Food safety issues are of the utmost concern to the world. They are hot issues, sensitive issues, misunderstandings and misunderstandings. The situation has been fundamentally improved in recent years.

China is a big country in food production and trade. In 2006, the total output value of food industry above designated size was 1,195.865 billion yuan, and the volume of import and export food trade reached 40.448 billion US dollars (excluding agricultural products). In 2006, the national food inspection rate was 77.9%. In the first half of 2007, the pass rate increased by 85.1%. The average pass rate of food quality in 31 provinces and municipalities was 89.2%. In the second half of 2007, it has risen to over 95%, and in recent years, China has Fully start and build a food safety guarantee system.

At the 6th China International Scientific Instruments and Laboratory Equipment Exhibition (CISILE 2008), the professor of the Chinese Academy of Agricultural Sciences, the executive director of the China Instrument and Control Society, the vice chairman of the Agricultural Instrument Association, and the expert of the China Analytical Testing Association, Mr. Jiang Shiqiang He won the applause of the audience. After the meeting, the author conducted a follow-up visit to Professor Jiang Shiqiang and conducted in-depth discussions on some of the issues.

"Biotechnology World" reporter: What are the current food safety standards in China? What is the status of China's food safety supervision system and inspection and testing system?

Jiang Shiqiang: In 2007, China has released more than 1,800 national standards related to food safety, and more than 2,900 food industry standards, including more than 650 mandatory national standards.

The scope of coverage includes: agricultural product production environment, irrigation water quality, rational use of agricultural inputs; animal and plant quarantine regulations; good agricultural practices; food pesticides, veterinary drugs, pollutants, harmful microorganisms, etc.; food additives and their use standards Hygienic standards for food packaging materials; special dietary food standards; food labeling standards; food safety production process management and control standards; food testing method standards; involving food, oilseeds, fruits and vegetables and products, milk and dairy products, meat and poultry eggs Edible agricultural products and processed foods such as products, aquatic products, beverages, wine, condiments, infant foods, etc., basically cover all aspects from food production, processing, circulation to final consumption.

China has established a strong food safety supervision system. The Chinese government insists on paying attention to food quality and safety from the source, improving the basic links and systems of food supervision, and strengthening food safety supervision. In order to ensure food safety, the Chinese government has established a concept of full-scale supervision, adhered to the work-oriented ideas of prevention and prevention at the source, and formed a regulatory work pattern of “national unified leadership, local government responsibility, departmental guidance and coordination, and joint action of all parties”. .

The framework of China's food safety inspection and testing system has basically taken shape. In terms of domestic food regulation, a batch of qualified food inspection and testing institutions has been established, and food safety has been formed with “national inspection agencies as the leading, provincial and departmental food inspection agencies as the main body, and municipal and county-level food inspection agencies as supplements”. Inspection and testing system. A total of 3,913 food testing laboratories passed the laboratory qualification certification (measurement certification), and the testing ability and testing level reached or approached the international advanced level.

China has launched the “National Agricultural Product Quality and Safety Inspection and Testing System” with a total investment of 5.906 billion yuan. The Food and Drug Administration System Infrastructure Project has a total investment of 8.8 billion yuan. The General Administration of Quality Supervision, Inspection and Quarantine and the industrial and commercial departments are also working hard to improve the corresponding inspection and testing system.

In the aspect of import and export food supervision, an import and export food safety technical support system led by 35 “national key laboratories” has been formed. There are 163 import and export food inspection and quarantine laboratories in the country, and 1,189 professional and technical personnel. .

Each laboratory can detect 786 safety and health items such as agricultural and veterinary drug residues, additives and heavy metal content in various foods, as well as various food-borne pathogens.

"Biotechnology World" reporter: What is the current status of China's food safety testing technology?

Jiang Shiqiang: Scientific instruments and testing techniques are technical support for ensuring food safety. The food safety testing technology mainly includes eight types of instruments and methods: instruments for detecting pesticide residues; instruments for detecting veterinary drugs and fishery residues; instruments for detecting toxic and harmful elements and their valence analysis; instruments for pathogenic bacteria testing and bacterial identification; Agricultural product testing equipment; instruments for detecting the quality and nutrient content of agricultural products; instruments for pre-processing samples; small and medium-sized instruments necessary for laboratories.

(1) Instruments for detecting pesticide residues. Including the following major categories. 1. Instruments for detection of organochlorine pesticide residues. 2. Instruments for detecting organic phosphorus pesticides. 3. Instruments for detection of carbamate pesticide residues. 4. Instrument for pyrethroid pesticide residue detection. 5. Apparatus for detecting pesticide residues in pesticides. 6. Instruments for pesticide residue detection.

