Secondary Processing and Technological Developments

This lesson covers secondary processing, fortification, food additives and GM foods, as required by the AQA GCSE Food Preparation and Nutrition specification (8585), section 3.6. You need to understand how primary ingredients are transformed into food products, how food is modified to improve nutrition and shelf life, and the role of technological developments.

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What Is Secondary Processing?

Secondary processing is the transformation of primary processed ingredients into food products that are ready for consumers to buy and eat (or cook).

Primary Processing	Secondary Processing
Wheat → Flour	Flour → Bread, pasta, cakes, biscuits
Milk → Pasteurised milk	Pasteurised milk → Cheese, yoghurt, butter, ice cream
Sugar cane → Sugar	Sugar → Jam, confectionery, baked goods
Cocoa beans → Cocoa	Cocoa → Chocolate
Fruit → Fruit pulp	Fruit pulp → Jam, juice, smoothies
Meat → Butchered cuts	Butchered cuts → Sausages, pies, ready meals

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Examples of Secondary Processing

Flour to Bread

Stage	Description
Mixing	Flour, water, yeast and salt are combined to form a dough
Kneading	Dough is kneaded to develop the gluten network (gives bread its structure)
Proving (fermentation)	Yeast ferments sugars in the flour, producing CO₂ (makes dough rise) and alcohol (evaporates during baking)
Shaping	Dough is shaped into loaves, rolls or other forms
Baking	Baked at approximately 200–230°C; yeast dies, gases expand, starch gelatinises, crust forms (Maillard reaction)
Cooling	Bread is cooled before slicing and packaging

Flour to Pasta

Stage	Description
Mixing	Durum wheat semolina (strong flour) is mixed with eggs (or water for dried pasta)
Kneading	Dough is kneaded until smooth
Shaping	Dough is rolled and cut or extruded through dies to create shapes (spaghetti, penne, fusilli)
Drying (for dried pasta)	Air-dried slowly to remove moisture; this gives dried pasta its long shelf life
Packaging	Packaged for sale

Milk to Cheese

Stage	Description
Pasteurisation	Milk is heat-treated to kill harmful bacteria
Adding starter culture	Lactic acid bacteria are added; they ferment lactose (milk sugar) into lactic acid, which acidifies the milk
Adding rennet	Rennet (an enzyme) causes the casein protein to coagulate, separating into solid curds and liquid whey
Cutting and draining	Curds are cut and whey is drained off
Salting	Salt is added for flavour and preservation
Pressing and moulding	Curds are pressed into moulds to form cheese shapes
Ageing (maturation)	Cheese is aged for weeks to years; flavour and texture develop during this time

Milk to Yoghurt

Stage	Description
Pasteurisation	Milk is heat-treated
Cooling	Milk is cooled to approximately 43–46°C (optimum for starter bacteria)
Adding starter culture	Lactobacillus and Streptococcus thermophilus bacteria are added
Incubation	Bacteria ferment lactose into lactic acid; this thickens the milk and creates the characteristic tangy flavour
Cooling	Yoghurt is cooled to stop fermentation
Adding flavours	Fruit, sugar, honey or other flavours may be added
Packaging	Packaged and refrigerated

Fruit to Jam

Stage	Description
Preparing fruit	Fruit is washed, chopped and weighed
Cooking with sugar	Fruit is cooked with sugar (typically 60% sugar by weight); the high sugar concentration acts as a preservative
Pectin and acid	Pectin (a natural carbohydrate) and acid (often lemon juice) are needed for the jam to set; some fruits are naturally high in pectin (apples, citrus)
Testing for setting point	The jam must reach 105°C (setting point)
Potting	Hot jam is poured into sterilised jars and sealed
Long shelf life	The high sugar content and sealed jar give jam a long shelf life

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Fortification

Fortification is the addition of vitamins and/or minerals to food to improve its nutritional value. This may be required by law or carried out voluntarily by manufacturers.

Mandatory Fortification in the UK

Food	Nutrients Added	Why
White flour	Calcium, iron, thiamin (B1), niacin (B3)	These nutrients are lost when bran and germ are removed during milling
White flour (from 2024)	Folic acid (vitamin B9)	To reduce neural tube defects (e.g., spina bifida) in babies
Margarine	Vitamins A and D	To match the vitamin content of butter; vitamin D supports calcium absorption

Voluntary Fortification