Chapter 1 Introduction
Food safety: Food safety refers to a state in which food and food-related products do not cause actual or potential harm to human health. It also refers to the various management methods and measures taken to ensure this state.
The main factors affecting food safety: natural toxic substances, natural allergic substances, biological hazards, chemical hazards, and physical hazards.
Chapter 2 Natural Toxic Substances in Animals and Plants
Prevention and control measures of solanine: found in potatoes
1. Store potatoes in a cool, ventilated, dry place or irradiate them to prevent potatoes from sprouting.
2. Those whose skin and flesh have turned black and green due to a lot of germination cannot be eaten; those whose flesh has sprouted less can be removed from the buds and bud bases, peeled and soaked in water for 30-60 minutes. When cooking, add a little vinegar and cook thoroughly to destroy the remaining toxins.
3. At present, there is no specific antidote for sprouted potato poisoning. Immediately after discovering the patient, use ipecac syrup to induce vomiting, and use 4% tannic acid solution, strong tea or 0.02% potassium permanganate solution to wash the stomach. Stop eating and destroy remaining poisoned food. Actively adopt symptomatic treatment measures such as infusions for critically ill patients.
Prevention and control measures of colchicine: found in fresh daylilies
1. Do not eat unprocessed fresh day lilies. It is best to eat dry products, soak them in water and swell before eating, which can ensure safety.
2. When eating fresh daylilies, they need to be processed before cooking. That is, first remove the long handle, scald it in boiling water, and then soak it in clean water for 2-3 hours (change the water in the middle). Fresh day lily must be heated until cooked before eating. The water in which fresh day lilies have been soaked cannot be used to make soup and must be discarded.
3. When cooking, mix it with other vegetables or meat, and control the intake to avoid poisoning caused by eating too much.
4. Once fresh daylily poisoning occurs, immediately wash the stomach with 4% tannic acid or strong tea, take egg white milk orally, and treat symptoms accordingly.
Toxic animal foods are almost all aquatic products. Common toxic substances in animals are: tetrodotoxin, shellfish toxin, fish histamine, and toad toxin.
Chapter 3 The impact of biological factors on food safety
Salmonella belongs to the family Enterobacteriaceae and is a gram-negative non-spore-forming bacterium. Types of clinical manifestations of poisoning: gastroenteritis type, cholera-like type, typhoid-like type, cold-like type, sepsis type.
Escherichia coli is a gram-negative bacterium.
Staphylococcus, Gram-positive cocci.
Vibrio parahaemolyticus, Gram-negative bacteria.
Clostridium botulinum, Gram-positive endophytic bacillus, anaerobic.
Bacillus cereus, Gram-positive bacteria.
Clostridium perfringens, anaerobic gram-positive bacteria.
Listeria, Gram-positive bacteria.
Classification of food-borne parasites: flesh-borne parasites, aquatic animal-borne parasites, aquatic plant-borne parasites, vegetable and fruit-borne parasites.
Chapter 4 The impact of chemical and physical factors on food safety
Pesticide residues: refers to the general term for the parent pesticide, its derivatives and impurities that remain in the environment, organisms and food after the use of pesticides.
Veterinary drug residues: refers to the original form, metabolites and impurities of drugs or chemicals that accumulate or are stored in animal cells, tissues and organs as well as in edible products after the administration of drugs to animals.
In terms of the hazards of drug residues: toxic effects, allergies and allergic reactions, bacterial resistance, flora imbalance, "three causes" (carcinogenesis, teratogenesis, mutagenesis), and hormone side effects.
★Food additive production management requirements: In addition to complying with GB2760 "Usage Standards for Food Additives" and GB14880 "Usage Standards for Food Nutritional Enhancers", the use of food additives should also comply with the following requirements:
1. Food additives must undergo sufficient toxicological identification to ensure that they are harmless to the human body when ingested for a long time within the permitted range of use.
2. Food additives should not have a damaging effect on the nutrients of the food, nor should they affect the quality and flavor of the food.
3. Food additives should contribute to the production, processing, manufacturing, storage and transportation of food, and have the functions of maintaining the nutritional value of food, preventing spoilage, enhancing sensory properties and improving product quality.
4. It is best to remove food additives after achieving the effect of use without entering the human body.
5. Food additives should be able to be analyzed and identified after being added to food.
6. Low price, rich sources of raw materials, easy to use, easy to store and transport.
Chapter 5 The Impact of Environmental Pollution on Food Safety
Atmospheric pollutants: fluoride, chlorine, asphalt smoke, acid rain, atmospheric dust and metal dust
Soil pollutants: pesticides, heavy metals, polycyclic aromatic hydrocarbons and phenolic substances, fertilizers, sludge and waste
Chapter 6 The Impact of Genetically Modified Technology on Food Safety
Transgenic technology: Also known as genetic engineering or DNA recombinant technology, it refers to extracting (synthesizing) the genetic material of different organisms at the molecular level, cutting it in vitro, splicing and recombining it with a certain carrier, and then introducing the genetic material into living cells or organisms. Relevant technologies that produce gene recombination phenomena in the body, allowing them to be expressed and inherited.
Genetically modified food GMF: refers to foods, food raw materials and food additives made or produced with genetically modified organisms.
★Transgenic technology experimental steps:
1. Use restriction endonucleases to cut genes to isolate specific gene fragments or synthetic target genes.
2. Prepare the vector gene, then connect the obtained target gene to the prepared vector using DNA ligase to form recombinant DNA, and use bacterial propagation to amplify the recombinant DNA.
3. Transfer the recombinant DNA into the recipient cells in minutes, so that it can be replicated and stored in the recipient cells.
