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J A Lucey - One of the best experts on this subject based on the ideXlab platform.
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physicochemical and emulsifying properties of Whey Protein Isolate wpi dextran conjugates produced in aqueous solution
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Dan Zhu, Srinivasan Damodaran, J A LuceyAbstract:The physicochemical and emulsifying properties of Protein and polysaccharide conjugates prepared under mild conditions were investigated. The covalently linked conjugates of Whey Protein Isolate (WPI) and dextran (DX, 440 kDa) were produced by incubating aqueous solutions containing 10% WPI and 30% DX at pH 6.5 and 60 °C for 48 h. After purification by anion-exchange chromatography and affinity chromatography, the conjugate had a weight-average molecular weight (Mw) of 531 kDa and a radius of gyration (Rg) of 30 nm as determined by size exclusion chromatography−multiangle laser light scattering (SEC-MALLS); the molar binding ratio of WPI to DX was calculated to be ∼1:1. The purified conjugate had significantly improved heat stability when subjected to 80 °C for 30 min and remained soluble over a range of pH from 3.2 to 7.5 and ionic strengths from 0.05 to 0.2 M in contrast to native WPI. The emulsifying ability and emulsion stability made with WPI−DX conjugate were also improved compared to WPI and gum ar...
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formation of Whey Protein Isolate wpi dextran conjugates in aqueous solutions
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Dan Zhu, Srinivasan Damodaran, J A LuceyAbstract:The conjugation reaction between Whey Protein Isolate (WPI) and dextran in aqueous solutions via the initial stage of the Maillard reaction was studied. The covalent attachment of dextran to WPI was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with both Protein and carbohydrate staining. The formation of WPI-dextran conjugates was monitored by a maximum absorbance peak at approximately 304 nm using difference UV spectroscopy. The impact of various processing conditions on the formation of WPI-dextran conjugates was investigated. The conjugation reaction was promoted by raising the temperature from 40 to 60 degrees C, the WPI concentration from 2.5 to 10%, and the dextran concentration from 10 to 30% and lowering the pH from 8.5 to 6.5. The optimal conjugation conditions chosen from the experiments were 10% WPI-30% dextran and pH 6.5 at 60 degrees C for 24 h. WPI-dextran conjugates were stable under the conditions studied.
Srinivasan Damodaran - One of the best experts on this subject based on the ideXlab platform.
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physicochemical and emulsifying properties of Whey Protein Isolate wpi dextran conjugates produced in aqueous solution
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Dan Zhu, Srinivasan Damodaran, J A LuceyAbstract:The physicochemical and emulsifying properties of Protein and polysaccharide conjugates prepared under mild conditions were investigated. The covalently linked conjugates of Whey Protein Isolate (WPI) and dextran (DX, 440 kDa) were produced by incubating aqueous solutions containing 10% WPI and 30% DX at pH 6.5 and 60 °C for 48 h. After purification by anion-exchange chromatography and affinity chromatography, the conjugate had a weight-average molecular weight (Mw) of 531 kDa and a radius of gyration (Rg) of 30 nm as determined by size exclusion chromatography−multiangle laser light scattering (SEC-MALLS); the molar binding ratio of WPI to DX was calculated to be ∼1:1. The purified conjugate had significantly improved heat stability when subjected to 80 °C for 30 min and remained soluble over a range of pH from 3.2 to 7.5 and ionic strengths from 0.05 to 0.2 M in contrast to native WPI. The emulsifying ability and emulsion stability made with WPI−DX conjugate were also improved compared to WPI and gum ar...
