Question

Polenske value of milk is due to
A. Fats
B. Water-soluble fatty acids
C. Water-insoluble fatty acids
D. Proteins

Answer 1

Hint:
The Polenske value, commonly referred to as the Polenske number, is a value discovered by fat analysis. It serves as a gauge for the volume of volatile fatty acids that saponification can extract from fat. These fatty acids are measured using the Polenske value. Therefore, the Polenske value is significant when characterising or identifying coconut oil. The amount of milligrammes of KOH required to neutralise the fatty acids produced by full hydrolysis of one gramme of an oil sample is known as the saponification value.
It serves as a gauge for the volume of volatile fatty acids that saponification can extract from fat. It is equivalent to the volume of 0.1 normal alkali solution in millilitres required for neutralising the water-insoluble volatile fatty acids extracted during distillation and filtration from five grammes of a certain saponified fat.

Complete answer:
When combined with water, fatty acids containing ten or more carbon atoms are almost insoluble and float to the top due to their reduced density. Fats do not dissolve in water due to the hydrocarbon chains' extreme non-polarity; instead, fat molecules have the propensity to group together. Triglycerides are another name for a fat molecule since it consists of three fatty acids joined to a glycerol molecule. Lipids include substances like fats, oils, and waxes.
So, the polenske value of milk is due to Water-insoluble fatty acids.

Option ‘C’ is correct

Note:
Fatty acids are typically less soluble in water as the carbon number rises. Glycerolipids and fatty acid esters are soluble in ethanol, chloroform, and diethyl ether but insoluble in water. Free fatty acids can move quickly from one location to another when they are unbound, at which point they can be incorporated into proteins and membrane lipids.
The tail dissolves well in butter and oil but is not soluble in water. Additionally, they have a "head" with two oxygen atoms, which has a far higher water solubility