Presentation on theme: "Simmons 1 ENVR 430: Foodborne Microbial Disease And Food Safety Suggested Reading: BrockChapter 29 – Food Preservation and Foodborne Microbial Diseases."— Presentation transcript:
Simmons 1 ENVR 430: Foodborne Microbial Disease And Food Safety Suggested Reading: BrockChapter 29 – Food Preservation and Foodborne Microbial Diseases pp. 950
Simmons 2 Where does your food come from????
Simmons 3 E. coli 0157:H7 - Spinach Date: Tue 19 Sep 2006 Source: FDA.gov Case Reports:To date, 131 cases of illness due to _E. coli_ infection have been reported to the Centers for Disease Control and Prevention (CDC), including 20 cases of Hemolytic Uremic Syndrome (HUS), 66 hospitalizations, and one death. Illnesses:Illnesses continue to be reported to CDC. This is considered to be an ongoing investigation. States Affected:There are 21 confirmed states: California, Connecticut, Idaho, Illinois, Indiana, Kentucky, Maine, Michigan, Minnesota, Nebraska, Nevada, New Mexico, New York, Ohio, Oregon, Pennsylvania, Utah, Virginia, Washington, Wisconsin, and Wyoming.
Simmons 4 E. COLI O157, UNPASTEURIZED MILK - USA (CALIFORNIA) Date: Fri, 22 Sep 2006 Source: CBS2.com Tainted milk has infected people with _E. coli_ [O157:H7] bacteria, prompting a recall of some milk products, health officials said Fri, 22 Sep Those infected got sick after drinking unpasteurized milk produced by Organic Pastures, a Fresno County, California dairy, according to the San Diego County Health and Human Services Agency. An 8-year- old San Diego County girl, a Riverside County boy, 7, and a 10-year-old girl in San Bernardino County got sick after drinking the contaminated milk. The state has ordered all Organic Pastures whole and skim raw milk to be pulled immediately from stores and consumers were encouraged to throw away any of the milk in their refrigerators. The recall order also affects raw cream and raw colostrum made by the dairy. Organic Pastures has been prohibited from producing raw milk for the retail market until further notice, officials said. The _E. coli_ outbreak was limited to raw, or unpasteurized milk, county health officials said. Most milk consumed in California is pasteurized, which reduces the risk of getting a bacterial illness. California – another outbreak!!
Simmons 5 Campus Health Alert - Confirmed E. Coli Cases Among UNC Students ( ) In recent days, three University students have developed confirmed cases of gastroenteritis caused by E. coli O157:H7 bacteria. This illness causes severe diarrhea (often bloody), abdominal cramps and is occasionally associated with severe complications, especially in young children and the elderly. The affected students developed symptoms between October 26th and 29th. Health authorities are investigating a small number of additional possible cases among University students. To date, the investigation by public health authorities has not identified any common source of exposure. Currently, there is no indication that other students are at risk. These bacteria usually make people sick within 10 days of exposure. The Orange County Health Department, working in consultation with the North Carolina Communicable Disease Branch, is investigating all of the cases involving the small number of UNC students. Officials from the University's Campus Health Services, Department of Environment, Health and Safety and other offices are monitoring the situation closely and collaborating in the investigation. If you experience severe diarrhea and abdominal cramps, you are encouraged to seek medical attention immediately. Following is a sampling of general tips from the Centers for Disease Control and Prevention on how you can prevent E. coli infection: 1.Washing hands frequently and well is the most important thing you can do to avoid bacterial illness. 2.People with diarrhea should wash their hands carefully with soap after bowel movements to reduce the risk of spreading infection. Anyone with a diarrheal illness should avoid swimming in public pools, sharing baths with others, preparing food for others, providing day care or direct health-care services. 3.Cook all meat and eggs thoroughly. You can decrease the risk of illness by not eating raw or undercooked meat or eggs. Use a digital instant-read meat thermometer to ensure thorough cooking. 4.If you are served an undercooked meat or eggs in a restaurant, send it back for more cooking and ask for a clean plate. 5.Avoid spreading harmful bacteria in the kitchen. Keep raw meat separate from ready-to-eat foods. Wash hands, counters and utensils with hot soapy water after they touch raw meat or eggs. Never place cooked food on the unwashed plate that held raw meat or eggs. Wash meat thermometers in between tests. 6.Wash fruits and vegetables under running water, especially those that will not be cooked. Bacteria are sticky, so even thorough washing may not remove all contamination. Remove the outer leaves of leafy vegetables. People at high risk of complications from food-borne illness may wish to eat cooked vegetables and peeled fruits.
