THE ADULTERATION CHECKLIST

Visibility: The oil samples were subjected to physical testing and visual examination. Odour: All the oils were subjected to odour and flavour tests for any off-odour/flavour. Suspended particles: This test is for detection of any foreign matter or impurity that may have entered the product during processing. Foreign matter in oil reduces its acceptability and may also result in bad odour, and can even be harmful to consumers. Refractive index: Refractive index is the ratio of the velocity of light in vacuum to the velocity of

light in the oil or fat. The oil should be clear and without any haziness. Acid value or free fatty acids: Acid value indicates the proportion of free fatty acids present in oil or fat. A high acid value indicates stale oil or fat stored under improper conditions. Refined oil acid value for most oil samples lies within 0.5. If any titratable acid other than a fatty acid is present in the oil sample, it will be an error. Saponification value: It helps to detect the presence of other oils/fats. Unsaponifiable matter: Unsaponifiable matter includes substances frequently found dissolved in fatty acids and drying oils which cannot be saponified by caustic treatment, but which are soluble in the normal fat solvents. Unsaponifiable matter consists of oil-soluble vitamins, hydrocarbons, higher alcohols and sterols that are not soluble in water after esterification. Iodine value: The iodine value is a measure of the unsaturated fats. It is expressed in terms of the number of centigrams of iodine absorbed per gram of sample ( iodine absorbed). A higher iodine value indicates a higher degree of unsaturation. Argemone oil: Argemone oil should be absent in edible oil.