大豆分离蛋白溶液/乳液酸化过程的微观流变学研究
|
摘要
首次通过粒子示踪微流变学结合宏观流变学方法研究了大豆分离蛋白(SPI)溶液及其稳定的乳液酸化过程中微观/宏观流变学性质的变化。宏观流变学研究表明:酸化过程中,SPI溶液和乳液体系的黏弹模量均先增大后减小,SPI溶液经历了溶液(G″>G′)-凝胶(G′>G″)-解凝(G″>G′)的过程,而SPI乳液则一直存在一定的黏弹性结构,表现为G′>G″;微观流变学结果显示,示踪粒子在SPI溶液和乳液体系酸化过程中的均方位移(MSD)均先减小后增大,MSD的幂指数最终均小于1;酸化时间较长时,示踪粒子的连续位移均呈负相关性,且乳液强于溶液。上述结果说明SPI溶液酸化过程中,蛋白质先聚集后解聚,而酸化过程后期,体系仍存在一定的蛋白质聚集体;SPI乳液酸化过程中,体系在最初状态存在一定的乳滴聚集体,之后形成蛋白质和乳滴双重聚集体,体系的黏弹性更强,在酸化过程后期,体系仍存在较强的未完全解聚的乳滴和蛋白质的聚集体。本研究结果说明了微观流变学与宏观流变学的互补性。
In this research, the microrheology and macrorheology of the soybean protein isolate(SPI) solution and the emulsion stabilized by SPI were first studied by particle tracking and bulk-rheology techniques. The macrorheology results show that the viscoelastic moduli of SPI solution and SPI emulsion increased first and then decreased during the acidification process. The SPI solution has gone through solution(G′>G″)-gel(G″>G′)-network decomposition(G″>G′) process, while the SPI emulsion has viscolastic structure with G′>G″ during the whole acidification process. The microrheology results show that the mean squared displacement(MSD) of the tracer particles embedded in the SPI solution and the SPI emulsion decreased first and then increased, and the power-law index of MSD was both smaller than 1 at the end of acidification. In the late stage of the acidification process, the successive displacement of the tracer particles is negatively correlated, and the correlation of the emulsion is stronger than that of the solution. The above results indicate that proteins first aggregate and then decompose in the acidification process of SPI solution, but in the late stage of acidification, a certain amount of protein aggregates still exist in the system. While in the acidification of SPI emulsion,the system has a certain amount of droplet aggregation in the initial state and then forms a double network structure of proteins and droplets with stronger viscoelasticity. But in the late stage of acidification, strong unresolved droplet and protein aggregates still exist. This research has reflected the complementarity of microrhology and macrorheology methods.
In this research, the microrheology and macrorheology of the soybean protein isolate(SPI) solution and the emulsion stabilized by SPI were first studied by particle tracking and bulk-rheology techniques. The macrorheology results show that the viscoelastic moduli of SPI solution and SPI emulsion increased first and then decreased during the acidification process. The SPI solution has gone through solution(G′>G″)-gel(G″>G′)-network decomposition(G″>G′) process, while the SPI emulsion has viscolastic structure with G′>G″ during the whole acidification process. The microrheology results show that the mean squared displacement(MSD) of the tracer particles embedded in the SPI solution and the SPI emulsion decreased first and then increased, and the power-law index of MSD was both smaller than 1 at the end of acidification. In the late stage of the acidification process, the successive displacement of the tracer particles is negatively correlated, and the correlation of the emulsion is stronger than that of the solution. The above results indicate that proteins first aggregate and then decompose in the acidification process of SPI solution, but in the late stage of acidification, a certain amount of protein aggregates still exist in the system. While in the acidification of SPI emulsion,the system has a certain amount of droplet aggregation in the initial state and then forms a double network structure of proteins and droplets with stronger viscoelasticity. But in the late stage of acidification, strong unresolved droplet and protein aggregates still exist. This research has reflected the complementarity of microrhology and macrorheology methods.
引文
[1]WAIGH A T. Microrheology of complex fluids[J].Reports on Progress in Physics, 2005, 68(3):685-742.
