Basics
What branch of food science studies bacteria in yogurt and salsa?
Microbiology
Name the five basic tastes.
Sweet, Sour, Salty, Bitter, Umami
What pigment makes tomatoes red?
Lycopene
What causes guacamole to turn brown?
Enzymatic browning (polyphenol oxidase + oxygen)
Name one common microbe that can contaminate salsa.
E. coli
Salmonella
Listeria
What does food science help us do with salsa ingredients?
Extend shelf life
Improve safety
Enhance flavor
Which salsa ingredient lowers pH and adds sourness?
Lime juice
What pigment makes purple onions colorful?
Anthocyanins
What slows enzyme activity in cut fruits and vegetables?
Acid (lime/lemon juice)
What’s one food safety rule when cutting vegetables?
Wash produce and use clean cutting boards
What happens to pH when lime juice is added to salsa?
It decreases (becomes more acidic)
Why does salt improve salsa flavor?
Enhances taste perception and balances flavors
Which pigments make peppers yellow, orange, or red?
Carotenoids
Why doesn’t lime stop browning completely?
Enzymes still work slowly, just less active
What’s the safest way to store salsa?
Refrigerate promptly after preparation
What’s one reason salsa changes after being stored overnight?
Enzymatic browning or Pigment breakdown
How does acidity make salsa safer to eat?
Slows microbial growth by lowering pH
What pigment gives green peppers their color?
Chlorophyll
How does refrigeration affect enzyme activity?
Slows down enzymatic reactions
Why is salsa more dangerous if left at room temperature?
Microbes grow rapidly in the “danger zone” (40–140°F)
Which two sciences are most important for salsa safety and flavor?
Microbiology & Chemistry
Compare salsa with and without lime. What would be different in flavor and safety?
Less tangy
Higher pH → more microbial risk
Why does salsa color fade after storage?
Pigments break down due to oxygen, light, and enzymes
Predict how salsa texture and color would change if no lime was added.
More browning
Softer texture
Higher microbial growth
A salsa outbreak was linked to unwashed cilantro. What went wrong, and how could it be prevented?
Microbial contamination → wash herbs thoroughly before use