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Determination of a Nitrogen Factor for Chicken Breast - FA0121

Nitrogen factors are analytical factors used to measure meat and fish content (i.e. the amount of meat or fish used) in compound products, and added water in raw meat and fish, and their products. They are used by both enforcement labs (public analysts) to check (QUID) labelling claims on meat and fish content, and by industry to check their raw materials and finished products.
Skinless chicken breast is the most used portion in the manufacture of retail chicken products and in catering. The UK cannot produce sufficient chicken breast to meet demand, and imports significant quantities of chicken breast and chicken breast preparations. The last extensive study to determine nitrogen factors for chicken (whole chicken, breast, leg etc) was funded by MAFF and published in 2000. The chicken breast nitrogen factor derived from this study was used extensively in investigating mislabelling of injected and tumbled chicken breast both in the UK and in many EU countries, and was publish in the Official Journal for the 2005 EC Coordinated Control Programme.
Since 2000 the genetics of chicken has changed and the rearings times before slaughter have reduced significantly, and it is important to re-assess whether the nitrogen factor for chicken breast has changed. The European Commission (DG-AGRI) is funding a project to determine the physiological water content of skinless chicken breast and skin-on legs, in order to enforce Regulation 543/2008 limiting the amount of extraneous water poultry and poultry parts can pick up during preparation in poultry plant. Chicken breast and leg samples have been collected from the 7 main EU producers of chicken, and analysed for moisture and protein. This small project will determine a representative sample of chicken breast from the 336 available, and will carry out some additional analyses (ash, fat and hydroxyproline) in order to combine these with the moisture and protein results of the same samples to give a statistically robust nitrogen factor. This work is therefore very cost effective The results will be published in a peer reviewed journal as with all previous nitrogen factor work carried out by the RSC-AMC Nitrogen Factors Sub-Committee.
84 samples will be chosen from the 336 samples of skinless chicken breast collected in 7 EU countries (UK, Germany, France, Spain, Italy, Poland, Netherlands) without any contact with water for the DG-AGRI Project. The 336 samples are taken from light and heavy Ross and Cobb birds, and the 84 samples will be chosen to be representative of the UK market in chicken breast. They will have already been analysed by the 8 NRLS (National Reference Labs) taking part in the DG-AGRI project for nitrogen and moisture.
Additionally, the 84 samples will be analysed for ash, fat and hydroxyproline, and the results combined with those from the Commission Project to give a robust nitrogen factor for chicken breast.
DG-AGRI has given permission to use some of the samples and results of analyses of chicken breast in its EU Project for this study.
Project Documents
• EVID4 - Final project report : FA0121 Chicken Breast final amend report evid4 Feb 14   (570k)
• FRP - Final Report : FA0121 Chicken Breast final report evid4   (569k)
• FRP - Final Report : Final Report   (141k)
• ANX - Annex : ANNEXES 1, 2 and 3 Final Report FA0121   (297k)
Time-Scale and Cost
From: 2012

To: 2013

Cost: £13,580
Contractor / Funded Organisations
Royal Society of Chemistry