Simmons 6 Two more cases of salmonella reported in N.C. Posted: Jan 21, 2009 Updated: Mar. 9, 2009 Two more cases linked to national salmonella scare involving peanut butter-based foods have been reported in North Carolina, bringing the number of cases in the state to six, state health officials said Wednesday afternoon. At least 485 people – 107 of whom were hospitalized – in 43 states and Canada have become ill since August. Six have died, including one person from Catawba County, according to the U.S. Centers for Disease Control and Prevention. The latest cases in North Carolina are in Onslow and Vance counties; previously reported cases were in Brunswick, Caldwell and Robeson counties. Among those infected was a 3-year-old child. Three of those patients, including the one who died in November, had been hospitalized. Meanwhile Wednesday, state scientists were helping to track down the source by looking at companies that make food with the peanut butter in question. Joe Reardon, a spokesman for the North Carolina Department of Agriculture and Consumer Services said microbiologists were testing an additional 51 samples of peanut butter products from a Kellogg's cracker plant in Cary to determine if the facility is contaminated by the bacteria. The Kellogg's plant receives peanut butter and peanut paste from a Georgia plant, owned by Peanut Corp. of America, to which the U.S. Food and Drug Administration has traced the contamination. The state is looking at 37 shipments of 47,000 pounds of peanut butter that the plant received since August. A number of tests conducted earlier this month have come back negative. Preliminary results from the final round of tests should be available by Friday, Reardon said. "We will have answers in the next 24 to 48 hours, and we're very interested," Reardon said. "We'll contact the FDA and CDC and share that information." Within the past week, a number of food companies such as Kellogg's and retailers such as Harris Teeter and Kroger have pulled products with peanut butter off the shelves as a precautionary measure. The FDA said Wednesday afternoon the list of products recalled is now more than 125. Kellogg Co. produces Keebler, Austin and Famous Amos brand snack crackers containing peanut butter. It confirmed Monday that salmonella had been found in a pack of Austin Quality Foods Toasty Crackers with Peanut Butter, but did not say which factory made that package. Other affected brand names include select products from Clif Bar, Luna, Nutrisystem and ZonePerfect. More products are being added on a daily basis. The investigation into the scare started earlier this month after lab tests found salmonella in an open 5-pound container of peanut butter from a Minnesota nursing home. Testing that the state's Public Health Laboratory completed on Jan. 12 showed a genetic match with the bacterial strain tied to 30 illnesses in Minnesota and others across the country. The CDC has said the bacteria behind the outbreak is common and not an unusually dangerous strain, but that the elderly or those with weakened immune systems are more at risk. At least five of the six people who died were elderly. All had salmonella when they died, though their causes of death haven't been determined. Symptoms of salmonella infection usually begin within three days of exposure to the bacteria and generally last less than a week. In the North Carolina cases, according to the state Department of Health and Human Services, lab results were received after most of the patients had recovered. Copyright 2009 by WRAL.com and the Associated Press.