4. Screen and identify recipient cells that have been successfully transformed with recombinant DNA.
5. Cultivate a large number of cells containing recombinant DNA to detect whether the foreign gene is expressed.
Chapter 7 Impact of Food Production Process on Food Safety
★ Factors affecting food safety during processing:
1. The design of food processing enterprises is not standardized, the production environment does not meet the hygiene requirements of food enterprises, the sources of toxic and harmful pollution are not kept away, and the wind direction, lighting, ventilation, dust prevention, sewage treatment, etc. are unreasonable.
2. Containers, packaging materials, tools, and pipelines used in the food production process are used improperly or cleaned and disinfected improperly, causing harmful substances to precipitate out of them, causing food contamination.
3. The raw and auxiliary materials and production water used for production do not meet the hygienic requirements, and raw and auxiliary materials that are rotten, moldy, insect-eaten or even contaminated by toxic substances are used, causing food contamination.
4. The production process does not meet the hygienic requirements, causing food contamination.
5. Use food additives or processing aids that do not meet hygienic requirements, causing food contamination.
6. Food adulteration and counterfeiting.
7. Poor personal hygiene and environmental hygiene cause microbial contamination of food.
Factory site selection: The food factory should be constructed in the suburbs of the town and in a place with a good surrounding environment.
Water quality control: Water for food processing and ice making must comply with the national GB5749 "Hygienic Standard for Drinking Water".
Separation technology: filtration, extraction, flocculation, membrane separation.
Common sterilization methods: high-pressure steam sterilization and pasteurization
Chapter 8 Food Safety Testing Technology
Conventional microbial technology: Sterilization and disinfection technology, Aseptic operation, Micro-operation, Staining technology, Medium preparation technology, Inoculation, separation and purification, strain preservation technology, Microbial enumeration technology, Microbial routine identification technology
GC-MS system composition: The gas chromatography-mass spectrometry system generally consists of four parts: a gas chromatograph, a mass spectrometer, an intermediate connection device for the gas chromatography mass spectrometer, and a computer.
The LC-MS coupling instrument consists of: liquid chromatography, interface, mass analyzer, detector, and data processing system.
Commonly used methods of ELISA: direct method to measure antigen, indirect method to measure antibody, double-antibody sandwich method to measure antigen, and competition method to measure antigen.
PCR amplification: template DNA denaturation, template DNA and primer annealing, primer extension
Nested PCR: Improving detection sensitivity and specificity
Reverse Transcription PCR: Detecting RNA
Multiplex PCR: detect single-copy gene rearrangements and abnormal insertion changes
Asymmetric PCR: Detects single-stranded DNA of a specific length.
Biosensor components: molecular recognition components, signal conversion devices, electronic measurement instruments
Chapter 9 Food Safety Evaluation
LD50: The amount required to cause the death of 50% of individuals in a group of subjects.
Risk Analysis: Risk Assessment Risk Control Risk Communication
Toxicity test: acute oral toxicity test, genetic toxicity test, 28-day oral toxicity test, 90-day oral toxicity test, teratogenicity test, reproductive toxicity test and reproductive and developmental toxicity test
Chapter 10 Good Manufacturing Practices GMP, Food Production License QS and Hygienic Standard Operating Procedures SSQP
Good Manufacturing Practice (GMP): It is a series of normative requirements for methods, monitoring measures and technology covering the entire process of food production, processing, packaging, transportation, and sales, formulated to ensure food safety and food quality.
Food Production License QS Sanitation Standard Operating Procedure SSQP
SSQP: Processing enterprises are formulated to ensure that their production operations meet the requirements stipulated in GMP, to ensure that undesirable factors are eliminated during the processing, and that the food they process meets hygienic requirements. They know how to implement cleaning, disinfection and sanitation during food production and processing. Maintain work instruction documents.
The significance of implementing GMP:
1. Ensure food quality
2. Promote the scientific and standardized quality management of food enterprises
3. Conducive to food entering the international market
4. Improve the level of supervision and inspection of food enterprises by health administrative departments
5. Promote fair competition among food companies
The significance of implementing QS:
1. The implementation of the food production licensing system is necessary to improve product quality and ensure consumer safety and health.
2. The implementation of the food production licensing system is necessary to ensure that food production and processing enterprises meet the basic conditions and strengthen the legal management of food production.
3. The implementation of the food production licensing system is to adapt to the needs of reform and opening up and create a good economic operating environment.
Chapter 11 Hazard Analysis and Critical Control Points HACCP
HACCP: It is a simple, reasonable, professional and advanced food safety and quality control system based on food safety prevention. It consists of two parts: food hazard analysis and critical control points. composition.
★Reasons for implementing HACCP:
1. HACCP is a quality management system that ensures food safety and prevents the spread of foodborne diseases.
2. HACCP has gradually become a global food safety management system, passing processing enterprises’ requirements for raw materials to raw material suppliers to ensure the safety of raw materials and reduce the original hazards of food.
3. HACCP is a systematic control system that can promptly identify all possible biological, chemical, physical and other hazards, establish preventive measures, and improve food safety.
4. The application of HACCP can make up for the shortcomings of traditional quality testing and supervision methods. It not only improves product quality and extends product shelf life, but also greatly reduces production costs. It is the most effective and economical method to ensure food safety.
5. The HACCP control program predicts potential hazards and proposes control measures to provide a basis for adopting new processes and new equipment.
6. HACCP has been recognized by government supervision agencies, media and consumers as the most effective food safety and hygiene quality control system at present. Enterprises can improve their credibility among consumers and promote product sales by implementing HACCP.
Seven basic principles of HACCP: conduct hazard analysis (HA), determine critical control points (CCP), establish critical limits (CL), establish CCP monitoring procedures (M), establish corrective actions (CA), and establish effective record keeping procedures (V), establish verification procedures (R).