Determining Fat Content in Meat
Keeping fat content consistent in sausage products will help to generate repeat sales by ensuring that product quality remains consistent. Many accurate & rapid methods exist to determine fat content. This video describes two accurate methods for rapidly determining fat content in ground meat products.
Meat processors and hobbyist wanting to learn more about determining fat content in ground meat products.
Two rapid methods to accurately determine fat content of ground meat.
- [Jonathan] This instructional video will teach you how to incorporate rapid quality measurements into your small scale, processed meat manufacturing establishment.
Keeping product quality perimeters consistent can lead to increased sales by ensuring more repeat business and expanding your customer base through improved brand reputation.
In this video, we will discuss two methods to accurately measure fat content of your raw materials.
Two rapid methods to accurately determine fat content of your raw materials and final product will be demonstrated.
All materials needed will be clearly shown and explained.
Manufacturing of processed meats in the olden days was inconsistent resulting in product that varied from day to day in terms of sensory and quality attributes.
As a general rule, product formulations were not written down and determining fat content was a guess, at best, by eyeballing the product as it was made.
Determining the fat content of raw materials today is essential to consistently meet the target fat content set by the company's formulations or to be within allowed limits of fat set by regulatory agency.
The use of a Pearson Square can be helpful in meeting the target fat percentage of a finished product when using two types of raw materials with differing fat contents.
This tool only works if one of the raw materials is less than the target percentage and the other is greater than the target percentage.
In the example shown, the center number in the square is our target fat content.
In this case, it is 30%.
If we have two meat raw materials with known fat percentages, we can determine how much of each raw material we need to meet our target of 30%.
First, place the target fat percentage in the middle of the square.
Next, enter the raw material type and fat content of the two meat sources on the top left and bottom left of our square.
After the known fat amounts are on the square, subtract across the square.
You should only end up with a positive number.
In the example shown, the larger number should be entered first for the subtraction to obtain a difference that is a positive amount.
As you can see, 30 minus 19 equals 11.
Since the values are subtracted across the square, the 11 should be placed at the bottom right.
You try the next subtraction.
This one is easier because 57 is larger than our target of 30.
Remember to subtract across the square.
What was your answer and where did you place it?
The answer is 27 and it is placed at the top right of our square.
How then can we determine the amount of each raw material needed to balance the product to meet our target fat content?
We need to determine the total amount by adding the two numbers on the right hand side of the square.
27 plus 11 equals 38.
If we divide 27 by 38, we see that 71% of our raw materials need to be the meat product entered on the top left of the square.
This also means that 29% of our meat source should be the raw material that was entered on the bottom left.
Make up a new problem or use information you currently have to try more examples.
Remember that you should never get a negative number as an answer.
Worker safety is of paramount importance when performing a modified Babcock method for fat determination.
At minimum, the employee performing the assay should always wear eye protection, a lab coat or apron, as well as corrosion resistant gloves and close toed shoes.
Since the individual is working with a concentrated corrosive acid, access to an eyewash and/or emergency shower, in case of an accident, should be considered.
In addition, having an ABC rated fire extinguisher near the area where the assay is being performed is a good idea.
Graduated Paley bottles or cheese bottles are commonly used in the dairy industry to determine fat content of a milk or cheese sample.
This glassware may be purchased for use of a nine gram or 18 gram sample as well as for obtaining various fat contents.
For this example, we will use a graduated Paley bottle with a rubber stopper for estimating fat of a nine gram sample size graduated for 50% fat content.
It is best to use coarsely ground meats that have been ground through a one half inch or three eighths inch grinding plate.
Take a representative sample of the raw material and chop or blend to a fine consistency using a mini food processor or blender.
Continue chopping for several seconds until the sample appears to be well blended.
Next, using a small digital scale, weigh out approximately nine grams of the chopped meat sample.
Be sure to tear the scale for the weight of any containers used to transfer the meat sample in.
To increase accuracy, you may want to consider weighing two nine gram samples from the blended sample.
Averaging duplicate samples for fat content can increase the precision of the results of this fat analysis method.
Some individuals may prefer to tear the bottle and weigh the sample to be measured directly in the glassware.
Regardless of the method used to weigh the sample, take care in transferring the blended meat product to the bottle.
Load the sample with a small metal or plastic spatula into the larger hole near the neck of the graduated portion of the bottle.
Next, transfer 10 grams of hot water in the 180 to 200 degree Fahrenheit temperature range to the same hole that the meat sample was placed.
Once the water has been added, cap the rubber stopper in the large filling hole near the neck of the graduated portion of the bottle.
