Which statements are true? When foods are extracted with an organic solvent with mixed polarity the yield contains:

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Not completely true, study the diagram again. Fatty acids are insoluble in water but soluble in an organic solvent because of their long carbon chain. Note that most fatty acids will be present as triglycerides.

Not completely true, study the diagram again. The diagram shows that the broad definition of total fat (ALL components soluble in organic solvent) includes cholesterol.

Not completely true. Phospholipids are poorly soluble in water and form a bilayer or micelle in watery environments. However, they are soluble in most organic solvents, thus are extracted.

Not completely true, study the diagram again. The diagram shows that the broad definition of total fat (ALL components soluble in organic solvent) includes also some vitamins like vitamin A, E and D.

Not completely true. Besides the mentioned fat classes also other components are extracted with an organic solvent. In the diagram you can see for example that also plant pigments and low molecular sugars are extracted.

Right! So with an organic solvent not only triglycerides but also other fats and other components are extracted.

In this case you will focus on (1) total fat determination by extraction with an organic solvent and (2) measuring fatty acids profile (expressed as triglycerides equivalents).

But first you will further refresh your knowledge on fatty acids and fats in foods.

Continue.....

Before focusing on the results of the biscuit analysis you will need some time to refresh your knowledge on dietary fats.

From an analytical perspective, total fat is usually defined as all components that are insoluble in water but soluble in organic solvent (e.g. alcohol, petroleum ether). For ‘fats’ several definitions exists:

1. Total fat (sometimes called lipids): all components insoluble in water but soluble in an organic solvent.

2. Fats: triglycerides (TG) (also called tri-acylglycerols)
& polar lipids

3. Fats: sum of fatty acids expressed as triglycerides (TG) .

Move with your mouse over the diagram to obtain more insight into the dietary fat classification.

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fatty acids

cholesterol

phospholipids

certain vitamins

triglycerides

other components

Broad definition

Narrow definition