2. Materials, Component and Their Application

2.1 Functional properties of protein in foods

Nature of food science and technology:

  • There are many different protein foods from animal and vegetable sources. By understanding the effect of agitation, or the addition of acids or heat, the structure of protein is altered and impacts on the sensory qualities of finished products (1.1, 3.1)

Understandings:

  • The chemical composition and structure of proteins

  • Denaturation and coagulation

  • Maillard reaction

  • Gelation of protein

  • Gluten formation

Application and guidance:

  • How amino acids are joined by peptide bonds to form polypeptide chains.

  • The difference in structure of globular and fibrous proteins.

  • Denaturation and coagulation of proteins through: heat, acid, agitation, enzymes and salt.

  • The effects of preparation and cooking methods of meat, fish and eggs.

  • How browning occurs through the Maillard reaction (non-enzymic browning) between protein chains and reducing sugars.

  • The gelation of proteins in products such as custard and cheese.

  • The role of gluten when making bread and pasta.

2.2 Functional properties of carbohydrate in foods

Nature of food science and technology:

  • Starch is often used to form the structure of baked food products and to thicken sauces. Sugar is widely used as a sweetener and when heated it adds colour to products, such as cakes and breads. (1.1, 3.1)

Understandings:

  • The chemical composition and structure of carbohydrates

  • Dextrinization

  • Caramelisation and crystallisation

  • Gelatinisation

  • Pectin gels

Application and guidance:

  • The structure of monosaccharides, disaccharides and polysaccharides.

  • The impact of dry heat, acids and enzymes on dextrinization of starch.

  • The impact of temperature, agitation and acidity and presence of other ingredients on the Caramelisation and crystallisation of sugar.

  • The impact of temperature, agitation and pH on gelatinisation of starch.

  • How the levels of amylose and amylopectin in different starches (e.g. potato starch, rice flour, corn flour) affects the organoleptic properties of starch.

  • The impact of acids on pectin gelation.

2.3 Functional properties of fat in foods

Nature of food science and technology:

  • Fats are obtained from plant and animal sources. The chemical composition of plant and animal fats affects the way it can be used to prepare food products e.g. smoke point, lamination of pastries. It is important to use the appropriate type of fat for the desired outcome. For example, butter is used to make pastry, and using oil would not give the desired shortening effect. (1.1, 3.1)

Understandings:

  • The chemical composition and structure of fats

  • Emulsification and homogenisation

  • Aeration and foams

  • Plasticity and shortening

  • Hydrogenation

  • Melting and smoke points

Application and guidance:

  • The structure of triglycerides, saturated fatty acids, unsaturated fatty acids (monounsaturated and polyunsaturated).

  • The impact of oil and water in the emulsification and homogenisation process.

  • How creaming, rubbing- in, whisking and layering are to aerate and create foams.

  • The role of the plasticity of different fats on shortening of food products.

  • The advantages and disadvantages of hydrogenating fats and oils.

  • How the chemical composition of fats impacts on the melting and smoke points of fats.

2.4 Functional properties of additives

Nature of food science and technology:

  • Additives are substances added to foods to perform specific functions. Their use can be controversial and consumers may be wary of their use. For example, the flavour enhancer monosodium glutamate (MSG), which has been reported to have negative side effects if consumed in large quantities. (1.1, 1.4, 3.1)

Understandings:

  • Classification of additives: natural, nature identical and synthetic additives

  • Functions of additives

  • Benefits and risks of additives in foods

  • Functions of sweeteners

Application and guidance:

  • Classifications and uses of additives in a range of food products (e.g. ready-made sauces, low fat yoghurts, confectionery, baked products).

  • The function of additives: flavours, flavour enhancers, colours, preservatives, antioxidants, stabilisers, emulsifiers sweeteners, thickening and gelling agents

  • The advantages and disadvantages of different types of additives to both the producers and consumers, e.g. consider MSG, saccharin and aspartame.

2.5 Functional properties of additional ingredients

Nature of food science and technology:

  • Additional ingredients have been used for many years to improve sensory qualities and shelf life of foods both domestically and commercially. (1.5, 1.12, 2.3)

Understandings:

  • Categories of additional ingredients: raising agents, acids and alkalis, and salt

  • Types of raising agents and their application

  • Types of acids and alkalis and their application

Application and guidance:

  • The different properties of additional ingredients used both domestically and commercially e.g. salting, pickling, fermentation and leavening.

  • The factors and processes that affect the function of different raising agents (yeast, baking powder, bicarbonate of soda) in the bread and cakes.

  • The use of adding acid to food products. e.g. ascorbic acid to prevent browning, vinegar to extend shelf life and lactic acid in cheese making, addition of acid to bicarbonate of soda.

2.6 Food fortification

Nature of food science and technology:

  • Vitamins are added to improve the nutritional quality of the food supply and to provide a public health benefit with minimal risk to health. For example, Vitamin B12 in breakfast cereals. (2.7)

Understandings:

  • Types of food fortification

  • Reasons for food fortification

  • Criticisms and limitations of food fortification

  • Food supplements

Application and guidance:

  • Four types of fortification: bio-fortification, synthetic biology, commercial fortification and home fortification.

  • How food can be fortified by replacing nutrients which were lost during manufacture (e.g. B group vitamins, minerals such as iron and calcium).

  • How food can be fortified to act as a public health intervention (e.g. fluoride in drinking water).

  • How food can be fortified to ensure the nutritional equivalence of substitute foods (e.g. to make butter and margarine similar in content, soy milk and cow milk).

  • How food can be fortified ensure the appropriate vitamin and mineral nutrient composition of foods for special dietary purposes (e.g. glutenfree products, low sodium).

  • The criticisms and limitations related to food fortification.

  • How food supplements can be used for health and body development.

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