0

Food chemistry - class-XII

Description: food chemistry
Number of Questions: 45
Created by:
Tags: methods of preserving food applied chemistry chemistry petrochemicals and polymers chemistry in everyday life chemistry in daily life evs - i
Attempted 0/43 Correct 0 Score 0

The sweeteners value of aspartame in comparison to cane sugar is:

  1. 550

  2. 100

  3. 600

  4. 2000


Correct Option: B
Explanation:
  • Sugar substitutes are substances that are used in place of sweeteners with sugar (sucrose) or sugar alcohols. They may also be called artificial sweeteners.
  • Natural sweeteners add to calorie intake and therefore many people prefer to use artificial sweeteners.
  • Aspartame is the most successful and widely used artificial sweetener. It is roughly 100 times as sweet as cane sugar. It is methyl ester of dipeptide formed from aspartic acid and phenylalanine. Use of aspartame is limited to cold foods and soft drinks because it is unstable at cooking temperature.

Which of the following is not a food additive?

  1. Preservatives

  2. Sweetening agents

  3. Flavours

  4. Oxidants


Correct Option: D
Explanation:

Antioxidants are added to food to prevent it from spoiling.

Name an artificial sweetener which is derivative of sucrose.

  1. Saccharine

  2. Sucrolose

  3. Sucrobenzamide

  4. Aspartame


Correct Option: B
Explanation:

Surolose is trichloro derivative of sucrose. Its appearance and taste are like sugar.

Match the column I with column II and mark the appropriate choice.

Column I Column II
(A) Alitame (i) Antihistamine
(B) Iodoform (ii) Artificial sweetener
(C) Prontosil (iii) Antibacterial agent
(D) Terfenadine (iv) Antiseptic
  1. (A) $\rightarrow$(i), (B) $\rightarrow$(ii), (C) $\rightarrow$(iv), (D) $\rightarrow$(iii)

  2. (A) $\rightarrow$(ii), (B) $\rightarrow$(iv), (C) $\rightarrow$(iii), (D) $\rightarrow$(i)

  3. (A) $\rightarrow$(iii), (B) $\rightarrow$(i), (C) $\rightarrow$(ii), (D) $\rightarrow$(iv)

  4. (A) $\rightarrow$(iv), (B) $\rightarrow$(iii), (C) $\rightarrow$(i), (D) $\rightarrow$(ii)


Correct Option: B
Explanation:
  • Antiseptics are applied to the living tissues such as wounds, cuts, ulcers and diseased skin surfaces. Iodoform is used as an antiseptic for wounds.
  • Alitame is high potency Artificial sweetener, the control of sweetness of food is difficult while using it.
  • Prontosil, also called sulfamidochrysoidine, trade name of the first synthetic drug used in the treatment of general bacterial infections in humans.It is an Antibacterial agent.
  • Antihistamines interfere with the natural action of histamine by competing with histamine for binding sites of receptor where histamine exerts its effect.Synthetic drugs, brompheniramine (Dimetapp) and terfenadine (Seldane), act as antihistamines.

Fermentation was discovered by:

  1. Vant Hoff and Le Bell.

  2. Louis Pasteur.

  3. Berzelius.

  4. Kolbe.


Correct Option: B
Explanation:

Louis Pasteur discovered fermentation.


 In 1860, he demonstrated that bacteria cause souring in milk, a process formerly thought to be merely a chemical change, and his work in identifying the role of microorganisms in food spoilage led to the process of pasteurization.

 Option B is correct.

Name two $\alpha$-amino acids, which form a dipeptide, which is 100 times more sweet than cane sugar?

  1. Aspartic acid

  2. Alanine

  3. Serine

  4. Phenylalanine

  5. Tryptophan


Correct Option: A,D
Explanation:

Aspartame is the artificial sweetener, which is 100 times more sweet than cane sugar. It is methyl ester of dipeptide formed from aspartic acid and phenylalanine.

Aspartame is unstable at cooking temperature. Where would you suggest aspartame to be used for sweetening?

  1. Soft drinks

  2. Cold drinks

  3. Both of them

  4. None of these


Correct Option: C
Explanation:

Aspartame is unstable at cooking temperature, hence it can used in soft drinks and cold drinks for artificial sweetening.

