Food Processing Quiz

Q. Casein is present in milk in 

1. Dispersed form
2. Colloidal form
3. Emulsion form
4. All of the above

Answer: b)

Casein: It is  the chief protein in milk and the essential ingredient of cheese. In pure form, it is an amorphous white solid, tasteless and odourless, while its commercial type is yellowish with a pleasing odour. Cow’s milk contains about 3 percent casein.

Pure casein is an amorphous white solid without taste or odour. Commercial casein is slightly yellow, with a pleasant odour. Dry casein keeps well if protected from insects and rodents; damp casein is quickly attacked by molds and bacteria and acquires a disagreeable odour. The specific gravity is 1.25 to 1.31. Casein is a mixture of phosphoproteins of differing molecular weight.

Casein is a lyophilic colloid akin to albumin and gelatin. It is isoelectric at pH 4.6 where its solubility in water is but 0.01 percent. 

Q. Lamination is

1. The method of wrapping the food article with certain packaging material and storing them at ambient temperature
2. Combination of two or more materials into a single homogeneous packaging web by means of adhesive, solvent or heat
3. A type of packaging where the material use for packaging is made from substance obtained from middle lamella of cell wall
4. Coating of zinc on the surface of iron to prevent it from rusting

Answer: b)

• Lamination adds protection against fingerprints and smudges, stains and spills, tears and wrinkles, marks and abrasions, plus oil, grease, dirt, moisture and other contaminants. Lamination improves appearance by enhancing the ink colors of the printed piece.

Q. Retort pouches are 

1. Equipment used for the sterilization of pouches
2. Pouch shaped retort used for the sterilization of packaging material
3. Type of color used for printing the LDPE used to pack low acid food
4. Heat sterilizable flexible packs

Answer : b)

Q. What is OTR

1. Odour transfer rate
2. Oxygen transfer rate
3. Oxygen testing results
4. Odour testing results

Answer: b)

OTR: OTR (oxygen transmission rate) is the steady state rate at which oxygen gas permeates through a film at specified conditions of temperature and relative humidity.

Q. Aluminum foil acts

1. as good barrier for vapor
2. as good barrier for oxygen
3. as good barrier for light
4. all of the above

Answer: d)

• Aluminum foil acts as a total barrier to light and oxygen (which causes fats to oxidise or become rancid), odours and flavours, moistness, and germs, and so it is used broadly in food and pharmaceutical packaging.