淬火温度对琼胶多糖凝胶过程的影响
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摘要
为表征琼胶多糖溶液在淬火后形成凝胶过程中分子构象的变化,提出脉冲梯度场核磁共振技术表征的新手段。通过测量溶液中琼胶多糖分子的质子信号强度和自扩散系数的变化,考察了淬火温度对琼胶多糖形成凝胶过程影响。研究发现,淬火发生30 min内,多糖质子信号强度及自扩散系数都急剧减小,而后在恒温测量(0.5~18 h)期间,多糖质子信号强度进一步减小。在恒温测量(0.5~18 h)期间,当淬火温度接近凝胶转变温度时,琼胶多糖分子的自扩散系数变大,而当淬火温度低于凝胶转变温度时,琼胶多糖的自扩散系数会减小。结果表明:淬火发生后凝胶分两步形成:首先,多糖分子形成聚合物网状结构;其次,随着时间的推移,越来越多的多糖分子进入到聚合物网状结构。如果淬火温度低于凝胶转变温度,体系的变化快而显著。
Changes in the molecular mobility of agar were measured by pulsed-field-gradient stimulated echo(PFGSTE) H NMR after quenching,in order to elucidate the effect of different quenching temperature on gelation in agar solutions.Both the echo signal intensity of agar I_(agar)(0) and the diffusion coefficient of agar D_(agar) showed a steep decrease during the initial cooling stage(in the first ca.30 minutes) and /ag?(0) decreased further with time going by,while D_(agar) increased a little after quenching occurred at around T_(s-g) and decreased a little when quenching temperature was below T.These results suggested that the gelation occurred in two stages:firstly the polysaccharide chains in agar aggregated into bundles to form a network when quenching happened.And then more and more agar chains were involved into the network.Changes became more rapidly and more obviously while the quenching temperatures was below T_(s-g).
Changes in the molecular mobility of agar were measured by pulsed-field-gradient stimulated echo(PFGSTE) H NMR after quenching,in order to elucidate the effect of different quenching temperature on gelation in agar solutions.Both the echo signal intensity of agar I_(agar)(0) and the diffusion coefficient of agar D_(agar) showed a steep decrease during the initial cooling stage(in the first ca.30 minutes) and /ag?(0) decreased further with time going by,while D_(agar) increased a little after quenching occurred at around T_(s-g) and decreased a little when quenching temperature was below T.These results suggested that the gelation occurred in two stages:firstly the polysaccharide chains in agar aggregated into bundles to form a network when quenching happened.And then more and more agar chains were involved into the network.Changes became more rapidly and more obviously while the quenching temperatures was below T_(s-g).
引文
[1]Nussinovitch A.Hydrocolloid applications;gum technology in the food and other industries[M].UK;Chapman&Hall,1997.
[2]薛志欣,杨佳朋,王广策.龙须菜琼胶多糖的提取、纯化与性能表征[J].食品科学,2007(8):174-177.
[3]刘志明,孙清瑞,王欣,等.板蓝根多糖胶冻得研制及其品质评价[J].食品科学,2011,32(8):327-330.
[4]刘俊山,李清华,朱丹实,等.柠檬酸及单糖复合钾离子对大豆种皮多糖凝胶性质的影响[J].食品科学,2015,36(1):27-30.
[5]Zhang H,Nishinari K,Williams M A K,et al.A molecular description of the gelation mechanism of curdlan[J].International Journal of Biological Macromolecules,2002,30:7-16
[6]Yamazaki E,Sago T,Kasubuchi Y,et al.Improvement on the freeze-thaw stability of corn starch gel by the polysaccharide from leaves of Corchorus olitorius[J].Carbohydrate Polymers,2013,94(1):555-560.
[7]Brenner T,Tuvikene R,Fang Y,et al.Rheology of highly elastic iota-carrageenan/kappa-carrageenan/xanthan/konjac glucomannan gels[J].Food Hydrocolloids,2015,44:136-144.
[8]Ngugen B T,Nicolai T,Benyyahia L.Synergistic effects of mixed salt on the gelation of K-carrageenan[J].Carbohydrate Polymers,2014,112:10-15.
[9]曾蓉.核磁共振对温敏性壳聚糖水凝胶机理研究的探索[D].上海:复旦大学,2006.
[10]Matsukawa S,Sagae D,Mogi A.Molecular diffusion in polysaccharide gel systems as observed by NMR[J].Progress in Colloid and Polymer Science,2009,136:171-176.
[11]Okada R,Matsukawa S,Watanabe T.Hydration structure and dynamics in pullulan aqueous solution based on~1 H NMR relaxation time[J].Journal of Molecular Structure,2002,602-603:473483.
[12]Zhang Q J,Matsukawa S,Watanabe T.Theoretical analysis of water H T_2 based on chemical exchange snd polysaccharide mobility during gelation[J].Food Hydrocolloids,2004,18:441-449.
[13]Hills B P,Cano C,Belton P S.Proton NMR relaxation studies of aqueous polysaccharide system[J].Macromolecules,1991,24:2944-2950.
[14]Abeltt S,Lillford P J,Baghdadi S M A,et al.NMR relaxation in polysaccharide gels and film[J].American Chemical Society Symposium Series,1976,34:344-359.
[15]Lewis G P,Derbyshire W,Abeltt S,et al.Investigations of the N.M.R.relaxation of aqueous gels of the carrageenan family and of the effect of ionic content and character[J].Carbohydrate Research,1987,160:397-410.
[16]McConville P,Pope J M.~1H NMR T_2 relaxation in contact lens hydrogels as a probe of water mobility[J].Polymer,2001,42:3559-3568.
