ASSAY OF VEGETABLE OIL

Vegetable oil

It constitutes an important component of human diet.

soybean, canola, sunflower and peanut.

Major edible vegetable oils in terms of production include from

Vegetable oil

They are source of edible FAs (saturated, monounsaturated or polyunsaturated), which play an important role in cellular metabolism as a way to store energy and also by providing energy when required.

triacylglycerol (95 - 98%)

minor compounds (2- 5%)

Vegetable oils are mainly constituted by _____ and complex mixtures of ______

Vegetable oil

These minor constituents show a broad qualitative and quantitative composition depending on the vegetable species from which they are obtained.

mono- and diglycerides

free fatty acids

phosphatides

sterols

protein fragments

various resinous

mucilaginous materials

oxidative products

The minor components of vegetable oil include _________

Vegetable oil

may rancid and hence lose its nutritional values and flavor upon improper extraction process, handling and storage.

Monitoring and maintaining edible oil quality

_______ are paramount importance to ensure safety of the product for consumptionof vegetable oils

Saponification value (SV), iodine value (IV), and acidity (AN)

the most commonly used parameters in characterizing the quality of oils and fats.

Acid Value

defined as the number of milligrams of Potassium hydroxide required to neutralize the free fatty acids present in one gram of fat.

Acid Value

It is a relative measure of rancidity as free fatty acids are normally formed during decomposition of triglycerides.

Acid Value

# of mg of KOH req’d to neutralize the FA in 1g of sx

Acid Value

# of ml of 0.1 NaOH req’d to neutralize the FA in 1g of sx

Acid number or acidity index

Acid value aka?

Analyte: Olive oil

VS: O.1 N sodium hydroxide

Indicator: Phenolphthalein TS

Endpoint: Light pink

USP specification: Less than or equal 5

In assay of Vegetable oil, what is the analyte, VS, indicator, endpoint and USP requirement?

Saponification

is the hydrolysis of esters.

Oils and fats

the fatty acid esters of the trihydroxy alcohol, glycerol.

saponification value

the number of milligrams of potassium hydroxide required to neutralise the fatty acids resulting from the complete hydrolysis of 1 g of the sample.

saponification value

also known as the SAPONIFICATION NUMBER OR KOETTSDORFER NUMBER

saponification value

# of mg KOH required to neutralized FA and saponify esters in 1G of substance

Blank determination

is performed to eliminate errors from all sources like those produced by absorption of CO2 by the alkali or by the alkalinity of the glass vessels.

Fats and oils

esters of triglycerides and fatty acids.

Fatty acid

consist of a long chain hydrocarbon and may contain carbon-carbon double bonds.

Unsaturated

Fatty acid is classified as

Iodine Value

The mass of iodine that reacts with the fat or oil is used to measure the unsaturation.

Iodine Value

used to find the iodine number of the fat or oil and this is used to indicate the degree of unsaturation in the fat or oil.

Unsaturated

The more iodine the more?

Iodine Value

Defined as the number of grams of iodine absorbed under specified condition by 100 grams of oil, fat, wax or other substance.

Iodine Value

Measure degree of unsaturation

Method I: Hanus method (Iodobromide) TS

Method II: Wij method

Method III: Hubl’s method

Methods of Iodine Value

Drying

• >120

• Linseed oil, Fish oil, Cod liver oil

Semi-drying

• 100 - 120

• Cottonseed oil, sesame oil

Non-drying

• <120

• Almond oil, Olive oil

Types of Fixed Oils

Analyte: Oilive oil

VS: 0.1 N Sodium Thiosulfate

Indicator: Starch TS

Endpoint: Disappearance of Blue Color

USP Specification: 79-88

Assay of olive oil in Iodine Value, what is the analyte, VS, Indicator, Endpoint and USP specification?