Today's pesticide multi-residue testing has been highly valued by developed countries. China has also announced that the sample pretreatment techniques used in the implementation of the eight national standards for pesticide multi-residue testing vary, but the instruments used are either GC-MS or LC-MS-MS.

(2) Instruments for detecting residues of veterinary drugs and fishery drugs. Veterinary drugs can be roughly divided into 15 categories, and the detection methods and instruments are the same.

Refer to AOAC, CAC, EU, Japanese standards and national standards, scientific instruments required for pesticide and veterinary drug residue testing, and China's industrial conditions can be summarized as follows:

(1) The main instrument for pesticide residue detection is GC equipped with various detectors, supplemented by HPLC, and characterized and confirmed by GC-MS. (2) The pesticide residue detection instruments are all GC-MS or LC-MS-MS. (3) The veterinary drug residue detection instrument has higher requirements than the pesticide residue detection block, and is generally detected by HPLC or GC-MS, and further qualitatively and confirmed by HPLC-MS and HPLC-MS-MS. (4) International high-end products are Agilent, Thermo, Waters, ABI, PerkinEImer, Dionex, Varian and other leaders. (5) China has made great progress in GC, HPLC and GC-MS in recent years. Such as East and West Electronics, Jingke, Tianmei, Wufeng, Wenling, Beifen, Elite, etc. Although there are still some gaps with the above international famous brands, I am sure that it is suitable for the preliminary qualitative and quantitative detection of food safety at the county and prefecture (city) level. The market is broad, and it is expected that domestically produced instruments will make a difference.

(3) Instruments for detecting toxic and harmful elements and their valence analysis

The most classic use of atomic absorption spectrometer (AAS). Atomic Fluorescence Spectrometer (AFS) with China's independent intellectual property rights is very distinctive and powerful. It can detect arsenic, lead, mercury, tin, selenium, tellurium, antimony, etc. It has high sensitivity, low detection limit and simultaneous detection of multiple elements. Cheap. ICP-MS has high sensitivity and the detection limit can reach ng/ml level, which has attracted attention, but it is expensive.

The valence of the elements is different, and the toxicity varies greatly. The foreign countries use HPLC-AAS, GC-AAS, HPLC-ICP-MS and CE-ICP-MS, but the price is expensive. The mass-produced LC-AFS combined instrument in China can meet the requirements of agricultural products and food safety testing, and the price is low. The detection of toxic and harmful elements in food safety testing can basically be done with domestically produced instruments, especially elemental valence analysis and county and prefecture (city) food safety quality inspection stations.

(4) Instruments for pathogen detection and bacterial identification

There are three main types of methods for the identification and testing of bacteria: traditional methods, numerical methods based on traditional methods, methods of chemistry and molecular biology, and many methods and instruments are derived. In the past, China has used traditional cultivation methods. In recent years, a large number of new foreign methods and instruments have been introduced. The wider ones are:

(1) Identification according to the metabolic utilization rate of the carbon source, such as API, ATB, VITEK, and the like.

(2) Using the specific binding and immune response between the antigen and the antibody to test the pathogenic bacteria, that is, using an ELISA method such as VIDAS.

(3) Using genetic testing technology to detect pathogens, such as DuPont's BAX system, RP system can be used for traceability.

(4) Bacterial identification based on characteristic fatty acid profiles, such as those developed by Agilent.

(5) Pathogen detection systems based on surface plasmon resonance (SPR) biosensors, such as the Biacore system.

(6) Based on the biochip as a platform, using a pathogen detection kit and a system for detecting pathogenic bacteria, such as a biochip detection system that has been developed and tested by Boao Biotechnology to detect 12 foodborne pathogenic bacteria.

Famous foreign manufacturers are Biomerieux, Dupont, Agilant, Biologe, GE Heailhcare and Biacore. There are no similar manufacturers in China in the past, only manufacturers that produce inhibitor zone detectors, which is a great defect. Fortunately, since 2000, Boao Biotech (Biochip National Engineering Center) has launched a biochip detection system, and the Chinese Academy of Sciences Electronics has launched the SPR series. From the world, the case caused by pathogenic bacteria is the first food safety, and it is expected that more domestic instruments will be launched and occupy this huge market.

