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SERVSAFE. CHAPTER 2 The Microworld. GOALS. TO FAMILIARIZE AND INTRODUCE THE THEORETICAL KNOWLEDGE OF: MICROBIAL CONTAMINANTS BACTERIA VIRUSES PARASITES FUNGI. FOODBORNE INFECTION VERSUS FOODBORNE INTOXICATION RECENT TRENDS IN FOODS ASSOCIATED WITH FOODBORNE ILLNESS
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SERVSAFE CHAPTER 2 The Microworld
GOALS TO FAMILIARIZE AND INTRODUCE THE THEORETICAL KNOWLEDGE OF: • MICROBIAL CONTAMINANTS • BACTERIA • VIRUSES • PARASITES • FUNGI
FOODBORNE INFECTION VERSUS FOODBORNE INTOXICATION • RECENT TRENDS IN FOODS ASSOCIATED WITH FOODBORNE ILLNESS • HAZARDS ASSOCIATED WITH FRESHER AND HEALTHIER FOODS • EMERGING PATHOGENS AND ISSUES • TECHNOLOGICAL ADVANCEMENTS IN FOOD SAFETY
OBJECTIVES AFTER COMPLETING THIS CHAPTER, YOU SHOULD BE ABLE TO: • IDENTIFY THE FOUR BASIC TYPES OF MICROBIAL CONTAMINANTS; GIVE EXAMPLES, AND DESCRIBE PREVENTIVE ACTIONS FOR EACH • DIFFERENTIATE BETWEEN FOODBORNE INFECTION AND FOODBORNE INTOXICATION AND IDENTIFY THE MAJOR CAUSES OF EACH
IDENTIFY THE MICROBIAL RISKS ASSOCIATED WITH VARIOUS TYPES OF FOOD • EXPLAIN THE CONDITIONS CONDUCIVE TO BACTERIAL GROWTH
MICROORGANISMS PATHOGENS TOXINS BACTERIA VIRUS PARASITE FUNGI SPOILAGE MICROORGANISM SPORES pH (ACIDITY) LAG PHASE VEGETATIVE MICROORGANISM LOG PHASE STATIONARY PHASE DEATH PHASE FAT-TOM TEMPERATURE DANGER ZONE AEROBIC ANAEROBIC FACULTATIVE WATER ACTIVITY(aw) HOST MOLD YEAST INFECTION INTOXICATION TOXIN-MEDIATED INFECTION VEHICLE FOOD IRRADIATION KEY TERMS
MICROORGANISMS-are small, living beings that can be seen only with a microscopePATHOGENS-microoganisms that can cause disease in living organismsTOXINS-(poisons), in food that is then ingested. Eating food contaminated with pathogens or their toxins is the leading cause of foodborne illness.
THE TWO GROUPS OF MICROORGANISMS • SPOILAGE MICROORGANISMSEXAMPLE: MOLD, which has an unpleasant appearance, smell, and taste, it seldom causes illness. • PATHOGENS EXAMPLE: SALMONELLA, E. coli, and the virus which causes Hepatis A, they cannot be seen, smelled, or tasted, often causes some form of illness.
BACTERIA • THE GREATEST CONCERN TO THE MANAGER • MORE COMMONLY INVOLVED IN FOODBORNE ILLNESS
BASIC CHARACTERISTICS OF BACTERIA THAT CAUSE FOODBORNE ILLNESS • They are living, single-celled organisms • Carried by a variety of means: food, water, humans, and insects • Under favorable conditions, they can reproduce very rapidly • Some can survive freezing • Some form into spores,a change that protects the bacteria from unfavorable conditions • Some can cause food spoilage; others can cause disease. • Some cause illness by producing toxins as they multiply, die, and break down.
