[123doc.vn] - nghien cuu chiet tach axit hydroxycitric tu la vo qua bua bang dung dich kiem

8/12/2019 [123doc.vn] - Nghien Cuu Chiet Tach Axit Hydroxycitric Tu La Vo Qua Bua Bang Dung Dich Kiem

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B GIO DC V O TO

I HC NNG

L TH CC

NGHIN CU CHIT TCH

AXT HYDROXYCITRIC T L, V QU BA

BNG DUNG DCH KIM

Chuyn ngnh : Ho Hu c

M s : 60.44.27

TM TT LUN VN THC S KHOA HC

Nng, Nm 2013


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Cng trnh c hon thnh ti

I HC NNG

Ngi hng dn khoa hc: GS.TS. O HNG CNG

Phn bin 1: PGS.TS. TRN TH X

Phn bin 2: TS.BI XUN VNG

Lun vn c bo v ti Hi ng chm Lun vn tt nghip Thc s

khoa hc hp ti i hc Nng vo ngy 31 thng 5 nm 2013

* C th tm hiu lun vn ti :

- Trung tm Thng tin - Hc liu, i hc Nng

- Th vin trng i hc S phm, i hc Nng.


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1

M U

1. L do chn tiTrn th giivic nghincu cy ba c ch trng t lu,

tnh n nay c rt nhiu cng trnh, nhiu ti nghin cu v cy

ba bao gm gm cc lnh vc khc nhau: nh chit tch, xc nh

thnh phn ha hc ca hp cht hu c, ng dng trong cng ngh

thc phm, cng ngh dc phm, c bit l cc ch phm gim bo.

Bnh bo ph khng ch nh hng n lao ng, sinh hot,

thm m m cn nguy hi nht nh n sc kho. Ngi trung ninv ln tui b bo ph s d mc cc bnh nh: huyt p cao, bnh

mch vnh, tiu ng, bnh Gout, tai bin mch no, si ti mt

Bo ph l bnh do m tch lu qu nhiu trong c th lm thay i

chc nng sinh l, sinh ho ca c th.

Cy ba l mt loi cy d trng, pht trin tt , cho nng xut

cao c hu ht trn a bn Min Trung, Ty Nguyn v trn th giicng c rt nhiu loi ba.Ngi Vit nam ta dng l ba lm mn n,

dng v b cha bnh ngoi da, bp non nhai n cha bnh ng

thai

HCA c chit t v qu ba c tc dng ngn chn qu trnh

tch ly m, ci thin bilance trong mu, km hm qu trnh chuyn

ha lng ng tha trong c th thnh m, gip ngn chn qutrnh bo ph. Ngoi ra, HCA cn ci thin gim cc loi m xu . Bn

cnh , HCA lm tng nng serotonin c vai tr kim sot s

thm n, lm tng qu trnh t hp glycogen v tng oxi ha, t

chy m thaDng lng t do ca HCA c xu hng khng n

nh, d b lacton ha nn vic tng hp mui i t HCA c

nghin cu nhm lm tng s n nh v hot tnh sinh hc ca HCA.


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2

Lowenstein m t cc mui ca HCA da trn cc kim loi kim,

kim th nh: kali, natri, canxi, cc mui ny d hp thu vo c th

con ngi v tng cng hiu qu gim cn. V vy vic to ra c

mui kim ca HCA cn c nng cao cht lng v hiu sut, v

cng cha thy cng trnh no nghin cu chit tch HCA bng cch

dng trc tip dung mi kim, vi cch ny c th ta s thu lng

HCA c hm lng cao hn.

Vi nhng l do trn m ti chn ti:Nghin cuchit tch

HCA trong l, v qu ba bng dung dchkim.2. Mc ch nghin cu

- Kho st qu trnh chit tch axit hidroxycytric t v qu ba

bng dung dchkim to mui.

- So snh hiu sut chit HCA bng dung dchkim v dung mi

nc s dng trc dy.

- ng gp thmnhng thng tin, t liu khoa hc v cy ba,to c s khoa hc ban u cho cc nghin cu su v ng dng ca axit

hidroxycytric .

