J. Dairy Sci., 29, J, 1976 . •

VARIATIONS IN FAT UNSAPONIFIABLE MATTER V' AND CHOLESTEROL CONTENTS OF GOAT MILK·

K.L. ARORA, M.P. BfNDAL and M.K. JArN

National Dairy Research Inslitute, Kamal (Haryana)

Reoeived OD 18 I""", 1~7S INTRoDucrroN

Un saponifiable constituents of cow and ?ufialo milk fat have been the subject of an

stlldy in our laboratory (Bindal Jain, 1972, 1973). Several factors responsi­for variations in unsaponifiable matter and

:!I0,lester,olofghee derived from cow and buffalo have been discussed. The present paper

res.:ri1les variations in levels of fat and total in goat milk due to breeds. stage

lactation and method of iSOlating milk fat. variations in frec and esterified cholesterol

"ntent due to breeds have also been induded.

MATERIALS AND METHODS

Individual milk samples were collected from 5 Beetal goats immediately

parturition during first 10 milkings. milk samples were collected at

intervals for the remaining lactation These milk samples were analysed for

total cholesterol contents. Ten batches "V"U"·V''''~ milk samples each of Alpine,

and Cross·Bred (Alpine x Beeta!) were analysed to study breed variations and lotal cholesterol contents. Com· samples each of Beetal and CrOSSbred were also analysed for levels of free and

~lied cholesterol.

batches · of herd milk samples were Into Desl ghee, Direct Creamery

. ghee (Srinivasan and Anantakrishnan,

1964) and buller fat (Folch. 1957) for studyin, variations in total cholesterol content due to the method of isolating mille fat. SamplC5 of DC ghe.: were also analysed for unsaponifiable matter by both [Sf procedure (1966) and Schwartz procedure ([966).

Total. free and esterified cholesterol content were estimated according to the methods of Bindal and Jain (1973. and 1912). Fat cootent was estimated by Gerber method (IS : 1958).

RESULTS AND DlSCUSS(ON

Fat conteat or goat milk

Herd milk samples (205 samples) contained rat varying between 3·8 and 6·9% (4·8%) (fable I). Of all the three breeds, milk of Cross·bred goats (Table 4) had highest milk fat (5 ·4%), followed by that of Beetal goats (5·2%) and lowest in Alpine goats (4·1%). These variations in fat content due to breeds were highly significant (P<;O·Ol). However. thedifrerences between falcontent of Cross· bred and Beetal goats milk were not significant. Dhingra (1934) had reported that lamaDapari goat milk contained higher fat levet (5·2%) than thnt of Barbari goats (4·9%) and Bectal goats (4·5%)"

V.rlatioDS in rat content due to siage of lad.tlOil

Ca) CollJ£tra[ period : The data (Pi,. a) have shown the average values for fat per cent in colostrum of 5 Beetal goats. These variations

this work has been submitted by one of the autho~ (KLA) to the Punjab UniverSity (Ina) in partial of Ihc Rquiremeatl Cor tlte dqree of M.Sc. (D8.ityiIlg).

191

192 Fal UlI$aponijiable Matter of Goat Milk

TABLE J Variolloas fa _ or fal, mw&pOIIlBoble _Iter, tow,

I'noe .. d ost>rIlIed cboIlSferol '" ",lit or aool ..... d.

Towards the end of lactation, fat rose to ' high leVel within a short span of IS ' It may be noted that the' .

Type of a.nolysis

. Pat ~ Uosaponifi.blc m.lt~r ",,:100 ml milk

-do-mg/IOOS rat

.d<>-Total cholesterol "".1100 mI milk q'IOO S (tal)

Free dlolestert>1 l1li/100 ml milk "" '100 <&/rat)

Eoteri6td che>le.t<col mB '100 ml milk UlB100 g (fat)

No. or samples

analysed

205

10 10 10 ID

20 20

10 10

10 10

Variations

16'5·29'7 (23'8)' 16'2-28-9 (23 '2)" 406-484 (460)' 405-461 (.:.48)1>

15·5·26·S (22'0) 379·467 (420)

'14'1-22'2 ('9'6) 339-392 (368)

1.6-J·' (2.6) J2-57 (52'2)

'lSI mctbod; bScbwarn IIl<tbod;. ·F.iiuret in pan:ntbesis .indjc.ate average valucs.

