【作者】 布丽君；

【导师】 李志西；

【作者基本信息】 西北农林科技大学 ， 粮食、油脂及植物蛋白工程， 2008， 硕士

【摘要】 紫外光谱指纹技术是一种新型的检测技术,具有灵敏度高、重现性好、稳定性强、操作便捷、适用范围广、成本低等特点,已广泛应用于中草药等领域的快速检测。紫外光谱指纹技术在发酵液态制品检测中的应用尚未见报道,将其应用于发酵液态制品的品质检测及质量控制具有重要意义。本研究以食醋、酱油以及酒类等发酵液态制品为研究对象,应用旋转蒸发以及紫外光谱曲线扫描等技术手段得到其紫外光谱曲线,对不同样品紫外光谱曲线之间的特性进行分析,建立了紫外光谱技术检测发酵液态制品的新方法,并通过对紫外光谱曲线进行相似度分析进一步研究了该方法的可靠性,初步建立了发酵液态制品紫外光谱指纹鉴定技术体系,主要研究内容包括:①建立发酵液态制品紫外光谱指纹鉴定的规范化操作规程;②紫外光谱指纹的特异性研究;③紫外光谱指纹的重现性研究;④紫外光谱指纹的稳定性研究;⑤杀菌处理对紫外光谱指纹的影响;⑥未杀菌食醋陈化期间的光谱指纹特性研究。取得了以下研究结果:(1)发酵液态制品紫外光谱指纹鉴定的规范化操作规程为:食醋按醋∶水=1∶6的比例稀释后在温度为45℃、真空度为0.0925Mpa的条件下旋转蒸发,馏出液以4.5g/100mL冰醋酸的水溶液为参比,在245nm～330nm的波长范围内扫描紫外吸收曲线;酱油按酱油∶水=1∶6的比例稀释后在温度为45℃、真空度为0.0925Mpa的条件下旋转蒸发,馏出液以蒸馏水为参比,在190nm～330nm的波长范围内扫描紫外吸收曲线;白酒以45%的无水乙醇水溶液为参比,在245nm～330nm的波长范围内扫描紫外吸收曲线;葡萄酒按酒∶水=1∶1的比例稀释后在温度为50℃、真空度为0.0925Mpa的条件下旋转蒸发,馏出液以蒸馏水为参比,在190nm～240nm的波长范围内扫描紫外吸收曲线。(2)经过杀菌处理的样品在不同保藏期内紫外光谱曲线相似度均在0.930以上,说明曲线基本不变化,稳定性好;而未经杀菌处理的样品在不同保藏期内紫外光谱曲线相似度均在0.860以下,说明曲线变异幅度大,稳定性差。未经杀菌的产品不能作为商品销售,指纹技术对非商品产品不适用。(3)未杀菌岐山香醋在不同陈化时段随时间的延长其紫外光谱曲线逐渐上移,抗氧化能力也逐渐增加;GC-MS测定结果表明,岐山香醋成分检测中酸类、酮类和酯类含量随着陈化期的延长缓慢下降,醇类、醛类、吡嗪类、恶唑类和呋喃类含量略有上升。陈化期的岐山香醋紫外光谱的变化、抗氧化能力的增强与其物质成分变化有一定关系。(4)食醋、酱油、白酒和葡萄酒的紫外光谱指纹特性的研究结果表明,不同样品的紫外光谱曲线有明显的特异性;同一样品在相同的条件下得到的紫外光谱曲线具有良好的重现性;同一样品在不同贮藏时段得到的紫外光谱曲线具有很强的稳定性,说明发酵液态制品的紫外光谱曲线具有典型的指纹特征。本研究所建立的指纹技术是一种用于发酵液态制品真伪鉴别和品种检测的有效手段。更多还原

【Abstract】 The fingerprint technique of ultraviolet(UV) spectrum is a new test technology and has been widely applied to many fields such as chinese herbal medicine as a rapid detection method with the characteristics of high sensitivity, good reproducibility and stability, convenient operation, extensive application, low cost etc. The application of fingerprint of UV spectrum to control and test the quality of liquid fermentation production has important significance and not been seen. Vinegar, soy sauce and liquor were used as the materials in the research, The rotary evaporator and UV-spectrophotometer were used to get the UV spectrum. The new method was found through the analysis of different UV spectrums. At the same time, The similarity of UV spectrums was used to determinate the reliability of the new method. The UV spectrum fingerprint identification system of fermented liquid products was preliminary established. The important contents of the research were as follows.①Found the standardized operations of the method.②Studied on the specific of the fingerprint of UV spectrum.③Researched on the reproducibility of the fingerprint of UV spectrum.④Studied on the stability of the fingerprint of UV spectrum.⑤Researched on the effect of sterilization dispose to the fingerprint of UV spectrum.⑥Studied on the characteristics of the fingerprint of UV spectrum of an unsterilized vinegar in its post-maturation. The results were as follows:(1)The standardized operation of the detection was: Dilution ratio of vinegar was vinegar : water=1 : 6, rotary evaporated the diluent at temperature 45℃, vacuum degree 0.0925MPa, use 4.5g/100mL acetic acid solution as the reference fluid scanned the UV spectrum of the distillate at the wavelength between 245nm and 330nm; Dilution ratio of soy sauce was soy sauce : water=1 : 6, rotary evaporated the diluent at temperature 45℃, vacuum degree 0.0925MPa, used distilled water as the reference fluid scanned the UV spectrum of the distillate at the wavelength between 190nm and 330nm;Use 45% ethanol water solution as the reference fluid scanned the UV spectrum of liquor at the wavelength between 245nm and 330nm;Dilution ratio of wine was wine : water=1 : 1, rotary evaporated the diluent at temperature 50℃, vacuum degree 0.0925MPa, use distilled water as the reference fluid scanned the UV spectrum of the distillate at the wavelength between 190nm and 240nm;(2)The similarities of the UV spectrum of the sample which was sterilized in different storage periods were more than 0.930,the result show that the stability of the UV spectrum was very good. But the similarities of the UV spectrum of the sample which was unsterilized in different storage periods were less than 0.860.the stability of the UV spectrum was bad. The product which was unsterilized couldn’t sale as commodity, The technology of fingerprint of UV spectrum wasn’t suitable for the product which wasn’t commodity.(3)The UV spectrum of unsterilized Qishan vinegar was upward displacement gradually with the storage time in different post- maturation periods, the antioxidant ability also increased with the storage time. The result of GC-MS testing show that the content of acids, ketones and esters was decreased gradually, the content of alcohols,aldehydes, pyrazines, oxazoles and furans was increased slowly. There were relationships among the changes of the UV spectrum of Qishan vinegar in the post- maturation periods, the antioxidant ability and the change of the material composition.(4)The research on the fingerprint characteristics of UV spectrum of vinegar, soy sauce, liquor and wine show that there were obviously specific on the UV spectrum among different samples; The reproducibility of the UV spectrums which produced by the same sample under the same condition were very good; The stability of the UV spectrums which produced by the same sample at different preservation periods were also good. All of the results suggested that the UV spectrums of fermentation liquid products had fingerprint characteristics typically. The fingerprint technology established in the research was an effective method to identity and test the liquid products of fermentation.更多还原