Total Polar Materials (TPM) testing is a method for measuring the quality of frying oil. TPM testing uses a sensor to measure the percentage of TPM in the oil, which indicates how degraded the oil is.
How it works
A TPM testing device, such as a food oil monitor, is used to measure the oil.
The sensor is placed into the oil and stirred gently until the light on the device flashes.
The light indicates the quality of the oil.
What it measures
TPM measures the amount of products in the oil that are created by oxidation processes. These products include free fatty acids, polymerized substances, and low molecular weight decomposition products.
As the oil ages, the TPM value increases.
What it indicates
A TPM value of 9–14% indicates the oil is suitable for cooking.
A TPM value of 14–20% indicates the oil is in its optimal frying range.
A TPM value of 24% or higher indicates the oil is no longer suitable for consumption.
Why it's important
TPM testing is a more accurate method for measuring oil quality than other methods, such as judging by color, smell, or time.
TPM testing is the most common method used in commercial kitchens.