What are the main testing indicators for food microorganisms?

The total number of bacterial colonies refers to the total number of bacterial colonies contained in the 1g or 1ml sample after the food sample has been processed and cultured under certain conditions. It can reflect the freshness of food, the degree of bacterial contamination, whether the food has deteriorated during the production process and the general hygienic conditions of food production. Therefore, it is one of the important basis for judging the hygienic quality of food.

2. Coliforms

Coliforms include some intermediate types of bacteria including Escherichia coli and Aerobacillus aerogenes. These bacteria are enterobacteria that live in the intestines of humans and warm-blooded animals. They are excreted with the stool. The higher the number of coliform bacteria in food, the greater the degree of fecal contamination of the food. Therefore, it is of broad significance to use coliform bacteria as a hygienic indicator of feces-contaminated food to evaluate the quality of food.

3. Pathogenic bacteria

Pathogenic bacteria are bacteria that can cause illness in people. For different foods and different occasions, certain reference flora should be selected for testing. For example: seafood uses Vibrio parahaemolyticus as the reference flora; eggs and egg products use Salmonella, Staphylococcus aureus, Proteus, etc. as the reference flora; rice and noodle foods use Bacillus cereus, Proteus, and mold etc. as the reference flora, canned food uses heat-resistant spores as the reference flora, etc.

4. Mold and its toxins

Our country has not yet formulated specific indicators for molds. Since many molds can produce toxins and cause diseases, toxin-producing molds should be tested. For example: Aspergillus flavus, Aspergillus parasiticus, etc. of the genus Aspergillus, citrinase and isoenzyme of the genus Penicase, Fusarium moniliforme of the genus Fusarium, Fusarium graminearum, etc.

5. Other indicators

Microbial indicators should also include viruses, hepatitis virus, swine fever virus, Newcastle disease virus, Marek's virus, foot and mouth disease virus, rabies virus, swine vesicular virus, etc.; in addition, from the perspective of food inspection, parasites are also classified as microorganisms by many scholars Inspection indicators: such as Trichinella spiralis, cysticerci, Sarcocystis cystis, roundworms, paragonimiasis, Toxoplasma gondii, mites, Fasciolopsis ginger, Clonorchis sinensis, etc.