3. i tng nghin cu v phm vi nghin cu

3.1. i tng nghin cu

V qu, l ca cy ba (Garcinia oblongifoliaChamp. Ex Benth.)

ti x Bnh Hi v Bnh Ho, huyn Bnh Sn, tnh Qung Ngi.3.2. Phm vi nghin cu

- Chit tch axit hidroxycytric bng phng php chng ninh

bng dung mi kim. Kim tra sn phm chit bng phng php

chun axit-baz, ph hng ngoi (IR) v phng php sc k lng

hiu nng cao (HPLC).

- Kho st nh hng ca cc yu t: Nng kim, t l rn


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3

lng, nhit , thi gian chng ninh ti hiu sut qu trnh chit tch

axit HCA bng dung dchkim gm KOH v NaOH.

- So snh cng ngh chit tch axit trong dung dchkim v dung

mi nc v hiu sut.

Hnh 1.1. Qu, l , hoa ca ba

4. Phng php nghin cu

4.1. Nghin cu l thuyt

Phng php nghin cu cc hp cht thin nhin, tng quan cc

ti liu v c im hnh thi thc vt, thnh phn ho hc, ng dngca mt s loi thc vt thuc h ba Clusiaceae.

4.2. Phng php thc nghim

Phng php chit tch:Phng php chit chng ninh sdng

dung dchl kim (KOH, NaOH)

Phng php phn tch cng c:Phng php sc k lng hiu

nng cao (HPLC), phng php quang phhp thnguyn t(AAS),phng php o phhng ngoi (IR).

5. ngha khoa hc v tnh thc tin ca ti

T cc nghin cu trn, ti thu c mt s kt qu vi

ngha nh sau:

- Xy dng quy trnh chit tch axit hidroxycytric to mui t

dung dchkim t v qu ba kh.


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b. Chit tch

c. nh lngHCA

d. Dn xut ca axit hydroxy citric

1.2.3. Tc dng ca HCA

1.3. CC PHNG PHP K THUT 3,7.

1.3.1. Phng php trng lng1.3.2. Phng php quang ph hp th nguyn t (AAS)

1.3.3. Phng php chng ninh

1.3.4. Phng php sc k lng cao p (HPLC)a. C s l thuyt ca phng php sc k

b. C s l thuyt ca sc k lng cao p

1.3.5. Phng php chun axit bazCHNG 2

NGUYN LIU V PHNG PHP NGHIN CU2.1. THIT B - DNG C - HA CHT

2.2. NGUYN LIU

2.2.1. iu tra s b cy ba: l, qu ba c hi t x Bnh

H, huyn Bnh Sn- Qung Ngi.

2.2.2.Thu nguyn liu

2.2.3. X l nguyn liu2.3. XC NH TNH CHT VT L

Ngyuyn liu c kim tra m, hm lng tro bng phng

php trng lng.

Cc ch phm HCK, HCNa sau chit tch,c c c kim tra

bng sc k lng cao p; quang ph hp ph nguyn t; cng hng

t ht nhn, ph hng ngoi IR.


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2.4. PHNG PHP HA L

S dng phng php chit tch HCA t l, v qu ba: chit

chng ninh bng dung mi kim theo cc yu t nng , t l rn

lng, nhit , thi gian . Tng lng axit trong dung dch chit c

xc nh phng php chun .

2.5. S QUY TRNH THC NGHIM

Kho stcc yu t

C lc

Dch c c

o ph PHLC o ph IR, ph cnghng ht nhn

Xc nh hm lngaxit

Xc nh cu trc muiHCK

Chngninhbng dungmi KOH,NaOH

-Nng

-Khi lng-Nhit -Thi gian

Dch chit

Dch lc

Xc nh m V qu da

X l nguyn liu

Nguyn liu sau khix l

o hm lngtro

o thnh phnkim loi nng

-Lm sch-Hong kh

-Xay nh

Ty mu, dng cnty mu pectin


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CHNG 3

KT QU V THO LUN

3.1. MT S TNH CHT VT L CA NGUYN LIU

3.1.1. Xc nh m ca nguyn liu

Hm lng nc trongl, v qu ba c xc nh bng phng

php trng lng v thu c kt qu: m trung bnh trong l ba

ti cao chim khong 70% khi lng l. m trung bnh trong v

qu ba ti cao chimkhong 84% khi lng v.

