In the Total Polar Materials (TPM) test, also known as Total Polar Compounds (TPC), low molecular weight decomposition products are a key indicator of oil quality, especially in frying oils. Here's a breakdown: What is the TPM test? The TPM test measures the total amount of polar compounds in oil. These polar compounds are formed as oil degrades due to high temperatures and repeated use, particularly in frying. A high TPM value indicates that the oil has deteriorated significantly and may no longer be suitable for consumption. Low molecular weight decomposition products These are substances formed during the breakdown of fats and oils, and they contribute to the overall TPM value. Some key examples include: Free fatty acids (FFAs): These are fatty acids that have been released from triglycerides (the main component of fats and oils). FFAs can contribute to undesirable flavors and odors in the oil. Aldehydes and ketones: These are formed through oxidation of the oil and can also c...