Simmons 7 Multistate Outbreak of Salmonella Infections Associated with Peanut Butter and Peanut Butter - Containing Products As of January 28, 2009, 529 persons from 43 states (one person from Canada) had been reported infected with the outbreak strain –infection might have contributed to eight deaths Salmonella serotype Typhimurium shared the same pulsed- field gel electrophoresis (PFGE) pattern in PulseNet King Nut creamy peanut butter –Peanut Corporation of America (PCA) –single facility in Blakely, Georgia –Only large lots/“tubs” of peanut butter affected NC connection – processing plant here made crackers (Austin brand) Identified major oversight for peanut butter transport in container trucks
Simmons 8 Senate HELP Moves Food Safety Bill Wednesday, Nov. 18, 2009 Spurred by outbreaks of food-borne illnesses in everything from spinach to peanut butter, the Senate Health, Education, Labor and Pensions Committee today approved a bill beefing up the FDA's ability to oversee the nation's food supply. The bill was approved on a voice vote. Passage came after several committee members introduced a number of amendments on a food tracing system, nutrition claims made about baby formula, and food labeling. The proposals were withdrawn in an effort to speed passage. "This mark is a forward-looking bill that comprehensively reforms our current food safety system yet is adaptable enough to keep pace with an evolving industry," said Senate HELP Chairman Tom Harkin. "It recognizes that preventive controls are an essential means to improve food safety, and it addresses the need to enhance surveillance, improve emergency response coordination, and heighten the scrutiny of imported foods.“ The bill's price tag was set at $825 million for FY10, and "such sums as necessary" for the following five fiscal years. It mirrors a companion bill introduced in the House by veteran Rep. John Dingell, D- Mich., which passed earlier this year by a wide margin. Passage is expected in the full Senate as well. The bill gives the FDA expanded access to food facilities if the Agriculture secretary believes a food or related food is tainted. It expands registration requirements of food facilities and gives the FDA the authority to set commodity-specific standards for the safety of fresh produce. And it directs the FDA to establish offices in at least five countries to improve the agency's overseas presence. Harkin said food contaminations account for 325,000 hospitalizations and 5,000 deaths annually in the United States. "These numbers are staggering and intolerable, and they are for us a call to action," he said. by Elaine S. Povich
Simmons 9 Food Safety in NC 1.President Obama has this as a priority 2.Steve Troxler, NC Commissioner of Agriculture, has this as a priority –Commissioner’s Food Safety Forum (5 yrs) 3.NC Food Safety Task Force (mandated by Governor Purdue) 4.NC Fresh Produce Safety Task Force –NCSU Kannapolis, NC campus
Simmons 10 Major Issues in NC 1.Traceability and microbial contamination 2.Economic impacts from outbreak or even recall 3.NC has smaller, diverse niche markets that are not duplicated in other states 4.Many “small farms” – how to compete with large farms in CA and AZ 5.No “East Coast” concerted effort similar to the “West Coast”
Simmons 11 Foodborne Disease Burden in The United States Estimated morbidity and mortality: –76 million illnesses / yr –325,000 hospitalizations / yr –5,000 deaths / yr Estimated costs: –billions $ –loss of consumer confidence –loss of profits Mead et al. (1999) Food-Related Illness and Death in the United States. Emerging Infectious Diseases 5(5):
Simmons 12 OUTBREAKS n = 2,751 CASES n = 86,058 => 29 deaths: 28 confirmed, 1 unknown etiology Number Of Reported Foodborne Disease Outbreaks, Cases, And Deaths, By Etiology, United States (Incl. Guam, Puerto Rico, U.S. Virgin Islands) Source: Surveillance for Foodborne Disease Outbreaks - United States, MMWR (2000) 49(SS01):1-51
Simmons 13 Only a Fraction of Foodborne Illnesses Are Routinely Reported to the CDC 1.Passive surveillance system 2.Many diseases not reportable 3.A complex chain of events must occur to report a foodborne infection to the CDC 4.Most household foodborne infections are not recognized or reported
Simmons 14 Foodborne Disease: Vehicles Fruits and vegetables and Other salad accounted for highest number of outbreaks Beef, chicken, and fish also important Most Foodborne Disease of Unknown Etiology
Simmons 15 Foods Implicated in Foodborne Illness: Meats Red Meats – High contamination in comminuted and processed meats (e.g. ground beef, sausage) High surface area, increased contact with processing equipment; increased handling; variety of sources (organs, trimmings, etc.). E. coli O157:H7 common etiologic agent in outbreaks assoc. with improperly cooked hamburger and other foods
Simmons 16 Foods Implicated in Foodborne Illness: Meats Poultry – High contamination levels in cut ‑ up poultry Increased handling, processing and contact with common equipment Salmonella and Campylobacter are prevalent in poultry flocks – can contaminate an entire processing plant via equipment and process baths ( e.g., chiller tank) – Eggs Endogenous contamination by Salmonella enteritidis in some flocks – Time and temperature abuse leads to proliferation in the egg – Raw / undercooked eggs a source of exposure and infection
Simmons 17 Foods Implicated in Foodborne Illness: Fish Contamination depends on type of seafood, quality of harvest water, and amount of processing, handling and storage Bivalve mollusks (oysters, clams, mussels, etc.); filter feeders – Accumulate enteric pathogens from fecally contaminated waters Crustaceans ( e.g. crabs, shrimp) – Acquire some pathogens by feeding on mollusks – Acquire high levels of vibrios from their water environment Fin fish – Outer surface and epithelial lining ( e.g. gut) contamination by enteric microbes in fecally contaminated waters; – Contamination during processing ( e.g., filleting).