Non-degradable and fat-soluble pollutant, such as DDT enters the food chain, the pollutant:

  1. magnifies in concentration at each trophic level

  2. degrades at first trophic level

  3. accumulates in the body fat of organism at the first trophic level and does not pass to second trophic level

  4. decreases in concentration at each trophic level


Correct Option: A
Explanation:
Biomagnification is the accumulation or increasing concentration of lipophilic pesticides in the top members of the food chain. 
During biomagnification, the concentration of non-degradable pesticide like DDT goes on increasing along the food chain and highest values occur in the consumers of the top trophic level. So, the value of pesticide will go on increasing at each trophic level. 

Thus, the correct answer is option A.

$NaCl$ is used as a food preservative and in freezing mixtures.

  1. True

  2. False


Correct Option: A
Explanation:

Bacteria cannot survive in salt conditions as water is completely extracted by salt due to its hygroscopic nature.

Therefore, $NaCl$ is used as a food- preservatives and in freezing mixtures.
So the given statement is true.

Which one of following is employed as a tranquilizer ?

  1. Chlorpheninamine

  2. Equanil

  3. Naproxen

  4. Tetracycline


Correct Option: B
Explanation:

Equanil is a diasaccharide [Everday life]

Currency notes can be marked with an invisible ink. Thieves can be trapped because this ink

  1. Shows up in ultraviolet light

  2. Turns red on adding alkali

  3. Turns blue on adding acid

  4. It attracted by a magnet


Correct Option: A
Explanation:

Invisible ink shows up in ultraviolet light.

Modern UV-invisible ink is mainly made by a fluorescent derived from things in nature that glow when exposed to an UV light.

Four samples of arhar dal were taken in four test tubes with some water in each and
labelled P,Q, R and S. A few drops of the following were added to these test tubes,
water to test tube P, HCl to test tube Q, NaOH to test tube R and alcohol to test tube S.
We would be able to confirm adulteration of the dal with metanil yellow in test tubes :

  1. Q

  2. Q and R

  3. R and S

  4. S and P


Correct Option: A
Explanation:

Metanil yellow adulteration in foods can be identified upon addition of HCl to the solution. 


As HCl with metanil yellow gives pink colour. 

Therefore, the adulteration could be confirmed only in test tube Q.

Hence the correct option is A.

A lot of controversy has been generated over the use of 'BVO' in soft drinks on the ground that it is carcinogenic (cancer-causing). What is 'BVO'?

  1. Brominated vegetable oil

  2. Basic vitamin overdose

  3. B-complex vitamin overdoes

  4. Bakery vanilla odour


Correct Option: A
Explanation:

BVO stands for brominated vegetable oil which is a food additive sometimes used to keep citrus flavoring from separating out in some sodas and sports drinks.

It is a complex mixture of plant derived triglycerides that have been reacted to contain atoms of the elements bromines bounded to the molecules.

Which of the following fibres is said to be very harmful for health?

  1. Sawdust

  2. Asbestos

  3. Hay

  4. Cellulose


Correct Option: B
Explanation:

Heavy exposure to asbestes over many years causes asbestosis which is a serious scarring condition of the lungs. This condition can cause progressive shortness of breath and in server cases can be fatal.

As regards the use of international food safety standards as reference point for the dispute settlements, which one of the following does WTO collaborate with?

  1. Codex Alimentarius Commission

  2. International Federation of Standards Users

  3. International Organization for Standardization

  4. World Standards Cooperation


Correct Option: A
Explanation:

Codex alimentarius commision was created in 1963 by FAO and WHO to develop food standards guidelines and related texts such as codes of practice under to joint FAO/WHO food standards programme. The main purpose of this program are protecting health of the consumer and ensuring fair trade practices in food trade.

Which of the following is used for preservation of biological substances and food materials?

  1. Liquid ammonia

  2. Liquid dinitrogen

  3. Liquid sulphur dioxide

  4. Carbon dioxide


Correct Option: B
Explanation:

Liquid nitrogen has many uses, mainly based on its cold temperature and low reactivity. Examples of common applications include:

1. The freezing and preservation of food products
2. The preservation of biological samples, such as sperm, eggs, and animal genetic sample.
3. Use as a coolant for superconductors, vacuum pumps, and other materials and equipment.
4. Use in cryotherapy to remove skin abnormalities.
5. The shielding of materials from the oxygen exposure
6. The quick freezing of water or pipe to allow work on them when valves aren't available
8. A source of extremely dry nitrogen gas.