3.1.2. Xc nh hm lng troHm lng tro trong v ba thp, chim 3,4 % khi lng v

ba kh, chng t lng cht v c v kim loi nng trong khng

nhiu.Hm lng tro trung bnh trong l qu ba kh l 1,42%. Hm

lng tro rt thp v chim khong 1,4% khi lng l ba kh, t hn

so vi v ba kh, nn lng cht v c v kim loi nng trong t.

Thnh phn kim loi nng trong l v qu ba thpnn t tiu chunv v sinh i vi lng thc, thc phm .C th s dng v qu ba

lm thc phm hoc dc phm m khng nh hng n sc khe

con ngi.

3.2. NGHIN CU CHIT TCH HCA TRONG V BAKH BNG DUNGDCHKIM

3.2.1. Dung dchKOHa. Quy trnh chit tch

L, v ba kh xy mn c cho vo bnh cu th tch 500ml vi

200ml dung mi KOH chng ninh bng sinh hn hilu, un thi

gian T(pht), nhit t0C. Sau lc phn b rn v dch chit bng

vi muslin. Tin hnh ty mu bng 5g than hot tnh ngm trong

nc m 30 pht, lc bng giy lc ra 2 ln vi 15 ml nc. Trn


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dch lc v ra, c c ri ta pectin bng cn 960, lc ta pectin. Bay

hi cn, c c dung dch v cn 50 ml ta thu c dch c, chia dch

c lm 2 phn. Phn 1 dng chun xc nh lng HCA ,

phn 2 em xc nh cng thc cu to axit HCA bng phng php

o ph IR v NMR, kim tra sn phm bng phng php o ph

HPLC.

b. Cc yu t nh hng

C 4 yu t nh hng n qu trnh chit tch m ta cn kho st

+ Nng kim ;Khi lng ba trong 1 lng dung mi ( t lR/L ).Nhit ; Thi gian.

- Nng kim

Kho st u tin ta lm vi lng ba trung bnh l 20 gam, th

tch dung mi l 200 ml, nhit l 750C, thi gian l 120 pht, yu

t nng KOH thay i. Mi trng trong dch sau x l s thay

i t axit n trung tnh, qua baz. Lng axit trong dch sau khi xl s bin i t d t (vn mi trng axit) n khi kim d qua mi

trng trung tnh, th ta s chn gi tr KOH ti im . Ban u

chun lng axit d trong dch bng dung dch chun NaOH 0,1N

vi cht ch th l phenolphtalein, chun t khng mu n c mu

hng th dng. Mt khc ta c lng KOH phn ng ban u s suy ra

lng axit phn ng trong , cng 2 kt qu li ta c tng lng axit.n gi tr KOH m ti mi trng ca dch thu c l baz, sau

khi o gi tr pH, tin hnh chun mu bng dung dch HCl chun

c nng l 0,1 N, chun 3 ln, ly gi tr trung bnh sau 3 ln

chun y, cht ch th l phenolphtalein, chun n khi no dung dch

t mu hng chuyn sang khng mu th dng, mi ln chun ly ra

5ml dung dch mu. T gi tr VHCLtiu tn ta suy ra lng KOH


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tc dng tham gia to mui. Ta c

VHCl. CHCL= Vdung dch mu. CKOH d

ly lng KOH ban u tr i lng d s c lng phn ng, t

y ta li tnh ra gi tr tng lng axit trong v ba khi chit bng

lng dung mi kia.Kt qu xc nh tng lng axit trong v ba

bng dung mi KOH theo nng qua bng 3.4

Nhn xt :

+ Khi tng nng KOH tng dn th th tch chun HCl tng

dn tc lng d axit trong dch b gim dn, khi KOH t gi tr l0,7M th mi trng baz, lc ny trong dch khng cn axit d .

+ Lng axit tng trung bnh l 24,95 % l tng i trung bnh,

tip tc ly gi tr nng l 0,7 M ny kho st yut th 2 l t l

rn lng.