BACTERIAL GROWTH To grow and produce, bacteria need the following: • Adequate time • Proper temperature • Ample moisture • Food • Appropriate pH (acidity) • The necessary level of oxygen
FOUR PROGRESSIVE STAGES (phases): LAG, LOG, STATIONARY, AND DEATH
LAG PHASE- an adjustment period LOG PHASE- a fast growing period VEGETATIVE MICROORGANISMS- In the process of reproduction STATIONARY PHASE- Just as many bacteria are growing as are dying. DEATH PHASE- The number of bacteria dying exceeds the number that are growing.
FOODMeat, poultry,dairy products, and eggsACIDITYGrow best in neutral foodsTEMPERATURE41 degrees F - 140 degrees FTIMEOXYGEN - AEROBIC- require oxygen ANAEROBIC- requires no oxygen FACULTATIVE- Can grow with or with out oxygen.MOISTURE- WATER ACTIVITY (aw)-the amount of moisture in a foodBest aw 0.85 and 0.97
MULTIPLE BARRIERS FOR CONTROLLING THE GROWTH OF MICROORGANISMS • MAKE TO FOOD MORE ACIDIC • RAISE OR LOWER THE TEMPERATURE OF THE FOOD • LOWER THE WATER ACTIVITY (aw) OF THE FOOD • LIMIT THE AMOUNT OF TIME THE FOOD IS IN THE TEMPERATURE DANGER ZONE.
MAJOR FOODBORNE ILLNESSES CAUSED BY BACTERIA • SALMONELLOSIS • SHIGELLOSIS • LISTERIOSIS • STAPHYLOCOCCAL FOOD POISONING • CLOSTRIDIUM PERFRINGENS ENTERITIS • BASCILLUS CEREUS GASTROENTERITIS • BOTULISM • CAMPYLOBACTERIOSIS • E. coli 0157:H7 • VIBRIO • YERSINIOSIS
VIRUSES- are the smallest of the microbial contaminants. BASIC CHARACTERISTICS OF VIRUSES • RELY ON LIVING CELLS TO REPRODUCE • DO NOT REQUIRE A POTENTIALL HAZARDOUS FOOD AS A MEDIUM FOR TRANSMISSION • THEY ARE NOT COMPLETE CELLS • THEY DO NOT REPRODUCE IN FOOD • SOME MAY SURVIVE FREEZING AND COOKING • THEY CAN BE TRANSMITTED FROM PERSON TO PERSON, FROM PEOPLE TO FOOD, AND FROM PEOPLE TO FOOD-CONTACT SURFACES • THEY USUALLY CONTAMINATE FOOD THROUGH A FOODHANDLER’S IMPROPER PERSONAL HYGIENE • THEY CAN CONTAMINATE BOTH FOOD AND WATER SUPPLIES.
MAJOR FOODBORNE ILLNESSES CAUSED BY VIRUSES • HEPATITIS A • NORWALK VIRUS GASTROENTERITIS • ROTAVIRUS GASTROENTERITIS
PARASITES- are organisms that need to live in or on a host organism in order to surviveHOST- is a person, animal, or plant on which another organism lives and takes nourishment BASIC CHARACTERISTICS OF FOODBORNE PARASITES • THEY ARE LIVING ORGANISMS THAT NEED A HOST TO SURVIVE • THEY GROW NATURALLY IN MANY ANIMALS SUCH AS SWAINE AND CAN BE TRANSMITTED TO HUMANS • MOST ARE VERY SMALL, OFTEN MICROSCOPIC, BUT LARGER THAN BACTERIA • THEY MAY BE KILLED BY PROPER COOKING OR FREEZING • THEY POSE HAZARDS TO BOTH FOOD AND WATER
MAJOR FOODBORNE ILLNESSES CAUSED BY PARASITES • TRICHINOSIS • ANISAKIASIS • GIARDIASIS • TOXOPLASMOSIS • INTESTINAL CRYPTOSPORIDIOSIS • CYCLOSPORIASIS
FUNGI- range in size from microscopic, single-celled organisms to very large, multicellular organisms.EXAMPLES- MOLDS, YEAST, AND MUSHROOMS BASIC CHARACTERISTICS OF FOODBORNE MOLDS • THEY SPOIL FOOD, AND SOMETIMES CAUSE ILLNESS. • THEY GROW UNDER ALMOST ANY CONDITION, BUT GROW WELL IN SWEET, ACIDIC FOODS WITH LOW WATER ACTIVITY. • FREEZING TEMPERATURES PREVENT OR REDUCE THE GROWTH OF MOLD BUT DO NOT DESTROY IT. • SOME MOLDS PRODUCE TOXINS CALLED AFLATOXINS. • MOLD CELLS AND SPORES MAY BE KILLED BY HEATING, BUT MOLD TOXINS MAY NOT BE DESTROYED. • TO AVOID ILLNESSES CAUSED BY MOLD TOXINS, THROW OUT MOLDY FOOD, UNLESS THE MOLD IS A NATURAL PART OF THE FOOD (e.g., cheeses such as Gorgonzola, bleu cheese, Brie, and camembert. These are specific types of molds which are grown in very specific conditions.)
