【目的】探讨pH对猪肉肌原纤维蛋白热诱导凝胶保水性及水的移动性影响。【方法】从猪肉中提取肌原纤维蛋白,用低场NMR(nuclear magnetic resonance)研究pH对肌原纤维蛋白热诱导凝胶中水的T2弛豫性质的影响。同时用离心法测量pH对肌原纤...【目的】探讨pH对猪肉肌原纤维蛋白热诱导凝胶保水性及水的移动性影响。【方法】从猪肉中提取肌原纤维蛋白,用低场NMR(nuclear magnetic resonance)研究pH对肌原纤维蛋白热诱导凝胶中水的T2弛豫性质的影响。同时用离心法测量pH对肌原纤维蛋白凝胶保水性(water holding capacity,WHC)影响。【结果】NMR结果拟合后得到水有4个组分,合并为对应水的3种状态即不可移动水、可移动水和自由水。随着pH升高,pH偏离肌原纤维蛋白的等电点(pI),代表可移动水的T2弛豫时间显著增加,其所占峰的面积和凝胶的WHC也随之增加。主成分分析结果发现,处于等电点附近的样品在样品评分图上与其它pH样品显著不同。【结论】凝胶保水性的增加主要是可移动水的增加,凝胶WHC增加的原因可能是肌原纤维凝胶后孔径增加,从而可以容纳更多的水。展开更多
用低场核磁共振(NMR)研究了微生物转谷氨酰酶(MTG)对猪肉肌原纤维蛋白凝胶质子核磁共振弛豫行为的影响。研究结果显示,NMR结果拟合后得到的水有4个组分,合并为对应水的3种状态即结合水、不易流动水和自由水。和对照相比,加酶处理后显著...用低场核磁共振(NMR)研究了微生物转谷氨酰酶(MTG)对猪肉肌原纤维蛋白凝胶质子核磁共振弛豫行为的影响。研究结果显示,NMR结果拟合后得到的水有4个组分,合并为对应水的3种状态即结合水、不易流动水和自由水。和对照相比,加酶处理后显著降低了猪肉肌原纤维蛋白热诱导凝胶的自旋-自旋弛豫时间(T2)。加入2 U.g-1剂量的MTG后,T22b值(对应于不易流动水)由226 m s(峰值)降低到188 m s。然而,当酶浓度增加时,T22b没有进一步降低。对衰减NMR信号拟合结果进行主成分分析显示,前两个主成分可以解释变异方差的80%,并且加酶和对照在样品评分图上显著分开。加入MTG后,凝胶中水质子的移动性显著下降。展开更多
Studying the skin care efficacy of recombinant humanized collagen based on in vitro level.The stability of the recombinant humanized collagen was first analyzed by treating at different temperatures,then its skincare ...Studying the skin care efficacy of recombinant humanized collagen based on in vitro level.The stability of the recombinant humanized collagen was first analyzed by treating at different temperatures,then its skincare efficacy based on in vitro level was evaluated by detecting the inhibition rate of elastase,the inhibition rate of collagenase,the protein content of type I collagen in human fibroblasts,the inhibition of reactive oxygen species(ROS)with human keratinocytes,and the effects of the recombinant humanized collagen on the expression of hyaluronic acid(HA),filaggrin(FLG)and transglutaminase 1(TGM1)in keratinocytes.The results showed that recombinant humanized collagen was able to maintain stability at temperatures below 70℃.With regard to its skincare efficacy,recombinant humanized collagen could inhibit elastase and collagenase activities and promote the increase of type I collagen content in human fibroblasts.It also showed good inhibition of ROS in keratinocytes in vitro and could increase the expression of HA,FLG,and TGM1 in keratinocytes.In short,the recombinant humanized collagen exhibited a favourable skin care effect in vitro level.This study proved that it has potential firming,anti-wrinkle,moisturizing,and repairing efficacy,and is a valuable cosmetic raw material.展开更多
文摘【目的】探讨pH对猪肉肌原纤维蛋白热诱导凝胶保水性及水的移动性影响。【方法】从猪肉中提取肌原纤维蛋白,用低场NMR(nuclear magnetic resonance)研究pH对肌原纤维蛋白热诱导凝胶中水的T2弛豫性质的影响。同时用离心法测量pH对肌原纤维蛋白凝胶保水性(water holding capacity,WHC)影响。【结果】NMR结果拟合后得到水有4个组分,合并为对应水的3种状态即不可移动水、可移动水和自由水。随着pH升高,pH偏离肌原纤维蛋白的等电点(pI),代表可移动水的T2弛豫时间显著增加,其所占峰的面积和凝胶的WHC也随之增加。主成分分析结果发现,处于等电点附近的样品在样品评分图上与其它pH样品显著不同。【结论】凝胶保水性的增加主要是可移动水的增加,凝胶WHC增加的原因可能是肌原纤维凝胶后孔径增加,从而可以容纳更多的水。
文摘用低场核磁共振(NMR)研究了微生物转谷氨酰酶(MTG)对猪肉肌原纤维蛋白凝胶质子核磁共振弛豫行为的影响。研究结果显示,NMR结果拟合后得到的水有4个组分,合并为对应水的3种状态即结合水、不易流动水和自由水。和对照相比,加酶处理后显著降低了猪肉肌原纤维蛋白热诱导凝胶的自旋-自旋弛豫时间(T2)。加入2 U.g-1剂量的MTG后,T22b值(对应于不易流动水)由226 m s(峰值)降低到188 m s。然而,当酶浓度增加时,T22b没有进一步降低。对衰减NMR信号拟合结果进行主成分分析显示,前两个主成分可以解释变异方差的80%,并且加酶和对照在样品评分图上显著分开。加入MTG后,凝胶中水质子的移动性显著下降。
文摘Studying the skin care efficacy of recombinant humanized collagen based on in vitro level.The stability of the recombinant humanized collagen was first analyzed by treating at different temperatures,then its skincare efficacy based on in vitro level was evaluated by detecting the inhibition rate of elastase,the inhibition rate of collagenase,the protein content of type I collagen in human fibroblasts,the inhibition of reactive oxygen species(ROS)with human keratinocytes,and the effects of the recombinant humanized collagen on the expression of hyaluronic acid(HA),filaggrin(FLG)and transglutaminase 1(TGM1)in keratinocytes.The results showed that recombinant humanized collagen was able to maintain stability at temperatures below 70℃.With regard to its skincare efficacy,recombinant humanized collagen could inhibit elastase and collagenase activities and promote the increase of type I collagen content in human fibroblasts.It also showed good inhibition of ROS in keratinocytes in vitro and could increase the expression of HA,FLG,and TGM1 in keratinocytes.In short,the recombinant humanized collagen exhibited a favourable skin care effect in vitro level.This study proved that it has potential firming,anti-wrinkle,moisturizing,and repairing efficacy,and is a valuable cosmetic raw material.
