CFS Food Packaging & Shelf Life 3

Question 1

What is the critical water activity level below which most mold species cannot grow?

Accepted Answer

0.80

Answer

Most common molds cannot grow at water activity below 0.80, though xerophilic molds can survive at levels as low as 0.70–0.75, which informs shelf life design for intermediate-moisture foods.

Question 2

What does MVTR stand for and why is it significant in packaging science?

Accepted Answer

Moisture Vapor Transmission Rate; it measures water vapor permeability through packaging

Answer

MVTR (Moisture Vapor Transmission Rate) quantifies how quickly water vapor permeates through a packaging material, which is critical for protecting moisture-sensitive foods like crackers or dried products.

Question 3

Ultra-high temperature (UHT) milk is most commonly packaged in which type of container to achieve room-temperature shelf stability?

Accepted Answer

Aseptic multilayer paperboard cartons (e.g., Tetra Pak)

Answer

UHT milk is packaged under aseptic conditions in multilayer paperboard cartons (such as Tetra Pak) that provide a barrier against oxygen, light, and microorganisms, enabling room-temperature storage.

Question 4

Intelligent packaging differs from active packaging primarily in that it:

Accepted Answer

Monitors and communicates information about product condition or history

Answer

Intelligent packaging uses sensors or indicators (e.g., time-temperature indicators, freshness sensors) to monitor and communicate information about product condition rather than actively altering the food environment.

Question 5

Which thermal packaging concept uses phase-change materials (PCMs) to maintain cold chain temperature during distribution?

Accepted Answer

Insulated passive packaging with PCMs

Answer

Insulated passive packaging incorporating phase-change materials absorbs or releases latent heat during phase transitions to maintain product temperature within a required range during cold chain distribution.

CFS - Certified Food Scientist Practice Test

CFS - Certified Food Scientist Practice Test

CFS Food Packaging & Shelf Life 3