Import Natamycin,Detect Residue

There are various methods for detecting the residual amount of natamycin in food. Here are some common detection methods:

1. High - performance Liquid Chromatography (HPLC)

Principle: Natamycin is separated based on the difference in its distribution coefficient between the stationary phase and the mobile phase, and then its content is detected by a detector.

Operation steps: Firstly, the food sample is pretreated, such as being crushed, extracted, and purified to obtain a sample solution suitable for analysis. The sample solution is injected into the high - performance liquid chromatograph. The mobile phase carries the sample through the chromatographic column to separate natamycin from other impurities. Then, the peak area or peak height of natamycin is detected at a specific wavelength by an ultraviolet detector or a diode array detector. By comparing it with the standard curve, the residual amount of natamycin in the sample is calculated.

Advantages: It has the advantages of good separation effect, high sensitivity, and strong accuracy. It can simultaneously detect the residual amount of natamycin in various foods and is one of the widely used detection methods at present.

Disadvantages: The instrument and equipment are expensive, the operation requirements are high, and the analysis cost is relatively high.

2. Thin - Layer Chromatography (TLC)

Principle: The sample solution is spotted on a thin - layer plate. Natamycin is separated by adsorption and distribution on the thin - layer plate, and then it is developed with a developer. By comparing it with the standard sample, the content of natamycin is determined.

Operation steps: After the food sample is extracted and purified, the sample solution and the natamycin standard solution are respectively spotted on a silica - gel thin - layer plate. The thin - layer plate is placed in the developing solvent for development to separate natamycin on the thin - layer plate. After the development is completed, the thin - layer plate is taken out, dried, and developed with a developer. By observing the color and position of the sample spot and the standard sample spot, the content of natamycin in the sample is estimated. It can also be quantitatively analyzed by scanning the spot with a thin - layer scanner.

Advantages: It is simple to operate, has a low cost, does not require complex instrument and equipment, and can handle multiple samples simultaneously.

Disadvantages: Its sensitivity is relatively low, and its accuracy is not as good as that of high - performance liquid chromatography. It may not be ideal for the detection of low - content natamycin residues.

3. Enzyme - Linked Immunosorbent Assay (ELISA)

Principle: Based on the principle of specific binding of antigen - antibody, natamycin is used as an antigen to prepare the corresponding antibody, and the natamycin in the sample is detected by enzyme - labeled antibody.

Operation steps: The natamycin antigen is immobilized on the enzyme - labeled plate. The sample solution and the enzyme - labeled antibody are added. The natamycin in the sample competes with the antigen immobilized on the plate to bind the antibody. Then, the substrate solution is added. The enzyme catalyzes the substrate to develop color. The absorbance is measured by an enzyme - labeled instrument, and the residual amount of natamycin in the sample is calculated according to the standard curve.

Advantages: It has high sensitivity, strong specificity, is easy and quick to operate, and is suitable for the screening and detection of a large number of samples.

Disadvantages: It requires the preparation of specific antibodies. The cost of the kit is high, and there may be cross - reactions. The pretreatment requirements for the samples are high.