[2]WAIGH A T. Advances in the microrheology of complex fluids[J]. Reports on Progress in Physics,2016, 79(7):074601.
[3]FURST E M. Applications of laser tweezers in complex fluid rheology[J]. Current Opinion in Colloid&Interface Science, 2005, 10(1/2):79-86.
[4]DHOLAKIA K, SPALDING G, MACDONALD M.Optical tweezers:the next generation[J]. Physics World, 2002, 15(10):31-35.
[5]VLAMINCK I D, DEKKER C. Recent advances in magnetic tweezers[J]. Annual Review of Biophysics,2012, 41(1):453-472.
[6]BAUSCH A R, WINFRIED M, SACKMANN E.Measurement of local viscoelasticity and forces in living cells by magnetic tweezers[J]. Biophysical Journal, 1999, 76(1):573-579.
[7]BRASOVS A, C?MURS J,?RGLIS K, et al. Magnetic microrods as a tool for microrheology[J]. Soft Matter, 2015, 11(13):2563-2569.
[8]CORRIGAN A M, DONALD A M. Passive Microrheology of solvent-induced fibrillar protein network[J]. Langmuir, 2009, 25(15):8599-8605.
[9]BRU P, BRUNEL L, FLEURY M, et al. Passive microrheology:non contact measurement of viscoelastic properties of biopolymers[J]. Tech Connect Briefs, 2011, 1:36-40.
[10]YANG N, LV R, JIA J, et al. Application of microrheology in food science[J]. Annual Review of Food Science and Technology, 2017, 8(1):493-521.
[11]WONG I Y, GARDEL M L, REICHMAN D R, et al. Anomalous diffusion probes microstructure dynamics of entangled F-actin networks[J]. Physical Review Letters, 2004, 92(17):178101.
[12]CAMPBELL L J, GU X, DEWAR S J, et al. Effects of heat treatment and glucono-δ-lactone-induced acidification on characteristics of soy protein isolate[J]. Food Hydrocolloids, 2009, 23(2):344-351.
[13]SCHULDT S, RAAK N, JAROS D, et al. Acid-induced formation of soy protein gels in the presence of NaCl[J]. LWT-Food Science and Technology,2014, 57(2):634-639.
[14]顾振宇,江美都,付道才,等.大豆分离蛋白乳化性的研究[J].中国粮油学报, 2000, 15(3):32-35.
[15]刘付.凝胶样蛋白稳定乳液的形成、流变性能及微结构研究[D].广州:华南理工大学, 2011.
[16]邵云.大豆蛋白稳定乳液的物化性质及油脂氧化稳定性研究[D].广州:华南理工大学, 2014.
[17]TORNBERG E. Functional characterization of protein stabilized emulsions:creaming stability[J]. Journal of Food Science, 1978, 43(5):1559-1562.
[18]CROCKER J C, Grier D G. Methods of digital video microscopy for colloidal studies[J]. Journal of Colloid and Interface Science, 1996, 179(1):298-310.
[19]SAVIN T, DOYLE P S. Static and dynamic errors in particle tracking microrheology[J]. Biophysical Journal, 2005, 88(1):623-638.
[20]MASON T G, WEITZ D A. Optical measurements of frequency-dependent linear viscoelastic moduli of complex fluids[J]. Physical Review Letters, 1995, 74(7):1250.
[21]MASON T G, GANG H, WEITZ D A. Rheology of complex fluids measured by dynamic light scattering[J]. Journal of Molecular Structure, 1996, 383(1/2/3):81-90.
[22]MASON T G, GANESAN K, VANZANTEN J H,et al. Particle tracking microrheology of complex fluids[J]. Physical Review Letters, 1997, 79(17):3282-3285.
[23]MASON T G. Estimating the viscoelastic moduli of complex fluids using the generalized Stokes-Einstein equation[J]. Rheological Acta, 2000, 39(4):371-378.
[24]MOSCHAKIS T. Microrheology and particle tracking in food gels and emulsions[J]. Current Opinion in Colloid&Interface Science, 2013, 18(4):311-332.