Milk can be preserved by adding a few drops of:

  1. formic acid solution

  2. formaldehyde solution

  3. acetic acid solution

  4. acetaldehyde solution


Correct Option: A
Explanation:

Formic acid $\Rightarrow H - \overset{O}{\overset{||}{C}} - OH$
Formic acid is used to preserve Milk.

Match the following

1) Food preservative a) Reserpine
2) Anti depressant b) Sodium benzoate
3) Lowers blood pressure c) Analgesic
4) Pain reliever d) Tofranil
-- e) Sodium cyclamate
  1. 1-a, 2-b, 3-d, 4-e

  2. 1-e, 2-a, 3-d, 4-b

  3. 1-b, 2-d, 3-a, 4-c

  4. 1-b, 2-e, 3-c, 4-d


Correct Option: C
Explanation:

Reserpine-  Lowers blood pressure 
Sodium benzoate- Food preservatives, which prevent spoilage of food due to microbial growth.
Analgesic-Analgesics reduce or abolish pain without causing impairment of consciousness, mental confusion, in coordination or paralysis or some other disturbances of nervous system
Tofranil-Anti depressant 

Arrange the following in decreasing order of the sweetening capacity.
(I) Saccharin
(II) Aspartame
(III) Alitame 

  1. I > II > III

  2. III > II > I

  3. III > I > II

  4. II > I > III


Correct Option: C

Full form of GFC is?

  1. Grazing food chain

  2. Grazing fish chain

  3. Gross food chain

  4. Green forest conservation


Correct Option: A
Explanation:

GFC means "Grazing Food Chain".

grazing food chain is a food chain in which the energy in the lowest trophic level is derived from photosynthesis.


 GFC is the major source of energy flow in the terrestrial ecosystem.

Which of the following statement is wrong about Abscisic acid :

  1. It helps in general plant metabolism

  2. It is antagonistic to $GA _3$

  3. It helps in seed maturation & dormancy

  4. Morphogenesis


Correct Option: A
Explanation:

It helps in general plant metabolism

Muddy water can be purified through coagulation by using :
  1. $\text{common slat}$

  2. $\text{alums}$

  3. $\text{sand}$

  4. $\text{lime}$


Correct Option: B
Explanation:

Muddy water can be purified through coagulation by using alums. 


It is added to the water so that the negatively charged colloidal particles clump together into Flocks which then float to the top of the liquid settle to the bottom of the liquid, or can be more easily filtered from the liquid, prior to further filtration and disinfection of the water.

Which of the following will not enhance nutritional value of food?

  1. Minerals

  2. Artificial sweeteners

  3. Vitamins

  4. Amino acids


Correct Option: B
Explanation:

Artificial sweeteners enhance the taste but will not enhance the nutritional value. Whereas minerals, vitamins and amino acid will increase the nutritional value as they are the important constituents of nutrition.

Which of the following are used as food preservative?

  1. Table salt

  2. Sodium hydrogen carbonate

  3. Cane sugar

  4. Benzoic acid


Correct Option: A,C
Explanation:
A preservative is a substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent  decomposition by microbial growth or by undesirable chemical changes.

Food preservation usually involves preventing the growth of bacteria,fungi (such as yest), or other microorganisms (although some methods work by introducing benign bacteria or fungi to the food), as well as retarding the oxidation of fats that cause rancidity.

The earliest cultures have used sugar as a preservative, and it was  commonplace to store fruit in honey. Similar to pickled foods, sugar cane was brought to Europe through the trade routes. In chemical pickling, the food is placed in an edible liquid that inhibits or kills bacteria and other micro-organisms. Typical pickling agents include  table salt.

Hence A & C are correct options.

Sugar is the main source of energy as it produces energy on metabolic decomposition. But these days low calorie drinks are more popular.

  1. True

  2. False

  3. Ambiguous

  4. None of these


Correct Option: A

Assertion: All chemical added to food items are called food preservatives.
Reason: All the chemicals increase the nutritive value of the food.

  1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

  2. Both Assertion and Reason are correct but Reason is NOT the correct explanation for Assertion.

  3. Both Assertion and Reason are incorrect.

  4. Assertion is correct but Reason is incorrect.

  5. Assertion is incorrect but Reason is correct.


Correct Option: C
Explanation:

Various chemicals are added to food. They are called food additives and are flavours and sweeteners, food colours (dyes), fat emulsifiers and stablising agents, flour improvers antistaling agents and bleaches, antioxidants, preservatives and nutritional supplements.
Thus, only few chemicals added to food items are called food preservatives.
and Only few chemicals increase the nutritive value of the food.
Hence, both Assertion and Reason are incorrect.

