Exploring the secrets of rice testing: guarding the safety line of staple food on the table

Rice is the staple food of more than half of the world's population, and its safety is related to public health. With the development of agricultural modernization, the number of links from rice planting to circulation has increased, and the risk of food safety has also increased. Rice testing can strictly control each link to ensure that every grain of rice meets safety standards.
1. Testing items
Pesticide residue detection
Organophosphorus, carbamate and other pesticides used in rice planting, if used improperly or if the safety interval is not reached before harvest, will cause excessive pesticide residues in rice. Long-term consumption will damage the human nervous system and endocrine system. For example, my country has strict standards for the residue of highly toxic methyl parathion in rice, which requires precise detection by gas chromatography-mass spectrometry.
Heavy metal detection
Rice may absorb heavy metals such as cadmium, lead, and mercury in soil and irrigation water during growth, among which cadmium pollution is a prominent problem. Rice with excessive cadmium will damage the human kidneys and bones and cause "Itai-itai disease". It can be accurately detected by atomic absorption spectrometer and inductively coupled plasma mass spectrometer. Once it exceeds the standard, it will be immediately prevented from entering the market.
Aflatoxin detection
When rice is stored, if the temperature and humidity are not properly controlled, it is easy to breed Aspergillus flavus and produce aflatoxin, which is a strong carcinogen. The test personnel generally use high-performance liquid chromatography with a fluorescence detector to accurately detect and strictly control its content.
Freshness detection
New rice tastes good and is nutritious, while old rice is the opposite. The freshness of rice can be judged by testing indicators such as fatty acid value and tasting score. For example, an increase in fatty acid value can be judged as old rice, ensuring that consumers buy fresh rice.
2. Detection method
Physical and chemical analysis method
Use gas chromatography-mass spectrometry to detect pesticide residues, use atomic absorption spectrometer to measure heavy metal content, and use the physical and chemical properties of the substance for analysis.
Immunological detection method
Represented by enzyme-linked immunosorbent assay (ELISA), it uses the principle of antigen-antibody specific binding to quantitatively detect aflatoxin through color changes. It is simple to operate and fast, and is suitable for screening a large number of samples.
Near-infrared spectroscopy
Based on the absorption characteristics of rice components to near-infrared light, a mathematical model is established to determine the freshness. No pre-treatment is required, and online detection and rapid classification can be performed.
3. Detection equipment
Gas chromatography-mass spectrometry
Used for pesticide residue detection, it can efficiently separate and identify pesticide components with high sensitivity.
Atomic absorption spectrometer
In heavy metal detection, the metal element is atomized and its absorption degree of light of a specific wavelength is measured to determine the content.
High-performance liquid chromatograph
Aflatoxin is detected with a fluorescence detector, and efficient separation and quantification are achieved by using the difference in distribution coefficients.
Near-infrared spectrometer
Emits near-infrared light and collects reflected light signals to determine the freshness of rice. It is simple to operate, fast to detect, and can be non-destructively detected.
Rice testing covers all links from farmland to table. With the help of strict testing items, scientific testing methods and advanced testing equipment, rice quality and safety are guaranteed. Consumers should pay attention to testing information and choose regular channels to buy. We look forward to more accurate, fast and convenient testing technology in the future, providing stronger guarantees for food safety.