Detection method for thermoduric bacteria in soybean protein and detection culture medium for thermoduric bacteria

Abstract

The invention relates to a detection method for thermoduric bacteria in soybean protein and a detection culture medium for thermoduric bacteria. The method comprises the following steps: adding a soybean protein sample into sterile saline solution, thereby preparing a soybean protein diluent; boiling the soybean protein diluent and then keeping temperature and heating; quickly cooling to room temperature; uniformly mixing the cooled soybean protein diluent with the detection culture medium for thermoduric bacteria; and culturing for 48h+ / -2h at 36 DEG C+ / -1 and counting the colony count of theculture medium. The detection method provided by the invention is not restrained by soybean protein gelation and is capable of accurately detecting the residual thermoduric bacteria quantity in the soybean protein; the detection method is simple and accurate and the effect is obvious; the culture medium for thermoduric bacteria is simple, the colony characteristics are obvious; the counting is easy, especially for the addition and additive proportion of triphenyltetrazolium chloride; the culture medium is not influenced by the soybean protein gelation; the display for the thermoduric bacteriais obvious; the colony of the thermoduric bacteria can be obviously observed.

Description

Technical field [0001] The invention relates to a method for detecting heat-resistant bacteria in soybean protein and a heat-resistant bacteria detection culture medium, belonging to the technical field of food hygiene detection. Background technique [0002] Heat-resistant bacteria are a type of bacteria that contain spores and survive heat processing. Under suitable conditions, the spores can be activated into nutrients and lead to food spoilage. Heat-resistant bacteria are widely distributed in nature and multiply on vegetables, fruits and other crops. It also contaminates food and beverages made from these crops. However, heat-resistant bacteria have higher heat resistance than other general fungi. Therefore, the detection of heat-resistant bacteria is much more difficult than that of other general fungi. [0003] At present, the commonly used detection methods for heat-resistant bacteria include conventional culture detection methods, molecular biology DNA analysis or 16SrRNA...

AI Technical Summary

Problems solved by technology

Due to the slow growth of heat-resistant bacteria, it takes 4-5 days for the conventional culture detection method to produce the test report, and the lag of the analysis results makes it impossible to guide the production in time

Although DNA analysis or 16SrRNA sequence analysis in molecular biology takes a short time to detect, the cost of detection is high and the detection steps are complicated. Generally, small fruit juice manufacturers will not use this molecular biology analysis method to control the quality of daily production.

[0004] In addition, the current research on heat-resistant bacteria mainly involves acidophilic heat-resistant bacteria in dairy products and fruit juices. The detection methods and reagents are all aimed at liquid food. Because soybean protein has good gelling properties, the existing liquid The method for detection of thermotolerant bacteria in medium or solids is not applicable to soy protein