Lesson 2 Study Guide PDF

# Lesson 2 Study Guide ## Learning Objectives: 1. Identify common environmental sources of foodborne microbes 2. Explain how foodborne microorganisms can enter and establish in food production environments 3. Describe how foods can become contaminated through food processing and food handling ##...

# Lesson 2 Study Guide ## Learning Objectives: 1. Identify common environmental sources of foodborne microbes 2. Explain how foodborne microorganisms can enter and establish in food production environments 3. Describe how foods can become contaminated through food processing and food handling ## Table 1: Ways in which food can become contaminated at five different locations/steps along the food supply chain. | Food Cultivation | Food Processing (Includes harvesting and any post harvest processing) | Transportation | Retail | Consumer Homes | |---|---|---|---|---| | - Animals (livestock feces) - Contaminated irrigation water - Soil - Runoff and flooding - Atmospheric sources (air and wind-borne microbes) - Improperly treated manure (E. coli, Salmonella)| - Workers and machinery - Hydro-cooling or dump tanks (internalization of microbes) - Improper cleaning or cross-contamination during washing - Animal feces or hair/skin during slaughtering - Equipment biofilms on surfaces such as slicers and tanks - Inappropriate manure use during cocoa fermentation - Microbial growth - Structural integrity issues - Poor employee practices during loading/unloading | - Poor hygiene in storage crates or transport vehicles - Cross-contamination from damaged packaging - Temperature fluctuations leading to | - Poor employee hygiene not washing hands or using dirty gloves) - Cross-contamination between raw and ready-to-eat foods - Contaminated utensils or equipment - Customers handling food items - Bioterrorism concerns in buffets - Sponges, cutting boards, refrigerator handles) - Reusable grocery bags (fecal bacteria present in unwashed bags) - Improper cleaning of fresh produce | - Poor food handling practices - Poor food storage (raw meat stored above RTE food) - Contaminated kitchen utensils (dishcloths, | ## Study questions 1. How can bacteria get inside of plant tissues? What is required? - How: Bacteria can enter plant tissues through natural openings like stomata or through damaged plant tissues caused by pests, environmental factors, or handling. - What is required: Light can induce bacterial chemotaxis toward stomata, and specific bacterial capabilities, such as motility (flagella), aid in penetration. Damaged or weakened tissue increases vulnerability. 2. How can bacteria get inside of eggs? - Through the Shell: Bacteria like Salmonella can penetrate the eggshell through cracks or directly via pores in the shell. - Through internal contamination: Salmonella can infect the chicken's ovary, leading to contamination of the egg while it is being formed. 3. What are the two main contamination sources of raw milk? - Cow udders and soil 4. What types of microorganisms contaminate seafood? Where do those microbes come from? - Vibrio spp. by naturally occurring in the marine environment, Sewage leaks and untreated waste runoff, fish farms 5. How do microbes get transferred from the outside of animals to the sterile meat? - During slaughter: - Contact with animal skin, hair, or feathers. - Cross-contamination during evisceration (e.g., intestinal rupture). - Improper cleaning of knives or equipment. - Contaminated worker gloves or tools. 6. Which parts of animals, fish, and birds contain the most microbes? - Animals: Feces, skin, and fur/hair. - Fish: Outer slime layer, gills, and intestines. - Birds: Feathers and feces. 7. When can environmental contamination be good? - Environmental contamination can be beneficial in cases like cocoa bean fermentation, where bacteria from the environment (e.g., lactic acid bacteria) help develop the desired flavor during fermentation processes. 8. Why are fruits and vegetables precooled after harvesting? - Precooling slows cell respiration and microbial growth, retains food structure, and reduces spoilage. 9. What category of microbes most commonly contaminate cocoa products and why? - Bacillus spp., including Bacillus cereus since during cocoa bean fermentation, bacteria from the environment are introduced. While many are harmless (e.g., lactic and acetic acid bacteria), Bacillus cereus can contaminate due to its ubiquity and ability to survive environmental conditions. 10. Why do hydrocooling and dump tanks pose food safety concerns? - Hydrocooling: While it prevents water loss from produce, it can lead to internalization of microbes like Listeria monocytogenes in fruits and vegetables through water infiltration. - Dump Tanks: They can harbor and spread microbial contaminants, such as Salmonella, if not properly cleaned and sanitized. 11. What are some common places that bacteria are found in food processing facilities? - Food Contact Surfaces: - Conveyor belts, slicers, and packaging equipment. - Storage tanks and dump tanks. - Non-Food Contact Surfaces: - Floors, drains, and air filters. - Cleaning sponges and tools like wrenches. - Workers and Equipment: - Gloves, uniforms, and improperly sanitized utensils. 12. What do FPE and RTE stand for? - Food processing environment - Ready To Eat 13. What is a biofilm, what is it composed of, and why are they a concern in food processing facilities? - Biofilm: A complex aggregation of microorganisms attached to a surface, embedded in a protective matrix of extracellular polysaccharides, DNA, proteins, and trapped food debris. - Concerns: Persistent contamination source. Difficult to remove and resistant to sanitizers. Causes recurring food contamination. 14. Do biofilms typically contain one type of bacteria or multiple? - Biofilms typically contain multiple types of bacteria, though single-species biofilms can also occur. 15. Where do the most number of food poisoning cases occur? - Most food poisoning cases occur in consumer homes due to improper food handling, poor hygiene, and cross-contamination during food preparation. 16. What are the food safety challenges associated with fast food restaurants and buffets? - Fast Food Restaurants: - High employee turnover leading to inconsistent training. - Bulk preparation and storage of food, increasing contamination risks. - Poor hygiene practices, such as improper cleaning of machines and utensils. - Buffets: - Open access allows for cross-contamination from people's hands or utensils. - Difficulty maintaining safe food temperatures (<4℃ or >60℃). - Risk of sick individuals contaminating the food.