Category: Food Packaging Technology Objective Questions

Food Packaging Technology Multiple Choice Questions & Answers (MCQs) on “Additives in Plastics”.

1. Which of the following is not a plastic colorant?
a) Diarylide
b) Tartrazine
c) Sudan stain
d) Oil blue A
Answer: b
Clarification: Tartrazine is not a plastic colorant. It is an artificial dye (Lemon yellow colored) used in foods. Sudan stain and Oil blue A are dyes and Diarylide is a pigment. Colorants are added to plastic to give it a desired colour.

2. What is the function of biostabilizers?
a) To regulate hardness
b) Obtain better impact resistance
c) Control surface tension
d) To prevent deterioration
Answer: d
Clarification: Biostabilizers helps to prevent deterioration of plastic. Biostabilizers are also called as antimicrobials because itdecreases susceptibility of plastic against microbial attack.

3. What is the function of fillers?
a) Increase conductance
b) Reduce sinkage
c) Increase stiffness and hardness
d) Improve ability to absorb shock
Answer: c
Clarification: Fillers help in increasing the stiffness and hardness of a plastic. Substances like photoinitiators increase electrical stability. Impact modifiers improve the ability to absorb shock. Blowing agents reduces sinkage.

4. Are foaming agents used in plastic?
a) True
b) False
Answer: a
Clarification: Foaming agents are also known as blowing agents. They are used during the process of blow moulding, to reduce or eliminate sink marks. It gives a foam structure to the plastic, hence the name foaming agent.

5. Which of the following is not a filler?
a) CaCo₃
b) SbO₃
c) Silica
d) Asbestos
Answer: b
Clarification: Antimony Trioxide (SbO₃) is not filler. Rest of these are fillers used in plastics. Fillers provide rigidity to the plastic, thereby increasing its tensile strength and toughness. It also increases elastic modulus and wear resistance.

6. Which of the following is not a lubricant used in plastic?
a) Silicone oil
b) Low mol wt PE
c) Neoprene
d) Halogens
Answer: d
Clarification: Halogens are not lubricants; they are flame retarders. Silicone oil, low molecular weight polyethylene and neoprene are lubricants. Lubricants are used to prevent any damage caused to plastic during its processing (especially the moulding process).

7. UV Stabilizers are added to plastics?
a) True
b) False
Answer: a
Clarification: UV stabilizers are added to plastics to increase the life of plastics, especially when exposed to UV lights. The following UV stabilizers are generally used- benzotriazoles, alkylated hindered phenol, benzophenones, etc.

8. Anti-oxidants used in plastic.
a) True
b) False
Answer: a
Clarification: Anti-oxidants are used in plastic to prevent oxidation. Plastics deteriorate due to oxidation – unstable melt flow properties, brittleness, discoloration and loss of tensile properties. Following are the commonly used anti-oxidants used in plastics-arylamines, phenols, phosphites and various sulfur compounds.

9. What is the function of plasticizer?
a) Improve rheology
b) Lower glass transition temperature
c) Increase electrical stability
d) Improve strength
Answer: b
Clarification: Plasticizers lower the glass transition temperature of plastics. Therefore, it helps to make the plastic more flexible. It does so by decreasing its viscosity in a way. Rheology is improved by lubricants. Substances like photoinitiators increase electrical stability and fillers improve strength.

10. Which among the following is a UV light absorber?
a) Phosphate esters
b) Quaternary ammonium compounds
c) Polyethylene glycol esters
d) Benzophenones
Answer: d
Clarification: Benzophenone is an additive used in plastics as a UV light absorber. These are used to increase the life of plastic and stabilize its color, mainly caused due to its exposure to sunlight – UV spectrum.

11. Halogens are used as _______ in plastics.
a) Flame retardant
b) UV light absorber
c) Antimicrobial
d) Antistatic agents
Answer: a
Clarification: Halogens are used as fire retardant in plastics. Halogens are generally added to thermoplastics to provide insulation, coat base plastic to exclude oxygen and create an endothermic cooling reaction.

12. Adipate diesters are _________
a) Flame retardant
b) Antimicrobial
c) UV light absorber
d) Plasticizers
Answer: d
Clarification: Adipate diesters are plasticizers used in plastic. Plasticizers are lubricants, which work by decreasing physical boding of the molecules and overcoming forces of attraction amongst them.

Food Packaging Technology Interview Questions and Answers for Experienced people on “Paper Making – 2”.

