ACT NO. 13 - Assay of Vegetable Oil

Question 1

It constitutes an important component of human diet. Major edible vegetable oils in terms of production include from soybean, canola, sunflower and peanut.

Answer 1

Vegetable Oil

Question 2

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.

Answer 2

Vegetable Oil

Question 3

Vegetable oils are mainly constituted by ________________ and complex mixtures of minor compounds (2- 5%) of a wide range of chemical nature. These minor constituents show a broad qualitative and quantitative composition depending on the vegetable species from which they are obtained.

Answer 3

triacylglycerol (95-98%)

Question 4

The minor components include mono- and diglycerides, free fatty acids, phosphatides, sterols, protein fragments, various resinous and mucilaginous materials and oxidative products.

Answer 4

Vegetable Oils

Question 5

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

Answer 5

IMPROPER

Question 6

What are the most commonly used parameters in characterizing the quality of oils and fats?

Answer 6

Saponification value (SV)
Iodine value (IV)
Acidity (AN)

Question 7

This is defined as the number of milligrams of Potassium hydroxide required to neutralize the free fatty acids present in one gram of fat. It is a relative measure of rancidity as free fatty acids are normally formed during decomposition of triglycerides.

Answer 7

Acid Value Determination

Question 8

Saponification is the hydrolysis of esters. Oils and fats are the fatty acid esters of the trihydroxy alcohol, glycerol.

Answer 8

Saponification Value Determination

Question 9

The saponification value of an oil is defined as the number of milligrams of potassium hydroxide required to neutralise the fatty acids resulting from the complete hydrolysis of 1 g of the sample.

Answer 9

Saponification Value Determination

Question 10

This 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.

Answer 10

Blank Determination

Question 11

Fats and oils are esters of triglycerides and fatty acids. The fatty acids consist of a long chain hydrocarbon and may contain carbon-carbon double bonds. If this is the case then the substance is classified as unsaturated.

Answer 11

Iodine Value Determination

Question 12

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

Answer 12

Iodine Value Determination

Question 13

Iodine Value Determination measures the degree of ___________?

Answer 13

UNSATURATION

Question 14

Methods in Iodine Value

Answer 14

Method 1: Hanus Method (Iodobromide)
Method 2: Wijs Method (Iodochloride)

Method 3: Hubl’s Method <unofficial></unofficial>

Question 15

Types of Fixed Oils

Answer 15

Drying >120
Semi-Drying 100-120
Non-Drying <100