葡萄酒的低场核磁共振弛豫谱.docxVIP

*葡萄酒的低场核磁共振弛豫谱彦1，2 ，刘青2 ，蹇华丽1 ，杨幼慧1李( 1．华南农业大学食品学院，广东 广州 510642;2． 广东检验检疫技术中心食品实验室，广东 广州 510623)摘 要: 低场 1 H － 核磁共振弛豫可以有效地测量食品中水分、油脂和酒精等组分，葡萄酒中水 O-H 基和乙醇C-H 基是产生共振弛豫谱的物理基础。采用 CPMG 方法和反转—恢复技术分别得到葡萄酒核磁共振横向弛豫和 纵向弛豫曲线，并使用连续谱迭代方法与离散谱拟合分析获得核磁共振弛豫谱。通过添加去离子水或 95% 食用 酒精配制不同酒精含量样品，由谱峰面积占比变化确定弛豫谱峰的归属。研究发现，T2 谱中弛豫时间较长的谱 峰反映了酒精的含量，且其峰面积占比随酒精体积浓度变化呈线性递增关系。随机抽样的实验结果表明，1 H － 核磁共振弛豫谱具有普适性，从而可建立基于 T2 谱的葡萄酒酒精度测量技术。关键词: 核磁共振; 弛豫谱; 葡萄酒; 酒精度中图分类号: O571. 23文献标志码: A文章编号: 0529 － 6579 ( 2012)05 － 0045 － 05Low-Field NMR Relaxation Spectrum of WineLI Yan1，2 ，LIU Qing2 ，JIAN Huali1 ，YANG Youhui1( 1． College of Food Science，South China Agricultural University，Guangzhou 510642，China;2． Food Testing Laboratory，Guangdong Inspection and Quarantine Technology Center，Guangzhou 510623，China)Abstract: As low field 1 H-NMR relaxation can effectively measure water，fat and alcohol content infoods，O-H in water and C-H in alcohol are the physical basic for resonance relaxation spectrum of wine． CPMG and inversion-recovery technique were applied to respectively obtain the transverse relaxation and longitudinal relaxation of the wine samples，and then the resonance relaxation spectrum was acquired by the continuous spectrum iteration as well as discrete spectrum fitting analysis． The samples were treated into certain proportions by adding deionized water or 95% edible alcohol． According to the variation of peak area ratio，the assignments of two relaxation peaks were determined． The study found that in trans- verse relaxation spectrum，the peak with a longer relaxation time reflected the alcohol content，and its ar- ea proportion had a positive linear correlation with alcohol concentration． In addition，random samples verified the universality of resonance relaxation spectrum and therefore，based on T 2 spectrum，a newmeasuring technique for wine alcohol content can be built up．Key words: Nuclear magnetic resonance; relaxation spectrum; wine; alcohol content核磁共振是指在外磁场中物质原子核自旋磁矩与磁场相互作用产生原子能级精细结构，