[17]Baldursd6ttir S,Kj0niksen A,Nystrdm B.The effect of riboflavinphotoinduced degradation of alginate matrices on the diffusion of poly(oxyethylene)probes in the polymer network[J].European Polymer Journal,2006,42:3050-3058.
[18]Walderhaug H,S?derman O,Topgaard D.Self-diffusion in polymer systems studied by magnetic field-gradient spin-echo NMR methods[J].Progress in Nuclear Magnetic Resonance Spectroscopy,2010,56:406-425.
[19]Dai B,Matsukawa S.NMR Studies of the Gelation Mechanism and Molecular Dynamics in Agar Solutions[J].Food Hydrocolloids,2012,26(1):181-186.
[20]Dai B,Matsukawa S.Elucidation of Gelation Mechanism and Molecular Interactions of Agarose in Solution by~1 H-NMR[J].Carbohydrate Research,2013,365:38-45.
[21]Zhao Q,Matsukawa S.Molecular mobility and microscopic structure changes in K-carrageenan solutions studied by gradient NMR[J].Carbohydrate Polymers,2013,95(1):458-464.
[22]Stejskal E,Tanner J.Spin diffusion measurements:spin echoes in the presence of a time-dependent field gradient[J].Journal of Chemical Physics,1965,42:288-292.
[23]Johnson Jr C.Diffusion ordered nuclear magnetic resonance spectroscopy:principles and applications[J].Progress in Nuclear Magnetic Resonance Spectroscopy,1999,34:203-256.
[2]薛志欣,杨佳朋,王广策.龙须菜琼胶多糖的提取、纯化与性能表征[J].食品科学,2007(8):174-177.
[3]刘志明,孙清瑞,王欣,等.板蓝根多糖胶冻得研制及其品质评价[J].食品科学,2011,32(8):327-330.
[4]刘俊山,李清华,朱丹实,等.柠檬酸及单糖复合钾离子对大豆种皮多糖凝胶性质的影响[J].食品科学,2015,36(1):27-30.
[5]Zhang H,Nishinari K,Williams M A K,et al.A molecular description of the gelation mechanism of curdlan[J].International Journal of Biological Macromolecules,2002,30:7-16
[6]Yamazaki E,Sago T,Kasubuchi Y,et al.Improvement on the freeze-thaw stability of corn starch gel by the polysaccharide from leaves of Corchorus olitorius[J].Carbohydrate Polymers,2013,94(1):555-560.
[7]Brenner T,Tuvikene R,Fang Y,et al.Rheology of highly elastic iota-carrageenan/kappa-carrageenan/xanthan/konjac glucomannan gels[J].Food Hydrocolloids,2015,44:136-144.
[8]Ngugen B T,Nicolai T,Benyyahia L.Synergistic effects of mixed salt on the gelation of K-carrageenan[J].Carbohydrate Polymers,2014,112:10-15.
[9]曾蓉.核磁共振对温敏性壳聚糖水凝胶机理研究的探索[D].上海:复旦大学,2006.
[10]Matsukawa S,Sagae D,Mogi A.Molecular diffusion in polysaccharide gel systems as observed by NMR[J].Progress in Colloid and Polymer Science,2009,136:171-176.
[11]Okada R,Matsukawa S,Watanabe T.Hydration structure and dynamics in pullulan aqueous solution based on~1 H NMR relaxation time[J].Journal of Molecular Structure,2002,602-603:473483.
[12]Zhang Q J,Matsukawa S,Watanabe T.Theoretical analysis of water H T_2 based on chemical exchange snd polysaccharide mobility during gelation[J].Food Hydrocolloids,2004,18:441-449.
[13]Hills B P,Cano C,Belton P S.Proton NMR relaxation studies of aqueous polysaccharide system[J].Macromolecules,1991,24:2944-2950.
[14]Abeltt S,Lillford P J,Baghdadi S M A,et al.NMR relaxation in polysaccharide gels and film[J].American Chemical Society Symposium Series,1976,34:344-359.
[15]Lewis G P,Derbyshire W,Abeltt S,et al.Investigations of the N.M.R.relaxation of aqueous gels of the carrageenan family and of the effect of ionic content and character[J].Carbohydrate Research,1987,160:397-410.
[16]McConville P,Pope J M.~1H NMR T_2 relaxation in contact lens hydrogels as a probe of water mobility[J].Polymer,2001,42:3559-3568.
[17]Baldursd6ttir S,Kj0niksen A,Nystrdm B.The effect of riboflavinphotoinduced degradation of alginate matrices on the diffusion of poly(oxyethylene)probes in the polymer network[J].European Polymer Journal,2006,42:3050-3058.
[18]Walderhaug H,S?derman O,Topgaard D.Self-diffusion in polymer systems studied by magnetic field-gradient spin-echo NMR methods[J].Progress in Nuclear Magnetic Resonance Spectroscopy,2010,56:406-425.
[19]Dai B,Matsukawa S.NMR Studies of the Gelation Mechanism and Molecular Dynamics in Agar Solutions[J].Food Hydrocolloids,2012,26(1):181-186.
[20]Dai B,Matsukawa S.Elucidation of Gelation Mechanism and Molecular Interactions of Agarose in Solution by~1 H-NMR[J].Carbohydrate Research,2013,365:38-45.
[21]Zhao Q,Matsukawa S.Molecular mobility and microscopic structure changes in K-carrageenan solutions studied by gradient NMR[J].Carbohydrate Polymers,2013,95(1):458-464.
[22]Stejskal E,Tanner J.Spin diffusion measurements:spin echoes in the presence of a time-dependent field gradient[J].Journal of Chemical Physics,1965,42:288-292.
[23]Johnson Jr C.Diffusion ordered nuclear magnetic resonance spectroscopy:principles and applications[J].Progress in Nuclear Magnetic Resonance Spectroscopy,1999,34:203-256.