Food Microbiology Chapter 2

What are intrinsic factors in food?

• Storage temperature

• Presence of competitor microorganisms

• Internal characteristics of the food product

• External environmental conditions

Which of the following is NOT an intrinsic factor?

• pH levels

• Nutrient content

• Water activity

• Relative humidity

At what pH do most microorganisms grow best?

• pH 4

• pH 5

• pH 6

• pH 7

Which microorganism can grow at a pH range of 1.5 to 8.5?

• Yeast

• Mould

• Bacteria

• All of the above

Which food has the highest water activity?

• Cookies

• Dried fruit

• Fresh meat

• Peanut butter

Which type of microorganism grows best at temperatures between 30-40°C?

• Psychrophiles

• Mesophiles

• Thermophiles

• Psychrotrophic

What is the effect of high relative humidity on low A_w foods?

• They lose moisture

• They gain moisture

• They remain unchanged

• They spoil faster

Which gas is used to control microorganisms in foods?

• Hydrogen

• Oxygen

• Carbon dioxide

• Nitrogen

Which of the following is an example of an antimicrobial constituent?

• Protein

• Sugar

• Eugenol

• Water

Which of the following foods is likely to spoil due to high moisture content?

• Dried fruit

• Canned food

• Fresh fish

• Instant coffee