(5·4-6·7%) were to() many. There was a continuous increase in fat level till 4th milking when the values rose to maximum (6·7%) followed by a sharp decrease during 5th and 61h milking (54%). Afterwards. the rat level

. sbowed an inCTeasing tTend. rt may be nOled that afteT sixth milking (when the fat level was minimum) colostrum ceased to dot aner boiling.

(b) PosNolosfral period: rt is evident from data (Fig. b) that the (at perrent in milk of post-coloSlral period was significantly lower (4·6%) than that of coloslral period (S · 8~~). These varialion~ in fat contrnl of milk during the post-colostral period of 5 Beetal goats weTe highly significanl (P .-,0 ·01). The fat content decreased continuously during 7-8 months of lactation when the fal level decreased to mini­mum (4·0%). It was followed by an iocreasing trend during the remaining period of lactation.

regard to variations in fat content of goat due to lactatio,.. is scant). '.'

UosapODifiable matter of goat /DU"

Ten samples of DC ghee prepaTed from milk were analysed in duplicate for un:>ap'!li fiable matter essentially according 10 method (IS : ) 966 J and Schwartz (J 966). The statistical analysis (Table I) ' shown that the variations in lbe un:saponifiJll malter content isolated by these two

. WCTe not significant. It confirms Ihe of SchwaTts procedUre for estimating uns;ap<!I! fiable matter for goat milk also. It noted that unsaponifiable manu goat milk (460 mgflOO g fat) was than that of cow (449 mg!IOO g fall and (398 mgllOO g fat) as Teported by and Jain (J973b). /.

Toto' tholesterol conleDt or &oat milk

The data given in Table I (20 herd samples) have shown variations in total lerol of goat milk. Nakanishi and (1932) reporled Ihat goat milk contained 14·0 choleslerolflOO ml milk . However, values (3 ·2 mg cholesterol/ IOO ml goat reported by Azim and Mustansir (1969) extremely low. It may be noled that ch content (420 mg.'JOO g fal) reported in study was higher than Ihat of cow (319 fal) and buffalo (-) 294 mg,llOO g fal) as poned by Bindal and Jain, \ 973c).

Relationship among milk fat, matler and 10t.1 cholesterol

Analysis of 20 herd milk samples had shown a highly significant cor ..... ll.ti~ belween milk fat and unsBpollifiable (r=().9727; P<;O.OI) between total cno.~

and unsaponifiable matter (r-O·S060,

. . KL. Arora et al.

FIG A.etalle ,.1_ lor tal .ad cholesterol or (0) «>10""' ..... d (b) ltIiIk of $ --' pr..

o !< ~ I',

t \ 40 ~

• , 36 { I 34

-0," "-"'Ii' on • '-" • I -' 8 10

A .-.-F.I~

B X - X - Total cholesterol (ms/loo s r.l)

C l;-b.- Total cholesterol (mg/loo tnt milk)

, ,

:' .• -,~

193

-J J 6-0

]I. s.a , 5.6

54 M ... ..

.n " CE :~

;: ]2 • ,JI,~ ...... ' 5-2 ... •

·

30 • II> , .... 0, .....

28 : ~ ~ 1'-'

:'l ... o ....

, , •

; f ,

/11-_.

2

,.' B SoD ,

l -« ; 4.2

C 4.0

3 4 5 r. 7 8 9 10 II 3.8

(Q) COLOSTRAl PER 100 (111 "l'ni/~'''Jl) .. (f,-) POST -COlOSTRAL Jl(RIOD (Ill lII>7IIlII)

" TABLE 1 '. toIalloashl, among tal, ...... ponUIable mailer and lotal ~ obolesterol 0' 1081 milk. )

)

h Standard error · ~ioo equatiOD of regressioD coefficient

Correlation coeffident&

0'002384 0-9721' '±0'05495

and between milk fat and total cbolesterol (r=0-4263, P<O;O-Ol).' rt has been further noted that fOf every unit increase in unsaponi fiab!e maUer, Ihere was a corresponding increase of 0-21t units of fat and every unit increase in total cholesterol was followed by corresponding increase of 0·7306 and 0-15 units of unsaponitiable matter and fat respe<:­lively_

0_7306Z + 9_28 0-0586 0-5061' ±0-2040 Variations in total cholesterol cootent or goat milk due to

0-013879 04263' '±O-0661S

Fat X lfnsaPQoifiable mailer (m8'loo 11'1 milk) Total cholesterol (mg'loo Ill! milk) S~fiC!IDt (P",O-Ol)

(P ';;;O-Oj) Ao.IIlY,js based OD !be .... ult of 20 composile

(a) Methods of isolating milk fat: Table 3 reveals the average cholesterol content of 10 samples each or 'desi' ghee, DC ghee and butter rat prepared from composite goat milk samples. The average increases from 'desi' ghee to DC ghee and butter fat were 2·\ and 19-5% res­pectively and that from DC ghee to butterfat was

194 Fat Unsaponifiable Matter of Goat Milk

TABLE 3

v .... t1 ... • lit total eboleskrol of II"'" ... Ii: tol/&h.e due 10 the ..,.tbo<I of IsoJUIoa.

