胶原多肽对白酒中4 种醛类物质的反应机理

通过紫外光谱、荧光光谱以及三维荧光光谱研究胶原多肽与白酒中糠醛、苯甲醛、乙醛、异戊醛的分子作用机理，为健康白酒的发展提供了理论依据。紫外吸收光谱表明，胶原多肽在198 nm波长处的吸收峰强度随糠醛和苯甲醛浓度的增大而增大；当乙醛和异戊醛浓度较低时，胶原多肽的紫外吸收未发生明显变化，而当乙醛和异戊醛浓度较高时，胶原多肽在198 nm波长处的吸收峰强度增加，且分别在波长约为280 nm和290 nm处产生了一个强度逐渐增加的新吸收峰。通过荧光光谱分析发现，白酒中的糠醛、苯甲醛、乙醛和异戊醛均对胶原多肽有明显的荧光猝灭现象，糠醛和苯甲醛表现为静态猝灭，而乙醛和异戊醛表现为动态猝灭；热力学计算表明，糠醛和苯甲醛与胶原多肽是以疏水作用力结合，且结合位点数约为1自发进行的反应。三维荧光光谱显示，4 种醛类物质与胶原多肽发生相互作用的强弱顺序为：糠醛＞苯甲醛＞异戊醛＞乙醛。顶空固相微萃取结合气相色谱-质谱联用分析结果表明，胶原多肽能够降低浓香型白酒中醛类物质的含量。

Reaction Mechanism of Collagen Peptide with Four Aldehydes in Chinese Liquor

In order to provide basic theoretical data for the healthy development of Chinese liquor(Baijiu),we studied the molecular mechanism of the interactions between collagen peptides and four aldehydes in Chinese liquor,furfural,benzaldehyde,acetaldehyde and isovaleraldehyde using ultraviolet-visible(UV-vis)spectroscopy,fluorescence spectroscopy and three-dimensional fluorescence spectroscopy.UV-vis absorption spectra indicated that the intensity of the absorption peak of collagen polypeptide at 198 nm was increased with increasing concentrations of furfural and benzaldehyde.Meanwhile,there was no significant change with acetaldehyde and isovaleraldehyde at lower concentrations.However,the absorption intensity was increased at higher concentrations of acetaldehyde and isovaleraldehyde,and new absorption peaks with increasing intensity were generated at wavelengths of about 280 nm and 290 nm respectively.Furthermore,fluorescence spectral analysis corroborated that all four aldehydes had obvious fluorescence quenching on collagen peptides,statically for furfural and benzaldehyde,and dynamically for acetaldehyde and isovaleraldehyde.Thermodynamic calculation revealed that furfural and benzaldehyde bound to collagen peptides predominately by hydrophobic interaction with about one binding site;the binding process was spontaneous.In addition,three-dimensional fluorescence spectral analysis suggested that the binding strengths between the four aldehydes and collagen peptide decreased in the order of furfural>benzaldehyde>isovaleraldehyde>acetaldehyde.Finally,the results of headspace solid-phase microextraction(HS-SPME)combined with gas chromatography-mass spectrometry(GC-MS)analysis showed that collagen peptide could reduce the content of aldehydic components in strong-flavor Chinese Baijiu.