms of denaturation degree of whey protein, particle size, textural properties, rheology and microstructure. The model systems with nanoparticulated whey protein exhibited significant larger particle size after heating and provided acid gels with higher firmness and viscosity, faster gelation and lower syneresis and a denser microstructure. In contrast, microparticulated whey protein appeared to only weakly interact with other proteins present and resulted in a protein network with low connectivity in the resulting gels. Increasing the casein/whey protein ratio did not decrease the gel strength in the Acidified Milk model systems with added whey protein aggregates.
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Interactions of Milk proteins with low and high acyl gellan: Effect on microstructure and textural properties of Acidified Milk
Food Hydrocolloids, 2016Co-Authors: Patrizia Buldo, Connie Benfeldt, Juan Pablo Carey, Ditte Marie Folkenberg, Hanne Bak Jensen, Sander Sieuwerts, Kalliopi Vlachvei, Richard IpsenAbstract:Abstract The effect of addition of low and high acyl gellan (LAG/HAG) at three different concentrations on the microstructure and texture of Acidified Milk systems with different casein to whey protein ratios was investigated. The systems with added LAG exhibited a continuous gel network whereas micro-phase separation occurred when HAG was added. The continuous gel network was indicative of complexation between the polysaccharides and casein, which in turn led to enhanced textural properties and reduced syneresis. Those properties were reduced by decreasing the casein to whey protein ratio as fewer complexes were formed. HAG appeared to be incompatible with casein micelles, which resulted in a micro-phase separated system. This caused decreased textural properties but a higher physical stability due to HAG present in the serum phase available to bind water. By decreasing the casein to whey protein ratio the textural properties were improved at expense of the physical stability, indicating a preferential binding between HAG and whey proteins.
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Effects of disulphide bonds between added whey protein aggregates and other Milk components on the rheological properties of Acidified Milk model systems
International Dairy Journal, 2016Co-Authors: Guanchen Liu, Søren B. Nielsen, Tanja Christine Jæger, Marianne N. Lund, Colin Ray, Richard IpsenAbstract:Abstract Micro- and nanoparticulated whey protein (MWP, NWP) were added to non-fat Milk model systems and processed into chemically (glucono-delta-lactone) Acidified Milk gels. Model systems contained 5% protein in total and were made at two levels of casein (2.5% and 3.5%, w/w) with and without the thiol-blocking agent N-ethylmaleimide. The systems were characterised in terms of thiol groups, gel electrophoresis, particle size, and rheology during processing (homogenisation, heat treatment and acidification). The results showed that the formation of disulphide-linked structures in Milk model systems was closely related to the increased particle size and rheological behaviour of the gels. MWP enriched systems produced, upon acidification, weak protein networks and required the addition of whey protein isolate (WPI) to increase gel strength. However, systems containing NWP exhibited pronounced increase in particle size and higher firmness of Acidified gels through both covalent and non-covalent interactions.
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Sensory and rheological characterization of Acidified Milk drinks
Food Hydrocolloids, 2008Co-Authors: Thomas Janhøj, Michael Bom Frøst, Richard IpsenAbstract:Abstract A set of 17 Acidified Milk drinks (AMDs), of which eight were drinking yoghurts (made by dilution of a yoghurt base) with 3–8% Milk solids non-fat (MSNF) and the remainder Milk–juice drinks (made from fruit concentrate and reconstituted Milk powder) with 3% MSNF, were submitted to descriptive sensory analysis and rheological characterization. The drinks were stabilized with pectin and/or carboxymethyl cellulose (CMC) (0–0.5%). The sensorially perceived Creaminess was found to depend linearly on Oral viscosity whereas the relationship between Creaminess and Smoothness depended on the level of MSNF. Drinking yoghurt stabilized using pectin were found to be shear thinning whereas pectin-stabilized Milk–juice drinks as well as either category of AMD stablilized by CMC were found approximately close to Newtonian behaviour. Viscometry data in the form of consistency index K could only predict sensory viscosity moderately well (r=0.70); in particular, for pectin-stabilized samples with 3% MSNF, the correlation was very poor (r=−0.15).