Simmons 18 Other Foods Implicated in Foodborne Illness Produce (fruits and vegetables) – fecal contamination in irrigation water and other fecal sources (animal droppings, birds, etc.) – inadequate or unsanitary harvesting, washing or processing. Dairy Products – In developed countries milk and related dairy products are usually made from pasteurized milk. Raw milk and products (e.g., cheeses) made from unpasteurized milk are high risk of bacteria contamination – Salmonella, Campylobacter, Brucella, Yersinia, Listeria
Simmons 19 Other Foods Implicated in Foodborne Illness Unpasteurized fruit juices and other beverages – fecal contamination from animal and human sources Deli, "Fast" and Restaurant Foods – salads, sandwiches, other fast, deli or restaurant foods – become fecally contaminated during preparation and handling Cereal and Grain: inadequate storage of cooked rice/grain
Simmons 20 Comparison Of # Outbreaks, # Cases, and # Deaths by Food Vehicle (All Etiologic Agents): Shellfish, Poultry, And Produce OUTBREAKS CASES DEATHS Shellfish81 2,547 3 Poultry70 2,707 0 Produce ,80511 MMWR (1996) 45(SS-5):1-66; MMWR (2000) 49(SS-01):1-51
Simmons 21 Foodborne Disease: Etiologic Agents Most reported outbreaks and cases are caused by bacteria : Salmonella Campylobacter E. coli Cl. perfringens Shigella Staph. aureus These pathogens were responsible for 22% reported outbreaks; 49% cases; 79% deaths from
Simmons 22 Food Poisoning vs. Food Infection Food poisoning or food intoxication: disease that results from the ingestion of food containing microbial toxins –Microbes that produced the toxins do not have to grow and are often not viable at the time the food is consumed Food infection: active infections resulting from ingestion of pathogen-contaminated foods –Microbes are actively growing in the host –Clinical illness associated with microbial infection, but may also be attributed to toxins produced by the actively growing microbes
Simmons 23 Salmonella Causes an estimated 1.4 million foodborne illnesses / year Est. 500 deaths / year Decrease risks for egg-associated infections of S. enteritidis by not eating raw or undercooked eggs ~40% of persons who died from S. enteritidis were residents of nursing homes; serious disease in others with weakened immune systems – Nursing homes, hospitals, and commercial kitchens should use pasteurized egg products for all recipes requiring pooled or lightly cooked eggs. Proper egg storage in homes.