Assertion : Preservatives are added to food items
Reason : Preservatives inhibit the growth of microorganisms

  1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

  2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

  3. Both Assertion and Reason are incorrect

  4. Assertion is correct but Reason is incorrect

  5. Assertion is incorrect but Reason is correct


Correct Option: A
Explanation:

A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.


Preservatives increase shelf life of food materials by inhibiting growth of micro organisms and that is the reason why they are added to food items. 

Assertion: Artificial sweeteners are added to the food to control the intake of calories.


Reason: Most of the artificial sweeteners are inert and do not metabolise in the body. 

Read the above assertion and reason and choose the correct option regarding it.

  1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

  2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.

  3. Both Assertion and Reason are incorrect.

  4. Assertion is correct but Reason is incorrect.

  5. Assertion is incorrect but Reason is correct.


Correct Option: A
Explanation:

Artificial sweeteners are added to the food to control the intake of calories.
Most of the artificial sweeteners are inert and do not metabolise in the body.

An example includes saccharine and its salts which are life savers for countless diabetics and is of great value to people who need to control the intake of calories.

Thus, both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

It is found in phosphorus and nitrogen

  1. inorganic impurities

  2. bacteria

  3. nutrients

  4. other microbes


Correct Option: C
Explanation:
Nitrogen and phosphorous are nutrints that are natural parts of aquatic ecosystems.Nitrogen is also most abundant element in the air we breath nitrogen and phosphorous support the growth of a lgee and aquatic plants,which prouide food and habbit for fish and smaller organisma that line in water.







Which of the following are artificial sweeteners?

  1. Sodium benzoate

  2. Saccharin

  3. Galactose

  4. Aspartame


Correct Option: B,D
Explanation:

For diabetic patients, sugar cannot be used as a sweetening agent. Artificial sweetening agents that are non-nutritive in nature are used as substituents for sugar (specially in soft drinks). 


Examples are saccharin (500 times sweeter than sucrose) and cyclamates. Aspartame (160 times sweeter than sucrose), another artificial sweetener is the methyl ester of the dipeptide aspartyl phenylalanine.

So, the correct options are B and D.

Which of the following is/are examples of artificial sweetener?

  1. Sucralose

  2. Saccharin

  3. Neotame

  4. Aspartame


Correct Option: A,B,C,D
Explanation:

Artificial sweeteners are used in one of two ways. They may be used directly in commercially processed foods, or they are mixed with one or more starch-based sweeteners before sale to consumers. Artificial sweeteners are so intensely sweet that dextrose or maltodextrin, or both, must be added to dilute their intense sweetness in order to imitate the sweetness of a sugar. Artificial sweeteners can not be sold directly to consumers since only infinitesimally small amounts are required to mimic sugar’s sweet taste. All of the given compounds are artificial sweeteners.

The food is kept at low temperatures in a refrigerator because it:

  1. saves money

  2. makes food more tastier

  3. kills bacteria present in the food

  4. is fashionable to keep the food in the refrigerator


Correct Option: C
Explanation:

Bacteria do not grow at low-temperatures. So, food is stored at low-temperatures in refrigerator.

Vitamin C is:

  1. Citric acid

  2. Lactic acid

  3. Paracetamol

  4. Ascorbic acid


Correct Option: D

On treating roll sulphur with an aqueous solution of calcium hydroxide :

  1. plastic sulphur is prepared

  2. milk of sulphur is prepared

  3. rhombic sulphur is prepared

  4. roll sulphur


Correct Option: B
Explanation:

When sublimed sulfur is boiled with lime water ,the lime is removed from the precipitate by washing with dil. $ HCl $; this is known as milk of sulphur and is used for treatment of various skin orders.

The yellow in egg yolk is a coloring caused by:

  1. An FD & C dye added to the egg.

  2. A carotenoid

  3. An anthocyanin

  4. Natural means..the fat is just yellow.


Correct Option: B
Explanation:

The yellow in egg yolk is a coloring due to the presence of carotenoid.
Hence option B is correct.

