Food Packaging - Final Exam

PET is used in food packaging

A. As monolayer material in trays for different MAP-applications

B. As a high gas barrier material, comparable to the performance of EVOH

C. As virgin PET (coming from crude oil) recycled PET (containing recycled content) or bio-PET (compostable)

D. As alternative to PP-trays which are not heat resistant

(A)

• APET/mono-PET trays are widely used for MAP meat, cheese, etc.; PET itself is not a high gas barrier comparable to EVOH and is usually combined with PE/EVOH when high barrier is needed.

• PET can be virgin or recycled and even bio-based, but bio-PET is not compostable; it is chemically the same PET.

• PET trays are often an alternative to PS or PVC; PP can also be heat-resistant, so "alternative to PP-trays which are not heat resistant" is wrong.

Following statements about bioplastics are given:

A. Bioplastics do not contain any additives

B. Some of the bioplastics are produced from renewable resources

C. Bioplastics can be used in combination with paper material

D. Bioplastics are compostable

(2) and (3)

Bioplastic may be bio-based, biodegradable, both or neither, and they do contain additives in practice.

Not all bioplastics are compostable; only certain grades are certified.

In the packaging material with multilayer structure PS/EVOH/PE, the function of PE is:

A. To give sealing properties to this packaging material

B. To improve the gas barrier of this packaging material

C. To give heat resistance properties to his packaging material

D. To increase the recyclability of this packaging material

(A)

• In multilayers like PS/EVOH/PE the PE inner layer provides heat-sealing and often contact layer functions; EVOH is the gas-barrier layer.

• PE does not primarily give high gas barrier, heat resistant, or recyclability here.

The O2-permeability of the plastic packaging material

A. Decreases by applying a metallization on the material

B. Increases with increasing thickness

C. Is 4 to 6 times higher than the CO2-permeability

D. Is independent of the storage temperature

(A)

• Metallization (e.g. Al layer) strongly reduces O2 permeability.

• Permeability decreases with increasing thickness and increases with temperature; it is not independent of temperature.

• CO2 typically permeates plastics faster than O2, so O2 permeability is not 4-6 times higher than CO2.

Packaging materials used for aseptic packaging

A. Should have a very good to excellent water barrier because of the long shelf life of the packaged food product.

B. Do not need good oxygen barriers because the food product is sterilized prior packaging

C. Should be heat resistance, because the sterilization of the packaging materials is done with steam or dry heat.

D. Do not neat no comply EU 10/2011, because of the decontamination step prior packaging

(A)

• Aseptic packs must protect against both oxygen and moisture to maintain quality for months.

• Good oxygen barrier is needed even though product is sterilized.

• Materials must be heat-resistant or chemically resistant depending on the sterilization method (steam, H2O2, etc), but that is not the distinguishing single statement here.

• They still must comply with EU 10/2011 (food contact legislation).

Packaging materials interact with food products in different ways. One of those interactions is migration. This is a process:

A. Where components from the packaging material are released in food product

B. Which defines how much gas is diffusing through the packaging material

C. Which is influenced by storage time and storage temperature

D. Where components from the food product are absorbed by the packaging material

(A)

Migration is the transfer of low-molecular-weight substances (oligomers, additives, monomers) from the packaging into the food; it depends strongly on time and temperature. Gas diffusion through a material is permeation, and sorption of food components into the material is scalping, not migration in the narrow legal sense.

Following statement about sorting and recycling of food packaging materials are given:

1. Multilayer plastics are difficult to recycle

2. Adding digital watermarks in the artwork on plastics con improve the sorting efficiency

3. Recyclable materials contain a minimum amount of recycled materials

4. The volume of a given packaging material on the market is an important factor whether or not this material is considered recyclable

Answer:

(1), (2), & (4)

In a HFFS-packaging machine:

A. The packaging material is formed by the machine into trays or pouches

B. It is not possible to apply modified atmosphere packaging

C. A sterilization step takes place after filling the food product into the packaging material

D. Preformed trays are fed into the machine

Answer:

(A)

Polyamide is used in food packaging because of its:

1. Biodegradable properties for coffee capsules applications

2. High temperature resistance for sterilization processes

3. Mechanical strength for big bag application

4. High gas permeability making it useful for fresh-cut vegetables

Answer:

(2) and (3)

Following statements about MAP are given. Which statement is correct?

A. The MAP-technology can be applied both for products in refrigerated storage as well as ambient storage

B. MAP is necessary step during aseptic packaging

C. When applying CO2 as component in the gas mixture, the headspace in the package should be as low as possible

D. The packaging material used for MAP should always contain a metallized layer

Answer:

(A)