Simmons 24 Campylobacter jejuni Causes an estimated 2.5 million foodborne illnesses / year Among the most common causes of enteric infection in humans overall Usually mild disease in immunocompetent hosts for immunocompromised hosts, antimicrobial therapy needed ~ 2 in 100,000 diagnosed infections lead to Guillan-Barre syndrome, a paralysis that lasts several weeks Primary vehicles: milk, poultry, pork colonization of poultry flocks almost universal; cells / processed bird inadequate cooking, cross-contamination primary causes of infection
Simmons 25 Escherichia coli E. coli 0157:H7 (EHEC) Causes at least 60,000 infections and 50 deaths per year Leading cause of kidney failure in children Produces a verotoxin (enterotoxin) similar to Shiga toxin Associated with undercooked meat, particularly ground meat E. coli (ETEC) “travelers diarrhea” Produces two heat-liable enterotoxins Associated with fresh vegetables Also, enteropathogenic (EPEC) and enterinvasive (EIEC) E. coli
Simmons 26 Clostridium Anaerobic spore-forming, gram-positive rod; ubiquitous in the environment Clostridium perfringens Most prevalent cause of food poisoning in the US (248,000 cases per year) Perfringens enterotoxin Generally self-limiting Clostridium botulinum Botulism – severe food poisoning Neurotoxin – seven distinct types of botulinum toxin Destroyed by high heat (80 o C, 10 m) Associated with foods not cooked after processing; home- canned vegetables, smoked fish vacuum-packed
Simmons 27 FOODNET: 1. Active lab-based surveillance 2. Survey of clinical labs 3. Survey of physicians 4. Survey of the population 5. Epidemiologic studies FoodNet also looks for: Listeria monocytogenes Vibrio spp. Yersinia enterocolitica Cyclospora Cryptosporidium
Simmons 28 HOWEVER, Recall that 68% of Reported FBDOs were of Unknown Etiology Retrospective analysis of clinical data shows that about 50% had incubations period of >15 hours, suggesting viral etiology. Viruses ( e.g., Noroviruses; human caliciviruses) are likely a much more important cause of foodborne disease outbreaks than is currently recognized. Local and state public health programs lack resources and expertise to diagnose viral pathogens, but methods are becoming increasingly available. Viral outbreaks are more likely to be detected in the future.
Simmons 29 Human Caliciviruses ex. Norwalk-like virus(es) Major agents of foodborne disease. Outbreaks due to fecally contaminated bivalve mollusks, deli meats, produce, and many other foods. Relatively persistent in the environment. Fecal-oral transmission in all age groups; worldwide; direct / indirect contact; secondary spread: common, 25-50%. Causes acute gastroenteritis: humans are only host; ~1-2 day incubation period and ~1-4 day duration; (diarrhea, vomiting, nausea, abdominal pain, anorexia, etc.) Multiplies in upper small intestine epithelium; blunts microvilli
Simmons 30 Hepatitis A Virus (HAV) Fecal-oral route of exposure Incubation period: 2-6 weeks Serious debilitating disease (general infection): fever, abdominal pain, headache, jaundice, nausea, diarrhea Fecally excreted at concentrations up to 10 6 infectious units per gram (>10 9 virions per gram) Infectious at relatively low doses Persistent in feces and on foods and environmental surfaces for weeks to months, depending on temperature and other environmental factors. Heat resistant: requires >60 o C for rapid inactivation. HAV associated with largest documented outbreak of shellfish illness ever recorded: – ~300,000 cases in Shanghai, China 1988 – Traced to consumption of clams harvested from a sewage-polluted area.
Simmons 31 Natural Toxins Marine Biotoxins Ciguatera poisoning (fish) Shellfish toxins (PSP, DSP, NSP, ASP) PSP=paralytic; DSP=diarrheal; NSP=neurotoxic, ASP=amnesic shellfish poisoning Scombroid poisoning (fish) Tetrodotoxin (Pufferfish) Fungal And Plant Toxins Mushroom toxins Aflatoxins Pyrrolizidine alkaloids Phytohaemagglutinin (Red kidney bean poisoning) Grayanotoxin (Honey intoxication) Toxin: A poison, usually a protein, formed by microorganisms. Exotoxins are given off as waste products of a microorganism. Endotoxins are contained within the cells, and are liberated only when the cell dies and disintegrates.
