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

Food	Nutrients Added	Why
Breakfast cereals	Iron, folic acid, B vitamins, vitamin D	To improve the nutritional value of a commonly eaten food; especially important for children
Plant milks	Calcium, vitamins B12, D and B2	To match the nutritional profile of cow's milk
Fruit juices	Vitamin C	Marketing advantage; replaces vitamin C lost during processing
Bread	Folic acid, calcium, iron	Some manufacturers add more than the legal minimum
Table salt	Iodine	Added in some countries to prevent iodine deficiency (not mandatory in the UK)

flowchart TD
    A["Fortification"] --> B["MANDATORY<br/>(Required by law)"]
    A --> C["VOLUNTARY<br/>(Manufacturer’s choice)"]

    B --> D["White flour:<br/>Calcium, Iron,<br/>Thiamin, Niacin,<br/>Folic acid"]
    B --> E["Margarine:<br/>Vitamins A & D"]

    C --> F["Cereals:<br/>Iron, Folic acid,<br/>B vitamins"]
    C --> G["Plant milks:<br/>Calcium, B12,<br/>Vitamin D"]

    style B fill:#e74c3c,color:#fff
    style C fill:#3498db,color:#fff

Exam Tip: Know the difference between mandatory and voluntary fortification. Mandatory = required by law (flour, margarine). Voluntary = the manufacturer chooses to add nutrients (cereals, plant milks). Be able to name the specific nutrients added.

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Food Additives

Food additives are substances added to food during processing to improve its properties. They have been used for centuries (salt, vinegar, sugar for preservation), but modern food technology uses a wide range of additives.

Types of Additives

Type	Purpose	Examples
Colourings	Add or restore colour to food	Sunset yellow (E110), tartrazine (E102), caramel (E150a)
Flavourings	Enhance or add flavour	Vanilla extract, monosodium glutamate (MSG/E621)
Preservatives	Extend shelf life by preventing microbial growth or oxidation	Sodium nitrite (E250, in bacon/ham), sulfur dioxide (E220), sorbic acid (E200)
Emulsifiers	Prevent oil and water from separating; create stable mixtures	Lecithin (E322, from soya), mono- and diglycerides (E471)
Stabilisers	Maintain the texture and consistency of food	Pectin (E440), guar gum (E412), xanthan gum (E415)
Antioxidants	Prevent fats from going rancid (oxidation)	Ascorbic acid/vitamin C (E300), tocopherols/vitamin E (E306)
Sweeteners	Provide sweetness without sugar (or with fewer calories)	Aspartame (E951), sucralose (E955), stevia (E960)
Raising agents	Produce gas to make baked goods rise	Baking powder (sodium bicarbonate + cream of tartar), E500

E Numbers

All approved food additives in the EU/UK are assigned an E number. The "E" stands for "Europe" and indicates that the additive has been tested and approved as safe.

E Number Range	Category
E100–E199	Colours
E200–E299	Preservatives
E300–E399	Antioxidants and acidity regulators
E400–E499	Emulsifiers, stabilisers, thickeners
E500–E599	Anti-caking agents, acids, bases
E600–E699	Flavour enhancers
E900–E999	Sweeteners, glazing agents

Arguments For and Against Additives