In recent years, food safety and quality issues have received increasing attention. The foods mentioned here are foods in a broad sense, including primary agricultural products such as grain, oilseeds, vegetables, aquatic products, livestock and poultry products, fruits, etc., as well as processed foods such as canned food, ham sausage, and edible food. Oil, instant noodles, pickles, condiments, etc. There are also more and more laboratories conducting food testing. In these laboratories, due to different natures, the testing items are different, and there are different requirements for the purchase and selection of instruments in the process of laboratory preparation and development.
The food inspection department is divided into two major items, one is to test the quality of the product; the other is to test the product's health project, the detection of this type of project is relatively difficult and high investment.
(1) Quality items include:
Moisture, salt content, sugar content, protein content, fat content, fiber content, vitamin content, acidity, and the like. For the testing of these items, if the funds are limited, chemical analysis can be used. It is only necessary to prepare the simplest oven, water bath, electric furnace, agitator, pulverizer, pH meter and other equipment.
If the funds are sufficient or there are more inspection batches, the corresponding testing items have corresponding special instruments available for purchase. In addition, there are some general-purpose instruments available for purchase, such as UV/Vis spectrophotometer, near-infrared analyzer, and automatic titrator. Fluorescence photometers are sometimes required to detect vitamins A and E. To detect nutrients such as calcium, zinc, iron, etc., an atomic absorption meter-flame detector can be purchased.
(2) Health projects include:
Microorganisms, additives, harmful elements, pesticide residues, veterinary drug residues, toxins, etc. For general food companies, microbiological testing laboratories should be built.
The microbiology laboratory should be constructed in accordance with the requirements of the biological laboratory standards. The necessary equipments include clean benches, incubators, autoclaves, electric stoves, etc. Other equipment is configured according to specific test items. If you have less money, you can buy it domestically. If you have more money, you can consider buying it. The price difference between the two is quite different.
b) Additives and harmful elements:
Some projects can use chemical methods such as nitrite, sulfur dioxide, heavy metal content, total arsenic, etc., but to meet the current national food hygiene requirements, you should purchase a gas chromatograph-hydrogen flame detector, liquid chromatography-ultraviolet/ A visible light detector, such as a general preservative (benzoic acid, sorbic acid, etc.), a sweetener (sodium cyclamate, sodium saccharin, etc.), a pigment (lemon yellow, carmine, etc.) can be detected. Purchase of atomic absorption spectrometer - graphite furnace detector, can detect harmful elements such as lead, chromium, cadmium, copper, nickel, etc., and also need an atomic fluorescence instrument to detect arsenic and mercury.
c) Residual pesticides
Gas chromatography for the detection of residual pesticides is essential. For the detection of organochlorine pesticides, an electron capture ECD detector is required. For the detection of organophosphorus pesticides, a flame photometric FPD detector or a nitrogen-phosphorus NPD detector is required. Nowadays, there are more and more projects for pesticide residue detection. To improve versatility, it is recommended to install a capillary column split/splitless inlet and install a capillary column. Compared with traditional packed columns, capillary column analysis projects have many separations and can reduce frequent column changes and improve analysis efficiency. There are more and more pesticide residues to be tested when exporting food processing enterprises. In order to control the quality of raw materials and products, gas chromatography-mass spectrometry can be configured. Generally, it is only necessary to formulate an electron bombardment EI source. If necessary, a negative chemical NCI source can be used. It is a four-stage mass spectrometer or an ion trap mass spectrometer. Personally, it can be used. Both instruments have advantages and disadvantages. Still depends on the specific work.
d) Residual veterinary drugs:
If the detection of residual veterinary drugs is carried out, there are not many items and there are many batches. It is conceivable to prepare an enzyme-linked immunosorbent instrument. The instrument has little input at a time, is easy to operate, and has high detection sensitivity. There are some disadvantages to using ELISA. First, the kit is a long-term consumable. If the batch is small, the cost will be higher. Second, the specificity is not good, there may be false positives. Third, if it is for a relatively long period of time. There are many internal testing items, and the cost is even higher than the instrument analysis. For export food enterprises with a certain scale, in order to meet the current limit requirements of the European Union, the United States, Japan and other developed countries, it is best to prepare a liquid chromatography-tandem mass spectrometer. The first instrument is recommended to be equipped with a triple quadrupole mass spectrometer with high sensitivity and good reproducibility. The instrument does not have to pursue high configuration, enough to use, but the sensitivity, stability, anti-pollution and other performance is better. It is best to buy a model with more users, and a user group similar to the one that is tested by itself. First, it indicates that there is no problem in the project to be tested by this type of instrument, and secondly, it is also convenient for future technical exchanges.