How is the percentage of meat content calculated? And can it be composed with collagen protein?
In the United Kingdom, the terms ‘lean meat content’ and ‘meat content’ are used as compositional characteristics for meat products. The “lean meat content” is the percentage of raw lean meat, free of visible fat, in the product, or the content of lean meat raw material that has been processed. The meat content is the total percentage of meat including fat (and possibly bone), calculated as raw meat, that has been used as an ingredient in the preparation of the product.
The chemical determination is based on the method of Stubbs and More. One starts from the nitrogen factor F, the average nitrogen content of the processed lean meat raw material, calculated on fat-free matter. From the analytical nitrogen content of the meat product found, one calculates the lean meat content:
%fat free meat= 100(% nitrogen/F)
The meat content is calculated by adding the analytical fat content of the product to the lean meat content: “meat content”=% lean meat + % fat = 100(% nitrogen/F) + % fat
Usually, the percentage of “fat-free meat” calculated according to the former formula is called the “lean meat” content in our country. In fact, it is not. What is calculated here is ‘completely fat-free meat’, while the English definition defines ‘lean meat’ as ‘meat-free of visible fat’, which will be a few percent more.
Nitrogen factor table
The nitrogen factor F depends on the type(s) of meat raw material in the product. Known values are as follows:
|– breast meat||3.90|
|– dark meat||3.60|
|– breast meat||3.90|
|– dark meat||3.50|
|– of unknown origin||3.55|
|– beef liver||3.45|
|– pork liver||3.65|
If mixtures of several meat raw materials have been used in unknown proportions, one usually takes the average of the relevant factors. When calculating the fat-free meat content or the meat content, only the meat nitrogen content (= the percentage of meat protein divided by 6.25) is taken into account. If protein-containing binders (e.g., non-meat proteins such as caseinate or soy protein) or other non-meat additives containing protein or nitrogen have been used in product preparation, then the total nitrogen content should be reduced by the nitrogen contribution from the non-meat ingredients.
Single product calculation
aangenomen: het betreft een product bereid uit varkensvlees meat content’=100(2,88/3,45) %+6,0%=89,5%
Composite product calculation
aangenomen: het product is bereid uit varkens- en rundvlees en bevat als bindmiddel 1% vleesvreemd eiwit met een stikstofgehalte van 15% stikstoffactor F=(3,45+3,55)/2=3,50 vleesstikstofgehalte = 2,08% – 0,01 x 15%=1,93% ‘meat content’=100(1,93/3,50) %+32,0%=87,1%
For products that lose a lot of moisture during the cooking process or are prepared from pre-cooked raw materials (e.g. corned beef), the found ‘meat content’ can be more than 100%. It should be noted that it is not the percentage of ‘cooked meat’ that is calculated, but the amount of raw material that is the basis for it (the ‘ingoing raw meat’).
Certain types of single products (e.g. bacon, cooked ham and shoulder) require a calculation of the percentage of ‘added water’ in the UK. This content is derived from the ‘meat content’ and the sum of the percentages of added additives (other than water):
% ‘added water’ =100%-‘meat content’-% added additives
Calculation example (Table 1)
- single product:
- assumed: prepared from pork (see preceding calculation example)
- meat content =89.5%
- added phosphate, calculated as pentasodium triphosphate = (0.60-0.0243 x 18.0) % x 1.73 = 0.28
- % “added water” =100%-“meat content – (contents of added phosphate, salt and carbohydrates) =100% – 89.5% – 0.28% – 3.0% – 1.0% = 6.2%.
In some agricultural quality regulations (including those for smoked sausage), the collagen-free meat protein content is used as a quality-defining characteristic. It represents the percentage of ‘muscle protein’ in the product and is defined as the crude protein content (%total nitrogen x6.25) minus the percentage of connective tissue protein (% collagen protein=% hydroxyproline x 8)