SAC 2 Preparation

Question 1

1a) Explain the functional property of flour when making sour cream pastry.

Answer 1

In pastry, flour provides structure for the product. Gluten and starch are responsible for this in flour. The structure allows products to hold a new shape. The cooked starch prevents products from collapsing once they have been removed from the oven and cooled.

Question 2

1b) Outline TWO functional roles of butter in pastry making.

Answer 2

Functional role 1:
Shortening effect: butter provides tenderness to the cooked food. The butter coats the starch grains and separates the gluten strands, preventing strong cohesion and providing a crisp shortening effect which is described as ‘short’.

Functional role 2:
Sensory properties: Butter enhances the flavour of pastry as well as giving it a moist, often oily texture and smooth mouth-feel. It also gives a rich flavour.

Question 3

1c) Explain how freezing extends the shelf life of the pie.

Answer 3

Freezing stops the growth of microbes (although the microbes are not killed) and the chemical and enzymatic changes, which cause loss of quality, are slowed.

Question 4

2a) Identify the part of the wheat grain flour comes from (1 mark)

Answer 4

The endosperm which is the body of the grain and is made of starch.

Question 5

2b) Describe the process that occurs when flour is mixed with stock and heated for 2 minutes (3 marks)

Answer 5

This process is called gelatinization.
Gelatinisation is the process that occurs where starch granules absorb liquid in the presence of heat and thicken the liquid, forming a gel.
While being heated, the mixture must be stirred to keep the starch evenly dispersed so the end product is smooth and lump free. It is important to boil the mixture as complete gelatinization does not occur until just before boiling point.

Question 6

2c)Explain why thigh fillets are a more suitable cut of chicken in the pie filling compared to breast fillets (2 marks)

Answer 6

The thigh fillet is from the more active part of the chicken so it is a tougher cut. It is darker in colour because it requires more oxygen to move about and is higher in fat. Domestic chickens do not fly so the breast meat is white and tender because there is less connective tissue. The thigh fillet is more suitable to be cooked in a pie than a breast fillet because the meat is cooked for a longer amount of time and therefore the breast would be more likely to become over cooked than the breast fillet.

Question 7

3a) Describe the changes in physical and chemical properties of the chicken thigh fillets when seared (step 2 from the recipe) (2 marks)

Answer 7

When chicken thigh fillets are seared, the Maillard reaction occurs. This causes the meat to brown. The proteins of the muscle fiber begin to denature. As the proteins change, there is contraction in the direction of the muscle fibre, resulting in the piece of meat shrinking and becoming hard.

Gelatin connective tissue - water soluble Gelatin

Chen. Nutrition, enzymes, aroma

Question 8

3b) Describe the cooking process boiling

Answer 8

Boiling is cooking food in water at 100oC. Boiling produces rapid bubbling all over the surface of the pan and evaporation of water as steam.

Question 9

3c) list 4 nutrients in meat

Answer 9

• Protein –essential for growth and development
• Iron –Important component of red blood cells
• Zinc –Important for a healthy immune system
• Fats –contribute to energy supply

Question 10

4a) Describe the difference between primary and secondary processing

Answer 10

During primary processing, the physical form of the food changes very little however during secondary processing the physical form, texture and flavor changes quite significantly.

Question 11

4b) 2 stages of primary and secondary processing on carrots (fill out table)

Answer 11

Primary

1. Harvesting either by machinery or by hand
2. Grading based on size, colour or maturity

Secondary

1. Cleaning to remove any dirt or stones
2. The carrots are blast chilled at -39oC for 20 minutes.

Question 12

4c) Carrots, onions and celery classification and another example.

Answer 12

Carrot Root vegetable Beetroot
Onion Bulb Garlic
Celery Stem vegetable Asparagus

Question 13

5a) 3 reasons for food processing

Answer 13

1. Ensure food is safe to eat
2. Makes some food edible
3. Extends shelf life

Question 14

5b) Identify the natural components of butter and eggs and discuss their contribution to the final sensory properties of a cupcake.

