本研究旨在探讨原花青素-铁网络涂层包裹乳酸菌后对发酵黑莓汁的影响。通过原花青素(Pc)与铁离子反应生成金属-多酚网络,将其包裹植物乳植杆菌BC17形成BC17@Pc-Fe保护结构,并应用于发酵黑莓汁中,研究原花青素-铁包裹乳酸菌后对黑莓汁发...本研究旨在探讨原花青素-铁网络涂层包裹乳酸菌后对发酵黑莓汁的影响。通过原花青素(Pc)与铁离子反应生成金属-多酚网络,将其包裹植物乳植杆菌BC17形成BC17@Pc-Fe保护结构,并应用于发酵黑莓汁中,研究原花青素-铁包裹乳酸菌后对黑莓汁发酵过程中的活菌数、总糖、还原糖、总酚、花色苷、pH、总酸以及抗氧化能力的影响。结果表明,包裹后的BC17的粒径由1990±156 nm增加至5560±901 nm,所带电荷由-13.77±1.44 mV增加至-4.05±1.48 mV;扫描电子显微镜研究显示,由原花青素和铁离子构成的金属-多酚网络成功包裹BC17。在发酵黑莓汁过程中,BC17@Pc-Fe组的活菌数能达到7.59±0.03 lg CFU/mL,显著(P<0.05)高于BC17组的活菌数(6.64±0.03 lg CFU/mL),其总糖和还原糖含量、总酚和花色苷含量与BC17组相比分别升高了13.29%±2.81%和6.49%±1.01%、4.47%±2.02%和33.96%±4.26%。同时,与BC17组相比,BC17@Pc-Fe组pH降低了2.72%±0.01%、总酸含量升高了4.60%±0.03%。经过抗氧化能力评估,BC17@Pc-Fe组的DPPH自由基清除率、ABTS+自由基清除率、·OH清除率以及亚铁离子还原能力比BC17组分别提高19.33%±2.94%、29.17%±2.82%、12.31%±7.22%和11.31%±0.03%,原花青素-铁网络涂层包裹BC17可以有效提高黑莓发酵汁的抗氧化能力。本研究通过改善乳酸菌生长和发酵性能来提升黑莓发酵汁的品质,为乳酸菌发酵果汁类产品提供了新思路。展开更多
The first example of Nd@C_(3)N_(4)-photoredox/chlorine dual catalyzed alkylation with unactivated alkanes as the alkyl sources has been developed,which allows for the synthesis of various 4-alkylated cyclic sulfonyl k...The first example of Nd@C_(3)N_(4)-photoredox/chlorine dual catalyzed alkylation with unactivated alkanes as the alkyl sources has been developed,which allows for the synthesis of various 4-alkylated cyclic sulfonyl ketimines.In this process,chlorine functions as both a redox and hydrogen atom transfer catalyst.The synergism of the reversible Nd^(2+)/Nd^(3+)and Cl^(ˉ)/Cl˙redox pairs significantly enhances overall photocatalytic efficiency.The in vitro anticancer activity of 4-alkylated products was evaluated by using the CCK8assay against both human choroidal melanoma(MUM-2B)and lung cancer(A549)cell.Compound 3da showed approximately triple the potency of 5-fluorouracil.展开更多
In the cooling crystallization process of thiourea,a significant issue is the excessively wide crystal size distribution(CSD)and the abundance of fine crystals.This investigation delves into the growth kinetics and me...In the cooling crystallization process of thiourea,a significant issue is the excessively wide crystal size distribution(CSD)and the abundance of fine crystals.This investigation delves into the growth kinetics and mechanisms governing thiourea crystals during the cooling crystallization process.The fitting results indicate that the crystal growth rate coefficient,falls within the range of 10^(-7)to 10^(-8)m·s^(-1).Moreover,with decreasing crystallization temperature,the growth process undergoes a transition from diffusion-controlled to surface reaction-controlled,with temperature primarily influencing the surface reaction process and having a limited impact on the diffusion process.Comparing the crystal growth rate,and the diffusion-limited growth rate,at different temperatures,it is observed that the crystal growth process can be broadly divided into two stages.At temperatures above 25℃,1/qd(qd is diffusion control index)approaches 1,indicating the predominance of diffusion control.Conversely,at temperatures below 25℃,1/qd increases rapidly,signifying the dominance of surface reaction control.To address these findings,process optimization was conducted.During the high-temperature phase(35-25℃),agitation was increased to reduce the limitations posed by bulk-phase diffusion in the crystallization process.In the low-temperature phase(25-15℃),agitation was reduced to minimize crystal breakage.The optimized process resulted in a thiourea crystal product with a particle size distribution predominantly ranging from 0.7 to 0.9 mm,accounting for 84%of the total.This study provides valuable insights into resolving the issue of excessive fine crystals in the thiourea crystallization process.展开更多
