Food Safety Book Flashcards
Food chain
- The transfer of food energy from plants to herbivores and then to carnivores (grazing food chain)
- The feeding of microorganisms on dead organic matter and the organisms that subsequently eat the herbivores (detritus food chain)
Definition of Food safety/hygiene
All conditions and measures that are necessary during the
- production,
- processing,
- storage,
- distribution and
- preparation of food
to ensure that it is safe, sound, wholesome and fit for human consumption.
Pre-harvest and Post-harvest: Meat and Milk
Meat
- Pre-harvest: up to slaughter
- Post-harvest: after slaughter
Milk
- Pre-harvest: in udder
- Post-harvest: bulk tank and plant
An animal is likely to be exposed to infectious and parasitic pathogens as well as residue-producing chemicals while still on the farm. If on-farm exposure to food-borne hazards is prevented, the hazards don’t enter the food chain. Maintaining a healthy, pathogen-free animal on the farm is primary prevention. Secondary prevention-cooking, freezing, pasteurization, etc.
Quality Assurance:
Corporate oversight function to state the corporate product quality objectives and goals as well as to affirm that the QC program is functional and achieving these objectives and goals.
Quality Control
On-line or production function that establishes and administers the day-to-day procedures.
FAO’s objective
objective: improve the production and distribution of food and other agricultural products
Codex Alimentarius objective
create internationally accepted standards for food production and safety.
3 Functions of Codex alimentarius:
- Facilitate international trade through the removal of non-tariff barriers caused by differing food standards.
- To protect the health of consumers and ensure fair trade practice in food trade.
- Promote coordination of all food standards work undertaken by international governments and NGOs.
3 Types of Codex Committees:
- General subject matter (food hygiene, residues, etc)
- Commodity committees
- Regional coordinating committees
Transportation issues
- Bruising occurs in all species but is most noticeable in sheep and pigs.
- Weight loss-result of breakdown of fatty and muscular tissues and loss of the water-holding capacity of muscle tissues.
- Salmonellosis-mixing can lead to cross-infection. Animals in a stable physiologic state are generally resistant due to production of butyric acid and other VFAs in sufficient concentrations to be bactericidal.
- Transportation of chickens and poultry can increase fecal excretion of Salmonella and Chlamydia (inhalation of aerosols containing Chlamydia is a hazard for poultry employees).
- Stress depletes glycogen reserves porcine stress syndrome
- –> Pale, soft, exudative (PSE)-↑ PCO2, ↓ pH, ↓ PO2, ↑ temp, RR and HR and adrenal hormone excretion.
- –> Dry, firm, dark (DFD)-↑pH due to ↓ lactic acid production.
What food item has the most regulatory control on it?
milk
Name 4 screening tests for milk
•California Mastitis Test (CMT) - viscosity and pH •Wisconsin Mastitis Test - viscosity •Modified Whiteside Test - viscosity •Catalase Test - tests the release of intracellular catalase.
Aquatic animal production - cat fish problems
• parasitic infections • O2 depletion
Aquatic animal production - shellfish problems
•Risk of illness due to eating shellfish exceeds the risk of illness traceable to any other foods of animal origin. •Often eaten raw. •Environmental conditions where they are produced (they filter their food from water and are subject to its pollution). •Organisms: Noroviruses, Hepatitis A (persists longest in oysters and clams), Vibrio vulnificus (due to warm temps and post-harvest issues). •National Shellfish Sanitation Program •Fecal coliform indicators do not always correlate well with presence of human pathogens (particularly viral). Not 100% effective. •Some pathogens can be removed by natural processes such as relaying the live animal to clean water and depuration. ***Public education about the risks associated with eating raw shellfish is essential.
