Conventional Food Additive Testing Methods

Food additives are chemical synthetic substances or natural substances added in the food production process to improve the color and flavor of food, and food additives can also improve the anti-corrosion ability of food, which plays a very important role in food production.

At present, most of the food additives used in China's food production are synthetic additives, and the more commonly used food additives are mainly sweeteners, colorants, color-protecting reagent, preservatives, bleach, antioxidants, thickening agents, and stabilizers, etc., if excessive use will cause a certain impact on the human body. In the 1980s, China made clear provisions on the scope and dosage of some food additives.

1. Detection method of molecular spectrum technology

Molecular spectroscopy is very common in conventional food additive detection methods, which uses molecular absorption of specific electromagnetic radiation to carry out a qualitative and quantitative analysis. This detection technology can detect the concentration of various food additives in flour, such as benzoyl peroxide, and the detection method is to use a portable spectrometer to detect the concentration of iodine in flour, iodine can be calculated benzoyl peroxide concentration through the concentration.

2. Chromatographic technology detection method

Food additive chromatography technology detection method is also a routine detection method, which mainly uses high performance liquid chromatography - diode array detector to detect food additives. The detection of hydroxybenzoate by chromatographic technology is mainly for the content of hydroxybenzoate. The hydroxybenzoate extracted by acetonitrile is detected by diode array detector. Another technique of chromatography is to use capillary micellar electrokinetic chromatography to detect food additives. The detection method is to separate the neutral solute from the dot component by using the hydrophobic core in the flow buffer.

3. Chromatographic technology detection method

This technology includes the high separation ability of liquid chromatography for complex samples, but also includes a unique technology of choosing mass spectrometry, which shows a strong analytical ability in the detection of food additives, can accurately obtain analytical results, and is widely used in the determination of food additives. Using the detection method of color mass coupling technology, more than ten kinds of banned food additives in wine can be detected in a relatively short time through the steps of gradient elution, separation and detection of food additives.

4. Gas chromatography detection method

Gas chromatography is one of the more mature chromatography methods, which is often used for the detection of food additives. The main principle is to vaporize the sample to be tested, and then separate it by N2 carrier gas through the fixed phase, and detect it by the corresponding detector, common detectors are: FID, NPD, TCD and ECD. Dehydroacetic acid, benzoic acid and sorbic acid in food were determined by gas chromatographic hydrogen flame method. The results showed that the recovery rate of these preservatives was 96%~104%. Gas chromatography is fast and suitable for daily chemical analysis.

5. Biosensor technology detection methods

The application of biotechnology is also reflected in the detection of food additives, where biotechnology uses biosensors for detection. In the sensor, due to the existence of biometric components and signal converters, complex food additive samples can be selected excellently, and has a high sensitivity to different components,. The composition of food additives can be analyzed accurately through rapid and continuous detection, so it has a wide range of applications in the biological process food industry and other fields.

6. High performance liquid chromatography method

In the detection of food additives, high performance liquid chromatography is widely used in the laboratory for the detection of food additives, the pH value of the tested solution needs to be adjusted before the detection, the impurities in the solution are removed after filtration, and the method of constant volume film is used for determination. If it is to test fruit juice, it is necessary to adjust the pH value of the tested solution to 6, and then use a certain amount of polyamide powder to stir fully, use methanol or formic acid solution to eliminate the natural pigment in the tested solution, until the tested solution is washed to neutral by removing ammonia, and then carry out the constant volume membrane test.