Simmons 32 Sources of Foodborne Enteric Microbial Contamination Food handler ‑ associated contamination: inadequate personal hygiene fecal contamination of foods ( e.g., hands) Food processing: equipment, packaging, and personnel may contaminate foods during processing
Simmons 33 Sources of Foodborne Enteric Microbial Contamination Food storage: time and temperature abuse bacterial growth Fecal contamination prior to harvest or collection: – Animal foods contaminated naturally (e.g., salmonella ) – Surface contamination ( e.g., feces on fur, feathers, hooves, etc.) – Shellfish and finfish contaminated in their environment Fecal (sewage) contamination of water pathogen uptake by filter ‑ feeding on waterborne particles – Fish and shellfish naturally colonized by aquatic pathogens (e.g. Vibrios) – Produce contaminated by irrigation with sewage or contaminated water or fertilization with nightsoil (feces) or animal feces.
Simmons 34 Human demographics -growing segments of the population at increased susceptibility to infections; ex. elderly Human behavior -changes in dietary patterns; ex. increasing consumption of produce, fish, shellfish Changes in agricultural industry and technology -greater geographic distribution of certain types of foods -mass production, rapid dissemination Microbial adaptation / evolution -environmental conditions; antimicrobial resistance -newly emerging human pathogens Public health infrastructure -limited or passive surveillance; monitoring; lack of $$ Factors Contributing to the Emergence of Foodborne Diseases
Simmons 35 Microbial Contamination of Foods Food spoilage: any change in the appearance, smell, or taste of a food product that makes it unacceptable to the consumer – May or may not make the food unsafe to eat Foods can be classified into categories with respect to spoilage: 1)Perishable foods 2)Semiperishable foods 3)Stable or nonperishable foods related to their moisture content or water activity
Simmons 36 Methods to Control Microbial Contamination of Foods 1.Prevention: keep enteric microbes out 2.Remove enteric microbes – Identify and remove contaminated food items and ingredients – Wash to remove contaminants filtration or other physical separation methods – Depurate or relay live shellfish. 3.Inactivate: kill / destroy microbes – Use of heat sterilize disinfect (e.g., pasteurize and cook to destroy pathogens) – Drying, dehydration and intermediate-moisture processing – Chemical treatments: disinfect and sanitize – Irradiation: UV and gamma (ionizing) radiation 4.Prevent growth of microbes – Use cold and freezing to prevent proliferation
Simmons 37 Methods to Control Microbial Contamination of Foods Prevent exposure to fecal contamination in the environment, after harvest or during processing, preparation and handling: Maintain uninfected herds and flocks of animals 1.Immunize animals against infectious diseases: Brucella abortus : brucellosis from cattle; raw milk/dairy products 2.Colonize animals with harmless microflora: colonize baby chicks with harmless bacteria competitive to Salmonella 3.Destroy animals harboring pathogens: Bovine Spongiform Encephalopathy (BSE; “mad cow” disease) – caused by a prion able to infect humans (neural tissue in meat) Maintain sanitation in the environment 1.harvest shellfish only from waters that are not fecally contaminated 2.irrigate fruits and vegetables with non ‑ fecally contaminated water 3.use uncontaminated fertilizer for fruits and vegetables
Simmons 38 Methods to Control Microbial Contamination of Foods Maintain adequate hygiene and sanitation during harvest, processing, storage and distribution 1.Use clean water for washing, processing, cleaning and worker hygiene 2.Adequate human and food waste treatment and disposal facilities 3.Plant and equipment sanitation: clean, sanitize, etc. 4.Personal hygiene, food handling practices and employee health (education, training and policies) Source control: use of non ‑ fecally contaminated foods and ingredients 1.Establish criteria, standards, and guidelines for measuring fecal contamination of foods (pathogens and microbial indicators) 2.Inspection, monitoring and surveillance (product testing)