- Khi lng v qu ba trong 1 lng dung mi ( t l R/L) :

Sau khi kho st nng kim , ly gi tr lng KOH l 0,7 M,khi lng ba lc ny l i lng thay i, vn tin hnh chng

ninh mu vi lng th tch dung mi l 200 ml, nhit l 750C ,

thi gian l 120 pht Sau khi x l theo cc bc trong s , mi

trng ca dch sau khi x l thu c l baz, chun lng KOH

d ri tnh ra lng KOH phn ng, t lng KOH phn ng tnh ra

tng lng axit .Gi tr thch hp nht trong kho st ny l t l khong 25 gam

ba trn 200 ml dung mi, tng lng axit l 25,01g /100g.

- Nhit

Ta tip tc kho st yu t nhit , gi nguyn cc iu kin

khc nh khi lng ba, lng dung mi, thi gian chit. Tip tc

thu ly dch x l nh cc bc trn ri chun xem lng KOH d


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bao nhiu rt ra iu kin chit c tng lng axit nhiu nht.

Vy nhit thch hp trong kho st ny l 750C, tng lng axit l

25,02g/100g.

- Thi gian

Yu t sau nh hng n qu trnh chit axit l thi gian.Yu t

thi gian thay i, cn cc yu t cn li c dnh nh khi lng ba,

lng dung mi, nhit . Tin hnh chit tch v x l dch chit nh

theo quy trnh v chun trn, tnh ra tng lng axit d v so

snh cc thng s.Lng axit thu c thi gian 150 pht l cao nht

(27,24g/100g).

KT LUN :

+ Sau khi kho st th rt ra iu kin thch hp chit HCA

trong dung dchkim KOH :

M= 25g, V KOH= 200ml, Nng l 0,7M, nhit 750

C , thigian l 150 pht

+Nhit v thi gian c nh hng ng k n lng axit c

chit ra

3.2.2. Nghin cu xc nh lng HCA trong dung dch KOH

bng phng php o ph HPLC:

kim tra sn phm mui to thnh ta tin hnh kim tra snphm mui HCK thu c bng ph HPLC ri so snh vi ph HPLC

ca HCCa chun.

Kt qu o ph HPLC cho thy thi gian lu ca mui HCK

tng hp l 3,253 pht. So snh vi kt qu o HPLC ca HCCa

chun c thi gian lu l 3,247 pht. Do c th kt lun l lng

mui HCK nhiu trong v.


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Tuy nhin, trn ph tng hp xut hin nhiu s pic nh. Nh

vy, ngoi lng ln HCK cn c ln cc tp cht khc. Hm lng

HCK trong mui tng hp c xc nh bng HPLC l 91,351%.

Hnh 3.1. PhHPLC ca HCCa Hnh 3.2. PhHPLC ca HCK

3.2.3. Dung dchNaOH

a. Quy trnh chit tch

Ging nh qui trnh chit tch HCA khi dng dung dchKOH,

dy ta ch thay KOH bng dungdchNaOH.

b. Cc yu t nh hng

Vn xt 4 yu t nh hng n qu trnh chit tch m ta cn

kho st:

+ Nng kim ; Khi lng ba trong 1 lng dung mi (t l

R/L);Nhit ; Thi gian

- Nng kimLt lngv quba 20 gam, th tch dung mi l 200 ml,

nhit l 750C, thi gian l 120 pht,yu t nng NaOH thay

i.

Lng axit tng trung bnh khi chit trong dung dch NaOH la

22,06 gam ( t hn so vi KOH l 24,95 g)

+ iu kin nng thch hp trong kho st ny l nng 0,6


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M, ly gi tr nng ny ta tip tc kho st cc yu t cn li.

- Khi lng ba trong 1 lng dung mi (t l R/L)

+ Sau khi kho st nng kim , ly gi tr lng NaOH l 0,6

M, khi lng ba lc ny l i lng thay i, vn tin hnh chng

ninh mu vi lng th tch dung mi l 200 ml, nhit l 750C ,

thi gian l 120 pht. Gi tr thch hp nht trong kho st ny l t l

khong 25 gam ba trn 200 ml dung mi, tng lng axit l 23,01g

/100g.

