5_Microbial Spoilage in Muscle Foods

pre-slaughter conditions of the animals

The microbial types and numbers on the meat can be affected by the ___

S.Y.C.A.L.E

(Salmonella enteric strains, Yersinia enterocolitica, Campylobacter jejuni, Aeromonas hydrophila, Listeria monocytogenes, and Escherichia coli)

Pathogenic microbial species contaminating meat from the gastrointestinal tract are

psychrotrophic aerobes and facultative anaerobes

Fresh meat storage in refrigerator is spoiled by ___

putrefaction

Meat spoilage results in the development of off-odor known as ___

psychrotrophic Lactobacillus

The vacuum- and gas-packaged meat and its products can be spoiled by

sliminess, souring, and greening

Spoilage of meat products occurs generally in three types:

Bacillaceae, Enterobacteriaceae, Lactobacillus, Pediococcus, and Streptococcus

Biogenic amines are formed by decarboxylation of amino acids during manufacturing and storage periods of sausage through the action of substrate-specific enzymes produced by microorganisms:

Biogenic amines

____are formed by decarboxylation of amino acids during manufacturing and storage periods of sausage through the action of substrate-specific enzymes produced by microorganisms: Bacillaceae, Enterobacteriaceae, Lactobacillus, Pediococcus, and Streptococcus.

decarboxylation of amino acids

Biogenic amines are formed by _____ during manufacturing and storage periods of sausage through the action of substrate-specific enzymes

Poultry

• is very high on the list of food poisoning outbreaks.

• is ideally suited as a culture medium for bacteria.

microflora, muscle type, product composition, and storage environment

The types of spoilage defects in seafoods will vary with the type of ___

seafood

In general, ___ is more susceptible to microbial spoilage than meat because meat has a lower pH and is less moist.

lower pH and is less moist

In general, seafood is more susceptible to microbial spoilage than meat because meat has a ___

utilization of NPN compounds

The early stages of microbial spoilage in fish involve ___, resulting in the formation of fatty acids, ammonia, and volatile compounds

formation of fatty acids, ammonia, and volatile compounds

The early stages of microbial spoilage in fish involve utilization of NPN compounds, resulting in the ____

Bacillus, Clostridium, Escherichia, Serratia, and Vibrio

The Seafoods can contain pathogenic bacteria contaminating from water and soil, such as ___

Gram-negative aerobic rods and facultative anaerobic rods and coliforms

constitute the major spoilage bacterial flora

Molds

are the chief spoilage microorganisms in smoked fish

release of body fluids from fish

Fish spoilage starts with ___

sickly sweet odor develops

Stages of spoilage:

• ?

• then a stale-fish odor due to trimethylamine,

• followed by ammonia odor

• finally putrid odors due to H2S and indole.

then a stale-fish odor due to trimethylamine

Stages of spoilage:

• a sickly sweet odor develops,

• ?

• followed by ammonia odor

• finally putrid odors due to H2S and indole.

followed by ammonia odor

Stages of spoilage:

• a sickly sweet odor develops,

• then a stale-fish odor due to trimethylamine,

• ?

• finally putrid odors due to H2S and indole.

finally putrid odors due to H2S and indole

Stages of spoilage:

• a sickly sweet odor develops,

• then a stale-fish odor due to trimethylamine,

• followed by ammonia odor

• ?

trimethylamine

Stages of spoilage:

• a sickly sweet odor develops,

• then a stale-fish odor due to _____,

• followed by ammonia odor

• finally putrid odors due to H2S and indole

ammonia odor

Stages of spoilage:

• a sickly sweet odor develops,

• then a stale-fish odor due to trimethylamine,

• followed by ____

• finally putrid odors due to H2S and indole

H2S and indole

Stages of spoilage:

• a sickly sweet odor develops,

• then a stale-fish odor due to trimethylamine,

• followed by ammonia odor

• finally putrid odors due to ___

• Surface characteristics

• Properties of substrate

• Physiological stage, Surface characteristics, Motility of the cells

Factors that influence the attachment of bacteria:

Biofilms

• due to quorum sensing, producing a sticky layer (produces exocellular matrix)

• Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, etc.

• Cell have the ability to adhere cause food contamination

• Cannot be eliminated entirely

• are easily attached and harder to eliminate in rougher surfaces

• Sanitizers are effective in younger ____

Bleach, Hydrogen peroxide, vinegar, baking soda

Products effective in eliminating food contaminants (in order):

Salmonella, E.coli, Ecoli O157:H7, Listeria

Bacteria Sensitive to cleaning agents:

Discoloration, Strong of odors, Development of Slime

Sensory characteristics in spoilage:

• Type of bacteria dominating

• Muscle type

• Product composition – sugar content (more sugar, more proliferated), lipid content

• Storage environment

• Storage duration

Muscle spoilage depends on these factors:

Refrigeration

slows mesophilic bacteria but does not inhibit psychrotrophs