[2]WAIGH A T. Advances in the microrheology of complex fluids[J]. Reports on Progress in Physics,2016, 79(7):074601.
[3]FURST E M. Applications of laser tweezers in complex fluid rheology[J]. Current Opinion in Colloid&Interface Science, 2005, 10(1/2):79-86.
[4]DHOLAKIA K, SPALDING G, MACDONALD M.Optical tweezers:the next generation[J]. Physics World, 2002, 15(10):31-35.
[5]VLAMINCK I D, DEKKER C. Recent advances in magnetic tweezers[J]. Annual Review of Biophysics,2012, 41(1):453-472.
[6]BAUSCH A R, WINFRIED M, SACKMANN E.Measurement of local viscoelasticity and forces in living cells by magnetic tweezers[J]. Biophysical Journal, 1999, 76(1):573-579.
[7]BRASOVS A, C?MURS J,?RGLIS K, et al. Magnetic microrods as a tool for microrheology[J]. Soft Matter, 2015, 11(13):2563-2569.
[8]CORRIGAN A M, DONALD A M. Passive Microrheology of solvent-induced fibrillar protein network[J]. Langmuir, 2009, 25(15):8599-8605.
[9]BRU P, BRUNEL L, FLEURY M, et al. Passive microrheology:non contact measurement of viscoelastic properties of biopolymers[J]. Tech Connect Briefs, 2011, 1:36-40.
[10]YANG N, LV R, JIA J, et al. Application of microrheology in food science[J]. Annual Review of Food Science and Technology, 2017, 8(1):493-521.
[11]WONG I Y, GARDEL M L, REICHMAN D R, et al. Anomalous diffusion probes microstructure dynamics of entangled F-actin networks[J]. Physical Review Letters, 2004, 92(17):178101.
[12]CAMPBELL L J, GU X, DEWAR S J, et al. Effects of heat treatment and glucono-δ-lactone-induced acidification on characteristics of soy protein isolate[J]. Food Hydrocolloids, 2009, 23(2):344-351.
[13]SCHULDT S, RAAK N, JAROS D, et al. Acid-induced formation of soy protein gels in the presence of NaCl[J]. LWT-Food Science and Technology,2014, 57(2):634-639.
[14]顾振宇,江美都,付道才,等.大豆分离蛋白乳化性的研究[J].中国粮油学报, 2000, 15(3):32-35.
[15]刘付.凝胶样蛋白稳定乳液的形成、流变性能及微结构研究[D].广州:华南理工大学, 2011.
[16]邵云.大豆蛋白稳定乳液的物化性质及油脂氧化稳定性研究[D].广州:华南理工大学, 2014.
[17]TORNBERG E. Functional characterization of protein stabilized emulsions:creaming stability[J]. Journal of Food Science, 1978, 43(5):1559-1562.
[18]CROCKER J C, Grier D G. Methods of digital video microscopy for colloidal studies[J]. Journal of Colloid and Interface Science, 1996, 179(1):298-310.
[19]SAVIN T, DOYLE P S. Static and dynamic errors in particle tracking microrheology[J]. Biophysical Journal, 2005, 88(1):623-638.
[20]MASON T G, WEITZ D A. Optical measurements of frequency-dependent linear viscoelastic moduli of complex fluids[J]. Physical Review Letters, 1995, 74(7):1250.
[21]MASON T G, GANG H, WEITZ D A. Rheology of complex fluids measured by dynamic light scattering[J]. Journal of Molecular Structure, 1996, 383(1/2/3):81-90.
[22]MASON T G, GANESAN K, VANZANTEN J H,et al. Particle tracking microrheology of complex fluids[J]. Physical Review Letters, 1997, 79(17):3282-3285.
[23]MASON T G. Estimating the viscoelastic moduli of complex fluids using the generalized Stokes-Einstein equation[J]. Rheological Acta, 2000, 39(4):371-378.
[24]MOSCHAKIS T. Microrheology and particle tracking in food gels and emulsions[J]. Current Opinion in Colloid&Interface Science, 2013, 18(4):311-332.