The table informs about changes made in the original datasets in order to obtain the food nutrient composition database. Therefore, it is composed of 954 food items (in the rows) and the columns correspond to those of the file "CNP-building-blocks.db - (1) food nutrient composition database of 954 food items". The following codes explain how concentration values in the nutrient composition database were obtained: (1) SD (source data), the value was available in the original sources (i.e. Lee et al. 1970, "Free sugars in fruits and vegetables", New York's Food Life Science Bulletin 1, 1-12; FAO 1970, "Amino-acid content of foods and biological data on proteins"; and BEDCA database, see http://www.bedca.net/); (2) ND (not defined), the value was not in the original sources and was set to zero; (3) MVR (missing value recalculated), the value was not present in the original sources and was calculated by equally distributing the total amount of the corresponding macronutrient category; (4) AVA+ (available value adjusted with increase), the value was available in the original sources but required to be proportionally increased (i.e. with respect to all other simple molecules) for the match between the sum of simple molecules and the total amount of the corresponding macronutrient category; (5) AVA- (available value adjusted with decrease), the value was available in the original sources but required to be proportionally decreased (i.e. with respect to all other simple molecules) for the match between the sum of simple molecules and the total amount of the corresponding macronutrient category.