- Nhit Vy nhit thch hp trong kho st ny l 750C , tng lng

axit l 23,03 g/100g.

- Thi gian

+ Thi gian c nh hng mnh ti lng axit chit c trong

cng lng dung mi v khi lng ba, thi gian chit cng lu th

lng axit thu c cng nhiu. Lng axit thu c thi gian 150pht l cao nht (25,13g/100g). Nhng nu ngm lu hn na th

lng axit khng thay i l bao nhiu.

Kt lunchung:

+ Sau khi kho st th rt ra iu kin thch hp chit HCA

trong dung dch kim NaOH :m= 25g, VKOH= 200ml, Nng l

0,6M, nhit 75

0

C, thi gian l 150 pht3.2.4. Nghin cu xc nh lng HCA trong v ba bngdung dchNaOH bng phng php o ph HPLC

kim tra sn phm mui to thnh ta tin hnh kim tra sn

phm mui HCNa thu c bng ph HPLC ri so snh vi ph

HPLC ca HCCa chun.


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Hnh 3.3. PhHPLC ca HCNa

Nhn xt:

Kt qu o ph HPLC cho thy thi gian lu ca mui HCNa

tng hp l 3,255 pht. So snh vi kt qu o HPLC ca HCCa

chun c thi gian lu l 3,247 pht. Do c th kt lun l kng

mui HCNa khng nhiu bng mui HCK.Tuy nhin, trn ph

tng hp xut hin nhiu s pic nh chng t cn c ln cc tp khc.Hm lng HCNa trong mui tng hp c xc nh bng HPLC

l 85.33%.

3.3. XC NH CU TRC HCK3.3.1. Xc nh cu trc HCK bng phng php o ph

hng ngoi IR

V hnh dng ph IR ca mui HCK v HCCa chun tng tnhau. Nh vy, c s b th kt lun mui c to thnh c cu trc

tng t vi mui chun ca axit(-)-hydroxy xitric.M lng axit tn

ti trong dch l dng mui


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Hnh 3.6. Ph IR ca HCCa chun. Hnh 3.7. Ph IR ca HCK

3.3.2. Xc nh cu trc HCK bng ph cng hng t htnhn

xc nh cu trc chi tit ca sn phm mui HCK to thnh ta

tin hnh o ph cng hng t ht nhn 1H- NMR v C13-NMR ca

HCK.

HO C COOK

H

C COOK HO

C

H

H COOK

Hnh 3.8. Cu trc mui Kali ca HCA

Ph C13

-NMR ca mui HCK c th hin hnh 3.9 trn c 03pic ti 42,249;76,416;78,859 kt qu tng ng ca methylene

cacbon(C-5), methylene cacbon(C-1), v cacbon bc 4(C-3) trong

mui HCK. Cc pic ti 177,951;180,073 l ca cacbonyl cacbon(C-2;

C-4 v C-6) ca 03 nhm cacboxylat trong mui HCK.


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Hnh 3.9. Ph C13-NMR ca mui HCK

Hnh 3.10. Ph 1H-NMR ca mui HCK

Kt qu kim tra phph C13- NMR v 1 H-NMR cho thy sn

phm mui HCK iu ch c c cng thc cu to ph hp vi

cng thc mui kali nh d on ban u hnh 3.8.

3.4. NGHIN CU CHIT TCH HCA TRONG L BA KH

BNG DUNG DCHKIM

3.4.1. Dung dchKOH

a. Quy trnh chit tch : Ging nh quy trnh chit tch phn

v qu.Ta ch dng nguyn liu l kh, xy mn.

b. Cc yu t nh hng


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C 4 yu t nh hng n qu trnh chit tch m ta cn kho st

+ Nng kim ; Khi lng ba trong 1 lng dung mi ( t l

R/L );Nhit ; Thi gian

- Nng kim :

Lng axit tng trung bnh l 3,21 % l tng i thp, so vi v

ba th lng nng cn thit a mi trng chuyn t mi

trng axit sang kim yu l thp hn so v ba.Vy to kho st ny

th nng KOH 0,3 M l thch hp.

