Why is important to measure sodium in food products?

Sodium occurs naturally in many foods and is also added in the form of salt. The sodium content of food has important implications for health.

Sodium is a nutrient and is part of the group of dietary minerals. Essential to life, it cannot be produced by the human body and thus has to be provided by the diet.

The physiological requirements of sodium of the human body are relatively low (estimated at the equivalent of 1 to 2 gram of salt per day) and are met by the diet.

Milk naturally contains sodium (approximately 45 mg/100 ml). Yoghurt and fresh cheeses (non-salted) contain very little sodium (from 30 to 60 mg /100g). In contrast, hard cheeses – because of added salt – contain much higher levels of sodium (from 200 to 1600 mg/100g). Within a family of cheeses and depending on the brands, large variations exist between sodium contents of the cheeses, depending on lower or higher addition of salt by the cheese maker.

Measuring Method

Sodium in Milk and Dairy Products can be measured with MA886 Digital Refractometer described here*.

The MA886 is an optical instrument that employs the measurement of the refractive index to determine sodium chloride concentration in aqueous solutions used in food preparation.

*Taking sample from Cheese


Mincing the sample incre- ases the surface area to allow as much salt to be released into the water as possible.


Dilute the sample with hot water to a 10% ratio.
After the sample melts, the fat will float to the top.



Collect the sample with a pipette from the layer underneath the fat.