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zeta potential of pectin stabilised casein aggregates in Acidified Milk drinks
International Dairy Journal, 2007Co-Authors: Marie Tholstrup Sejersen, Tina Salomonsen, Claus Rolin, Ross Clark, Richard Ipsen, Soren Balling EngelsenAbstract:Abstract High-methoxy (HM) pectin is commonly used to improve the stability of Acidified Milk drinks (AMDs) and zeta potential measurements can aid in elucidating the mechanisms responsible for the improved stability. Pectin was added to an AMD model system in concentrations of 0.0%, 0.1%, 0.3% or 0.5% and the samples were subjected to heat treatment at 75 °C for 20 min; control samples were not heated. A change in zeta potential from positive to negative values with addition of pectin was observed. Increasing the pectin concentration resulted in a more negative zeta potential. Heat treatment caused a decrease in the numeric value of the zeta potential, which indicates a partial desorption of pectin from the protein aggregates.
Tsutomu Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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aerosolized surfactant and dextran for experimental acute respiratory distress syndrome caused by Acidified Milk in rats
Acta Anaesthesiologica Scandinavica, 2003Co-Authors: X G Cui, Katsumi Tashiro, H Matsumoto, Y Tsubokawa, Tsutomu KobayashiAbstract:Background: Inhibition of pulmonary surfactant by plasma-derived proteins is an important pathogenetic factor of acute respiratory distress syndrome (ARDS). Inhalation of aerosolized surfactant may be suitable for early treatment of ARDS. However, requirement of a high dose is a drawback. Because dextran reverses surfactant inhibition, we examined whether dextran improves the therapeutic effects of aerosolized surfactant in rats with experimental ARDS. Methods: Acidified Milk (pH 1.8, 1.5 ml kg−1) was injected into the trachea of the rats ventilated with pure oxygen using 2.45 kPa peak inspiratory pressure and 0.74 kPa positive end-expiratory pressure. When PaO2 decreased to <13 kPa, the rats were assigned to four groups: control group (n = 8), receiving no material; D-only group (n = 6), receiving aerosolized dextran for 45 min; S-only group (n = 8), receiving aerosolized modified natural surfactant (MNS) for 30 min; and S-plus-D group (n = 9), receiving aerosolized MNS for 30 min followed by aerosolized dextran for 15 min. Results: In the control group and D-only groups, the mean PaO2 remained at 38 kPa for 180 min (P < 0.01 vs. S-only group). Conclusion: Inhalation of aerosolized dextran potentiates the effects of aerosolized surfactant by prolonging the therapeutic response.
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Aerosolized surfactant and dextran for experimental acute respiratory distress syndrome caused by Acidified Milk in rats.
Acta anaesthesiologica Scandinavica, 2003Co-Authors: X G Cui, Katsumi Tashiro, H Matsumoto, Y Tsubokawa, Tsutomu KobayashiAbstract:Background: Inhibition of pulmonary surfactant by plasma-derived proteins is an important pathogenetic factor of acute respiratory distress syndrome (ARDS). Inhalation of aerosolized surfactant may be suitable for early treatment of ARDS. However, requirement of a high dose is a drawback. Because dextran reverses surfactant inhibition, we examined whether dextran improves the therapeutic effects of aerosolized surfactant in rats with experimental ARDS. Methods: Acidified Milk (pH 1.8, 1.5 ml kg−1) was injected into the trachea of the rats ventilated with pure oxygen using 2.45 kPa peak inspiratory pressure and 0.74 kPa positive end-expiratory pressure. When PaO2 decreased to
Milena Corredig - One of the best experts on this subject based on the ideXlab platform.
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Nanoemulsions and Acidified Milk gels as a strategy for improving stability and antioxidant activity of yarrow phenolic compounds after gastrointestinal digestion.
Food research international (Ottawa Ont.), 2019Co-Authors: Marisol Villalva, Milena Corredig, Laura Jaime, Elena Arranz, Zhengtao Zhao, Guillermo Reglero, Susana SantoyoAbstract:Abstract The aim of this study was to improve the stability and antioxidant activity of yarrow phenolic compounds upon an in vitro simulated gastrointestinal digestion. Therefore, two types of caseins-based delivery systems, sodium caseinate stabilized nanoemulsions (NEs) and glucono delta-lactone Acidified Milk gels (MGs), were formulated containing an ultrasound-assisted yarrow extract (YE) at two concentrations (1 and 2.5 mg/mL). Formulations with 1 mg/mL of YE were chosen based on their higher encapsulation efficiency to perform the in vitro digestion experiments. After digestion, YE-loaded NEs only partially protected phenolic compounds from degradation; meanwhile the phenolic composition of YE including in MGs after digestion was quite similar to undigested YE. Moreover, the antioxidant activity of MGs after digestion was higher than NEs digested samples, which confirms the higher protection of YE phenolic compound by the Milk gels systems. This research demonstrated the potential use of Acidified MGs as carriers to improve the stability and antioxidant activity of yarrow phenolic compounds. Therefore, these matrices could be employed to develop new dairy products enriched with phenolic compounds.