Never add water to acid.
Although this process is safe, adverse reactions or even explosions can occur when improper techniques are followed.
Now that proper order is being followed, we can slowly add 15 milliliters of sulfuric acid by adding the liquid down the neck of the bottle.
Adding the acid in three to five milliliter increments with slow, steady swirling motion of the bottle will ensure an appropriate hydrolysis reaction.
Do not swirl the sample too fast as foam can build in the neck of the bottle which may impede clear readings from the graduated segment of the bottle.
When adding acid to the liquid meat sample, the color of the contents will appear very dark or black in color and the bottle will become very warm due to the reaction.
After the sample is dissolved and there appear to be no clumps of product in the dark solution, hot water is again added, this time through the upper neck of the bottle to a point of about 45 degrees on the graduated portion of the neck portion on the bottle.
Take care not to overflow the liquid out of the top.
As an optional step, the sample bottles may be placed in a centrifuge to spin the sample down.
The bottles can be centrifuged for about five minutes at low speed.
Be sure the apparatus comes to a complete stop before removing the glass bottles from the centrifuge.
This will reduce the likelihood of breaking the glass and risking injury to the employee performing the assay.
To read the sample, place the glass bottle on a flat surface so that the meniscus or cubature of the liquid can be clearly seen.
The extracted fat layer will be on top of the water layer within the calibrated neck of the bottle.
Begin by reading the graduated number at the top of the fat phase as well as the bottom.
Subtract the bottom reading from the top to determine the fat content of the sample.
If duplicate samples were run, average the two fat contents by adding the numbers together and dividing by two.
Next we will investigate using a microwave to dry duplicate samples of pork products.
This method really determines the percent chemical lean of the sample being measured.
Fat content can then be determined as a simple subtraction.
The microwave method will show the steps involved to determine the percent moisture of samples.
The accuracy of the method relies on the fact that moisture and fat are negatively correlated.
In other words, as moisture in meat increases, fat content decreases and vise versa.
To perform the analysis, you will need the following equipment and supplies.
A microwave with a minimum wattage of 600 to 700 watts and a turntable, a mini food processor or blender to prepare the sample, a scale to measure the weight of the sample, a glass or a high density plastic beaker in the 200 to 250 milliliter range, sand or salt to warm the oven prior to sampling, an absorbant cloth or high-quality disposable paper towel to cover the beaker, and an elastic band to secure the paper towel to the beaker.
To prepare the sample, start with raw materials that have been ground through a one half inch or three eighths inch grinding blade.
Place a representative sample of the ground product into a mini food processor or blender.
Chop the sample until it is well blended.
Next, tear the beaker so that the reading on the scale is zero.
Ensure that your scale is sensitive to 1/10th of a gram.
After zeroing the scale, spread 20 grams of the meat sample in the bottom of the beaker with a small spoon or spatula.
If your microwave is equipped for convection heating, power on the convection option to preheat the microwave oven.
Alternatively, a beaker of 500 grams of salt may be placed into the oven and heated on high power for five minutes.
Leave the warmed beaker in the oven prior to and during drying of the sample.
When utilizing this process, it is important to know how long you should dry the sample.
Errors in accuracy occur when a sample is either too wet or too dry.
To determine the drying time for your oven, set an initial drying time to begin with.
For example, four minutes.
After heating the sample, remove from the oven to allow the sample to cool enough to transfer to the scale.
Weigh the sample and record the weight.
Next, place the sample back into the oven for an additional minute.
Reweigh the sample to determine if weight loss has occurred.
If the sample lost weight, begin again with fresh samples and increase the dry time.
If the sample did not lose weight, begin again with fresh samples and reduce the initial drying time by 15 to 30 seconds to determine the calibrated drying time for your oven.
Once your oven has been calibrated, you may begin drying your duplicate samples to determine the percent moisture.
After drying is complete, reweigh the dried sample to determine the dried weight.
In this example, our dried weight was 5.5 grams.
The percent moisture is determined by subtracting the dried weight from the raw weight and then dividing the dry weight by the initial sample weight of 20 grams.
Multiplying the answer by 100 converts to a percentage.
For accuracy purposes, the duplicate samples should be within 1% of one another or less.
As long as the duplicates are within 1% moisture of one another, the duplicate samples may be averaged together.
The percent chemical lean can be determined from the equation shown.
Chemical Lean equals the percent moisture determined from drying multiplied by a constant of 1.27 and then adding 1.1.
A simple subtraction is used to determine fat content.
100 minus the percent chemical lean previously determined equals percent fat.