Some scientists believe that a chemical widely used as a preservative and a colouring agent in foods gets converted to an acid in the stomach, affects the genes and causes cancer in human beings. Identify that substance.

  1. Ferric chloride

  2. Sodium nitrite

  3. Vinegar

  4. Sulphur dioxide


Correct Option: B
Explanation:

Sodium nitrite and nitrate closely are related chemicals that have been used for centuries to preserve meat. While nitrate itself is harmless, it easily converts to nitrite, which when combined with secondary-amine compounds forms nitrosamines, a powerful cancer-exacerbating chemical. This chemical reaction occurs easily during the frying process.


Salt is used in our food because:

  1. it makes the food tasty

  2. we sweat and lose salt

  3. it helps in production of hydrochloric acid required to digest the food

  4. it makes water absorb food particles better


Correct Option: A
Explanation:

It balances the sweetness and helps suppress other flavors, such as bitterness. Salt contains the element sodium, which is an essential nutrient need by the body in Small amounts. When salt is added to processed meats, it restructures the proteins, which then act as binding and emulsifying agents.

Which of the following is used as a food preservative?

  1. Citric acid

  2. Sucralose

  3. Salts of sorbic acid

  4. Ascorbic acid


Correct Option: A,C,D
Explanation:
Citric acid is used both as a natural flavor enhancer and preservative in a variety of foods, such as jams and jellies, canned fruits and vegetables. It's also used in ice cream, fruit drinks, candy, and carbonated beverages.
Sucralose is an artificial sweetener and sugar substitute.
Sorbic acid and its salts, such as sodium sorbate, potassium sorbate, and calcium sorbate, are antimicrobial agents often used as preservatives in food and drinks to prevent the growth of mold, yeast, and fungi. In general the salts are preferred over the acid form because they are more soluble in water, but the active form is the acid.
Ascorbic acid is a popular natural ingredient preservative. It can be used as a preservative in a vast array of food products, including bread, cured meats, jams and jellies, and other sauces and spreads.
therefore option A, C and D are correct

Modern oil-based paints contain oils that can dry to form strong, adhesive films by cross-linking of fatty acid chains. Some of these drying oils' are mentioned here. Can you pick the false one?

  1. Linseed oil

  2. Turpentine oil

  3. Soyabean

  4. Castor oil


Correct Option: B
Explanation:

Drying oils are prone to hardening upon exposure to air, due to free radical base polymerization, thus forming a flexible, transparent and waterproof film. This property is exhibited by linseed, turpentine and soybean oils. 

Stearic acid is.

  1. An unsaturated fatty acid

  2. A saturated fatty acid

  3. Essential fatty acid

  4. A simple lipid


Correct Option: B

________ act as protective agent on the surface of animals and plants.

  1. Carbohydrates

  2. Vitamins

  3. Nucleic Acids

  4. Wax


Correct Option: D
Explanation:

Wax act as a protective agent on the surface of animals and plants. It protects animals and plants from excessive loss of moisture. It protects the plants and fruits from becoming infected with fungi and bacteria.


Wax contains esters of long chain fatty acids and long chain alcohols or sterol.

Hence, option D is correct.

High molecular weight alcohols are present in:

  1. waxes

  2. fats

  3. oils

  4. phospholipids


Correct Option: A
Explanation:

waxes are monoglycerides, these are form by the condensation reaction between monohydroxy alcohol and fatty acid, this is the high molecular weight compound.

Example- Bee wax 
( Hexacosyl palimitate $\rightarrow$ Hexacosyl alcohol+ Palmitic acid)
$C _{26}H _{53}OH + C _{15}H _{31}COOH \overset{-H _2O}\rightarrow C _{26}H _{53}COOC _{15}H _{31}$ 

Four oils $A, B, C$ and $D$ have the following values of melting points.
(a) $258$ K (b) $273$ K (c) $295$ K (d) $303$ K
Among these, which oil is prohibited from consumption by cardiac patients?

  1. a

  2. b

  3. c

  4. d


Correct Option: D
Explanation:

The oils having higher unsaturation in the fatty acid component have very low melting points. Hence, on the consumption of these oils there is less chance of blockage of blood vessels. The saturated oils have higher melting points and they get solidified easily. Therefore they block the blood vessels and so are prohibited from consumption by cardiac patients. Hence oil D is prohibited from consumption by cardiac patients.

- Hide questions