Final Exam (New Cards) Flashcards
Why would adding shrimp to kimchi be a concern?
Shrimp or fish introduce new pathogens to the process
What is a risk to consider with cheese brining?
Brine is about 10% salt and is not routinely replaced. Salt tolerant bacteria like Listeria or Staph aureus could persist in these conditions.
Challenges of sampling
Microbes are rarely homogenously distributed
Reduce spoilage (growth phase)
Extend lag phase for as long as possible
Avoid log phase
Methods to kill spoilage microbes
Hot filling
High pressure pasteurization
Radiation
Electric pulse fields
UV
Ozone
Lactic acid spoilage
Produce gas
Create slimes
Milkiness
Souring from acids
Discoloration from oxidative compounds
Meat, dairy, produce
Post processing contaminants
LM
Salmonella
Staph
What could go wrong with open exposure cleaning methods?
Open exposure, high moisture manufacturing equipment typically requires disassembling, foaming, and hands on scrubbing (COP). Splash back from floors/walls, not enough contact time, and poorly trained personnel all present challenges.
ATP to measure cleaning effectiveness
ATP is the energy source in all living cells and can be used as a general measure of cellular materials. An ATP sensor provides “relative light units” measurement for comparison which gives a measure of how clean a surface is.
What can go wrong when cleaning low moisture food environments?
Low moisture food manufacturing environments require limited, out of place, well-separated cleaning with limited water usage. If water is mistakenly added to the production line it could allow for microbial growth. You must break down equipment often for cleaning.
What is Clean-In-Place and what are examples of when it can be used?
CIP is wet cleaning where water and chemicals are cycled through equipment. This is useful for complex piping. Things that could go wrong could be dead-ends, improper flow rate, incorrect chemical use, and scratched/damaged equipment. This is used for pasteurizers.
What are the 3 official functions of preservatives?
Slow product spoilage caused by mold, air, bacteria, or yeast; maintain the quality of the food; help control contamination that can cause foodborne illness
What are the 3 antimicrobial preservative methods?
Physical removal of microbes (filtration, centrifugation); static agents that prevent microbial replication, and cidal agents that kill microorganisms
What are the 3 official functions of preservatives?
Slow product spoilage caused by mold, air, bacteria, or yeast; maintain the quality of the food; help control contamination that can cause foodborne illness
How does HACCP focus on preventing foodborne illness and injury?
Knowing/predicting/anticipating where hazards with food safety may arise during manufacturing, storage, and preparation
Doeing something to control/reduce the likelihood of those products occurring
Explain Redox potentials (Eh).
Aerobic bacteria require oxidized conditions. A positive mV reading means oxygen is present. Anaerobic bacteria require reduced conditions (negative mV reading). Microaerophilic bacteria require slightly reduced conditions. Facultative anaerobes can grow under either aerobic or anaerobic conditions by adapting their metabolism. Some examples of redox values of foods: Juices +300-400mV, Solid meats -200mV, cheeses -20 to -200mV. Aerobes can lower the Eh by using O2.
What are compatible solutes?
Compatible solutes are neutral compounds that can be synthesized or accumulated from the environment with transporters. Examples include amino acids (proline), sugars (trehalose), polyols (glycerol), betaine, and ectoine. In addition to conferring tolerance to desiccation and dehydration, the may also confer cross protection to different stresses such as heat, cold, and oxidation.
Describe osmotic stress/shock.
Osmotic stress happens when a change in the solute sugar concentration around a cell causes a change in water movement across the membrane of cells. Moisture gets pulled from the cell. Because chemical reactions and metabolic activities require an aqueous environment, nutrient transport becomes difficult.
What is the benefit of using pathogens in the stationary phase for studies?
We want to test microbes in the stationary phase because they are the strongest possible form of the microbe. These microbes are using their maximum survival efforts. They are unable to grow and must put all efforts towards survival.
Structure of immunoglobulin
All immunoglobulins share the Fc region, the other regions are variable and responsible for binding to specific antigens. Antibodies are produced by B cells.
What pathogen is most commonly found in manufacturing envionments
LM
When using HAACP there is an emphasis on
Monitoring the Ccp within the process
What bacteria is often associated with spoilage of these products (bacon) (growth in the purge)
LAB
Origin of foodborne viruses infecting humans
Human feces
One of the post potent carcinogens
Mycotoxin
Alfatoxin
Testing food for a pathogen has the following challenge
Non uniform distriubtion of bacteria in food
Starlink corn issue
Contained a human allergen
Innate immune players
Phagocytic cells
Antimicrobial peptides
Lymphocytes
Lymphocytes are a type of white blood cell/leukocyte that play an important role in the immune system as circulating immunocompetence cells that can recognize and react to antigens.
They include B cells that produce antibodies that are used to attack invading microbes. They also include T cells that destroy the body’s own cells when they have been taken over by microbes
Phagocytes
Phagocytes are a type of white blood cell/leukocyte that use phagocytosis to engulf bacteria and foreign particles. They bind to the pathogen and internalize them in a phagosome which acidifies and fuses with
lysosomes to destroy the contents.
Phagocytic cells include neutrophils, macrophages, mast cells and dendritic cells)
M Cells
M cells are specialized epithelial cells of the muscosa-associated lymphoid tissue responsible for transporting unmodified antigens from the lumen of the intestine to the underlying lymphoid tissue without digesting them.
Dendritic cells
Dendritic cells are a type of leukocyte/WBC that are specialized antigen-presenting cells. They are responsible for capturing, processing, and presenting antigens to T cells. They are constantly sampling their surroundings for signs of infection to initiate and develop the adaptive immune response.
Mast cells
Mast cells are a type of white blood cell that release histamine and other inflammatory mediators that help recruit other immune cells to the site of infection. They are involved in pathogen recognition, inflammation, antigen presentation, and T cell regulation. They are part of both the innate and adaptive immune system.