3 Basic Characteristics that are important in a processing facility
- Imperviousness to chemicals and microorganisms 2. Resistance to wear and corrosion 3. Ease of cleaning
Flooring in a processing plant
•Most significant item in construction •Intense wear •Concrete-concern about cracks •Brick/tile-must be layered over a concrete base and bonded with an acid-resistant and waterproof mortar •Wood-unacceptable where water is used •Synthetic poured floors-no seams
Walls in a processing plant
•Smooth, flat, impervious •Brick, tile, plaster •Concrete - OK if latex or rubberized paints are used to seal it •Wood, plasterboard, porous acoustical board - unacceptable •Coving - desired construction feature-makes cleaning easier
Ceilings in a processing plant
•May serve as a source of contamination •Shouldn’t chip, peel, deteriorate or retain dust or condensation •Water pipes running along the ceiling should be enclosed
Equipment in a processing plant
•Stainless steel-easy to clean and is resistant to wear and corrosion •Plastics may be used, but some deteriorate rapidly when exposed to disinfectants
Cutting boards in processing plant
•Single piece of hardwood •Approved plastic or rubber-plastic
Small tool sanitizer
•Required in slaughter plants to minimize cross-contamination with infectious agents •Required minimum temp - 180°F •Thermal death point - 170°F for most pathogenic organisms
Water potability in processing plant
•If nonpotable water is used, the pipes must be identified to avoid cross-contamination with potable supply •Less than 2.3 coliforms/100ml based on 5 10 ml samples
Offal
•Red meat - edible parts of the animal other than muscle meat •Poultry - inedible parts of the bird •Must process offal rapidly!
What are the essentials of poultry processing?
•Only healthy poultry should be processed. •Abundant supply of potable water •Birds with feathers and feet attached should be handled in areas separate from areas where evisceration is done. •Care taken in removing the digestive organs (especially the lower gut) •Eviscerated carcasses should be chilled ASAP. •Personal cleanliness of employees and constant cleaning of equipment
What steps are involved in poultry processing?
•Shipping broilers-potential bruising and broken bones •Slaughter •Defeathering-mild scald and hard scald •Processing- –> Heads of older hens and turkeys are left attached –> Heads of broilers are removed –> Legs are cut off (carcasses not washed after this point) –> Removal of giblets, removal of lungs, removal of ovaries/testis –> Chiller-rapid chilling –> Packing/grading
What are the 5 methods of meat preservation
5 methods: • Heat • Cold • Dehydration • Irradiation • Addition of chemicals
what is the objective of meat preservation?
Control microbial contamination and autolytic changes caused by enzyme action at the cellular level.
Heat meat preservation method
•>140ºF, moist heat better •Canning=commercially sterile (surviving organisms are incapable of further growth) •pH of food affects the temp requirements •B. stearothermophilus-indicator organism •Temp, pressure and time •Some canned products (ham) can’t be heated to temps that render them sterile, so then must be refrigerated. Kills surface organisms only. •Curing agents inhibit bacterial growth •Lower pH may be processed and canned at a lower temp, because spores in acids are less resistant to heat and can be destroyed at lower temps. •Smoking- –> Dries the meat surface and inhibits oxidation. –> Smoke deposits phenolic compounds on the surface that inhibit fat oxidation.
Cold meat preservation methods ex. curing and freezing
•<40ºF most pathogens do not grow but most are not killed (especially important with Listeria and Yersinia) •32-35ºF most effective •Humidity maintained at 88-92%
Curing as meat preservation
–> Aid to subsequent preservation by refrigeration –> Curing salts inhibit psychrophilic microorganisms more stable product –> Not necessary to freeze cured meats –>Staph can live in upto 25% salt environment, so does not get killed with curing
Freezing as meat preservation
–> Should be frozen rapidly –> Frozen to -10ºF then stored at 0ºF –> Pork products can’t be maintained as long because of the higher amounts of unsaturated fat.