1. Which of the following was the first paper making machine?
a) Fourinder machine
b) Cylinder machine
c) Twin-Wire Formers
d) Roller Presses
Answer: a
Clarification: The first paper making machine was Fourdrinier machine of 1804, named after its financiers Henry and Sealy Fourdrinier, two prosperous London stationers who purchased the patent interests of the Frenchman Didot Frères. In this, paper is made by depositing a very dilute suspension of fibers from a very low consistency aqueous suspension (greater than 99% water) on to a relatively fine woven screen, over 95% of the water being removed by drainage through the wire. The fibers interlace in a generally random manner as they are deposited on the wire and become part of the filter medium.

2. Paper greater than ________ is considered paperboard.
a) 300 μm
b) 200 μm
c) 500 μm
d) 400 μm
Answer: a
Clarification: Paper greater than -2 (i.e., grams per square meter or GSM).

3. _________ are used to produce heavy multi-ply boards.
a) Fourinder machine
b) Cylinder machine
c) Twin-Wire Formers
d) Roller Presses
Answer: b
Clarification: Cylinder machines are used to produce heavy multi-ply boards. They produce a sheet that is much stronger in the direction of flow than that produced on Fourdrinier machines. A cylinder covered with a wire cloth is rotated partially submerged in a stock suspension. Because of a vacuum applied inside the cylinder, water drains inward through the wire cloth, and the paper web is formed on the outside. The web is picked up by a felt, which is pressed onto the top of the cylinder by a rubber roll. A series of vats provide individual plies of fiber which are subsequently matted together.

4. ___________ are particularly used for lightweight sheets, corrugated media and linerboard grades.
a) Fourinder machine
b) Roller Presses
c) Twin-wire formers
d) Cylinder machine
Answer: c
Clarification: Twin-wire formers are particularly used for lightweight sheets, corrugated media and linerboard grades. In this, the paper web is formed between two converging forming screens by means of a flow box and the water is drained from the slurry by pressure and later by vacuum. A typical twin-wire forming unit is the inverform, which was designed to provide a new method for the manufacture of single and multi-ply sheets at high speeds. Successive layers of fiber are laid down sequentially on the felt, with water being removed upwardly, overcoming the difficulty experienced in the conventional downward removal of water through several layers of board at high speed.

5. The moisture content of the paper sheet before entering the dryer is _______
a) 35%–40%
b) 35%–50%
c) 45%–60%
d) 75%–90%
Answer: d
Clarification: After leaving the forming fabric of the papermaking machine, the sheet (which has a moisture content of 75%–90% depending on type) passes to the press and dryer sections for further water removal.

6. The moisture content of the paper sheet after passing through the rotary presses is _______
a) 80%–90%
b) 60%–70%
c) 40%–50%
d) 10%–20%
Answer: b
Clarification: Rotary presses (which may have solid or perforated rollers, often with internal suction) receive the sheets on continuous felts, which act as conveyers and porous receptors of water. On leaving the press, the moisture content is typically 60%–70%, again depending on type.

7. The final moisture content of paper after pressing and drying is __________
a) 4%–10%
b) 10%–20%
c) 1%–5%
d) 40%–50%
Answer: a
Clarification: The paper is after passing through a series of steam-heated rollers is dried to a final moisture content between 4% and 10%. Other types of dryers are used for special products or situations. For example, the Yankee dryer is a large, steam-heated cylinder, which dries the sheet from one side only, and is used extensively for tissues and to produce machine glazed (MG) papers, the latter having a glazed or shiny surface from intimate contact with the polished dryer surface.

8. The application of chemicals to the surface of a paper web is done with _______
a) Stew press
b) Scaling press
c) Screw press
d) Size press
Answer: d
Clarification: The application of chemicals to the surface of a paper web is done with a size press. In a size press, the dry paper is passed through a flooded nib, where a dispersion of functional chemical contacts both sides of the paper. Excess liquid is then squeezed out in the press and the paper is re-dried.

9. An optimum concentration of coating solution for improving water resistance of paperboard is _____
a) 1.5 w/v%
b) 2.5 w/v%
c) 3 w/v%
d) 1 w/v%
Answer: c
Clarification: An optimum concentration of coating solution for improving water resistance of paperboard was 3 w/v %. It gives a coating thickness of 28 μm equivalent to 49.5 GSM. There is an increase in the water resistance of paperboard when it is coated with PLA. A coating thickness between 4.7 to 42.7 μm decreases water vapor permeability from 4.8 to 25.5 times, while decreasing water absorptiveness from 11.9 to 17.9 times.