YEASTS • SPOILS FOOD RAPIDLY • CARBON DIOXIDE AND ALCOHOL ARE PRODUCED AS YEAST SLOWLY CONSUMES FOOD. • PRODUCES A SMELL OR TASTE OF ALCOHOL • MAY APPEAR AS A PINK DISCOLORATION OR SLIME AND MAY BUBBLE • GROW WELL IN SWEET, ACIDIC FOODS WITH LOW WATER ACTIVITY, SUCH AS JELLIES, JAMS, SYRUP, HONEY, AND FRUIT JUICES. • FOODS SPOILED WITH YEAST SHOULD BE DISCARDED
FOODBORNE INFECTION VERSUS FOODBORNE INTOXICATION • FOODBORNE INFECTIONS- results when pathogens grow in the intestines of someone who has eaten food contaminated by those pathogens. Typically, will have a fever, which does not appear immediately. • FOODBORNE INTOXICATIONS- are caused by eating food containing poisonous toxins, such as (intestinal toxins that are produced by pathogens.) • FOODBORNE TOXIN-MEDIATED INFECTIONS- result from eating food that contains pathogens. The pathogens grow in the intestines and produce toxins that can cause illness.
RECENT TRENDS IN FOODS ASSOCIATED WITH FOODBORNE ILLNESS • EGGS ASSOCIATED WITH SALMONELLA • FOODS ONCE CONSIDERED SAFE ARE NOW SEEN AS POTENTIAL VEHICLES FOR FOODBORNE PATHOGENS- examples produce and highly acidic foods.
HAZARDS ASSOCIATED WITH FRESHER AND HEALTHIER FOODS • NATURAL OR ORGANIC FOODS WITHOUT ADDITIVES OR PRESERVATIVES • FOODS FROM ALL OVER THE WORLD ARE BECOMING MORE ACCESSIBLE. • ALTERING THE MAKEUP OF A FOOD
EMERGING PARTHOGENS AND ISSUES • FROM 1988 TO 1992, non-typhoid SALMONELLA strains caused 69 % of the bacterial outbreaks in the U.S. • FROM the early 1990’s to present numerous reports of E. Coli 0157H7 bacterial outbreaks in the U.S.
TECHNOLOGICAL ADVANCEMENTS IN FOOD SAFETY • FOOD IRRADIATION • ELECTRON PASTEURIZATION • HIGH PRESSURE PROCESSING • BACTERIOCINS • VARIOUS LIGHT TREATMENTS (laser light, ultraviolet light, and pulsed light)
FOOD IRRADIATION- often called cold pasteurization, involves exposing food to an electron beam or gamma rays. BENEFITS OF FOOD IRRADIATION INCLUDE: • REDUCTION OR ELIMINATION OF PATHOGENS AND SPOILAGE MICROORGANISMS • REPLACEMENT OF CHEMICAL TREATMENTS OF FOODS • EXTENDED SHELF LIFE OF FOODS