- Khi lng l ba trong 1 lng dung mi ( t l R/L)Gi tr thch hp nht trong kho st ny l t l khong 25 gam

ba trn 200 ml dung mi, tng lng axit vn thp, l 3,32 g/100g.

- Nhit

Ta tip tc kho st yu t nhit , gi nguyn cc iu kin

khc nh khi lng ba.Vy nhit thch hp trong kho st ny l

750

C , tng lng axit l 3,30 g/100g.- Thi gian

Lng axit thu c thi gian 150 pht l cao nht ( 3,65

g/100g). Nhng nu ngm lu hn na th lng axit khng thay i

l my m thm ch cn b gim

Kt lun:

+ Sau khi kho st th rt ra iu kin thch hp chit HCAtrong l ba bng dung mi kim KOH : M= 25 g, V KOH= 200 ml,

Nng l 0,3M, nhit 750C , thi gian l 150 pht

+ Nhit v thi gian c nh hng ng k n lng axit

c chit ra.

3.4.2.Dung dchNaOH

a. Quy trnh chit tch :


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Tng t nh trn, v cng xt 4 yut nh hng n qu trnh

chit tch m ta cn kho st: Nng kim; Khi lng ba trong 1

lng dung mi (t l R/L);Nhit ; Thi gian.

- Nng kim :

Lng axit tng trung bnh khi chit trong dung mi NaOH l

2,15 gam (t hn so vi KOH l 24,95g)

- Khi lng ba trong 1 lng dung mi (t l R/L):

Gi tr thch hp nht trong kho stny l t l khong 25gam

ba trn 200ml dung mi, tng lng axit l 2,98g/100g. y l lnggi tr thp.

- Nhit :

Nhit thch hp trong kho stny l 850C, tng lng axit l

3,12 g/100g.

- Thi gian:

Lng axit thu c thi gian150 pht l cao nht (3,36g/100g).

Kt lun :

Sau khi kho st th rt ra iu kin thch hp chit HCA t l

trong dung mi kim NaOH :

m= 25g, V NaOH= 200ml, Nng l 0,4M, nhit 850C , thi

gian l 150 phtNhit v thi gian c nh hng ng k n lng axit c

chit ra, v iu kin c bn l ging vi dung mi KOH .

3.4.3. Nghin cu xc nh lng HCA trong dung mi kim

bng phng php o ph HPLC

kim tra sn phm mui to thnh ta tin hnh kim tra sn

phm mui HCK thu c bng ph HPLC ri so snh vi ph HPLC


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ca (-)-HCCa chun.

Kt qu kim tra bng ph HPLC th hin hnh 3.11 v hnh

3.12.

Hnh 3.11. Ph HPLC HCK chit t l

Nhn xt:

Kt qu o ph HPLC cho thy thi gian lu ca mui HCK ca

l ba tng hp l 3,235 pht. So snh vi kt qu o HPLC ca

HCK chun c thi gian lu l 3,247 pht. Do c th kt lun l l ba vn c hm lng HCA nhng rt t.

Hnh 3.12. Ph HPLC HCNa chit t l


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3.5. SO SNH HIU QU 2 PHNG PHP CHIT BNG

DUNG DCHKIM V DUNG MI NC

3.5.1. So snh tng lng axit trong v ba bng phng

php chit trong dung mi kim v nc qua tng khi lng

Tin hnh chit tch axit trong 2 loi dung mi vi cc yu t c

bn nh nhau sau : khi lng ba l 25 g, nhit l 750C, thi gian

l 150 pht, th tch dung mi l 200ml, i vi dung mi l kim th

nng l 0,7 M.

