Application of casein plate method in quantitative analysis of protease activity

Abstract

The invention discloses application of a casein plate method in quantitative analysis of protease activity. According to the application, the casein plate method is utilized for detecting the activityof protease in colored food, it is shown through a result that the casein plate method is good in linear relationship, good in precision and repeatability and low in detection limit, and a result ofdetection for the activity of the protease in a colored sample is accurate, and a new method is provided for detection for the protease activity. The application has the advantages that the situationcan be effectively avoided that due to the sample has a too deep color, errors are caused, and a detection result is inaccurate, there are no requirements for the color and shape of the sample, the casein plate method can be applied to detection for light-color samples or colorless samples and can also be applied to detection for deep-color samples such as red pitaya, and the method is simple to implement, wide in application range and capable of meeting the general detection requirements. The casein plate method can be effectively applied to detection for the activity of enzymes in deep-colorproducts such as soy sauce and tea leaves.

Description

technical field [0001] The invention relates to the technical field of protease activity detection, in particular to a method for preparing perilla sauce by a mixed-bacteria fermentation method. Background technique [0002] Proteolytic enzyme, referred to as protease, is an enzyme that hydrolyzes proteins. It is a group of large and complex enzyme molecules with highly specific proteolytic functions. Catabolism. Protease activity analysis is an important step in the research and application of protease. Based on protease-induced substrate cleavage strategies, although colorimetric and fluorometric methods have been widely developed in protease activity assays, overlapping optical signals and complicated chemical labeling processes limit the application of the methods. Protease activity has been detected using fluorescence methods, but methods based on calorimetric techniques, radioactivity, immunoassays, electrophoresis, amperometric, optical, etc. have also been reported...

AI Technical Summary

Problems solved by technology

The detection results of these methods are accurate, but the detection results are prone to errors when detecting colored foods, mainly because the ultraviolet spectrophotometer uses the principle of light scattering, and when the color of the sample is too dark, the absorbance value is too large, resulting in errors

The principle of measuring protease activity by Folin’s phenol method is: use casein as a substrate, measure the amount of amino acids produced after reacting with the sample for a period of time, and then calculate the protease activity of the sample. The disadvantage of this method is that there are many factors affecting the reaction system. If it contains citric acid, glycerin, glycine, Tris buffer, hyaluronic acid, dithiothreitol, mercaptoethanol, ethylenediaminetetraacetic acid (EDTA) and urea and other substances, it will cause interference; and it is affected by protein The impact of specificity, and the color intensity of different proteins is slightly different due to the content of tyrosine and tryptophan, and the measurement results are prone to errors

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