10. __________ are widely used in paper coatings for oil and moisture resistance in microwave popcorn bags.
a) Chlorochemicals
b) Hydrogen peroxide
c) Fluorochemicals
d) Polyphenols
Answer: c
Clarification: Fluorochemicals are widely used in paper coatings for oil and moisture resistance in microwave popcorn bags. It is also used in fast-food paper packaging for muffin and french-fry bags, sandwich/burger wrappers and small pizza and burger boxes. The perfluorocarbon moiety in these classes of products has the effect of lowering the surface energy of the individual paper fibers which greatly contributes to the holdout of low surface energy liquids such as greases and oils.

11. Pigments are added at the wet end of the paper machine and serve to fill the sheet.
a) True
b) False
Answer: b
Clarification: The given statement is false. Though functionally and chemically similar, fillers and pigments are distinguished from one another in that fillers are added at the wet end of the paper machine and serve to fill the sheet; pigments are added at the size press and serve to alter the surface of the sheet.

12. Pigments comprise ______ of the dry solids in paper coatings.
a) 10%–30%
b) 70%–90%
c) 40%–50%
d) 60%–90%
Answer: b
Clarification: Pigments comprise 70%–90% of the dry solids in paper coatings. They are generally designed to mask or change the appearance of the base stock, improve opacity, impart a smooth and receptive surface for printing or provide special properties for particular purposes.

13. Paper has a definite caused by the greater orientation of fibers.
a) Yield
b) Strain
c) Stretch
d) Grain
Answer: d
Clarification: Paper has a definite grain caused by the greater orientation of fibers, in the direction of travel of the paper machine, and the greater strength orientation that results partly from the greater fiber alignment and partly from the greater tension exerted on the paper in this direction during drying.

14. The grain direction is known as the machine direction (MD), while the cross direction (CD) is the direction of the paper at right angles to the MD.
a) True
b) False
Answer: a
Clarification: The given statement is true. The grain direction is known as the machine direction (MD), while the cross direction (CD) is the direction of the paper at right angles to the MD. The grain of paper must be taken into account in measuring all physical properties. Most of the physical properties of paper depend on direction, that is, the MD, CD and thickness direction (z-direction).

15. Usually, there is less variation in paper properties in the MD than in the CD.
a) True
b) False
Answer: a
Clarification: The given statement is true. Usually, there is less variation in paper properties in the MD than in the CD. It is because variations occur slowly in the MD, whereas in the CD they may occur quite suddenly for a variety of process related reasons. In addition, the CD strength normally varies depending on how far the sample was taken from the edge of the sheet.

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.

Food Packaging Technology Multiple Choice Questions & Answers (MCQs) on “Edible, Biobased and Biodegradable Food Packaging Materials”.

1. Which amongst the following is not a food grade polymer?
a) Ethylene Propylene Diene monomer
b) Polyurethane
c) Polyvinyl Chloride
d) Viton
Answer: c
Clarification: Polyvinyl Chloride (PVC) is not a food grade polymer. It is toxic in nature. A polymer is a labeled food grade when it is inert and doesn’t react with food in a harmful manner. Ethylene propylene diene monomer, polyurethane and viton are food grade polymers.

2. Traditional packaging is more sustainable than edible packaging.
a) True
b) False
Answer: b
Clarification: Edible packaging material is more sustainable than traditional packaging material. It is because of its biodegradable property. Traditional packaging material leaves residues on degrading, whereas edible packaging does not. Therefore, making it more sustainable and suitable for the environment.

3. Which of the following is not a mechanism of film formation in edible coating?
a) Simple co-acervation
b) Complex co-acervation
c) Polymerisation
d) Gelation
Answer: c
Clarification: Polymerisation is not a mechanism of film formation in edible coating. Simple co-acervation, compound co-acervation and gelation are mechanisms of film formation in edible coating. Polymerisation is a phenomenon when monomers combine together to form a polymer. Film formation mechanisms are those which tell about the interaction of film and the substrate.

4. ____________ and ___________ are used to make edible packaging material.
a) Minerals and vitamins
b) Proteins and vitamins
c) Water and proteins
d) Proteins and carbohydrates
Answer: d
Clarification: Proteins and carbohydrates are used to make edible packaging material. The protein based material includes-gluten, zein, soy,etc. Carbohydrates based material includes-chitosan, cellulose, dextrin, pectin,etc.