Method of bolatioCl'

'D..,r Sbee DClhcc Butur rat

Total cholesterol WDtents"

(mJ. /JCiO mt milk)·

lJ-9-18'~ (I~-O) 304-344 l322"9) 11-4-20-6 m -2) 307·352 1329'7) 14"6-23-0 (17-8) 337-405 (385-8)

• - Siani6 .... nt (1'<0-01); CD: 0-7348 b ... Si~ot (1'<0-01); CO : 11·30 • = ADalysis b&scd on the leSult of 10 composite

.. mplts •• = Figures In panntllesis indicate the a~go values,

17-0%_ These varialions in total cholesterol content between odesi' ghe.: and b\ltt~r fat and thaI betwun DC gber and bUlIerfat were highly significant fP<O-D1) whereas those: between 'd~si' ghee and DC ghee were not significant.

Bindal and Jain (19738) had similar trend in case of cow milk fats _ They found that a lower cholesterol in 'desi' ghee and DC ihu' 10 its losses in butter milk/skim milk churning/skimming,

(b) Bruds .- The average lotal clIcl!esl!Ci contents of 10 samples each of Alpine, ' and Cross·bred goats bave been given These variations in lotal clIolesterol expressed as mg cholesterol/ IOO ml between Alpine and Beetal and Cross· bred goats were highly (P(O-Ol) whereas between Corss·bred Beetal goats, these variation s were .ot,,!1, ...... It may be noted that slIch variations expressed as mg "holestcrol/ IOO g rat significant between milks of Alpine and , goats.

(d Stage oJ Lactatjon :

(i) Colostral period: The first colostl (Fig, a) in all five animals contained

TABLE 4

V ..... _· In tot, 101.1, f'«e ud ut.rified dolnlnol co.I<.I> or g<.t milk dtt<IO IIrtedL

Type of analysis Alpine"

Fal (1'ercent)" 3-3·$'6 Total choleoterol

(m&lIOO mI miIk)b 12-3-23"4 ("'1 ,.100 If,,)" 327~22

Free cholesterol_ (marlOO ml milk)" (mg! 100 II fat)'

Esterifiecl cholesterol (ms 'IOIl ml mllk)P (lilt/lOll 8 ratj'l

• - lieoificaDt (P<e: O,Oll; CD : 0'6772 ,, -- .ipificanl (P<D.OI): CD : 3-30 • - .l&niIi~1 (P<O_05); CD : 36-72 " - t·value : O,S388NS F _ I-value : O,8093NS p .,; I-value : O.4\l3SNS Q _ t·value : O.4133NS

( 4'10)

( 16"0) (387-2)

Beellll" Cross-bred"

4'1-6'2 (S '21) 4-S.S"

15-5-26-8 (21-7) 18-6·26-9 379-458 ( 415) 383~97

1)" ·24'5 (19'2) 16·1·22--7 327-409 ( 363) 145-392

,-3-4.2 ( 2'1) 1"·3-6 31-60 (52) 33-65

NS - NOll-Sisnificant "Aoa!)'. i. bale<! on leSults oflO'COIIlPOsltt

samples_ "Firum in parenthesi' iodicale the

value,

K.L. Arora ~t al. 195

:amou,u of cholesterol (38·6 mgllOO ml. milk; mg/IOO g fat). Cholesterol content de·

Crease:.:! sharply in the subsequent milkings and minimum (21·2 mgj (OO ml milk; 396 mg/ g fat) during 'sixth milking (when milk

t~t5ed to clot on boiling) followed by another "p'IVarutrend till 9th milking (26·1 mg/lOO mJ

454 mg!IOO g fat). Earlier workers

fat). (n other words, total cholesterol present in goat milk was made up of 88% of free cho­lesterol and 12% of esterified cholesterol. Bind'll and lain (1972) have reported free and esterified cholesterol in cow and buffalo milk fat in the ratio of 85 : 15 and 77 ; 23 res­pectively. Apparently. esterified cholesterol in goat milk fat (11% of the total cnoJesterol) was less than. that of cow (15%) as well as buffalo (23 %) milk fat.

