Total Polar Materials (TPM) in Frying Oil Samples as a Quality Measure

Total Polar Materials (TPM) are a group of chemical compounds formed in oils and fats during continuous frying and heating processes. TPM is considered an important measure of oil quality, indicating its degradation and oxidation due to repeated use at high temperatures.

Importance of Measuring TPM

1. Helps assess the quality of the oil used for frying.
2. A high TPM percentage means the oil has undergone chemical changes such as oxidation, hydrolysis, and polymerization.
3. Oils with high TPM may contain compounds harmful to health, such as aldehydes and oxidized fatty acids.

Permissible Values

According to many health regulations, the TPM percentage should not exceed 25-27%; otherwise, the oil must be discarded. Some countries set the maximum limit at 30%.

Methods of Measuring TPM

1. Traditional Laboratory Methods

• Gravimetric Analysis
• Spectrophotometry
• Gas Chromatography (GC) Analysis

2. Rapid Measuring Devices (TPM Meters)These use electronic sensors to measure total polarity directly in hot oil and provide instant results without the need for complex laboratory analyses.

How Does TPM Affect Product Quality?

1. As the TPM percentage increases, the oil becomes more viscous and darker in color, which may affect the taste, aroma, and texture of fried products.
2. Oils with high TPM may increase the likelihood of forming acrylamide, a harmful compound associated with health risks.

How to Maintain Oil Quality

To maintain oil quality and reduce the TPM percentage during frying, here are some practical tips:

1. Choosing the Right OilUse oils with a high smoke point and good resistance to oxidation, such as:

• High-oleic sunflower oil
• Canola oil
• Refined palm oil
• Soybean oilAvoid oils rich in polyunsaturated fats (like corn oil) because they oxidize quickly.

2. Temperature Control

• Avoid heating the oil to more than 180°C because high heat accelerates the formation of polar compounds.
• Use an accurate thermostat to maintain the appropriate temperature and prevent burning.

3. Reducing Oil Exposure to Air and Moisture

• Moisture from food increases hydrolysis and accelerates TPM formation.
• Minimize re-stirring the oil during cooking to avoid incorporating oxygen.
• Store used oil in tightly sealed containers away from light and heat.

4. Filtering the Oil Regularly

• Use mechanical or active carbon filters to remove degraded particles and reduce thermal decomposition.
• Filter the oil daily with repeated use.

5. Minimizing Food Debris in Oil

• Charred food crumbs accelerate reaction with the oil and increase TPM.
• Use clean frying baskets and shake foods to remove excess before placing them in the oil.

6. Do Not Mix New Oil with Old OilMixing new oil with old oil accelerates the degradation of the new oil, so it is best to completely renew the oil when needed.

7. Monitoring TPM Percentage Regularly

• Use a TPM meter to check oil quality before each use.
• If the TPM percentage exceeds 25-27%, the oil must be replaced.

Types of TPM Measuring Devices

There are TPM measuring equipments or oil filtration systems; here are the available options:

First/ TPM Measuring DevicesThese devices measure the total polar compounds percentage directly in hot oil, providing accurate results within seconds. Some reliable devices include:

• Testo 270 – An easy-to-use digital device that gives fast and accurate measurements.
• Ebro FOM 330 – Suitable for restaurants and food industries, withstands high oil temperatures.
• Frycheck TPM Meter – An economical option suitable for quick use.
• A device that measures with very high accuracy and is easy to use is - VITO FT.

Tips When Choosing a TPM Device:

1. Ensure it works at hot oil temperatures (130-180°C).
2. Choose a device with a clear and easy-to-read digital display.
3. Some devices support automatic analysis to determine when to change the oil.

Second/ Oil Filtration SystemsFilters help extend oil life by removing impurities and degraded particles, reducing the TPM percentage. Some effective systems include:

• VITO Oil Filter Systems – Reduces impurity buildup and extends oil life by up to 50%.
• Miracle Oil Filter Machine – Ideal for commercial kitchens and small factories.
• Pitco Portable Oil Filtration System – Easy to use and suitable for deep fryers.

Tips When Choosing a Filtration System:

1. Ensure it is suitable for the type of oil used and your production volume.
2. Use active carbon filters to reduce degraded compounds and unwanted odors.
3. Filter the oil daily to maintain its quality.

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