FOR PHYSICOCHEMICAL PARAMETERS Iodine value | Saponification value | Unsaponifiable matter | Refractive index | Acid value | Argemone oil
| Suspended particles | Visibility | Odour Iodine value
Requirement: 100–145 The iodine value is a measure of the unsaturated fats. All brands were within the specified limit. Vijaya, Sundrop and Fortune Sunlite scored higher in
The saponification value helps to detect the presence of other oils/fats. It is expressed as the number of milligrams of potassium hydroxide (KOH) required to saponify one gram of the sample. Saponification value of sunflower oil should be between 188 and 194. All brands were within the specified limit. Vijaya, Freedom and Fortune Sunlite scored higher in
Unsaponifiable matter includes substances frequently found dissolved in fatty acids and drying oils that cannot be saponified by caustic treatment, but which are soluble in the normal fat solvents. Unsaponifiable matter must not be more than 1.5 per cent by weight of sunflower oil. All brands were within the specified limit. Freedom, Nature Fresh and Fortune Sunlite were
found lowest in unsaponifiable matter.
Refractive index (at 40 degrees Celsius)
This is the ratio of the velocity of light in vacuum to the velocity of light in the oil or fat. All brands were within the specified limit. They were
clear and without any haziness.
Requirement: 6.0 maximum The acid value is the number of milligrams of potassium hydroxide necessary to neutralize the free acids in one gram of sample. All brands were within the specified limit. Freedom, Vijaya, Gemini and Sundrop were found
with lowest acid value.
Argemone oil is extracted from argemone seeds. It is a kind of weed whose seeds look like mustard seeds and contains oil that is highly toxic. Consumption of this oil can lead to health disorders among children. Edible-oil brands are obliged to mention ‘contains no argemone oil’ on their packs. Argemone oil was not detected in any brand.
This test is for detection of any foreign matter or impurities, which may form or infiltrate during the processing. These should be absent, as foreign matter in oil reduces its acceptability to consumers and may result in bad odour, and can also be harmful to consumer. All brands were free of suspended particles.
All the brands were subjected to visual examination, to ascertain if they were transparent and slightly pale-yellow in colour, and without foreign particles. While dark pale-yellow oily liquid showed in Gemini and Sunpure, it was dark-yellow in the case of Sundrop and Freedom. Healthy Heart was light paleyellow, and the rest of the eight brands were a paleyellow oily liquid.
All the oils were subjected to tests to verify any off-odour/flavour. All brands were free of any objectionable odour.