In reply to:
But as the original book was written years ago it is possible that everything they tested was reasonably fresh and not subjected to supermarket storage methods.
John, I have the last 3 UK editions of the book (it is revised about every 10 years) and the numbers for basic foods do change, so they are retesting. The current edition was published in 2002 so the testing would have been done during the '90s. They obtain their samples from the usual supermarkets etc, so that the results are as near to what is actually consumed by the customer as possible. But I don't know whether additional testing is done for the US edition.
From the introduction to the 6th UK edition . . .
It is essential that food composition tables are regularly updated for a number of reasons . . . the nutritional value of many of the more traditional foods has changed. This can happen when there are new varieties or new sources of supply . . . ; with new farming practises which can affect the nutritional value . . .
For most foods a number of samples were purchased at different shops, supermarkets or other retail outlets. The samples were not analysed seperately but were pooled before analysis. When the composite sample was made up from a number of different brands of food, the numbers of the individual brands purchased were related to their relative shares of the retail market.
This we prescribe though no physician . . .
Our doctors say this is no month to bleed. (Rich. II)
Edited by bilko on 01/27/04 09:32 AM (server time).
'Then you should say what you mean,' the March Hare went on. 'I do,' Alice hastily replied; 'at least - at least I mean what I say - that's the same thing , you know.' 'Not the same thing a bit!' said the Hatter.