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ph stability and thermal properties of microbial transglutaminase treated Whey Protein Isolate
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Kingsley K Agyare, Srinivasan DamodaranAbstract:Whey Protein Isolate (WPI) was treated to various extents using microbial transglutaminase (MTGase) and changes in pH-stability and thermal stability of its Protein components were investigated. The MTGase treatment significantly increased the denaturation temperature (T(d)) of beta-lactoglobulin in WPI, from 71.84 degrees C in the untreated sample to 78.50 degrees C after 30 h of incubation with MTGase. The enthalpy change of denaturation of WPI did not change upon cross-linking, indicating that the increase in T(d) was primarily due to covalent cross-linking and not due to an increase in nonpolar interactions within the Protein. The surface hydrophobicity (S(o)) of the Protein decreased upon cross-linking; however, this decrease was not due to burial of the surface hydrophobic cavities in the Protein interior, but due to occlusion of the hydrophobic cavities to the fluorescent probes. Fluorescence emission and circular dichroism spectroscopic analyses revealed no major changes in the secondary and tertiary conformations as a result of cross-linking. However, unlike native WPI, the cross-linked Protein exhibited a U-shaped pH-stability profile with maximum turbidity at pH 4.0-4.5. The study revealed that even though enzymatic cross-linking significantly improved the T(d) of beta-lactoglobulin in WPI without causing major structural changes, a reduction in the hydrophilic-hydrophobic balance of the Protein surface as a result of elimination of the positive charge on lysyl residues caused precipitation at pH 4.0-4.5.
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formation of Whey Protein Isolate wpi dextran conjugates in aqueous solutions
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Dan Zhu, Srinivasan Damodaran, J A LuceyAbstract:The conjugation reaction between Whey Protein Isolate (WPI) and dextran in aqueous solutions via the initial stage of the Maillard reaction was studied. The covalent attachment of dextran to WPI was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with both Protein and carbohydrate staining. The formation of WPI-dextran conjugates was monitored by a maximum absorbance peak at approximately 304 nm using difference UV spectroscopy. The impact of various processing conditions on the formation of WPI-dextran conjugates was investigated. The conjugation reaction was promoted by raising the temperature from 40 to 60 degrees C, the WPI concentration from 2.5 to 10%, and the dextran concentration from 10 to 30% and lowering the pH from 8.5 to 6.5. The optimal conjugation conditions chosen from the experiments were 10% WPI-30% dextran and pH 6.5 at 60 degrees C for 24 h. WPI-dextran conjugates were stable under the conditions studied.
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proteose peptones and physical factors affect foaming properties of Whey Protein Isolate
Journal of Food Science, 1994Co-Authors: Haiming Zhu, Srinivasan DamodaranAbstract:Effects of peptides and nonProtein components of Whey on Whey Protein Isolate (WPI) were studied using a differential pressure method. Decay of WPI foam followed biphasic first-order kinetics, but was affected by solution conditions. WPI foam stability exhibited two pH optima (5.0 and 8.5). Addition of 0.02–0.15M NaCl progressively decreased foaming capacity and foam stability. Addition of 0.01–0.2% proteose-peptones caused a sharp decrease in foam stability, but did not affect WPI foaming capacity. Foam stability was increased by addition of up to 20% lactose. Removal of proteose-peptones should greatly improve foaming properties of Whey Proteins.
Dan Zhu - One of the best experts on this subject based on the ideXlab platform.
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physicochemical and emulsifying properties of Whey Protein Isolate wpi dextran conjugates produced in aqueous solution
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Dan Zhu, Srinivasan Damodaran, J A LuceyAbstract:The physicochemical and emulsifying properties of Protein and polysaccharide conjugates prepared under mild conditions were investigated. The covalently linked conjugates of Whey Protein Isolate (WPI) and dextran (DX, 440 kDa) were produced by incubating aqueous solutions containing 10% WPI and 30% DX at pH 6.5 and 60 °C for 48 h. After purification by anion-exchange chromatography and affinity chromatography, the conjugate had a weight-average molecular weight (Mw) of 531 kDa and a radius of gyration (Rg) of 30 nm as determined by size exclusion chromatography−multiangle laser light scattering (SEC-MALLS); the molar binding ratio of WPI to DX was calculated to be ∼1:1. The purified conjugate had significantly improved heat stability when subjected to 80 °C for 30 min and remained soluble over a range of pH from 3.2 to 7.5 and ionic strengths from 0.05 to 0.2 M in contrast to native WPI. The emulsifying ability and emulsion stability made with WPI−DX conjugate were also improved compared to WPI and gum ar...