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the stabilizing behaviour of soybean soluble polysaccharide and pectin in Acidified Milk beverages
International Dairy Journal, 2006Co-Authors: Akihiro Nakamura, Ryuji Yoshida, Hirokazu Maeda, Milena CorredigAbstract:The mechanisms of stabilization of soybean soluble polysaccharide (SSPS) and high methoxyl pectin (HMP) in Acidified Milk drinks were studied focusing on the differences in behaviour between the two polysaccharides. The changes in casein micelles size during acidification with glucono-δ-lactone or by direct acidification were measured using light scattering. When HMP was added to skim Milk before acidification, pectin adsorbed on the surface of the casein micelles via electrostatic interactions and prevented casein aggregation. Results suggested that adsorption of pectin occurred from the beginning of acidification and somewhat affected the rearrangement of casein micelles in the pH range between 5.8 and 5.0. On the other hand, SSPS, at concentrations up to 2% (w/w), did not interact with caseins at pH >4.6. At pH <4.2 SSPS showed better stabilizing properties than HMP. In addition, between pH 4.2 and 3.2, SSPS-stabilized acid dispersions were not affected by pH, while dispersions homogenized with pectin showed a size distribution that depended on pH. The differences in structure between SSPS and HMP account for the unique functionalities of the two polysaccharides in acid Milk systems.
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Pasteurization affects aggregation of Acidified Milk dispersions and pectin
2006Co-Authors: Brian W. Barnes, Milena Corredig, Louise WickerAbstract:Commercial pectins were added at stabilizing levels to Acidified Milk dispersions and the effect of pectin type and pasteurization on the pectin-protein interaction was evaluated by gel permeation chromatography with in-line multi-angle light scattering, refractive index, and UV detectors. Commercial pectins had no apparent effect on the differences in molecular weight distributions of the soluble material in the dispersions. The weight average molecular weight (M w ) of individual pectins were 1.2 to over 4 million and were polydisperse with M w /M n ratios greater than 1.0. The M w of soluble components in the mixed dispersions were 2-8 times higher than pectin alone and had greater polydispersity. Pasteurization had a greater effect on molecular weight distributions and polydispersity than pectin type. A second, high molecular weight aggregate was observed in all pasteurized samples. This aggregate was 10 times larger after pasteurization compared to non-pasteurized samples.
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The stabilizing behaviour of soybean soluble polysaccharide and pectin in Acidified Milk beverages
International Dairy Journal, 2006Co-Authors: Akihiro Nakamura, Ryuji Yoshida, Hirokazu Maeda, Milena CorredigAbstract:The mechanisms of stabilization of soybean soluble polysaccharide (SSPS) and high methoxyl pectin (HMP) in Acidified Milk drinks were studied focusing on the differences in behaviour between the two polysaccharides. The changes in casein micelles size during acidification with glucono-δ-lactone or by direct acidification were measured using light scattering. When HMP was added to skim Milk before acidification, pectin adsorbed on the surface of the casein micelles via electrostatic interactions and prevented casein aggregation. Results suggested that adsorption of pectin occurred from the beginning of acidification and somewhat affected the rearrangement of casein micelles in the pH range between 5.8 and 5.0. On the other hand, SSPS, at concentrations up to 2% (w/w), did not interact with caseins at pH >4.6. At pH
X G Cui - One of the best experts on this subject based on the ideXlab platform.
