Ferulic acid inclusion complexes(FA-HP-β-CD)effects on tyramine accumulation and gene expression of Enterobacter hormaechei MW386398 in traditional smoked horsemeat sausages were studied.Reverse transcription-quantit...Ferulic acid inclusion complexes(FA-HP-β-CD)effects on tyramine accumulation and gene expression of Enterobacter hormaechei MW386398 in traditional smoked horsemeat sausages were studied.Reverse transcription-quantitative polymerase chain reaction(RT-qPCR)was used to identify the expression of tyrosine decarboxylase(TDC)clusters in the tyramine producing pathway.In addition,relevant parameters such as microbial growth,moisture content,pH,and tyramine accumulation in pure cultures and during fermentation of smoked horsemeat sausages were evaluated.Ferulic acid(FA)and FA-HP-β-CD inclusion complexes both significantly decreased tyramine accumulation,as well as significantly inhibited tyrosine decarboxylase(tdcA)and tyrosine/tyramine antiporter(tyrP)genes expression(p<0.05).Furthermore,FA and FA-HP-β-CD inclusion complexes both reduced the number of Enterobacteriaceae in smoked horsemeat sausages,but did not alter the main microbiota.However,FA-HP-β-CD inclusion complexes exhibited stronger ability in hindering TDC related gene expression,reducing tyramine accumulation and antibacterial properties.These results indicate that FA-HP-β-CD inclusion complexes are able to reduce tyramine accumulation in smoked horsemeat sausages by inhibiting Enterobacteriaceae growth and gene expression.展开更多
Covalent complexes of bovine bone proteins(BBP)with four polyphenols(chlorogenic acid(CA),quercetin(Q),rutin(R),epigallocatechin gallate(EGCG))with were prepared to increase the high-value utilization degree of bovine...Covalent complexes of bovine bone proteins(BBP)with four polyphenols(chlorogenic acid(CA),quercetin(Q),rutin(R),epigallocatechin gallate(EGCG))with were prepared to increase the high-value utilization degree of bovine bone.The differences in coupling effect and structural and functional properties between the conjugates were also investigated.The results showed that EGCG-BBP had the highest polyphenolic equivalent at 88.05 mg/g protein and the lowest sulfhydryl group content.EGCG-BBP also had the best covalent effect.The SDS-PAGE and fluorescence spectra results revealed that the molecular weight of the conjugates increased significantly as different polyphenols conjugated with the aromatic amino acids in BBP,resulting in significant changes in the structure of EGCG-BBP.Fourier Transform infrared spectroscopy(FTIR)analysis demonstrated that the amide I band of conjugates was slightly shifted,indicating that the polyphenols were covalently bonded with BBP.Based on the results of this study and well-established mechanisms,it could be speculated that the best covalent effect of EGCG may be not only due to the eight phenolic hydroxyl groups but also to its two benzene rings,which are greatly increased in its reaction site.In terms of functional characteristics,EGCG-BBP had the highest 1-diphenyl-2-picryl-hydrazyl radical(DPPH·)scavenging capacity,while Q-BBP had the best solubility.Thus,this study provides a theoretical basis for different polyphenols’structural and functional effects on covalently modified proteins.展开更多
基金This work was supported by grants from the National Natural Science Foundation of China(No.32060547)the key science and technology research projects of Xinjiang production and construction team(No.2020AB012).
文摘Ferulic acid inclusion complexes(FA-HP-β-CD)effects on tyramine accumulation and gene expression of Enterobacter hormaechei MW386398 in traditional smoked horsemeat sausages were studied.Reverse transcription-quantitative polymerase chain reaction(RT-qPCR)was used to identify the expression of tyrosine decarboxylase(TDC)clusters in the tyramine producing pathway.In addition,relevant parameters such as microbial growth,moisture content,pH,and tyramine accumulation in pure cultures and during fermentation of smoked horsemeat sausages were evaluated.Ferulic acid(FA)and FA-HP-β-CD inclusion complexes both significantly decreased tyramine accumulation,as well as significantly inhibited tyrosine decarboxylase(tdcA)and tyrosine/tyramine antiporter(tyrP)genes expression(p<0.05).Furthermore,FA and FA-HP-β-CD inclusion complexes both reduced the number of Enterobacteriaceae in smoked horsemeat sausages,but did not alter the main microbiota.However,FA-HP-β-CD inclusion complexes exhibited stronger ability in hindering TDC related gene expression,reducing tyramine accumulation and antibacterial properties.These results indicate that FA-HP-β-CD inclusion complexes are able to reduce tyramine accumulation in smoked horsemeat sausages by inhibiting Enterobacteriaceae growth and gene expression.
基金The authors are grateful for the financial support by Xinjiang Production and Construction Corps Scientific and Technological Research Projects(2020AB012).
文摘Covalent complexes of bovine bone proteins(BBP)with four polyphenols(chlorogenic acid(CA),quercetin(Q),rutin(R),epigallocatechin gallate(EGCG))with were prepared to increase the high-value utilization degree of bovine bone.The differences in coupling effect and structural and functional properties between the conjugates were also investigated.The results showed that EGCG-BBP had the highest polyphenolic equivalent at 88.05 mg/g protein and the lowest sulfhydryl group content.EGCG-BBP also had the best covalent effect.The SDS-PAGE and fluorescence spectra results revealed that the molecular weight of the conjugates increased significantly as different polyphenols conjugated with the aromatic amino acids in BBP,resulting in significant changes in the structure of EGCG-BBP.Fourier Transform infrared spectroscopy(FTIR)analysis demonstrated that the amide I band of conjugates was slightly shifted,indicating that the polyphenols were covalently bonded with BBP.Based on the results of this study and well-established mechanisms,it could be speculated that the best covalent effect of EGCG may be not only due to the eight phenolic hydroxyl groups but also to its two benzene rings,which are greatly increased in its reaction site.In terms of functional characteristics,EGCG-BBP had the highest 1-diphenyl-2-picryl-hydrazyl radical(DPPH·)scavenging capacity,while Q-BBP had the best solubility.Thus,this study provides a theoretical basis for different polyphenols’structural and functional effects on covalently modified proteins.
