不同发酵时间奶酪光谱学性质的差异性分析

Difference analysis of spectral properties of cheese at different fermentation times

中文关键词:  发酵时间  奶酪  光谱性质  差异性

英文关键词:fermentation time  cheese  spectral properties  difference

中文摘要:

      目的 探究发酵时间对奶酪产品营养组分和光谱学性质的影响规律。方法 采用理化分析、质构、紫外光谱、核磁共振、红外光谱等技术, 对不同发酵期的2种奶酪产品(25 d和50 d)的主要组分和光谱学性质进行了分析比较。结果 与25 d奶酪相比, 50 d奶酪产品中的水分、脂肪、蛋白质及可溶性糖含量呈极显著降低(P<0.01), 而硬度、咀嚼性呈极显著增加(P<0.01)。傅里叶变换红外光谱法分析表明2种奶酪的吸收峰存在差异, 与蛋白质结构有关。核磁共振法分析表明发酵初期奶酪的自由水大量流失, 后期以结合水为主。此外, 不同溶剂提取液的紫外-可见吸收光谱法分析结果表明分级提取法下乙酸乙酯提取液中存在吸收峰差异, 与α, β-不饱和酸、酯或酰胺等物质有关, 而分别提取法下石油醚提取液存在吸收峰差异, 与风味物质饱和醛类化合物有关。结论 不同发酵期奶酪的光谱性质具有差异性, 可以作为评价奶酪发酵期的特征指标。

英文摘要:

      Objective To study the influence rule of fermentation time on nutritional components and spectroscopic properties of cheese products. Methods The main components and spectroscopic properties of 2 kinds of cheese products (25 day and 50 day) in different fermentation periods were analyzed and compared by physical and chemical analysis, texture, ultraviolet spectrum, nuclear magnetic resonance, infrared spectrum. Results Compared with 25 day cheese, the content of water, fat, protein and soluble sugar in 50 day cheese products decreased significantly (P<0.01), while the hardness and chewiness increased significantly (P<0.01). The analysis results of Fourier transform infrared spectrum showed that the absorption peaks of the 2 kinds of cheeses were different, which was related to the structure of protein. The analysis results of nuclear magnetic resonance analysis showed that the free water of cheese was largely lost in the early stage of fermentation, and the bound water was dominant in the later stage. In addition, the analysis results of ultraviolet visible absorption spectra of different solvent extracts showed that there were differences in absorption peaks in ethyl acetate extracts by hierarchical extraction method, which were related to α, β-unsaturated acids, esters or amides, while there were differences in absorption peaks in petroleum ether extracts by separate extraction methods, which were related to saturated aldehydes of flavor substances. Conclusion The spectral properties of cheese in different fermentation periods are different, which can be used as a characteristic index for evaluating cheese fermentation period.