Quality Parameters: Edible Vegetable Oils

FSSAI specifies standards for numerous edible oils (Mustard, Groundnut, Coconut, Sunflower, Soyabean, Palm, Blended Oils, Vanaspati, etc.). Key testing parameters include:

Physical Characteristics

Appearance, Odour, Taste: These are the initial sensory characteristics evaluated. The oil should be clear and free from any cloudiness or sediments. The odour and taste should be characteristic of the specific oil and free from any rancid or off-flavours.
Colour: The colour of the oil is assessed visually and should be within the acceptable range for the specific oil.
Refractive Index: This is a measure of how light bends when passing through the oil. It is a characteristic property of each oil and can be used to assess its purity and identify adulteration.
Specific Gravity: This is the ratio of the density of the oil to the density of water. It is another characteristic property that can be used to assess the quality and purity of the oil.

Chemical Parameters

Moisture & Insoluble Impurities: Max limits for purity. Excessive moisture can promote microbial growth and reduce the shelf life of the oil. Insoluble impurities indicate the presence of extraneous matter and affect the oil’s clarity and quality.
Acid Value / Free Fatty Acids (FFA): Indicator of hydrolytic rancidity (freshness/storage quality). These parameters measure the amount of free fatty acids present in the oil, which are produced by the hydrolysis of triglycerides. High values indicate poor quality or improper storage.
Peroxide Value: Measures oxidative rancidity. This parameter measures the amount of peroxides present in the oil, which are formed by the oxidation of unsaturated fatty acids. High values indicate that the oil has undergone oxidation and may have a rancid flavour.
Saponification Value: Helps identify oil/fat type. This parameter measures the amount of alkali required to saponify (hydrolyze) a given amount of oil. It is related to the average molecular weight of the fatty acids in the oil and can be used to identify the type of oil or fat.
Iodine Value: Indicates degree of unsaturation. This parameter measures the amount of iodine that reacts with a given amount of oil. It is related to the number of double bonds present in the fatty acids and indicates the degree of unsaturation. Oils with high iodine values are more prone to oxidation.
Unsaponifiable Matter: Limits non-fatty material. This parameter measures the amount of material in the oil that cannot be saponified by alkali. It includes components such as sterols, hydrocarbons, and pigments. High levels of unsaponifiable matter can indicate the presence of adulterants or impurities.

Adulteration Tests

Argemone Oil Test: Mandatory for mustard oil. Argemone oil is a toxic oil that can be used to adulterate mustard oil. This test is mandatory to ensure that mustard oil is free from argemone oil contamination.
Mineral Oil Test: Detects non-edible mineral oil contamination. Mineral oil is a non-edible oil that can be used to adulterate vegetable oils. This test is used to detect the presence of mineral oil in vegetable oils.
Castor Oil Test: Detects castor oil adulteration. Castor oil has a distinct taste and properties. This test is used to detect the presence of castor oil in other vegetable oils.

Other Key Parameters

Trans Fatty Acids: Specific limits, especially for Vanaspati/partially hydrogenated oils. Trans fatty acids are unsaturated fatty acids that have a trans configuration. They are formed during the partial hydrogenation of vegetable oils. High levels of trans fatty acids are associated with adverse health effects. FSSAI has set specific limits for trans fatty acids in vegetable oils, especially for Vanaspati and partially hydrogenated oils.
Vitamins: Minimum levels for mandatory fortification (Vitamin A & D) where applicable. FSSAI has mandated the fortification of certain vegetable oils with Vitamin A and Vitamin D to address nutritional deficiencies in the population. These regulations specify the minimum levels of vitamins that must be present in the fortified oils.