ICAR AIEEA-PG Ice Cream & Frozen Dairy Desserts: practice questions

1 · Overrun calculation and control · easy

100 L of mix gives 190 L of ice cream. What is the overrun?

1. 90%
2. 53%
3. 190%
4. 47%

2 · Overrun calculation and control · hard

A standard sets a minimum of 525 g of ice cream per litre. With a mix density of 1.10 kg/L, what is the maximum overrun allowed?

1. 47.7%
2. 57.5%
3. 52.3%
4. 109.5%

3 · Mix calculation: serum point and algebraic methods · medium

In the same 100 kg mix (30 kg cream, 9.67 kg skim milk powder, 15 kg sugar, 0.3 kg stabiliser), how much water is added?

1. 45.03 kg
2. 61.70 kg
3. 54.70 kg
4. 60.33 kg

4 · Classes of frozen desserts and their standards · easy

Under the U.S. federal standard, ice cream must contain at least:

1. 10% milk fat and 20% total milk solids
2. 5% milk fat and 2.5% milk protein in total
3. 12% milk fat and 36% total food solids
4. 8% milk fat and 28% total milk solids

5 · Mix processing: pasteurisation, homogenisation and ageing · easy

Why is ice cream mix aged at about 4 °C for several hours?

1. To crystallise fat, hydrate stabilisers and let emulsifiers act
2. To allow the starter culture to develop flavour before freezing
3. To dissolve air into the mix ready for whipping
4. To pasteurise the mix slowly at a low temperature

6 · Mix processing: pasteurisation, homogenisation and ageing · medium

Why is lower homogenising pressure used for high-fat ice cream mixes?

1. High-fat mixes do not need any homogenisation at all
2. High pressure melts the fat permanently in rich mixes
3. High-fat mixes cluster readily at high pressure
4. High pressure removes fat into a cream layer

7 · Hardening, storage and heat shock · medium

Why must ice cream be hardened quickly after the freezer?

1. Fast hardening adds new air cells that raise overrun
2. Slow hardening makes the fat melt and churn into butter
3. Slow hardening grows fewer, larger crystals
4. Fast hardening converts lactose into a glassy state

8 · Ice cream structure: ice crystals, air cells, fat network · easy

Physically, ice cream is best described as:

1. A partly frozen foam with ice, air and fat in unfrozen serum
2. An oil-in-water emulsion with no air cells
3. A frozen sugar solution with no dispersed phases of any kind in it
4. A gel of casein with trapped sugar crystals

9 · Defects and their causes · medium

Shrinkage of ice cream in packages is associated with:

1. Low overrun and constant storage temperature
2. Low sugar and slow hardening
3. High overrun and temperature or pressure fluctuations
4. High fat and long ageing

10 · Overrun calculation and control · hard

A batch freezer turns 10 L of mix (density 1.10 kg/L) into ice cream whose density is 0.62 kg/L. What is the overrun?

1. 56.4%
2. 43.6%
3. 77.4%
4. 177.4%