5. _________ is a protein based material for edible coating.
a) Chitosan
b) Acylglycerol
c) Collagen
d) Alginate
Answer: a
Clarification: Collagen is a protein based material for edible coating. Chitosan and alginate are polymer based material for edible coating. Acylglycerol is a lipid based material for edible coating.

6. Complex co-acervation includes addition of hydrosoluble non-electrolyte.
a) True
b) False
Answer: b
Clarification: Simple co-acervation includes addition of hydrosoluble non-electrolyte. Complex co-acervation is simple precipitation of polymer complex, when two hydrocolloids of opposite charges are mixed.

7. Gelation is a ________ of formation of edible coating.
a) Consequence
b) Mechanism
c) Result
d) Prerequisite
Answer: b
Clarification: Gelation is a mechanism of formation of edible coating. Gelation is a process when the heating of polymers leads to its denaturation, followed by gelation or coagulation on cooling. Gelation is also known as thermal coagulation.

8. Edible packaging has comparable water vapor transmission rates.
a) True
b) False
Answer: a
Clarification: Biobased polymers are generally hydrophilic in nature. So are many traditional polymers like nylon, ethylvinyl alcohol, etc. Permeability may increase when humidity increases in both cases. Hence, we can say that edible packaging has comparable water vapor transmission rates.

9. Cohesive forces between ___________ is a principal of film formation.
a) Inner membrane and cell wall
b) Film and substrate
c) Endocarp and mesocarp
d) Polymer molecules
Answer: d
Clarification: Cohesive forces between polymer molecules are a principle of film formation. It is responsible for the barrier properties of the film. It helps in decreasing the permeability and hence transmission rates of gases and water respectively.

10. Adhesive forces between _______________ is a principal of film formation.
a) Polymer molecules
b) Inner membrane and cell wall
c) Film and substrate
d) Endocarp and mesocarp
Answer: c
Clarification: Adhesive forces between film and substrate are a principle of film formation. It is responsible for keeping the film intact. This forms an edible film, which can be consumed along with the food.

11. Which of the following properties make edible/biodegradable packaging material better than the traditional packaging material?
a) Compostability
b) Water vapor transmission rate
c) Oxygen transmission rate
d) Thermal properties
Answer: a
Clarification: Compostability makes edible/biodegradable packaging material better than the traditional packaging material. Compostability is also known as biodegradability. It is the property when the package meets its end life, how well a material decomposes. Biodegradable packets degrades faster and better than the traditional polymers.

12. Which of the following statement is false about edible/biobased packaging material when compared to traditional packaging material?
a) Improved product flavor
b) Resistance to oxygen permeability
c) Low water vapor permeability
d) More sustainable
Answer: c
Clarification: Edible / biobased packaging material has a higher water vapor permeability than traditional packaging material. However it is better than traditional packaging material since it helps improving product flavor, has a higher resistance to oxygen permeability and is more sustainable.

13. Chitosan, a polymer based material for edible coating, also has _______ properties.
a) antifungal
b) antioxidant
c) antifogging
d) thickening
Answer: a
Clarification: Chitosan, a polymer based material for edible coating, also has antifungal properties. Chitosan is used as an edible coating in cucumbers and bell pepper, where its primary function is – moisture barrier.

14. What does PHB stand for?
a) Polyhydrobutyl
b) Polyhydroxybutyrate
c) Polyhydroxybutene
d) Polyhydroxybutane
Answer: b
Clarification: PHB stands for Polyhydroxybutyrate. It is a polyester, popular as a food grade packaging material for snacks, dry products and etc. It is a biodegradable semi-crystalline thermoplastic material produced via fermentation of renewable carbs.

15. CEN headquarters are located in __________
a) Brussels
b) London
c) New York
d) Rome
Answer: a
Clarification: CEN (European Committee for Standardisation) headquarters are located in Brussels, Belgium. It is responsible for the preparation of certain standards on compostability, in order to increase sustainability.

Food Packaging Technology Multiple Choice Questions & Answers (MCQs) on “Types of Paper”.

1. _________ is made from bleached pulp.
a) Kraft paper
b) Coarse paper
c) Fine paper
d) Glassine paper
Answer: c
Clarification: Fine paper is made from bleached pulp. Paper is divided into two broad categories- fine paper and coarse papers. Fine papers are generally used for writing paper, bond, ledger, and book and cover papers. Whereas, coarse papers are generally made of unbleached kraft softwood pulps and are used for packaging.

