Lecture 2 Flashcards
What is food spoilage?
The original nutritional value, texture, and flavor of the food are reduced.
The food may become ________ to people and unsuitable to eat.
Harmful
What is an example of nutritive spoilage?
Destruction of riboflavin in milk upon contact with sunlight
What is an example of aesthetic spoilage?
Wilted lettuce and discolored fruits
What are the 3 types of food spoilage?
Nutritive, Aesthetic, and Poisonous
What are the common causes of food spoilage?
Microorganisms, enzymes, insects, improper storage, physical damages
Where is a high number of bacteria present in meat?
Hide, hair hooves, and GI Tract
In healthy living, muscle bacteria is _________.
Very low
What is nonintact meat?
Beef that has been injected/enhanced with solutions, mechanically tenderized by needling, cubing, or pounding devices
What are common microorganisms present in beef hide?
Staphylococcus, Micrococcus, Pseudomonas, Fungi, Yeast, and Mold.
__________ of muscle influences the microbial growth and type of spoilage.
Composition
What gets converted to lactic acid after death?
Glycogen
Why is lactic acid important?
It helps the meat maintain a low pH and prevents bacterial growth
What type of growth can occur with dried meat?
Fungal growth
Fungal growth results in what?
whiskery, airy, cottony gray-black spots on beef.
What happens to the meat if an animal is tired before slaughter?
A depletion of glycogen from muscle leads to dark, firm, dry meat.
What are the 3 types of spoilage for processed meat?
Slimy, souring and greening.
What causes slimy spoilage?
the growth of yeast, LAB, and B.thermosphacta
What causes souring?
When bacteria utilize lactose and other sugars to produce acids.
What causes the greening of fresh meats?
Caused by the growth of bacteria which produce H2S
What are the main sources of microbes on poultry?
Skin, feathers, feet, and litter
Where does cross-contamination occur in the poultry industry
When they are hanging and bleed
What steps are taken to reduce contamination?
Rapid cooling, slush ice, carbon dioxide chilling system, use of portable water.
What are the primary causes of spoilage in the poultry industry?
Prolonged distribution or storage time
Inappropriate storage temperature
High initial bacterial counts
High post-rigor meat pH
What organisms are involved in the spoilage of poultry?
Pseudomonas, Aeromonas, Shewanella putrefaciens
What influences fish microbiota?
Environment, season, harvesting process, water temp, chilling after catching.
Higher water temp results in fish with ________ microorganisms.
Higher
What types of microbes dominate fish from tropical water?
Bacillus and Micrococcus
What dominates fish and shellfish from temperate waters?
Vibrio
What is produced by gram-negative bacteria?
Histamine
True or False. Shellfish has more free Amino Acids and carbohydrate in form of Glycogen.
True
What compound gives off a fishy odor?
Trimethylamine
What is oxidative rancidity?
Unsaturated fat reacts with oxygen in the storage environment.
What are GMPs to avoid contamination?
use of hot water, spray system, application of antimicrobial (Chlorine, PAA), organic acid (lactic, citric, propionic, acetic)
When elevated what reduces bacterial growth?
CO2
What is the purpose of irradiation?
To reduce vegetative cells of pathogenic bacteria
What is the purpose of HPP?
To denature enzymes and extend shelf life
What are the advantages of HPP?
Eliminate potential for post-packaging contamination
Higher consumer acceptance
Sensory quality remains unchanged
Retains fresh quality commodity
