Download Oils and Fats

Oils and Fats
1- Oils and fats are members of:
a- Simple lipids.
b- Compound lipids.
c- Derived lipids.
d- Both a & c.
2- Waxes are:
a- Fatty acids.
b- Esters of fatty acids and glycerol.
c- Esters of fatty acids and high molecular weight alcohol.
d- All of the above
3- Derived lipids are:
a- Fatty acids
b- Sterols
c- Phosphoric acid and carbohydrates
d- All of the above
4- Fixed oils and fats contain traces of free fatty acids due to:
a- Oxidative rancidity
b- Hydrolysis in the presence of moisture
c- Heating at high temperatures
d- All of the above
5- When oils and fats are heated strongly, they decompose with the
production of:
a- Free fatty acids
b- Glycerol
c- Acrolein
d- All of the above
6- Unsaponifiable part in an oil or fat is:
a- Glyceride part or ester part
b- Non-glyceride or no-ester part.
c- Ester of fatty acids and long chain alcohol.
d- All of the above
7- The following are unsaponifiable part of oils and fats Except:
a- Steroids.
b- Vitamins, A, D and E.
c- Hydrocarbons
d- Glycerides
8- Oils and fats are:
a- Simple triglycerides
b- Diglycerides
c- Mixture of mixed triglycerides
d- Monoglycerides
9- The carbon atoms in fatty acids are:
a- Odd number arranged in branched chain and carboxylic group.
b- Even number arranged in straight chain and carboxylic group.
c- ester of alcohols and acids
d- None of the above
10- The difference between the point of incipient fusion and complete
fusion is known as:
a- Refractive index
b- Melting point
c- Solidifying point
d- None of the above
11- Saponification value is defined as, the number of mg of alcoholic
KOH required to:
a- Neutralize the free fatty acids present in 1 gm oil or fat.
b- Hydrolize and react with the glycerides present in 1 gm oil or fat.
c- Both a and b.
d- None of the above
12- Presence of mineral oil as an adulterant in vegetable oil will:
a- Decrease the S.V.
b- Decrease the I.V.
c- Both a and b.
d- Increase I.V. and S.V.
13- The degree of unsaturation is measured in terms of, the weight of
halogen fixed by;
a- One gram of oil
b- 5 gm of oil
c- 100 gm of oil.
d- All of the above
14- Oils having high I.V. are classified as:
a- Non-drying oils
b- Semi-drying oils
c- Drying oils
d- None of the above
15- Waxes has:
a- Very small I.V.
b- High I.V.
c- I.V. similar to that of vegetable oils
d- None of the above
16- Animal fat and butter have:
a- High I.V.
b- Zero I.V.
c- Low I.V.
d- None of the above
17- Iodine and thiocyanogen are added to the double bonds present in
linoleic acid as follows:
a- Both adds and saturate the two double bonds
b- Thiocynogen adds to the two double bonds, while iodine adds to
one.
c- Both adds and saturate one of the two double bonds
d- Iodine saturate the two double bonds, while (SCN)2 adds to one.
18- Diene value is useful for:
a- Conjugated double bonds.
b- Isolated double bonds
c- Saturated fatty acids
d- All of the above
19- The glycerides of butter fat contain:
a- High % of long chain fatty acids
b- Low % of short chain fatty acids.
c- High % of short chain fatty acids
d- None of the above.
20- Acetyl value equal:
a- S.V. for acetylated hydroxyl fatty acids
b- S.V. of non acetylated oil
c- S.V. for acetylated oil - S.V. of non acetylated oil
d- None of the above
True and False Statements
1- Rancidity which leads to formation of low molecular weight fatty acids
results in decrease in the S.V.
2- S.V. Is useful in the identification of oils and fats.
3- Oils with high I.V. are liable to rancidity and are liquids at room
temperature.
4- Thiocyanogen is obtained by the reaction of Br2 with Pb(SCN) 2 in
ether.
5- I.V and Thiocynogen value are equal when determined for lenoleinic
acid.
6- the glycerides of butter fat contain low percentage of short chain fatty
acids and its S.V. is low.
Give reasons:
1- Rancidity increases acetyl value.
2- In the determination of S.V., Ph.Ph. is used as indicator (M.O. can not
be used), when excess potassium hydroxide is back titrated with standard
HCl solutin.
3- Alcoholic KOH is used for the S.V. of oils and fats, while aqueous
KOH is used for saponification of oils and fats in case of Richert-Meissel
value.
4- Iso-oleic acid present in hydrogenated fats, not present in natural oil or
fat.
5- During hydrogenation of oils, the mixture of oil, Ni, and hydrogen, is
heated just to start hydrogenation and further heating is not necessary.
Write short notes on:
1- Oxidative rancidity
2- a- Define, Polenske and Kirchener values.
b- Pro-oxidants and anti oxidants
3- Detection of hydrogenated oils in butter fat