The moisture content of Edible Oils is taken as the loss of weight resulting from air drying of Edible Oils sample up to 105⁰C for a period of one hour. The value recorded should be regarded as relative rather than absolute, as some thermal degradation and oxidation of the sample may occur during the test condition

Equipment

·         Analytical balance,

·         Oven dryer,

·         Desiccators,

·         Dishes.

Procedure

·     Prepare the requisite number of dishes by drying in an air oven with lids off. Transfer the covered dishes to desiccators and allow cooling to room temperature.

·       Weigh the dish plus lid.

·      Weigh 5 to 10g of sample evenly over the dish surface and replace the lid, determine the weight accurately, the sample addition and weighing should be carried out.

·       Switch on the Oven dryer, and set the temperature below 105⁰C.

·      Dry the test portion in flat dish with tight-fit cover, for 1 hour up to 105⁰C. Remove dish cover, cool in desiccators, and weigh.

·    Set the Temperature at 105^oC and retry during 1 hour and repeat process until change in weight between successive dryings at 1hour intervals is ≤ 2 mg.

·    At the completion of drying, replace the lids and allow cooling to room temperature in desiccators, weigh the dish plus sample

          Calculation and Expression of Results

Express the Moisture content as a percentage of the original sample weight,

Moisture, %m/m =

Where,

C: Weight in g of dry matter and dish,

B: Weight of Test sample portion and dish

A: Weight of Empty dish.

References

ISO 662: 2016 - Determination of Moisture Content and Volatile matter in animal and Vegetable Oils and Fats.