Dehydration as meat preservation
•Effective- –> Enzymatic processes within the cells are slowedretards autolytic changes –> Unfavorable for bacterial growth •Hot-air drying- –> Preserves meat up to 12 mo –> Fatty meats tend to become rancid –> Raw meat cannot be dehydrated •Freeze-drying –> Preserved both cooked and raw meat –> Shelf-life depends on ambient temp
Irradiation as meat preservation
•Destroys foodborne pathogens found in meat •May be effective even after a product is frozen and boxed •Uses ionizing radiation from a radioactive isotope of cobalt or from devices that generate a stream of electrons or X-rays •Also maintains the freshness of food by inhibiting the production of microbial enzymes that breakdown cellular integrity •4 treatments- –>Radappertiziation-destroys all organisms –>Radicidation-inactivates non-spore-forming pathogens –>Radurization-destroys spoilage organisms –>Disinfestation-destroys insects •Is considered to be an “additive” to food •Approved for use in pork, poultry, fruits, vegetables, spices and grains •WHO and Codex support food irradiation
Chemicals as meat preservation
•Pathogenic or spoilage microorganisms are destroyed because an unfavorable environment is created •Water-largest single ingredient of any curing preparation •Salt-bacteriostatic agent inhibiting microbial growth by increasing osmotic pressure •Nitrate/nitrite salts –>Color fixative and preservative –>Often used concurrently –>Protect against C. botulinum –>Nitrates must be converted to nitrites to be effective –>Bacterial reduction of nitrate to nitrite is pH dependent (less at acidic pH) –>Toxic if ingested in high quantities (restricted use) –>Nitrosamines=carcinogenic •Sugar-reduce the flavor that salts add to a product •Phosphates –>Adjunct to curing agents to improve the water-holding capacity of the product –>Causes increase pH –>Can be toxic (restricted) •Ascorbates –>Adjunct to curing agents –>Fix color of product and prevent fading –>Minimal bacteriostatic effect on spoilage and mold-producing microorganisms •Acids –>Lactic and acetic acids –>Decrease of 1 pH unit increases the bacteriostasis 10 fold •Gases –>CO2 -decrease growth of surface contaminants –>Ozone-bactericidal action on airborne microorganisms
♣ Disadvantages of using chemicals as preservation in foods:
• Odor that may mask abnormal meat odors • Hazardous to human health • Accelerate development of fat rancidity • Application of curing agents –>Dry or liquid form to the surface –>“Stitch-pumping”-injection into a major vessel
inedible foods
foods not normally used for human food condemned foods Food that is normally used but have been rejected Rendering: •Separating fat from its connective tissue stroma •Final treatment of inedible offal •Low temp (120°F)-C. perfringens, Staph aureus and Salmonella survive •High temp (239°F-270°F)-produce inedible fats and meals. Possible recontamination of the meal during further handling •Dry rendering-generally used for condemned and inedible products destined for animal feed •Wet rendering-remove liquid fat from edible meat •Centrifuge-continual addition of meat to the system rather than batches. Bacterial contamination can be a serious problem.
Lard
pork-produced from the “killing” fats (removed during the sanitary dressing procedure) and “cutting” fats
Tallow
beef or mutton fatty tissue
Oleo
high grade tallow from beef or mutton
Partially defatted tissue
lean, edible product from beef and pork fatty trimmings removed during boning
Time and Temp requirements for pasteurization
o 145°F/30 min (long-time holding) o 161°F/15 sec (high temp-short time) o 280°F/2 sec (ultra-pasteurized)
equipment for pasteurization
•Clarifier-centrifugal = device to remove any solid foreign material. Can also be used to separate cream and skimmed fractions •high temperature short time (HTST) unit pasteurizer •Homogenizer –> Milk is pumped through a small orifice under high pressure –> Temp must be sufficient to inactivate lipase •ultra high temperature (UHT) 138°F/2 sec
Name 4 ways to evaluate effectiveness of pasteurization
- Salt conductivity test 2. Phosphatase inactivation curve -inactivation temp slightly above that which is needed to destroy most of the microbes likely to contaminate milk. It is used to detect effectiveness of pasteurization and post-processing contamination. false pos results are possible 3. Mesophile test- UK 4. Coliform test-presence of coliforms results from contamination from a source after pasteurization.
How to high fat or sweetened milk products differ from pasteurization of milk?
