2.1 Using the laboratory data
Of course, the process of analysing foods in a laboratory is too slow and expensive to be used all the time. Once a particular food has been analysed, that data can be made available to other people. The Food Standards Agency and Public Health England produce a book called The Composition of Foods, which collects this data (Figure 4). It is currently in its seventh summary edition, published in 2014. It is more commonly known as McCance and Widdowson because of the names of its original authors. Be aware that McCance and Widdowson is aimed at food professionals, not members of the general public.
The data book contains tables in which you can look up the data for any food you like, for example:
- cereals and cereal products
- eggs and egg dishes
- fruit, nuts and seeds
- herbs and spices.
The tables give the full analysis of each food or food product. This includes not only the protein, fat and carbohydrate content (including the breakdown of the fat and carbohydrate types) but also the vitamins, salt, etc. Small businesses producing only few foods can buy just the relevant chapters of the book online.
An enterprising company has produced software that makes the information from McCance and Widdowson more easily available. For any recipe, you can enter the quantity of each ingredient into the program and it will automatically produce the nutritional data. This can then be displayed in the various different forms that are used on food packaging. If you should want to change your ingredients to produce a low-fat or low-salt version of your recipe, you can try different combinations of ingredients with the software to get an immediate analysis.
The one type of food for which it is not recommended that you use anything but chemical analysis of your product is fried foods. Why do you think fried foods are not ideally suited to being analysed using data tables?