Based on Edexcel Textbook
pg 10-11 Functional foods
Functional foods contain an added ingredient not normally found in foods that is supposed to promotr good health. We all have about 1kg of bacteria in our gut that is usually in balance between bad and good but poor diet, stress, food poisoning or antibiotics can disrupt the balance. Prebiotics and probiotics boost the number of good bacteria over the bad. Prebiotics contain sugars called oligosaccharides that the body does not digest but are food for the good bacteria in the gut. Probiotics are produced by fermentation.
Stanol ester is an additive in foods that is supposed to reduce cholesterol. It come from plant sterols. Studies have shown that including stanol estersin your diet can reduce cholesterol by up to 10% so makers of products like benecol claim that their products reduce cholesterol.
But do functional foods really improve our health? There are doubts to the certainity of what manufacturers claim products do and if they really improve our health. Some scientists think functional foods should be tested like drugs before claims are made. A balanced diet can provide many of the additives in functional foods so it could be unnecessary to spend the extra money.
pg 12-13 MakingYoghurt and Soy Sauce
Milk can be preserved by turning it into yoghurt or cheese. To make yoghurt, milk is heated to sterilise it then it is stirred thoroughly and milk protein is added. A starter culture of Lactobacillus bacteria is added while the milk is still warm. The bacteria ferment the sugar lactose into lactic acid. This lowers the pH od the milk to the point when the milk proteins coagulate to become semi-solid. The raw yoghurt is then cooled quickly and can either be packaged as it is or flavours can be added.
Soy Sauce is a fermented sauce made from soya beans:
- Soya beans are cooked and mixed with ground roasted wheat.
- Aspergillus mould is added and the mixture is spread out on warm shallow trays supplied with air.