(V), genetically modified agricultural products testing equipment

The detection of foreign genes in agricultural products is divided into gene level detection and gene transcription level detection. The instrument is divided into three parts according to the detection procedure:

1. Instruments and equipment for DNA sample preparation: kits, oscillators, centrifuges, etc.

2. Instruments and equipment used for gene amplification: mixed liquid, fidelity DNA polymerase, PCR amplification instrument, and the like.

3. Separation, analysis and verification of instruments and equipment: electrophoresis system, microplate reader, quantitative PCR instrument, etc.

Famous foreign manufacturers are BI0-RAD, Thermo-Life Sciences, GE; domestic manufacturers that do not have complete production of the above instruments are a defect. However, there are companies that produce centrifuges, electrophoresis instruments, microplate readers, and PCR instruments, such as Tianmei, Liuyi, Tianneng, Sanke, Langji, and Boji.

(6) Instruments for detecting the quality and nutritional content of agricultural products. Mainly: 1, fixed nitrogen analyzer Kjeldahl nitrogen analyzer or Dumas nitrogen / protein analyzer; 2, fat analyzer; 3, cellulose analyzer; 4, milk, juice detector; 5, sugar ( Brix) detector; 6, near-infrared agricultural product quality analyzer; 7, food safety rapid analyzer series (determination of nitrite, formaldehyde, hanging white block, sulfur dioxide, peroxide value and pesticide residues, etc.). In recent years, several kinds of instruments have been produced in China, such as Shanghai Fiber Instrument Factory, Concentration Technology-Yingxian, Shanghai Jingke, Ji-Swan and so on. 8. Amino acid analyzer. There are no commercial products in China.

(7) Instruments for pre-treatment of samples

Food quality and safety testing is in extremely complex matrices (in samples), detecting μg, ng-level residues and contaminants. Traditional sample preparation techniques have become bottlenecks and even powerless, so a series of new technologies have replaced traditional technologies. The trend of equipment, these new technologies are:

(1) Solid extraction instrument, domestic products and use will soon become popular.

(2) Solid phase micro-extraction (SPME). Companies such as Varian and Supelco have introduced SPME automatic extraction/injection methods.

(3) Matrix solid phase dispersion extractor (MSPDE). This technology was first proposed in 2000. The advantage is that traditional methods such as homogenization, sedimentation, centrifugation, and pH adjustment are not necessary.

(4) Supercritical Fluid Extraction (SFE). The advantage is that it is simple, efficient, fast and selective without using organic solvents.

(5) Gel dialysis extractor (GPC). The advantage is that the purification capacity is large and the recovery rate is high, which is convenient for connection with other analytical instruments.

Other new technologies such as microwave digestion extractor, microporous liquid membrane extraction, nano-enriched materials, as well as headspace, purge and trap, fully automatic heating and pressure rapid solvent extraction, etc., will be in food, agricultural products. Play a role in safety testing. These sample pretreatment equipments have completed research and development tasks in China, passed the acceptance of results, and some have entered the industrial demonstration, and have been able to provide formal products with similar performance to foreign products such as: Shanghai Spectrum, Xinyi, Beijing Ruili, Feng Jiehua, Chengdu Colin and so on. These products are large in demand and wide in scope, and we hope to form an industrial scale as soon as possible.

(8) Small and medium-sized instruments necessary for laboratories

In the past, when building laboratories in China, we only paid attention to large-scale instruments and equipment and neglected the necessary small and medium-sized equipments, which resulted in only one developed mind and no dexterous limbs. These small and medium-sized instruments and equipment should be equipped in a targeted manner according to different inspection tasks and functional requirements. There are many enterprises in China, and their performance has also been greatly improved. They have been able to basically meet the actual requirements, and should focus on improving the performance and even the appearance of national products.

Although the methods and instruments described above are confirmed by the domestic and international food safety testing standards, there are complex sample processing, time-consuming, low-flux, difficult to achieve fast, simple, high-throughput, and even on-site detection. Therefore, rapid screening and detection technology and instruments have always been highly valued at home and abroad. For a variety of purposes, there are a range of methods and instruments, from test strips, cards, test kits based on different basics, to multi-residue analysis techniques and instruments based on color/mass spectrometers.

"Biotechnology World" reporter: Please talk about the expectations of China's food and agricultural products safety rapid detection technology and instruments.