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aerosolized surfactant and dextran for experimental acute respiratory distress syndrome caused by Acidified Milk in rats
Acta Anaesthesiologica Scandinavica, 2003Co-Authors: X G Cui, Katsumi Tashiro, H Matsumoto, Y Tsubokawa, Tsutomu KobayashiAbstract:Background: Inhibition of pulmonary surfactant by plasma-derived proteins is an important pathogenetic factor of acute respiratory distress syndrome (ARDS). Inhalation of aerosolized surfactant may be suitable for early treatment of ARDS. However, requirement of a high dose is a drawback. Because dextran reverses surfactant inhibition, we examined whether dextran improves the therapeutic effects of aerosolized surfactant in rats with experimental ARDS. Methods: Acidified Milk (pH 1.8, 1.5 ml kg−1) was injected into the trachea of the rats ventilated with pure oxygen using 2.45 kPa peak inspiratory pressure and 0.74 kPa positive end-expiratory pressure. When PaO2 decreased to <13 kPa, the rats were assigned to four groups: control group (n = 8), receiving no material; D-only group (n = 6), receiving aerosolized dextran for 45 min; S-only group (n = 8), receiving aerosolized modified natural surfactant (MNS) for 30 min; and S-plus-D group (n = 9), receiving aerosolized MNS for 30 min followed by aerosolized dextran for 15 min. Results: In the control group and D-only groups, the mean PaO2 remained at 38 kPa for 180 min (P < 0.01 vs. S-only group). Conclusion: Inhalation of aerosolized dextran potentiates the effects of aerosolized surfactant by prolonging the therapeutic response.
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Aerosolized surfactant and dextran for experimental acute respiratory distress syndrome caused by Acidified Milk in rats.
Acta anaesthesiologica Scandinavica, 2003Co-Authors: X G Cui, Katsumi Tashiro, H Matsumoto, Y Tsubokawa, Tsutomu KobayashiAbstract:Background: Inhibition of pulmonary surfactant by plasma-derived proteins is an important pathogenetic factor of acute respiratory distress syndrome (ARDS). Inhalation of aerosolized surfactant may be suitable for early treatment of ARDS. However, requirement of a high dose is a drawback. Because dextran reverses surfactant inhibition, we examined whether dextran improves the therapeutic effects of aerosolized surfactant in rats with experimental ARDS. Methods: Acidified Milk (pH 1.8, 1.5 ml kg−1) was injected into the trachea of the rats ventilated with pure oxygen using 2.45 kPa peak inspiratory pressure and 0.74 kPa positive end-expiratory pressure. When PaO2 decreased to
Hongbin Zhang - One of the best experts on this subject based on the ideXlab platform.
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Influence of the degree of esterification of soluble soybean polysaccharide on the stability of Acidified Milk drinks
Food Hydrocolloids, 2020Co-Authors: Zhixiang Cai, Yue Wei, Yalong Guo, Hongbin ZhangAbstract:Abstract Soluble soybean polysaccharide (SSPS), an anionic polysaccharide extracted from the by-product of soybean protein, has been widely used as a stabilizer for the stabilization of casein dispersions. The methyl esterified carboxylic group of galacturonic acid (GalA) in SSPS has a vital influence on its physicochemical and functional properties. In particular, the degree of esterification (DE) of SSPS plays an important role in the stability of Acidified Milk drinks (AMDs). Thus, in this work, the DE of SSPS was determined by 1H NMR spectroscopy and titration method. The influence of DE of SSPS on the stability of AMDs was comprehensively investigated and evaluated by using LUMiSizer. It was found that the SSPS with a low DE showed better stabilization in AMDs compared to SSPS with a high DE. Zeta potential measurements can aid in elucidating the mechanisms responsible for the improved stability of AMDs, which showed that the decrease in DE resulted in the more negative zeta potential of SPSS coated casein particles. These results demonstrated that SSPS with a low DE has a high ability to stabilize AMDs, mostly due to the large electrostatic repulsive force of SSPS and the steric repulsive force of adsorption layer that is formed on the surface of casein particles.
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Impact of distribution of carboxymethyl substituents in the stabilizer of carboxymethyl cellulose on the stability of Acidified Milk drinks
Food Hydrocolloids, 2018Co-Authors: Zhixiang Cai, Hongbin ZhangAbstract:Abstract The influences of molecular parameters such as molecular weight ( M w ), the degree of substitution (DS) and especially the distribution of carboxymethyl substituents within the anhydroglucose unit (AGU) of carboxymethylcellulose (CMC) on the rheological properties of CMC solutions and the stability of Acidified Milk drinks (AMDs) induced by this cellulose ether have been comprehensively investigated and evaluated by LUMi-Sizer. The DS and the distribution of carboxymethyl substituents are characterized by means of 1 H NMR spectroscopy using a set of acid-hydrolyzing CMC samples. A new CMC molecular parameter of R i indicating the individual degree of substitution at the position of either C-2 ( R 2 ) or C-6 ( R 6 ) in AGU is proposed to evaluate the influence of distribution of carboxymethyl substituents on the stability of the Milk drinks. It is found that the distribution of carboxymethyl substituents also plays a key role in the stability of AMDs. The stability of the drinks increases not only with increasing the M w and DS but also with decreasing the R 2 or increasing the R 6 of CMC. This fact is explained on the basis of CMC with a higher individual DS at C-2 position resulting in higher electronegativity, thus increasing the electrostatic repulsion between CMC-adsorbed casein particles in the colloidal system, thereby contributing to a better stability to AMDs. These findings provide an insight into fabricating better stability of AMDs induced by CMC.
