FTIR光谱法整体评价蜂王浆新鲜度的研究

测定了在不同温度下经过不同时间贮存后的蜂王浆的FTIR光谱，以新采收蜂王浆的红外谱图为参考标准谱，利用光谱比对软件进行了一系列的相关分析。结果表明：不同贮存条件下的蜂王浆红外光谱图中酰胺Ⅰ带(1 700～1 600 cm-1)波段的相关系数和相对峰强度I_{1 647}/I_{1 541}，I_{1 647}/I_{1 409}，I_{1 647}/I_{1 247}和I_{1 647}/I_{1 054}都随着蜂王浆贮存时间延长和温度升高而降低，且与贮存时间存在着良好的线性关系，变化幅度顺序为28＞16＞4＞-18 ℃。因此，初步选定红外光谱图中酰胺Ⅰ带的相关系数和4个相对峰强度(I_{1 647}/I_{1 541}，I_{1 647}/I_{1 409}、I_{1 647}/I_{1 247}和I_{1 647}/I_{1 054})作为新鲜度的评价指标，相关系数的阈值设定为0.910 0，4个相对峰强度的阈值分别设定为1.744，2.430，3.345和1.412。只要有1个或多个指标低于相应的阈值，可初步判定此蜂王浆是不新鲜的。该方法利用FTIR光谱法并结合计算机辅助解析技术能从宏观上、整体和快速地评价蜂王浆的新鲜度。

Research on Overall Assessment of Royal Jelly Freshness by FTIR Spectroscopy

Fourier transform infrared spectra (FTIR) of royal jelly (RJ) stored at different temperature and after different stor-age periods were measured, a series of correlation analysis among the spectra were carried out by using the spectra of new-har-vested RJ as a standard. The results showed that the correlation coefficient of amidc band I and the relative intensity ratios of I_(1647)/I_(1541), I_(1647)/I_(1409), I_1647/I_1247 and I_(1647)/I_(1054) of RJ samples' spectra decreased with extension of storage time and tempera-ture, and existed good linear correlations with the storage time, with the order of their change extent being 28 ℃＞16 ℃＞4 ℃＞-18℃. According to the spectra change laws and practical experiences of RJ storage, the correlation coefficient of amide band I and four relative intensity ratios I_(1647)/I_(1541), I_(1647)/I_(1409), I_(1647)/I_(1247) and I_(1647) /I_(1054) were selected as assessment indexes of RJ freshness. The threshold value of correlation coefficient was set to be 0. 910 0, and the threshold values of the four relative intensity ratios were set to be 1. 744, 2. 430, 3. 345 and 1. 412 respectively. Once one or more indexes are lower than the corre-sponding threshold values, the RJ sample can be considered as a stale sample. So, FTIR spectroscopy combined with several da-ta-processing methods would be an effective method for overall assessing the freshness of RJ.