Milk products-those that have a higher fat content than milk and/or contain added sweeteners have to be heated to 150°F for 30 min or 166°F for 15sec. Increase in temp needed because the product is more viscous.
contamination of raw cheese
•soft cheeses made from raw milk can be a source of Brucella or Salmonella, because the pH is not low enough to kill pathogens. -> 4 organisms-Salmonella, Listeria, enteropathogenic E. coli, Staph aureus -From contaminated equipment or personnel -All can be eliminated by pasteurization 148°F for 16 sec
contamination of non-fat dried milk
any enterotoxin present before the milk is dried will maintain its toxicity even though the microorganisms are killed
contamination of ice cream
Foodborne illness if raw or inadequately pasteurized ingredients are used. There can be post pasteurized contamination
Egg Processing
Washed at 90°F with alkaline detergent Egg products more likely to have microbial contamination than shell eggs Minimize contamination during egg-breaking • Only edible quality eggs should be used • Eggs candled to remove undesirables • Eggs should be spray washed and sanitized before breaking • Separate washing and breaking rooms to decrease contamination via aerosols • A separate draw off room with positive-pressure air flow Internal contamination of eggs by Salmonellae from the environment
Requirements on egg pasteurization
Egg Inspection Act (1970) -all whole eggs for use in egg products must be pasteurized at 140°F for 3 ½ min -Higher temps required for separated yolks and for products having added salt or sugar (usually an HTST unit)
quality of aquatic animal food determined by?
•Quality of the environment they came from prior to harvest •Standards of sanitation during harvest, handling, storage, processing
goal of seafood processing
•Decrease temp of fish •Keep level of microbial contamination to a minimum
Steps in aquatic animal processing
•Bleeding-must be done soon •Gutting-removes the digestive enzymes and bacteria that initiate spoilage in freshly caught fish. May also be helpful to prevent the migration of parasites (anisakid nematodes) from the gut into the flesh of the fish. •Washing-clean, cold water to decrease surface slime and spoiling bacteria. Is usually done whether the fish have been bled and gutted or not •Icing-temp control is the most important element in the preservation and processing of fish. (Holding temp 32-39°F). Used crushed ice or refrigerated seawater •Storage-shallow trays or boxes
Finfish prep
•Farm-raised- greater control provided at all levels of production •Wild fisheries-variable. Method of harvest will have an impact on product quality and subsequent processing
Crustacean and Mollusk prep
•Crustaceans are extremely prone to post-mortem deterioration. Lobsters, crabs and crayfish are iced and shipped alive. •Exoskeleton-increase amount of handling and cleaning and increases opportunity for contamination •Mollusks- –> iced and shipped directly –> Consumption-increased risk as a large amount are consumed raw
What are Psychrophiles?
They are psychrotrophes capable of replication at extremely low temps (32-45°F)
meat quality
the physical or chemical properties that relate to its processing and palatability characteristics.
Name 5 factors that influence meat quality
1.Water-holding capacity-natural moisture content of muscle is 68-78%. Excessive moisture lost in processing or through improper cooking will result in a less tender product that is perceived to be poorer quality. 2.Color-influences the consumer’s perception of the quality more than actual palatability. 3.Texture 4.Tenderness-collagen of connective tissue and contractile apparatus of myofibrillar proteins. 5.Marbling-intramuscular fat
Name 3 causes of meat deterioration
- microbial changes 2. chemical changes 3. enzymatic changes
describe microbial changes in meat deterioration
-Usually occurs as a product is handled in the plant -Growth of contaminating microorganisms depends on environmental conditions as well as the inherent characteristics of meat itself -7 different microbial changes: –> acid production –> gas production-risk of serious intoxication –> slime formation-mass accumulation of microbes on the meat surface (Lactobacilli, Micrococci and yeasts) –> mold growth-vacuum packaging is helpful –> greening-bacterial greening from surface contamination after processing. H2O2 causes greening –> green rings-associated with heavy population of bacteria before cooking and processing –> green cores-increase processing temp to 155°F to prevent
describe enzymatic changes in meat deterioration
?
oxidative changes in meat deterioration and prevention
-Fat is especially susceptible -Prevention- —> antioxidants of inert gases can be added —> storing the product away from heat and out of light —> wrapping to prevent exposure to air