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Influence of homogenisation and the degradation of stabilizer on the stability of Acidified Milk drinks stabilized by carboxymethylcellulose
LWT - Food Science and Technology, 2014Co-Authors: Hongbin ZhangAbstract:Abstract The present work deals with the influences of both homogenisation and the degradation of carboxymethylcellulose (CMC) on the stability of two kinds of Acidified Milk drinks (AMDs), directly Acidified Milk drinks and yoghurt drinks. The effect of homogenisation pressure for direct acidification process was investigated and evaluated. The experimental results showed that homogenisation was required to achieve a significantly small particle size (0.7 μm in the present work) and to prevent sedimentation and serum separation. However, homogenisation at too high pressures was not beneficial for the stability of the colloidal systems. The occurrence of degradation of CMC during homogenisation weakened the stabilisation effect of CMC. A qualified homogenisation pressure of 20 MPa should be chosen to achieve a good stability when a usually practical pressure range of 0–30 MPa was applied. In addition, the stability of directly Acidified Milk and yoghurt drinks prepared under the same homogenisation pressure was also investigated. While their stability increased with increasing CMC concentration, the degradation of CMC at low pH during storage gave rise to instability of the final products.
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influence of molecular weight and degree of substitution of carboxymethylcellulose on the stability of Acidified Milk drinks
Food Hydrocolloids, 2009Co-Authors: Hongbin Zhang, Ping Chen, Long Huang, Jianjun ZhouAbstract:Abstract The influence of molecular weight ( M w , 250,000, 700,000) and degree of substitution (DS, 0.7, 0.9 and 1.2) of carboxymethylcellulose (CMC) on the diameter and ζ-potential of casein micelles during acidification in diluted dispersions and on the stability of Acidified Milk drinks was investigated. The experimental results suggested that CMC with high M w or low DS would result in thick adsorbed layer onto casein micelles. The ζ-potential of CMC-coated casein micelle increased with increasing the M w of CMC with the same DS while at a fixed M w the ζ-potential for CMC with high DS (1.2) increased in comparison with those for CMC with low DS (0.7 and 0.9). Both M w and DS of CMC influenced the stability of Acidified Milk drinks. CMC with high M w increased the viscosity of Acidified Milk drinks significantly and therefore contributed to the stability. CMC with high DS resulted in high ζ-potential of CMC-coated casein micelles, increasing the electrostatic repulsion between casein particles, which prevented the phase separation in Acidified Milk drinks. It was also found that the amount of CMC needed for efficient coverage of casein micelles increased with increasing the M w of CMC. Above the efficient coverage concentration, the long-term stability of Acidified Milk drinks with high M w CMC was better than that with low M w CMC.
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The stabilization mechanism of Acidified Milk drinks induced by carboxymethylcellulose
Le Lait, 2007Co-Authors: Hongbin Zhang, Ping Chen, Long Huang, Jianjun ZhouAbstract:In the present work carboxymethylcellulose (CMC) was used as a stabilizer to avoid the flocculation of Milk proteins in Acidified Milk drinks. The particle diameter and ζ-potential evolu- tion during acidification of casein micelles in CMC were studied. The experimental results indicate that the adsorption of CMC takes place at and below pH 5.2 and that electrosorption may be the driving force for the adsorption of CMC onto the casein micelles. The stability of Acidified Milk drinks induced by CMC could be explained presumably by steric stabilization caused by the an- chor of CMC onto the casein micelles' surface rather than electrostatic repulsion. Above pH 5.2 phase separation of the casein/CMC mixture corresponding to thermodynamic incompatibility was found at high CMC concentration, while below pH 5.2 the adsorption of CMC led to either sta- bilization or bridging among casein micelles depending on the CMC concentration. In addition, the non-adsorbed CMC (serum CMC) increased the viscosity of the serum and thus contributed to preventing casein micelles from precipitating. Acidified Milk drink / carboxymethylcellulose (CMC) / casein micelle / electrosorption / stability
