The Lab Test of Purity: RM Value Explained

How do laboratories detect whether ghee has been adulterated with cheaper fats such as palm oil or vegetable vanaspati? One of the key quality parameters used is the Reichert-Meissl (RM) Value.

The RM Value measures the amount of volatile short-chain fatty acids, such as butyric acid, naturally present in milk fat. These fatty acids are a distinctive characteristic of genuine dairy fat and are either absent or present in very low amounts in most vegetable oils and animal body fats. Because of this, the RM Value is widely used as an indicator of the purity of ghee.

• FSSAI Standard: Pure ghee should have a minimum RM Value of 24.
• Desi Cow Ghee: Traditionally produced Desi cow ghee often records an RM Value in the range of 28–31, although the exact value can vary depending on factors such as breed, feed, and season.
• Adulteration Detection: When cheaper vegetable oils, such as palm oil or vanaspati, are mixed with ghee, the RM Value generally decreases, making it easier to identify adulteration through laboratory testing.

A higher RM Value, when considered alongside other quality parameters, is a strong indicator that the ghee contains genuine milk fat and has not been significantly adulterated with vegetable oils.

Summary Table: Commercial Ghee vs. Traditional Vedic Ghee