:Biflldal and lain, (973c) also reported llimilar trend in the cholesterol variations

cow and butl"alo colostrum.

(ii) Post coloJ/ral period : It is evident from data (Fig. b) that the variations (18·3·29·4

Variations 10 free and esterlOed clIoles~rol

content of goat milk dDe to breeds

.... ~I!/'YI ml milk; 369-558 mg/lOO g The variations (Table 4) in free (363-372 mg/ I 00 g fat) and esterified (52 mg/!OO g fat) cholesterols due to breeds (Cross-bred and Beetal) were not significant statistically. Bindal and Jain (1972) reported rree cholestuol content (248 mg/ IOO g fat for cow ghee and 212 mg/too g fat for buffalo ghee) and esterified chOlesterol contenl (42 mg/IOO g rat for cow ghoe and 64 mg/IOO g fat ror buffalo ghee) of milk fat. Amongst the milk of three species goat milk had the highest level of free cholesterol whereas its esterified cholesterol was almost equal to that of cow milk but lower than that of buffalo milk.

in cholesterol content in milk of all >J>.'elalgoats were too many. rt is also apparent

total cholesterol contenl in colostrum mg/IOO g fat) was much higher than in

milk (459 mg/lOO g fat).

. Afler coloslral period. there waS a regular !cr,",.i,n .. trend in lotal cholesterol with the

in stage of lactation. This trend more significant (Fig. b) when figures

expressed as cholestetol mg/ IOO g Towards the end of lactation (9·llth

when the animals started dryi ng off. total cholesterol content shoot up (600 mgt

, fat) tremendouslY. More recently. and Jain (19730) reported peak values

mg%) rot total cholesterol content and buffalo milk during 9th months

.. calving and very high values (365-500 mg%) Ihe end of lactation. In case of cow

uUlla,u milk, Gulvadyet aJ. (1962) also two peak periods for total

~le!:ter,ol content, one during 2-Stb months ll!ic:tation and the other towards tbe end

..... "u, •• the latter being more marked.

esterlOed cholesterol cootent of goat

level of free cholesterol (Table I) .,'.<WI/UN ml milk; 368 mg/ IOO g fat) in

was about 7 times that of esterified (2·6 mg/IOO I mille; 52-2 mgllOO g

SUMMARY

Goa[ mille con lained rat ~1. ranging between 3·8 and 6·9%. Variations in fat cOntent due to breed and stage of 18ctalioo were significant. Tile data for the levels of unsapoaifiable matter estimated by 1Sl procedUre (460 lng/too g fat) and Schwartz method (448 mg/IOO g fat) were compa,able and this confirms the validity of Sehwarts method for estimation of uosapon;­flab!. matter from goat milk also. The varia­tions in total cholesterol content or goat milk due to breeds (Alpine. Beeta! and Cross· bred), stage oflaetation and method of isolatin& milk rat ('Desi' ghee, DC ghee and butter fat) were bighly significant. The correlation6 between milk fat and unsapoQifiable matter

196 Fat Unsaponifiable Malter of Goat Milk

(r-0·9727), between total cholesterol and un· saponifiable matter (r-0·5061) and between milk fat and total cholesterol (r-0·4263) were also statistically significant. Total cholesterol (22·2 mgllOO rnl milk) Dr goat milk waS made up of 88% DUree cholesterol and 12% of esteri­fied cholesterol. The variations in free and esterified cholesterol due to breeds were not significant.

ACKNOWLEDGEMENTS

The authors thank Dr. D. Sundaresan, Director and Dr. N.C. Ganguli, Dairy Chemist for their interest in the work. The valuable help and guidance towards statistical planning of this work by Mr. M. Gurnani , Associate Professor, are highly appreciated.

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Bindal, M,P. and Jain, M,K. (1973.) Sci" 4:1, 10, 918,

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IS. (1958) Indian Stand.rd. : 1224, 0/ f ar ;n ,"'haft milk ~.·QPCJra(ed milk, milk. /Jutif'r milA- and at'am b,. Guher

IS, (1966) Indian Standards : 3~8, .Jompling (md 'rs( for gh«. 34.

Jenness, R . and Palton, S, (1966) Principk. Chfmi.l"/ry. John WiU~y and Soru, loc . ..... ,.

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