Nitrogen and protein content measurement and nitrogen to protein conversion factors for dairy and soy protein-based foods: a systematic review and modelling analysis

The Joint FAO/WHO Expert Meetings on Nutrition (JEMNU) was established in 2009 to provide scientific advice to the committees of the Joint FAO/WHO Food Standards Programme (i.e. Codex) or Member Countries. JEMNU aims to provide relevant scientific advice in an independent, timely and cost-effective manner; therefore, JEMNU will be convened when there is a specific request from a Codex Committee or Member Countries.

Currently being discussed at the Codex Committee on Nutrition and Foods for Special Dietary Uses (CCNFSDU) is the most appropriate nitrogen to protein conversion factor (or factors) to use in estimating protein content of soy-based ingredients and milk-based ingredients used in infant formulas and follow-up formulas. To provide guidance on this topic, at the 39th Session of CCNFSDU in 2017, the Committee requested that JEMNU be convened to review the evidence and develop evidence-informed guidance regarding nitrogen to protein conversion factors.

FAO and WHO convened the first meeting of JEMNU in Geneva, Switzerland from 16 to 17 July 2019. 

A systematic review of the literature was commissioned to inform discussions at the meeting and serve as the evidence base on which recommended conversion factors were identified.