蜂王浆不同贮存条件下蛋白质二级结构的Fourier变换红外光谱研究

蜂王浆的质量与贮存时间和温度相关。测定了在不同温度下经过不同时间贮存后的蜂王浆Fourier变换红外光谱，应用去卷积和曲线拟合方法对蜂王浆的酰胺Ⅰ带进行分析，以期得到其蛋白质二级结构的组成。结果表明：这些蜂王浆之间存在明显而有规律的光谱差异，蛋白质二级结构的组成之间也存在显著差异。随着贮存时间增加和温度升高，蜂王浆蛋白质二级结构的α-螺旋和β-折叠分别显著减少和增加，β-转角也有增加的趋势，其变化幅度为28 ℃＞16 ℃＞4 ℃＞-18 ℃。这些结果与蜂王浆应该低温保存的理论相符。FTIR红外光谱结合去卷积、二阶导数和曲线拟合方法是评价蜂王浆品质和新鲜度的一种有效方法。

FTIR Assessment of the Secondary Structure of Proteins in Royal Jelly under Different Storage Conditions

The quality of royal jelly has a high positive correlation with its storage periods and temperature. In the present paper, Fourier transform infrared spectra (FTIR) of royal jelly was measured with different temperatures and storage periods, and the compositions of the secondary structure of protein were determined by curve-fitting analysis of the amide Ⅰ bands in the FTIR spectra. The results showed that the spectral differences were observed among these types of samples, the composition of the secondary structures of protein exhibited extreme difference, and the rate of α-helix decreased and β-sheet increased dramatically with the increase in storage temperature and periods. The content of β-turn also tended to increase, and the order of their change extent was 28 ℃＞16 ℃＞4 ℃＞-18 ℃. These results met the theory that royal jelly should be kept under lower temperature. So, FTIR spectroscopy combined with several data-processing methods, such as secondary derivative, deconvolution, and curve fitting would be an effective method for assessing the quality and freshness of royal jelly.