Food Spoilage and Safety

food spoilage

deterioration of food quality making it undesirable

food safety

ensuring food is free from hazards that cause illness

food preservation

methods to slow spoilage and prevent illness

true or false, conditions for spoilage can also support pathogens

true

5 steps to spoilage

1. initial microbal contamination

2. microbial growth and metabolism

3. chemical changes

4. sensory changes

5. microbial overgrowth and competition

causes of food spoilage

microbial activity

enzymatic reactions

chemical/physical factors

factors affecting spoilage

intrinsic- pH, water activity, nutrients

extrinsic- temp, humidity, atmosphere

implicit- microbial interactions

meat

Pseudomonas → slime

Brochothrix thermosphacta → sour odors

Lactic acid bacteria → sour

dairy

Lactococcus, Lactobacillus, Pseudomonas, yeasts, molds

produce

yeasts, molds, Erwinia, Pectobacterium

breads

molds, rope spoilage (Bacillus)

danger zone

40-140F

conditions favoring spoilage

Temperature: Danger zone 40–140°F (4–60°C).

Oxygen: Aerobic vs. anaerobic growth.

Moisture: High water activity increases spoilage.

Time: Extended storage promotes growth.

spoilage detection methods

Sensory: Odor, color, texture, slime, gas, mold.

Microbiological: Plate count, detection of spoilage organisms.

Chemical: pH, peroxide value.

Instrumental: ATP, electronic noses.

biological

salmonella, listeria, e. coli

chemical

allergens, residues

physical

metal, glass, bone

spoilage

Quality concern, often detectable.

food safety

health concern, often invisible

spoilage

prevent with preservation

safety

maintain with HACCP controls