文摘本研究旨在探讨原花青素-铁网络涂层包裹乳酸菌后对发酵黑莓汁的影响。通过原花青素(Pc)与铁离子反应生成金属-多酚网络,将其包裹植物乳植杆菌BC17形成BC17@Pc-Fe保护结构,并应用于发酵黑莓汁中,研究原花青素-铁包裹乳酸菌后对黑莓汁发酵过程中的活菌数、总糖、还原糖、总酚、花色苷、pH、总酸以及抗氧化能力的影响。结果表明,包裹后的BC17的粒径由1990±156 nm增加至5560±901 nm,所带电荷由-13.77±1.44 mV增加至-4.05±1.48 mV;扫描电子显微镜研究显示,由原花青素和铁离子构成的金属-多酚网络成功包裹BC17。在发酵黑莓汁过程中,BC17@Pc-Fe组的活菌数能达到7.59±0.03 lg CFU/mL,显著(P<0.05)高于BC17组的活菌数(6.64±0.03 lg CFU/mL),其总糖和还原糖含量、总酚和花色苷含量与BC17组相比分别升高了13.29%±2.81%和6.49%±1.01%、4.47%±2.02%和33.96%±4.26%。同时,与BC17组相比,BC17@Pc-Fe组pH降低了2.72%±0.01%、总酸含量升高了4.60%±0.03%。经过抗氧化能力评估,BC17@Pc-Fe组的DPPH自由基清除率、ABTS+自由基清除率、·OH清除率以及亚铁离子还原能力比BC17组分别提高19.33%±2.94%、29.17%±2.82%、12.31%±7.22%和11.31%±0.03%,原花青素-铁网络涂层包裹BC17可以有效提高黑莓发酵汁的抗氧化能力。本研究通过改善乳酸菌生长和发酵性能来提升黑莓发酵汁的品质,为乳酸菌发酵果汁类产品提供了新思路。
基金supported by grants from the Provincial Natural Science Foundation of Hunan(No.2023JJ60335)。
文摘The first example of Nd@C_(3)N_(4)-photoredox/chlorine dual catalyzed alkylation with unactivated alkanes as the alkyl sources has been developed,which allows for the synthesis of various 4-alkylated cyclic sulfonyl ketimines.In this process,chlorine functions as both a redox and hydrogen atom transfer catalyst.The synergism of the reversible Nd^(2+)/Nd^(3+)and Cl^(ˉ)/Cl˙redox pairs significantly enhances overall photocatalytic efficiency.The in vitro anticancer activity of 4-alkylated products was evaluated by using the CCK8assay against both human choroidal melanoma(MUM-2B)and lung cancer(A549)cell.Compound 3da showed approximately triple the potency of 5-fluorouracil.
基金supported by Priority Academic Program Development of Jiangsu Higher Educatior(PPZY2015A044).
文摘In the cooling crystallization process of thiourea,a significant issue is the excessively wide crystal size distribution(CSD)and the abundance of fine crystals.This investigation delves into the growth kinetics and mechanisms governing thiourea crystals during the cooling crystallization process.The fitting results indicate that the crystal growth rate coefficient,falls within the range of 10^(-7)to 10^(-8)m·s^(-1).Moreover,with decreasing crystallization temperature,the growth process undergoes a transition from diffusion-controlled to surface reaction-controlled,with temperature primarily influencing the surface reaction process and having a limited impact on the diffusion process.Comparing the crystal growth rate,and the diffusion-limited growth rate,at different temperatures,it is observed that the crystal growth process can be broadly divided into two stages.At temperatures above 25℃,1/qd(qd is diffusion control index)approaches 1,indicating the predominance of diffusion control.Conversely,at temperatures below 25℃,1/qd increases rapidly,signifying the dominance of surface reaction control.To address these findings,process optimization was conducted.During the high-temperature phase(35-25℃),agitation was increased to reduce the limitations posed by bulk-phase diffusion in the crystallization process.In the low-temperature phase(25-15℃),agitation was reduced to minimize crystal breakage.The optimized process resulted in a thiourea crystal product with a particle size distribution predominantly ranging from 0.7 to 0.9 mm,accounting for 84%of the total.This study provides valuable insights into resolving the issue of excessive fine crystals in the thiourea crystallization process.