Answer 14

Natural component/final sensory
Butter/ fat/richness, aeration(with sugar), colour, aroma
Eggs /protein/binding, aeration, structure(volume and richness), setting(coagulate with heat and set a filling)

Question 15

Describe the processes used to pasteurise and homogenise milk and explain the importance of pasteurising and homogenising in primary processing of milk.
i) Pasteurising

Answer 15

Milk is pasteurised using the High Temperature Short Time (HTST) process. This involves pumping the milk continuously through heat exchangers to shock heat the milk to 72oC. It is held at this temperature for 15 seconds and then shock-cooled to 2oC. This process kills disease-producing bacteria (pathogenic bacteria)such as those that cause tuberculosis. Pasteurised milk is therefore safer to drink and keeps longer than untreated milk.

Question 16

5c) Describe the processes used to pasteurise and homogenise milk and explain the importance of pasteurising and homogenising in primary processing of milk.
ii) Homogenising

Answer 16

The process of homogenisation is carried out by forcing the milk through small nozzle-like openings or between closely positioned plates. This process is important because it slows down the separation of the cream by making the fat globules smaller without changing the nutritional composition of the milk.

Question 17

5d) Cupcakes are cooked by baking. Describe how heat is transferred when baking. (3 marks)

Answer 17

When baking, heat is provided by a combination of convection heat from air circulating through the oven, as well as heat radiating from the oven walls. Baked food is cooked without the addition of fat or oil.

Question 18

6a) Jam making is a great way of preserving fruits. The main ingredients for a berry jam include berry fruits, sugar and lemon juice. Outline the functional roles for each ingredient. (3 marks)

Answer 18

• Berry fruits: Berry fruits have a medium level of pectin and acid. Pectin (a natural component is fruits) along with sugar and acid helps jam set as well as prevent spoilage. It is essential in the gelling process of the preserves to develop a thick, slightly firm and spreadable consistency.

• Sugar: The role of sugar in jam is twofold.
First it helps to preserve the fruit by creating an environment that is hostile or unsuitable for the growth of microorganisms.
Second, sugar assists in the formation of a gel that sets the jam.

• Lemon juice: Lemon juice is used for the citric acid, which is added to raise the acid levels and assist in the gelling of the cooked jam.

Question 19

6b) Describe a test you can undertake to determine if the jam is ready to be placed in a jar. (2 marks)

Answer 19

To test if a jam is ready you can use the gel test. One method is the cold plate test where you place a tablespoon of hot jam onto a cold plate, leave for a few minutes then push your finger through the middle of the jam; if it remains in two distinct halves, the setting stage has been achieved.

Question 20

6c) Other summer fruit, such as apricot, can be preserved by dehydration and heat processing (bottling).
Explain how both dehydration and heat processing (bottling) can extend the shelf life of apricot?
i) Dehydration (2marks)

Answer 20

Dehydration is the removal of moisture or water from food. The aim of drying food is to reduce the water content down to between 5 per cent and 25 per cent so bacteria that cause decay cannot survive. When moisture is removed from apricots, microorganisms cannot grow. Dried apricots need to be stored in a cool, dark and dry environment and, if packaged in airtight containers, will have a longer shelf life.

Question 21

6c) Other summer fruit, such as apricot, can be preserved by dehydration and heat processing (bottling).
Explain how both dehydration and heat processing (bottling) can extend the shelf life of apricot?
ii) Heat processing (bottling) (2marks)

Answer 21

Apricots can be preserved by increasing the temperature above 60-70oC to kill harmful bacteria that can cause food spoilage or illness. Bottling is a method of preserving food by heating it in a container, which in the domestic or small kitchen is usually a glass bottle or jar. The heat kills micro organisms that cause food spoilage, and creates a partial vacuum that seals the bottle so the apricots are stored in a controlled environment.

Question 22

Recipe: chicken and veg pie
Sour cream crust
Appearance:
Aroma:
Flavour:
Texture:

Filling:
Appearance:
Aroma:
Flavour:
Texture:

Answer 22

Sour cream crust
Appearance: golden brown
Aroma: buttery and savoury
Flavour: rich pastry
Texture: short and flaky

Filling:
Appearance: brown/green
Aroma: savoury
Flavour: 
Texture: thick,

Question 23

How to prepare a pie to freeze:

Answer 23

Allow to cool completely in the fridge. Cover with cling film or put in an airtight container and label clearly with a date. Check the freezer temperature with a thermometer to ensure it is operating at a low enough temperature.