Biological detection technology has developed rapidly in recent years and has attracted much attention in food microbiology testing. Since most foods are derived from animals, plants and other natural organisms, they naturally have the ability to distinguish substances and react. Biotechnology, which uses biological materials to reflect with chemical substances in food to achieve the purpose of testing, shows great application potential in food inspection. It has several advantages like specific biological recognition function, high selectivity, accurate results, high sensitvity, specificity, trace and speediness etc. The more widely used methods include enzyme-linked immunosorbent technology, PCR technology, biosensor technology and biochip technology etc.
Enzyme-linked immu-nosorbent assay (ELISA) is an immunoassay method developed on the basis of immunoenzymology, which combines the high specificity of antigen-antibody reaction and the efficient catalytic action of enzymes. The basic principle is to use the enzyme labeled antigen or enzyme labeled antibody as the main reagent and to treat the substance qualitatively or quantitatively through the enzyme-catalyzed color reaction of the substrate in the complex. It is widely used in the microbiological analysis of food -- pesticide and veterinary drug residues, illegal additives, biological toxins, pathogenic microorganisms, genetically modified food and so on, such as the determination of enrofloxacin, clenbuterol and basophilic and salt-tolerant proteus. ELISA is an useful tool for investigating food-borne disease outbreaks and identifying responding pathogens, which has become a food microbiology testing method with its advantages of strong specificity, high sensitivity, accuracy and speediness.
PCR (polymerase chain reaction) technology, that is polymerase chain reaction technology, is a method of enzymatically synthesizing specific DNA fragments in vitro.
Biosensor is a physical sensor that combines biometric elements with target substances. Due to its high specificity and sensitivity, fast response speed and low cost, it has become an important tool in food testing. It mainly used in the testing of food additives, pathogenic bacteria, pesticides and antibiotics, biological toxins etc., such as the rapid determination of nitrite, salmonella typhimurium, organic phosphate and carbamate, aflatoxin B1 in food. The biochip method is a new microanalysis technology that integrates molecular biotechnology, microprocessing technology, immunology, computer and other technologies. The analysis process is integrated on the chip to achieve the continuity, integration, miniaturization and informatization of sample detection. It can be applied to the detection and analysis of food-borne microorganisms, viruses, drugs, mycotoxins and genetically modified foods in the food microbiological testing.