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DAIRY CHEMISTRY

 

Chemistry of Fluid Milk

Compiled by: - Mr. Abhay Pandey

 

Q1:In the milk definition as per FSSAI it is mentioned to exclude the milk obtained from the animal 15 days before or 5 days after calving because of

A. Abnormal composition

 

Q2:The milk component which is in highest concentration in all the species is

A. Water

 

Q3: Higher demand for minerals for the optimum growth of the young one of

A. Rabbit

 

Q4:The reason for high lactose content in human milk is

A. To maintain the osmotic pressure

 

Q5:Human milk contain a very low level of protein percentage because

A. Infant takes long time to doubles its birth weight

 

Q6: The exotic cattle breed which can produce high fat containing milk is

A. Friesian

 

Q7: Individual cows produce milk with variation in composition because

A. Genetic inheritance

 

Q8: The milk constituent which shows variation during the milking is

A. Fat

 

Q9: The season during which the animal produces milk with good fat percentage is

A. May

 

Q10: The fat-free portion of milk is known as

A. Plasma

 

Q11:The major milk constituent existing completely in soluble state is

A. Lactose

 

Q12: The stabilization of fat in milk is attained by

A. Fat globule membrane

 

Q13: The milk constituent chiefly responsible for the light scattering property of milk is

A. Fat globules

 

Q14: The milk constituent with low density is

A. Milk fat

 

Q15:The primary structure of a proteins molecules will consists of

A. Polypeptide chains

 

 

Q16:Polymorphism in proteins is caused by changes in

A. Sequence of amino acids

 

Q17:As per the latest protein nomenclature of the milk protein the first letter denotes

A. The class of the protein

 

Q18:The family name of the given protein is indicated by

A. Greek name before the class name

 

Q19:The sequence of the amino acids in the primary structure of the protein is dictated by thesequence of

A. Trinucleotide codons

 

Q20:The major fraction of the milk proteins is

A. caseins

 

Q21: The scientist who first attempted to study polymorphism in milk is

A. Aschaffenburg and Drewry

 

Q22: The proteose peptone fraction of milk is obtained from

A. whey protein

 

Q23.that all portion except casein is called

A.milk serum

 

Q24:Latest technique adopted to study milk protein fractions

A. Electrophoresis

 

Q25:The common property of all the fractions of casein is

A. Insolubilization at pH 4.6

 

Q26:The casein fraction having two predominantly hydrophobic regions is

A.alpha s1-Caseins

 

Q27:The casein fraction having a negatively charged head and an uncharged essentially hydrophobic tail is

bita Casein

 

Q28:The chief carbohydrate moiety associated with the glycoprotein of the casein fractions is

A.N-acetyl neuraminic acid

 

Q29:The site of action of chymosin on the k casein molecule is

A. Phe(l05)-Met(l06)

 

Q30:The first chemical method for fractionation of casein was developed by

A. Rowland

 

Q31:Separating the casein from milk is done by using

A.10% TCA

 

Q32:From milk the Non-casein-nitrogen fraction is obtained by

A. Adding 10% acetic acid

 

Q33:In milk the necessity to have casein in micelle form is

A. Protecting calcium sensitive fractions

 

Q34:The stability of milk during several heat treatment is decided by the milk constituent

A. casein

 

Q35:The core of the casein micelle consists of loosely packed

A. Hydrophobic substances

 

Q36:The effect of heating milk on the calcium phosphate content in casein micelles is

A. Increases

 

Q37:Among the various fractions of casein the fraction which is not sensitive to the presence of ionic calcium is

A.kappa casein

 

Q38:The carbon compounds which are required for the normal functioning of the living organisms and which can not be synthesize by the body are known as

A. Vitamins

 

Q39: The fat soluble vitamin which is present in highest concentration in milk is

A. Vit.A

 

Q40: Milk is a poor source for the vitamin

A. Vitamin A

 

Q41:The main importance of the Vitamin E in human nutrition is

A.Acts as antioxidant

 

Q42:The vitamin that is formed by UV irradiation of 7-dehydrocholesterol in animals particularly in the skin is

A.Cholecalciferol D3

 

Q43:The whey protein originating from the blood and synthesized in liver is

A. Bovine serum albumin

 

Q44:The two light chains and two heavy chains of the IgG1 and IgG2 are joined by

A. Disulphide bond

 

Q45:The fraction that is formed by the partial hydrolytic degradation of bita-casein is

A. Proteose- peptone

 

Q46:The approximate protein percentage in the fat globule membrane is

A. 50.0 % of the membrane materialc

 

Q47:The occurrence of non-protein nitrogen component in milk is due to

A. Protein metabolism

 

Q48:Any change caused in the native state of protein structure is known as

A. Denaturation

 

Q49: The most heat sensitive fraction of whey protein is

A. Immunoglobulin

 

 

Q50: The extent of protein denaturation could be lowered or even protected by

A. Interaction with kappa -casein

 

Q51: When the salt concentration is high enough, the proteins will lose their solubility because of

A. Dehydrating the protein molecules

 

