微波辐照泸州国窖白酒体系介电谱及氢键分析

Complex Dielectric Spectra and Hydrogen Bond Association Analysis of Baijiu after Microwave Irradiation

为了研究微波辐照对泸州国窖白酒催陈中氢键缔合的影响。用小功率微波发生装置对3组不同浓度白酒进行定时恒温辐照,测量其反射系数并演算复介电谱。用1HN+2D介电弛豫模型对白酒复介电谱参数拟合。结果表明,乙醇浓度为43%vol的白酒的介电常数虚部减少是因为微波辐照破坏了白酒体系整体氢键网络,而个体氢键的寿命变短;乙醇浓度为52%vol的白酒经微波辐照后的介电常数虚部几乎没有变化,其慢驰豫时间随温度的升高先小幅增大后小幅减小,其代表个体氢键断裂与形成的快驰豫时间几乎没有发生波动;乙醇浓度为60%vol的白酒经微波辐照后,介电常数虚部增大,加速了其整体氢键网络的重排,个体氢键寿命随温度的升高先小幅下降后又增大。研究为微波催陈白酒,水与乙醇的氢键网络体系分析研究提供了积极的参考。

In order to study the effects of microwave irradiation on the hydrogen bond association in Luzhou Guojiao Baijiu during artificial aging,three groups of Baijiu samples with different ethanol concentrations were irradiated by using low-power microwave generator at constant temperature and regular time.The reflection coefficients were measured and the complex dielectric spectra were calculated.1HN+2D dielectric relaxation model was used to fit the parameters of the complex dielectric spectra.The results showed that,the imaginary part of the dielectric constant of 43%vol Baijiu was reduced because the whole hydrogen bond network was destroyed by microwave irradiation,and the individual hydrogen bond life was shortened;the imaginary part of the dielectric constant of 52%vol Baijiu hardly changed after microwave irradiation,its slow relaxation time first increased slightly and then decreased slightly with the increase of temperature,and the fast relaxation time of individual hydrogen bond fracture and formation hardly fluctuated;the imaginary part of the dielectric constant of 60%vol Baijiu increased,accelerating the rearrangement of its overall hydrogen bond network,and the individual hydrogen bond life decreased slightly at first and then increased with the increase of temperature.The study has provided reference for the study of the hydrogen bond network in Baijiu,and the artificial aging of Baijiu by microwave irradiation.