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formation of Whey Protein Isolate wpi dextran conjugates in aqueous solutions
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Dan Zhu, Srinivasan Damodaran, J A LuceyAbstract:The conjugation reaction between Whey Protein Isolate (WPI) and dextran in aqueous solutions via the initial stage of the Maillard reaction was studied. The covalent attachment of dextran to WPI was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with both Protein and carbohydrate staining. The formation of WPI-dextran conjugates was monitored by a maximum absorbance peak at approximately 304 nm using difference UV spectroscopy. The impact of various processing conditions on the formation of WPI-dextran conjugates was investigated. The conjugation reaction was promoted by raising the temperature from 40 to 60 degrees C, the WPI concentration from 2.5 to 10%, and the dextran concentration from 10 to 30% and lowering the pH from 8.5 to 6.5. The optimal conjugation conditions chosen from the experiments were 10% WPI-30% dextran and pH 6.5 at 60 degrees C for 24 h. WPI-dextran conjugates were stable under the conditions studied.
Weiwei Sun - One of the best experts on this subject based on the ideXlab platform.
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study on the rheological properties of heat induced Whey Protein Isolate dextran conjugate gel
Food Research International, 2011Co-Authors: Weiwei Sun, Xiaoquan Yang, Jinmei Wang, Jinbo Zhang, Ye Zhang, Erli ZhengAbstract:Abstract Effect of glycosylation on the rheological properties of Whey Protein Isolate (WPI) during the heat-induced gelation process was evaluated. Significant changes in browning intensity, free amino groups content and SDS-PAGE profile showed that the conjugate of WPI and dextran (150 kDa) was successfully prepared using the traditional dry-heating treatment. For the conjugate, during the heating and cooling cycle, the curves of G′ and G″ were considerably shifted to lower values and their shapes varied comparing to the corresponding spectra of initial WPI and WPI + dextran mixture. After holding at 25 °C, G' reached a value of about 2200 Pa, only a tenth of the value that obtained in the initial WPI gel. Moreover, frequency sweep measurements revealed that the stiffness of gel was greatly reduced in the conjugate, although a typical elastic gel was still formed. All data showed that the rheological properties of thermal gelation could be modified upon the covalent attachment of dextran.
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properties of Whey Protein Isolate dextran conjugate prepared using pulsed electric field
Food Research International, 2011Co-Authors: Weiwei Sun, Xinan Zeng, Xiaoquan Yang, Xiao JiaAbstract:Abstract Effect of pulsed electric field treatment on Whey Protein Isolate–dextran conjugation in aqueous solution via Maillard reaction was investigated. Significant changes in browning intensity, free amino group content and SDS-PAGE profile showed that Whey Protein Isolate–dextran conjugate was successfully formed using pulsed electric field treatment. Moreover, higher pulsed electric field intensity enhanced the extent of glycosylation. Meanwhile, the secondary structure of Whey Protein Isolate had a considerable loss due to the covalent attachment of dextran. The functional properties, such as solubility, emulsifying activity and emulsion stability were also evaluated. Compared with initial Whey Protein Isolate, the solubility and emulsifying properties were significantly improved. At the same time, glycosylation also inhibited heat-induced aggregation after treated at 80 °C for 20 min. All data showed that pulsed electric field treatment could be applied as a means to prepare WPI–dextran conjugate with better functional properties.
Xiao Jia - One of the best experts on this subject based on the ideXlab platform.
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properties of Whey Protein Isolate dextran conjugate prepared using pulsed electric field
Food Research International, 2011Co-Authors: Weiwei Sun, Xinan Zeng, Xiaoquan Yang, Xiao JiaAbstract:Abstract Effect of pulsed electric field treatment on Whey Protein Isolate–dextran conjugation in aqueous solution via Maillard reaction was investigated. Significant changes in browning intensity, free amino group content and SDS-PAGE profile showed that Whey Protein Isolate–dextran conjugate was successfully formed using pulsed electric field treatment. Moreover, higher pulsed electric field intensity enhanced the extent of glycosylation. Meanwhile, the secondary structure of Whey Protein Isolate had a considerable loss due to the covalent attachment of dextran. The functional properties, such as solubility, emulsifying activity and emulsion stability were also evaluated. Compared with initial Whey Protein Isolate, the solubility and emulsifying properties were significantly improved. At the same time, glycosylation also inhibited heat-induced aggregation after treated at 80 °C for 20 min. All data showed that pulsed electric field treatment could be applied as a means to prepare WPI–dextran conjugate with better functional properties.