Q52:The plasma membrane covering the lipid material during its transport in to the lumen of the alveoli is known as

A. Fat globule membrane

 

Q53:The proportion of the proteins in the fat globule membrane material is

A. 50.0%

 

Q54: The major component of the proteins of the fat globule membrane are

A. Enzymes

 

Q55:The fat globules in milk exist in a stable emulsion because of

A. Presence of MFGM

 

Q56:The role of the MFGM proteins of milk in the human health is due to

A. Its neutraceutical effect

 

Q57:A reference method used for determination of protein content in milk is

A. Kjeldahl method

 

Q58: A rapid methods for determining the casein content of milk for cheese preparation is by

A. Formol titration method

 

Q59: Protein estimation using the absorption of ultra violet radiation at wavelengths in the neighborhood of 280 nm, is possible because of the

A. Presence of specific amino acids

 

Q60:The method of protein estimation by preparing a suspension of insoluble protein and studying the light scattering property is known as

A. Turbidimetric method

 

Q61: The reagent used to estimate quality of nitrogen in the digested samples by colori metric method is

A. Amido black

 

Q62:Resorption of milk constituents during dry period of an animal is brought about by the enzyme

A.Lipases and proteinases

 

Q63:Transformation of one micromole of substrate by an enzyme per minute under standard conditions is regarded as

A. One unit of enzyme activity

 

Q64: The effect of extreme high or low pH on the activity of an enzyme is

A. Denatures the enzyme

 

Q65:Enzyme which is a constituent of leucocytes

A. Catalase

 

Q66:In bovine milk the enzyme having maximum activity is

A. Lactoperoxidase

 

Q67:The enzymes which liberate fatty acids from lipoproteins and chylomicrons of the blood is

A. Lipoprotein lipase

 

Q68:The enzyme whose concentration is high in colostrums and is located in serum is

A. Acid phospho monoesterase

 

Q69:The fraction of casein on which plasmin act is

A. k-casein

 

Q70: The milk enzyme which is having bactericidal action is

A. Lysozyme

 

Q71:The enzyme which is having carbohydrate moiety is

A. Lipoprotein lipase

 

Q72:The oxidase enzyme is very prominent in bovine milk and associated with the fat globule membrane is

A. Xanthine oxidase

 

Q73:Growth of micro organisms in milk is inhibited by the enzyme

A.Lactoperoxidase

 

Q74:The enzyme which transfers the galactose from UDP –galactose is

A. Lactose synthase

 

Q75:The enzyme whose concentration in milk increases with the increase of leukocytes count is

A. Catalase

 

Q76:The enzyme whose activity in cow's milk depends to some extent on the Molybdenum content of the feed consumed is

A. Xanthine oxidase

 

Q77:The milk constituent which plays an important role in the development of colour in heated milks is

A. Lactose

 

Q78:In milk the main disaccharide having glucose and galactose moieties is

A. Lactose

 

Q79:The process of spontaneous change between the alpha and bita configurations is known as.

A. Mutarotation

 

Q80:The lactose content in human milk is

A. 7%

Q81:The structure of lactose when presented in Haworth projection, the alpha configuration places the position of the hydroxyl group on Carbon 1 will be

A. Downwards

 

Q82:The designations of lactose refers to the configuration on the number one carbon of the monosaccharide

A. Glucose

 

Q83: At equilibrium the amount of alpha form of lactose in solution is

A. 37.3%

 

Q84:The specific rotation of bita form of lactose is

A. +35.00

 

Q85:The most stable form of lactose is its

A. alpha form

 

Q86:The form of lactose crystal obtained above 93.5?C is

A. bita Lactose anhydrate

 

Q87:Crystallization of lactose is inhibited by the presence of

A. Gelatin

 

Q88:The common shape of lactose crystals is

A. Tomahawk

 

Q89:When the lactose solution is dried rapidly and the viscosity increases quickly the crystals formed are

A. Amorphous lactose

 

Q90:The density of alpha-lactose monohydrate is

A. 1.540

 

Q91:Mild oxidation of lactose with reagents like alkaline copper, iodine or picrate forms

A. Lactobionic acid

 

Q92:The development of organism Bifidobacterium bifidum in the intestinal flora in the gut of breast-fed infants takes place in the presence of

A. Lactase enzyme

 

Q93:The enzyme lactase suitable for industrial processing of whey or lactose is obtained from the yeast

A. Kluveromyces lactis

 

Q94:Acid hydrolysis of lactose can be brought about by using

A. 1.0 to 3 .0 N Hydrochloric acid

 

Q95:Enzyme which hydrolyses lactose is

A.bita-galctosidase

 

 

Q96:An important naturally occurring protein food with a high content of reducing sugar is

A. Milk

 

Q97:The milk components which are involved in the Maillard type of browning are

A. casein and lactose

 

Q98: The Maillard browning affect the palatability of dehydrated milk by producing

A. Disagreeable flavour materials

 

Q99:Which amino acid residue in the protein is most destroyed by the thermal treatments (0 to 90°C) in the presence of lactose?