2. _________ is a translucent, machine-finished paper which has been hydrated to give oil and grease resistance.
a) Kraft paper
b) Bleach paper
c) Waxed paper
d) Greaseproof paper
Answer: d
Clarification: Greaseproof paper is a translucent, machine-finished paper which has been hydrated to give oil and grease resistance. Prolonged beating or mechanical refining is used to fibrillate and break the cellulose fibers which absorb so much water that they become superficially gelatinized and sticky. This physical phenomenon is called hydration and results in consolidation of the web in the paper machine with many of the interstitial spaces filled in.

3. Which of the following is often used for packaging butter and similar fatty foods?
a) Glassine paper
b) Greaseproof paper
c) Vegetable parchment paper
d) Waxed paper
Answer: b
Clarification: Greaseproof paper is often used for packaging butter and similar fatty foods. The satisfactory performance of greaseproof papers depends on the extent to which the pores have been closed. Provided that there are few interconnecting pores between the fibers, the passage of liquids is difficult. However, they are not strictly “greaseproof” because oils and fats will penetrate them after a certain interval of time. Despite this, they are often used for packaging butter and similar fatty foods since they resist the penetration of fat for a reasonable period.

4. __________ is typically coarse with exceptional strength.
a) Bleached paper
b) Parchment paper
c) Kraft paper
d) Fine paper
Answer: c
Clarification: Kraft paper is typically coarse with exceptional strength, often made on a Fourdrinier machine and then either machine-glazed on a Yankee dryer or machine-finished on a calender. It is sometimes made with no calendering so that when it is converted into bags, the rough surface will prevent them from sliding over one another when stacked on pallets.

5. Which of the following paper has excellent wet strength?
a) Bleached paper
b) Vegetable parchment paper
c) Kraft paper
d) Waxed paper
Answer: b
Clarification: Vegetable parchment paper has excellent wet strength. It involves passing a web of high quality, unsized chemical pulp through a bath of concentrated sulfuric acid. The cellulosic fibers swell and partially dissolve, filling the interstices between the fibers and resulting in extensive hydrogen bonding. Thorough washing in water, followed by drying on conventional papermaking dryers, causes reprecipitation and consolidation of the network, resulting in a paper that is stronger wet than dry (it has excellent wet strength, even in boiling water), free of lint, odor and taste, and resistant to grease and oils.

6. Which of the following papers is made from strong sulfite pulp?
a) Kraft paper
b) Waxed paper
c) Vegetable parchment paper
d) Glazed imitation parchment paper
Answer: d
Clarification: Glazed imitation parchment (GIP) is made from strong sulfite pulp, which is heavily enginesized and glazed to give the necessary degree of protection. Special finishing processes provide qualities ranging from rough to smooth, brittle to soft and sticky to releasable.

7. _________ is generally used as an interleaver between slices of food such as meat or pastry.
a) Vegetable parchment paper
b) Kraft paper
c) Bleached paper
d) Waxed paper
Answer: a
Clarification: Because of its grease resistance and wet strength, it strips away easily from food material without defibering, thus finding use as an interleaver between slices of food such as meat or pastry. Labels and inserts in products with high oil or grease content are frequently made from parchment. It can be treated with mold inhibitors and used to wrap foods such as cheese.

8. The refractive index of glassine paper is around.
a) 1-2
b) 2-3
c) 3-4
d) 4-5
Answer: c
Clarification: The refractive index of glassine paper is around 1-2. Due to the intimate interfiber hydrogen bonding the refractive index of the glassine paper approaches the 1.02 value of amorphous cellulose, indicating that very few pores or other fiber/air interfaces exist for scattering light or allowing liquid penetration. The transparency can vary widely depending on the degree of hydration of the pulp and the basis weight of the paper. The addition of titanium dioxide makes the paper opaque, and it is frequently plasticized to increase its toughness.

9. Waxed papers provide a barrier against _________
a) Penetration of oxygen only
b) Penetration of vapors only
c) Penetration of liquids and vapors
d) Penetration of liquids only
Answer: c
Clarification: Waxed papers provide a barrier against penetration of liquids and vapors. Many base papers are suitable for waxing, including greaseproof and glassine papers. The major types are wet-waxed, dry-waxed and wax-laminated. Wax-sized papers, in which the wax is added at the beater during the papermaking process, have the least amount of wax and therefore give the least amount of protection.

