CPT Shelf Life & Product Protection

Question 1

Which unit is most commonly used to express Moisture Vapor Transmission Rate (MVTR) in packaging films?

Accepted Answer

g/m²/day

Answer

MVTR is most commonly expressed as grams of water vapor transmitted per square meter per day (g/m²/day) under defined temperature and humidity conditions.

Question 2

The Oxygen Transmission Rate (OTR) of a packaging material is critical for products that are susceptible to oxidative rancidity. Which of the following materials has the LOWEST OTR?

Accepted Answer

Ethylene vinyl alcohol (EVOH)

Answer

EVOH (ethylene vinyl alcohol) provides an exceptionally low oxygen transmission rate, making it one of the best barrier materials against oxygen permeation.

Question 3

In accelerated shelf life testing (ASLT), the Arrhenius equation is used to predict product shelf life at ambient temperature. What does the Q10 factor represent?

Accepted Answer

The increase in reaction rate for a 10°C rise in temperature

Answer

Q10 is the factor by which the rate of a chemical or biological reaction increases with a 10°C rise in temperature, typically ranging from 2 to 3 for most food quality degradation reactions.

Question 4

Water activity (aw) is a critical parameter for predicting microbial shelf life. Which aw level represents the threshold below which most bacteria cannot grow?

Accepted Answer

0.91

Answer

Most spoilage and pathogenic bacteria cannot grow below an aw of approximately 0.91, making this a critical threshold for microbial safety and shelf life.

Question 5

Which type of packaging test measures the rate at which gases permeate through a film under a partial pressure differential?

Accepted Answer

Gas permeation test

Answer

Gas permeation testing directly measures the transmission rate of gases (O₂, CO₂, N₂) through a packaging film driven by the partial pressure difference across the film.

(CPT) Certified Packaging Technologist Practice Test

(CPT) Certified Packaging Technologist Practice Test

CPT Shelf Life & Product Protection