A. Lysine

 

Q100:The substances which inhibits the Maillard reaction in milk powders is

A. Active sulfhydryl groups

 

Q101:A chemical decomposition of condensed substances containing a sugar compound that occurs spontaneously at high temperatures is known as

A. Pyrolysis

 

Q102:The chief physical change that could be observed in the sugar during caramelization is

A. Brown discolouration

 

Q103:The characteristic colour produced during caramelization is due to the

A. Caramelen

 

Q104:The most important condition for the caramelization of sugars is

A. High temperature

 

Q105:The contribution of lactose to the baked products

A. Colour

 

Q106:Lipids are class of compounds insoluble in

A. Water

 

Q107:The common name for the fatty acid, n-Octadecanoic acid is

A. Stearic acid

 

Q108:The C18:1 stands for ___________ fatty acid

A. Oleic acid

 

Q109:Natural fatty acids found in plants and animals are composed of even numbers of carbon atoms because of

A. Bio synthesis process

 

Q110:The C16:0 stands for ___________ fatty acid

A. Palmitic acid

 

Q111:The form in which bulk of the milk fat exists in milk is

A. Emulsion

 

 

Q112:The ester of fatty acid with long chain monohydric alcohol is known as

A. Wax

 

Q113:The major class of milk lipid is

A. Triacylglycerol

 

Q114:The chief sterol found in the milk fat is

A. Cholesterol

 

Q115:In the milk fat the phospholipids are located in

A. Fat globule membrane

 

Q116: In milk fat, fatty acid present in the highest proportion is

A. Palmitic acid

 

Q117:Components of the fat globule membrane are arranged according to the

A. Polarity and hydrophobicity

 

Q118:In milk fat globules the high melting triglycerids are located in

A. Surface of the fat globule

 

Q119:When the secondary hydroxyl group of the glycerol molecule is shown on the left hand side the position of the fatty acid in the Sn1 position will be shown

A. The right side of the 1st carbon atom above

 

Q120:The notation used for showing the oleic acid will be

A.18:1

 

Q121:In the composition of the lipids of bovine whole milk the component having highest concentration is

A. Triacylglycerides

 

Q122:The lipid which acts as a solvent for many apolar substances in milk is

A. Triacylglycerols

 

Q123:The triglycerides are not very reactive at room temperature while the reaction that could be observed at higher temperatures will be

A. Oxidation of the double bonds of unsaturated fatty acids

 

Q124:The most abundant compound lipid in milk is

A Phospholipid

 

Q125:The compound lipid which is having surface active property is

A. Lecithin

 

Q126:A compound lipid having a sugar group bound to its molecule is

A. Cerebrosides

 

Q127:The nitrogen group which is attached to lecithin molecule

A. Choline

 

 

Q128:Important role of phopholipids in milk is

A. To stabilize fat emulsion

 

Q129:The major constituent of unsaponifiable matter of milk fat is

A. Cholesterol

 

Q130:The amount of unsaponifiable matter of milk fat by weight is

A. 0.300 - 0.450%

 

Q131:The cholesterol content in bovine milk fat is

A. 0.25 - 0.4%

 

Q132:The saponifiable form of cholesterol is

A. Esterified cholesterol

 

Q133:The cholesterol is mainly associated with

A. Fat globule membrane

 

Q134:The carbon compounds of diverse structures which are required for normal functioning of living organisms and which can not be synthesize by the body are known as

A. Vitamins

 

Q135: The fat soluble vitamin which is present in highest concentration in milk is

A. Vitamin A

 

Q136:Milk is a poor source of vitamin

A. Vitamin K

 

Q137:The main importance of vitamin E in human nutrition is

A. Acts as antioxidant

 

Q138:The vitamin that is formed by UV irradiation of 7-dehydrocholesterol in animals is

A.Cholecalciferol

 

Q139:The constituent which determines the stability of proteins in milk is

A. Salts

 

Q140:The electrical conductivity of milk is largely determined by the

A. Chloride

 

Q141:The mineral constituent which exists completely in soluble state is

A Sodium

 

Q142:The essential metallic component associated with lactoferrin is

A. Iron

 

Q143:The freezing point of milk largely depends upon

 Chloride and lactose

 

Q144:For heat stability of milk it is necessary to maintain the physical equilibrium between

A. Milk salts in colloidal and soluble form

 

Q145:The salt in milk which is present completely in soluble state

A.Sodium chloride

 

Q146:The compounds which are having the capacity to tie up a particular ions are known as

A. Sequestering agents

 

Q147: The pH at which all the calcium and phosphate will be withdrawn from the colloidal state and converted into soluble state is

A. 5.2

 

Q148: Salt balance of milk is a ratio of soluble

A.(K+ Na )/ (Citrate+ PO4)

 

Q149: The solubilization of small amount of metal in milk cause development of

A. Metallic flavour

 

Q150:The most important consideration for choosing an ideal metal for milk contact surface is

A. Non toxic

 

Q151:The choice of the metal presently used for several milk contact surfaces is

A. Stainless steel (18:8)

 

 

References:

1.      ICAR E- course

2.      NDRI students class notes

3.      Previous year question papers


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