10. ________ is prepared by further treating greaseproof paper in a supercalender.
a) Waterproof paper
b) Machine finished paper
c) Glassine paper
d) Glazed paper
Answer: c
Clarification: Glassine paper is produced by further treating greaseproof paper in a supercalender where is it carefully dampened with water and run through a battery of steam-heated rollers. It derives its name from its glassy, smooth surface, high density and transparency.

Food Packaging Technology Assessment Questions and Answers on “Food Packaging Materials – 2”.

1. The headspace maintained in wine bottles is around _______
a) 10mm
b) 20mm
c) 15mm
d) 25mm
Answer: c
Clarification: The headspace maintained in wine bottles is around 15mm. Headspace is the space between cap of the bottle and the food product. Headspace is essential to avoid spilling while opening.

2. Wine can be packed in transparent glass bottles.
a) True
b) False
Answer: b
Clarification: The given statement is false. Wine should always be packed in colored or tinted glass bottles (generally dark green/ brown). Exposure to sunlight makes it more susceptible to oxidation, hence resulting in a dull, flat, oxidized flavor.

3. The filler gas used in wine cans is _______
a) O₂
b) He
c) CO₂
d) N₂
Answer: d
Clarification: The filler gas used in wine cans is N₂. It is necessary to increase the internal pressure in the cans to prevent collapse. Internal pressure is approximately 170kPa.

4. Wine can be packed in a fiberboard box.
a) True
b) False
Answer: a
Clarification: The given statement is true. Wine can be packed in a fiberboard box, which is laminated (internally) by PVdC copolymer-coated PA-LDPE laminate. It is also known as a Bag-in-Box (BIB) package.

5. Which of the following is used for microwave ovenable trays?
a) PVC
b) HDPE
c) PET
d) PS
Answer: c
Clarification: PET (Polyethylene Terephthalate) is used for microwave ovenable trays. It is also used for “boil‐in‐the‐bag” products which are frozen before use. It has a oriented crystalline structure (35-45% crystallinity), making it stable upto 140-160°C.

6. Which of the following plastic polymer is used for chips packaging?
a) PVDC
b) PP
c) PE
d) LDPE
Answer: a
Clarification: PVDC- Polyvinyldiene Chloride has excellent water vapor and gas barrier properties. Not only this, its heat sealing characteristics and resistance to oils & fats makes it an ideal choice to pack chips.

7. Which of the following plastic polymers is used for packaging of fresh produce?
a) Dextrose
b) PS
c) PVdC
d) LDPE
Answer: b
Clarification: PS – Polystyrene has very high vapor and gas transmission rate – hence, making it a breathable film. However, it is not suitable for heat sterilization and deteriorates on exposure to sunlight. This film is crystal clear and sparkling, enabling consumers to see through it.

8. R-enamel is used for high acidic foods.
a) True
b) False
Answer: a
Clarification: The given statement is true. R-enamel stands for Regular enamel. It includes – phenolic resin or epoxy phenolic coating (resole phenolic) with BPA epoxy and H₃PO₄ catalyst.

9. Purple staining is related to a defect in which packaging?
a) PET bottles
b) Glass bottles
c) Metal cans
d) Paperboard
Answer: c
Clarification: Purple staining is observed in metal cans. This defect refers to the blackening of inner side of can. It occurs when sulphur containing food reacts with iron in the can to form purple iron sulphide.

10. Which of the following is most widely for packaging raw fruits & vegetables?
a) PVC
b) OPP
c) BOPP
d) LLDPE
Answer: d
Clarification: Blend of polyolefilms –mainly LLDPE is used for packaging raw fruits & vegetables . Film contains pigments to protect it from sunlight. LLDPE is stretchable and transparent, enabling consumers to look into the packet.

11. Which of the following materials is most suitable for the packaging of pre-processed vegetables?
a) HDPE, LLDPE, PVC
b) PVdC, OPP, HDPE
c) OPP, LDPE, LLDPE
d) PS, BOPP, HDPE
Answer: c
Clarification: Most suitable are polymeric blend of LLDPE, LDPE or OPP with EVA copolymer.

Vegetable	Packging material and thickness
Peeled potato, both whole and sliced	LDPE, 50 μm
Grated carrot	OPP, 40 μm, microperforated LDPE-EVA-OPP, 30-40 μm
Sliced beetroot	LDPE, 50 μm
Grated beetroot	OPP, 40 μm, microperforated OPP,PE EVA-OPP 30-40 μm
Shredded white cabbage	OPP, 40 μm, LDPE-EVA-OPP, 30-40 μm
Shredded onion	OPP, 40 μm