Calculating fat % from visual lean?

Hi

Does anyone have figures for average fat % of given visual lean cuts? Or perhaps know of a calculation I could use to get a figure which is better than 80vl = 80% meat 20% fat? 

We produce sausages of varying meat % and I want to be able to estimate how much fat will be in a particular sausage given the meat % and the VL used. In the past I have assumed that an 80VL will have ~20% fat but have recently read that an 80VL pork trim will more likely have 25-28% fat if you include internal fat marbling. 

Thanks 

Alfie

In days of old we used a crude device that simply broiled a specific sized portion at a predefined distance from the sample and consistent temp. The leachate was then measured by a ruler. When I was in college we would buy ground beef at many of the local stores, analyze the fat and moisture content in the Food Science Lab, and then publish weekly results in the school newspaper. Crude. And I do not remember the name of the machine. (I think it was a Hobart F101 Fat Tester).

In the recent past the USDA accepts the Univex FA-73. It was tested against the AOAC method of determining fat content as well as the Modified Babcock method (for ground beef). See Youtube: https://www.youtube....h?v=hLYUq9TYruI

If you are serious about having an accurate %age: Now we have the modern version: DSC HFT 2000f Fat Analyzer.

YouTube: https://www.youtube....h?v=o7-6Jh2CsbE

Also NDC's InfraLab Analyzer. Uses NIR technology. Youtube: https://www.youtube....h?v=Q19bsLFibcA

I am sure there are other machines. But if you are serious about QC then you need to get a real measuring analyzer and not just charts + math.

Good luck.

I am attaching a white paper on chemical lean measurement.  It briefly mentions various methods including new DEXA technology.  You can check CL (or fat content) of 100% of product through this non-destructive method.

Thanks for the help!

I understand that out-right analysis is preferable and we do preform fat tests on finished products however I was curious whether there exists a paper with average meat fat data - similar to what I imagine nutritional programmes such as A La Calc use to calculate their nutritionals - as this would be helpful to refer to for new recipe developments.