Food Packaging Technology Multiple Choice Questions & Answers (MCQs) on “Food Packaging Materials – 1”.
1. Which of the following is used to pack carbonated soft drinks?
a) HDPE
b) PET
c) PS
d) PVC
Answer: b
Clarification: PET – Polyethylene Terephthalate is widely used to pack carbonated soft drinks. The PET bottle is usually fitted with either a standard aluminium roll-on closure or a pre-threaded plastic cap, both either in the standard or pilfer-proof form.
2. Which of the following is used to pack fried snack foods?
a) LDPE
b) PET
c) PS
d) PVC
Answer: a
Clarification: LDPE- Low Density Polyethylene is widely used to pack fried foods. Paperboard cans lined with a barrier polymer such as aluminium foil is sealed with LDPE-foil end.
3. Which of the following is used to pack coffee?
a) PET & LDPE
b) HDPE
c) HDPE & PS
d) PET & PVC
Answer: a
Clarification: Metalized PET laminated to LDPE is frequently used to pack coffee. This layer of polymer prevents staling and loss of flavor volatiles or chemical changes in the volatile components caused by moisture and O2 absorption.
4. Which of the following is used for packaging of milk in pouches?
a) Polyvinyl
b) Polyethylene Terephthalate
c) Polyethylene
d) Polyester
Answer: d
Clarification: Polyester pouches are used for packaging milk. Packaging materials used for milk should ideally not transmit more than 8% of incident light at 500nm wavelength and not more than 2% at 400nm wavelength. Other materials used for the same include – polypropylene, polystyrene, poly vinyl chloride, polyvinyldiene chloride (cryovac), rubber hydrochloride (pliofilm), polyester, polyamide (nylon), saran (a mixed polymer).
5. Which of the following materials is used in packaging yoghurt in cups?
a) Low Density Polyethylene
b) Polystyrene
c) Polyvinyl Chloride
d) High density Polyethylene
Answer: b
Clarification: Polystyrene cups are used in packaging yoghurt. Other than yoghurt, it is also used in packaging ice-creams. Amongst all varieties of Polystyrene, thermoformed HIPS(High Impact Polystyrene) in the form of small cups or larger tubs, with either an aluminum foil/plastic laminate or a paper/plastic laminate heat seal lid or closure is used.
6. Which of the following is used for primary packaging of butter?
a) Oiled Paper
b) Kraft Paper
c) Wax Paper
d) Parchment Paper
Answer: d
Clarification: Vegetable parchment is the primary packaging used in butter. The main control points in the packaging of butter include- oxidation, water permeability and vapor permeability. Aluminum foil (0.009 mm thick) laminated either to 40 gsm greaseproof paper or vegetable parchment. Other types of packaging include plastic tubs thermoformed from white-pigmented HIPS or PVC with a tight-fitting lid of the same material.
7. Which of the following material is used as a primary package in biscuits?
a) PE
b) LDPE
c) PVC
d) BOPP
Answer: d
Clarification: BOPP (bioriented polypropylene) filmis used as a primary package in biscuits. For higher quality products, duplex OPP or OPP combinations such as OPP/PE, OPP/PET, OPP/PVdC in the appropriate thickness and sealing range are used. It offers effective barrier against gas, odor and light. The plastic polyfilm is used in combination with an inner aluminium layer of approximately 7 microns.
8. Which of the following material is used as a primary package in bread?
a) HDPE
b) LDPE
c) PS
d) PVC
Answer: b
Clarification: LDPE (Low Density Polyethylene) is used as a primary package in bread. The LDPE bag is sealed with PS tag. Vacuum packaging is not sustainable as crushing could take place. Gas mixture in the packaging usually ranges from 100% CO2 to 50:50 CO2:N2.
9. Which of the following is the abrasion resistance layer in a retort pouch?
a) Polypropylene
b) Nylon
c) Aluminum Foil
d) Polyester
Answer: b
Clarification: Nylon is the abrasion resistance layer in a retort pouch. Propylene is the physical food contact layer (primary package). It is a heat seal surface and provides flexibility.
10. Which of the following polymer is used as a printing surface?
a) Polypropylene
b) Nylon
c) Aluminum Foil
d) Polyester
Answer: d
Clarification: Polyester is the printable surface as well as the outermost layer in a retort pouch. It also provides strength. Aluminum foil is the barrier layer of a retort. It protects from light, gases and odors.
11. Tetrapak has _______ layers.
a) 4
b) 5
c) 6
d) 7
Answer: c
Clarification: Tetrapak has 6 layers. The innermost to outermost layers are –
i) Polyethylene (innermost)
ii) Paper
iii) Polyethylene
iv) Aluminium
v) Polyethylene
vi) Polyethylene (outermost).
12. What is the function of Polyethylene in Tetrapak?
a) Mechanical rigidity
b) Gas barrier
c) Abrasion resistance
d) Liquid barrier
Answer: d
Clarification: Polyethylene serves multiple functions in Tetrapak (paperboard carton). The innermost layer is used as a liquid barrier and to bind layers of aluminum, primary layer, paper, printing layer together.
13. Which is the thinnest layer in Tetrapak?
a) Polyethylene
b) Paper
c) Nylon
d) Aluminium
Answer: d
Clarification: Aluminium foil is the thinnest layer in Tetrapak(paperboard carton). It is around 7 microns in width. Aluminium provides the best gas barrier and prevents exposure to sunlight.
14. Which is the thickest layer in Tetrapak?
a) Polyethylene
b) Paper
c) Nylon
d) Aluminium
Answer: b
Clarification: Paper is the thickest layer in Tetrapak. Tetrapak is also known as paperboard carton because of the same. Paper is bound to other layers by polyethylene.
15. Nylon is used in Tetrapak.
a) True
b) False
Answer: b
Clarification: The given statement is false. Nylon is not used in Tetrapak. It is used in retort pouches instead. Nylon acts as an abrasion resistance surface in retort packets. However, in Tetrapak paper is used to provide mechanical rigidity. Paper is combined with polyethylene film for abrasion resistance.