Simmons 39 Heat and Thermal Treatment Effects of heat vary with food composition and microbe food composition: water, fat, proteins, carbohydrates, salts and pH organism factors: form, composition, growth stage, age, etc. Sterilize (or nearly sterilize) foods (destroys all viable microbes) – heat >100 o C; usually uses high pressure and steam – typical target temperature is 115 ‑ 116 o C for about 60 minutes ex. retorting of canned foods Pasteurization – intended to kill pathogens but does not sterilize the food – often used prior to subsequent cold storage so pathogens or spoilage organisms do not proliferate High Temperature ‑ Short Time Method: 72 o C; 15 sec. (milk) Low Temperature ‑ Long Time Method: 62.8 o C for 30 min. (milk) – pasteurization times and temperatures for other foods depend on the effects of heat on the food, food composition and the target organisms of interest
Simmons 40 Drying, Dehydration, and Desiccation Low moisture foods: usually <15% moisture Intermediate moisture foods (IMF): 15-50% moisture – fruits, cakes, syrups, candies, jams, milks, some meats and cheeses Sun (natural) drying: often used for fruits Heat drying (dehydration; desiccation) Freeze drying (lyophilization; cryophilization) Condensing or evaporating: reducing moisture in a liquid food; e.g., evaporated or sweetened condensed milk. Drying destroys some enteric microbes but is not very effective for others
Simmons 41 Chemical Treatments Preservatives: – Most are designed to control certain bacteria and molds Generally, ineffective against viruses and protozoan cysts – Propionates, sorbates, benzoates and p ‑ hydroxybenzoates: molds – Nitrates and nitrites (ex. for Clostridium botulinum; Cl. perfringens ) – Sulfur dioxide and sulfites – Acetic, lactic and other organic acids – NaCl and sugars – Ethylene and propylene oxides Disinfectants and sanitizers: – Used to treat (by washing or dipping) certain meats and produce – Chlorine, peroxyacetic acid, ozone, hydrogen peroxide – Concentrations: 10s to 100s of mg/L; contact times: seconds to minutes – Organic acids (acetic, lactic and citric) at 2-7%; less effective
Simmons 42 Food Irradiation Ionizing radiation (X ‑ rays and gamma rays) – Becoming more widely used gamma radiation from Co-60 and Cs-137 sources – Effectiveness depends on: organism, composition of the food, temperature, and presence of oxygen undesirable changes in foods from excessive radiation UV radiation – low (monochromatic 254 nm) and medium (polychromatic) – used primarily for beverages: water, juices, ciders, etc.
Simmons 43 Shellfish Depuration and Relaying Place live bivalve mollusks shellfish in clean flowing seawater – normal pumping, feeding and related activity rids accumulated microbes Relaying: – transfer shellfish from contaminated (restricted) waters to uncontaminated natural estuarine waters – typical holding times in the clean water are two weeks or longer Depuration: – Place restricted shellfish in shore ‑ based tanks of clean, flowing seawater under controlled conditions for periods of several days – Factors influencing deputation efficiency: tank geometry and loading water quality temperature
Simmons 44 Hazard Analysis / Critical Control Points (HACCP) A program of process control to (1) identify microbial hazards, (2) identify the most vulnerable (critical) sites or steps in the process and (3) implement an in ‑ house monitoring system for quality assurance and hygiene. Incorporates elements of: (i) education and training (iv) inspection (ii) ingredient or commodity control (iv) microbiological and (iii) process control related surveys HACCP is designed and implemented on a commodity-specific and production facility-specific basis
Simmons 45 Foodborne Safety in the Home Investigations from outbreaks indicate that consumers do not always take precautions to reduce the risks of foodborne infections About half of all Salmonella cases result from unsafe handling of food in the home Many experts believe the kitchen harbors more potentially dangerous bacteria than even the bathroom Individuals at increased risk and others in the population may be unaware of the risks involved, or of risk-reducing practice(s)
Simmons 46 Steps to Prevent Foodborne Illness 1.Clean: wash hands and surfaces often 2. Separate: don't cross-contaminate 3. Cook: cook to proper temperatures (minimum 160 o F) 4. Cool / chill: refrigerate promptly (refrigerator= 41 o F)
Simmons 47 Questions and Comments Have a Great Thanksgiving!!