However, due to increasing levels of sophistication and complexity in nutrition science, there is a greater demand for complete, current and reliable FCD, together with information on a wider range of food components, including bioactive compounds.
However, due to the amount of information already available and in order to avoid the need to analyse every food for every vitamin, values from the scientific literature were included, although the tables are still predominately based on analytical data.
Chemical analysis of food samples carried out in analytical laboratories is typically the preferred method for creating FCD.
This includes accounting for factors that could affect the nutrient content of a food as purchased (e.g. region and/or country of origin, season, brand, fortification) or as consumed (e.g. storage, preparation and cooking methods).
Ideally, the methods used for analysis should have been shown to be reliable and reproducible, i.e. those recommended by organisation such as the Association of Official Analytical Chemists (AOAC) or the International Organization for Standardization (ISO).
It is not feasible to determine FCD using chemical analysis for every nutrient in every food type due to insufficient resources.
Another approach commonly used by FCD compilers is to ‘borrow’ or ‘adopt’ nutrient values that were originally generated by another organisation.
An important step for both new analytical FCD and for values borrowed from other sources is for the compiler to evaluate the quality of the data before it can be added into FCDBs.
In addition, a range of data quality measures need to be undertaken relating to the food identity and sampling and analytical aspects.
FCDBs provide values for energy and nutrients including protein, carbohydrates, fat, vitamins and minerals and for other important food components such as fibre.
[12] A list of International FCDBs can be found on the National Food Institute - Technical University of Denmark's (DTU) website.