Jiang Shiqiang: China's agricultural products and food production enterprises are large in number, small in scale, scattered, and the rule of law and self-discipline are very weak. The population is large, and there are many consumers and beams, which constitutes a frequent food safety problem. In addition to environmental factors and objective factors of production conditions, most of them stem from the violation and abuse of pesticides, veterinary drugs and additives. Therefore, it is difficult to monitor the food safety status from the source in a timely, rapid and comprehensive manner solely by the above series of laboratory testing methods and instruments. Therefore, the speedometer has a special meaning. There are many principles and instruments for speed measurement technology, but they are very mature and outstanding. China has fewer industrialized and mature instruments. Here are five categories of instruments that I personally like and disagree with:

(1) Immunoassay methods and instruments

Including radioimmunoassay, enzyme free, fluorescence free, chemiluminescence free and colloidal gold standard. The pesticide residue enzyme immunoassay technology is listed as one of the three pillar technologies of pesticide residue detection by AOAC. It has high specificity, accuracy, rapidity, detection of pesticide and veterinary drug residues, detection of pathogenic bacteria, toxins and transgenic detection, testing instruments. Mainly enzyme-linked immunosorbent assay, there are many productions in China. The reason why this method has not been widely used in China is that the instrument has a single function and the imported kit is too expensive, but there is no perfect kit in China.

In the future, it is advisable to further study various influencing factors of ELISA methods, and to develop recombinant antigens, multiple targets, directed transformation of enzymes, molecular evolution in vitro, and automated enzyme-linked immunoassay.

(2) High-speed attention should be paid to new rapid measurement technologies such as biosensors and molecular imprinting technologies.

Biosensors are characterized by diversification, miniaturization, intelligence, integration, low cost, high sensitivity, high recognition and practicality, which have attracted great attention at home and abroad. There are many types, the fastest growing and widely used SPR biosensors are sensitive, fast, no need to mark, convenient, and real-time. Its combination with other new technologies will introduce a new set of methods and instruments for rapid food safety screening and testing, most of which are represented today by Biacore AB and TI and Bio-RAD in the United States. Among them, Biacore, which combines SPR detection system, biosensor chip, microfluidic system, etc., with different kits, constitutes a system for rapid screening and detection of veterinary drug residues, pathogenic bacteria and toxins. In China, three SPR instruments have been developed on behalf of the Institute of Electronics of the Chinese Academy of Sciences. The development direction is: high-throughput, high-sensitivity and portable, small and micro.

(3) Biochip and microchip lab.

It has high-flux, high-sensitivity and fast characteristics, and it has been paid great attention to its application in food safety and disease diagnosis. China National Biochip Center and other units have developed and produced biochip technology platforms (instruments and kits) for foodborne pathogen detection, foodborne virus testing and veterinary drug residue testing, which will be further oriented to the field, rapid measurement, and direction. The development of microchip labs.

(4) It is advisable to pay attention to special electrochemical sensors

Electrochemical sensors are small, sensitive, diversified, low-cost, etc. The use of special electrochemical sensors and the construction of food safety rapid detectors are also taken seriously at home and abroad, for example, the combination of nanotechnology and electrochemical technology to build rapid detection. An instrument for the toxic and harmful heavy metals in food; using a new nanoperoxide sensor and a nano metal/oxide sensor to form a rapid detector for rapid detection of total bacterial counts and E. coli. These three speedometers have been included in the national science and technology support project, and prototypes have been produced.

(5) Understanding of enzyme inhibition method and instrument application

In China, the enzyme inhibition method and instrument were first introduced as the rapid measurement technology. In fact, this method was proposed by the United States as early as 1951. In 1968, Canada improved, and China began to develop it in the 1980s. In recent years, more than a dozen commercial instruments have been introduced and promoted. In view of the fact that this method can only detect organophosphorus and carbamate class II pesticides, and the inhibition rate of different kinds of pesticides varies greatly, it is inevitable that the pesticide residue will exceed the standard with a uniform inhibition rate, which will inevitably produce false positive or false. A negative missed test can be said to be the current "fast test method". It is only applicable to the initial inspection of the grassroots level and plays a warning role. When the phenomenon of exceeding the standard is found, it must be retested and confirmed by standard methods. The negative reaction should also be sampled proportionally and retested and confirmed by a reliable method. The application of the rapid detection method is clearly defined in the second paragraph of Article 36 of the Agricultural Product Quality and Safety Law.

Professor Jiang Shiqiang repeatedly stressed that a sound food safety guarantee system should be embodied as: complete system, sound laws and regulations and standards, perfect institutions, personnel and equipment, advanced inspection and testing technology and equipment, timely monitoring and testing. powerful. The technical support is scientific instruments and testing techniques.