ICAR AIEEA-PG Emerging & Non-thermal Dairy Processing: practice questions

1 · Hurdle technology · easy

Which hurdle mainly preserves sweetened condensed milk?

1. Low pH from lactic fermentation
2. Nisin from starter bacteria
3. Low water activity from high sugar
4. High oxygen in the can

2 · High pressure processing · medium

How does high pressure pretreatment of cheese milk typically affect rennet curd?

1. No curd forms at all
2. A softer gel with lower yield always
3. The milk becomes UHT-like and unrennetable
4. Firmer gel and higher yield

3 · Ohmic, microwave, radio-frequency and infrared heating · easy

Which process can turn cheese pieces into crunchy puffed snacks?

1. Cold plasma
2. Microwave-vacuum drying
3. UV-C treatment
4. Ohmic heating in brine

4 · Irradiation and UV-C treatment of milk · medium

Which treatment of milk was authorised in the EU in 2016 to raise vitamin D?

1. Gamma irradiation of raw milk
2. Cold plasma on butter
3. UV light on pasteurised milk
4. Ohmic heating of cream

5 · Carbonation and carbon dioxide to extend shelf life · easy

Which raw milk spoilage organisms does dissolved CO2 inhibit most?

1. Lactic acid bacteria
2. Psychrotrophs such as Pseudomonas
3. Thermophilic spore-formers
4. Bacteriophages

6 · Carbonation and carbon dioxide to extend shelf life · medium

Why is CO2 more effective in chilled products?

1. Bacteria absorb more CO2 when warm
2. Its solubility rises at low temperature
3. It reacts with ice crystals to form acid
4. CO2 is insoluble above 0 °C

7 · Carbonation and carbon dioxide to extend shelf life · medium

How is CO2 added to raw milk mostly removed before sale?

1. It stays in the milk as a permitted preservative
2. By freezing the milk
3. By adding sodium hydroxide
4. By heating and vacuum degassing in processing

8 · Microencapsulation and nanotechnology · easy

Which microencapsulation method is most widely used industrially?

1. Spray drying
2. Complex coacervation
3. Liposome formation
4. Supercritical expansion

9 · Microencapsulation and nanotechnology · medium

Why is fish oil encapsulated before adding it to milk or yoghurt?

1. To prevent oxidation and mask fishy flavour
2. To make it soluble in water without emulsifier
3. To raise its melting point above 100 °C
4. To convert omega-3 into omega-6 fatty acids

10 · 3D printing and other new formats · medium

Why does processed cheese print well?

1. It melts on heating and sets on cooling
2. It is a powder that sinters in a laser
3. It sets by rennet action in the nozzle
4. It never changes viscosity with temperature