NiCE Factors Database

The NiCE (Nitrogen Conversion Estimate) Factors Database provides the first harmonized, food-specific nitrogen-to-protein conversion factors (NCFs) covering the complete EFSA FoodEx2 Exposure hierarchy. 
This data publication presents the final compiled dataset, including values for the purified-protein factor (kA), the food factor (kP), and their mean (k) for all FoodEx2 food items. 
NCF values originate from analytical measurements and the scientific literature, comprising both source-reported factors and factors derived from amino acid and nitrogen/protein data. 
All values were systematically quality-assessed, selected based on predefined data quality criteria, aggregated, and hierarchically propagated across the FoodEx2 structure using a standardized computational framework. 
The resulting dataset represents a comprehensive, transparent, and quality-oriented reference for food-specific NCFs and is intended to support accurate protein calculation in food composition databases, dietary assessment, and nutrition research. 
A detailed description of the database development and methodology is provided in the associated scientific publication.