Analysis method for nondestructive test of water activity of white wine yeast by low field nuclear magnetism

Abstract

The invention discloses an analysis method for nondestructive test of water activity of white wine yeast by low field nuclear magnetism, and belongs to the technical field of analytical chemistry. According to the method, firstly a standard equation between the actual water activity of a sample and a first peak point value of an attenuation curve obtained by detecting a sample by a low field nuclear magnetism method is established; when a to-be-tested sample is detected, firstly, the first peak point value of the attenuation curve of a large-curvature sample is obtained by detecting a sample by a low field nuclear magnetism method, and then the obtained first peak point value is substituted into the standard equation, so as to obtain the water activity of the to-be-tested sample. The method disclosed by the invention lays a foundation for rapid, nondestructive and online detection of sample water activity.

Description

technical field [0001] The invention belongs to the technical field of analytical chemistry, and in particular relates to an analysis method for the nondestructive detection of the water activity of liquor koji by low-field nuclear magnetic resonance. Background technique [0002] "Qu is the bone of wine", and Daqu plays a vital role in the production of sauce-flavored and Luzhou-flavored liquors. The purpose of its preparation is mainly to provide multi-functional bacterial strains, multi-enzyme systems, various flavor substances and their precursors for liquor fermentation, and also serve as part of raw materials. In the production process of Daqu, bacteria and yeast first grow inside the block, so that the temperature of the center of the koji rises, and the heat and water disperse to form a surface layer suitable for mold growth, and the mold begins to grow on the outer layer; then, with the distribution of water, Mold grows endogenously, and the curved surface graduall...

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Problems solved by technology

According to the principle of nuclear magnetic resonance spectroscopy, the relaxation signal is related to the number of spin nuclei. Although there have been some reports on the determination of the oil and water content of grain particles, these reports are only for small-volume raw materials and focus on the detection of water content. It is not suitable for detecting the water activity of relatively large volumes of koji or other samples

Although there are also methods for detecting water activity in the prior art, the detection is relatively slow, especially for samples with low water content, which often takes several minutes to tens of minutes; the detection system is also relatively small, generally only tens of milliliters of samples, and the average It is destructive, and the sample needs to be pulverized for detection. This process may cause changes in water activity, which limits its application range.

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