Bng 3.24. Tng lng axit chit trong cc loi dung mivi iu kin kho st

Dung mi Tng lng axit thu c (g/100g)

KOH 27,24

NaOH 25,13

Nc 18,89

Nhn xt :- Trong cng mt iu kin tin hnh chit tch th dung mi

nc cho ra tng lng axit t nht (18,89 g/100g), cn dung mi

KOH cho ra lng axit l cao nht (27,24 g/100g ), gia NaOH v

KOH th dung mi KOH cho ra lng axit cao hn

3.5.2. So snh lng axit HCA trong v ba qua phngphp chit trong dung dch kim v nc qua hiu sut

Bng 3.25. Tng lng axit HCA chit trong cc loi dung mi

vi iu kin kho st

Dung mi Hm lng HCA (g/100g) Hiu sut ( %)

KOH 24,83 91,16

NaOH 21,44 85,33

Nc 16,09 85,18


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Nhn xt :

Hiu sut ca phng php chit bng dung mi KOH l cao nht

, cho ra lng axit HCA l 24,83 g/100g. K tip l dung mi NaOH

vi lng axit l 21,44 g/100g, thp nht l dung mi nc vi lng

axit l 16,09g/100g

Kt qu trn cho thy kh nng tng tc chit axit trong dung

mi kim cao hn so vi dung mi nc cng iu kin chit tch,

trong 2 dung mi kim th dung mi KOH tng tc tt hn dung mi

NaOH.

3.6. So snh lng axit HCA ca l v ca v qu qua phngphp chit trong dung dchkim v nc qua hiu sut :

Lng axit HCA chit c bng dung mi kim vn cao hn so

vi dung mi nc d l chit vi v ba hay l ba.Trong 2 dung

mi kim th dung mi KOH cho ra hiu sut cao hn NaOH.

Hiu sut khi chit vi l ba thp hn nhiu so vi v ba l dohm lng axit khc nhau gia l v v cng s tng tc gia cc

cu t vi dung mi trong qu trnh chit.

Bng 3.26. Tng lng axit HCA chit trong cc loi dung mi

vi iu kin kho st

Loi mu Dung miLng HCA

(g/100g)

Hiu sut (%)

V ba

KOH 24,83 91,16

NaOH 21,44 85,33

Nc 16,09 85,18

L ba

KOH 1,83 50,01

NaOH 1,57 47,00

Nc 1,48 30,03


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3.6.1. So snh cc ch tiu v cng ngh chit tch HCA trong

dung mi kim v dung mi nc

a.i vi dung dch kim

+ Nhc im :

1. Phng php ny ph hp l chng ninh bng bp cch thy

vi lng ln, hn ch dng ni p sut v c th dung mi kim lm

bo mn h hi dng c.

2. Dung mi pha ch ng nng ,gi n nh mi trng pH t

8-8,7, mi trng kim yu nn phc tp hn dung mi nc. 3. V dung mi ngay ban u l kim nn s phn ng vi ht cc

lng axit trong nn quy trnh chit tch v tinh ch thu c axit

c kt qu sau cng c th s t tinh khit hn do c ln mui ca cc

axit trong ba.

+ u im :

1. Lng axit v lng mui chit ra c nhiu hn do tng tccc dung mi kim vi ba, nn hiu sut chung to mui s cao hn so

vi dung mi l nc.

2. V c s tng tc mnh gia dung mi v axit trong ba tng

i mnh nn thi gian chit c th rt ngn hn so vi dung mi

nc.

b. i vi dung mi nc+Nhc im:

1. Hiu sut thp hn hn so vi phng php dng dung mi l

kim.

2. Thi gian chit cng ko di hn mi chit c ht lng axit

trong ba.


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+ u im :

1. V dung mi l nc nn c th dng phng php chng ninh

vi cc dng c khc nhau nh ni p sut, bp cch thy...

2. Dung mi nc t tp cht hn.

3.6.2 . Kt lun

Mi phng php u c nhng hn ch v u im nht nh,

trong sn xut nn c bin php dung ha v hiu sut ln tinh

khit cho ra sn phm tt hn.


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KT LUNV KIN NGH

Kt lun

Trong ti nghin cu chng ti thu c mt s kt qu nh

sau:

1/ m trung bnh trong l chim 70%, trong v qu ba kh:

84,34 %, Hm lng trot rung bnh trong l 1,42%, v qu ba

kh:1,4 % .

Thnh phn kim loi nng gm

2/ chit tch thnh cngHCA trong ba bng dung dch KOHvi iu kin :

- V ba kh : 25 g, nng KOH l 0,7M , th tch dung mi l200 ml, nhit l 750C,thi gian l 150 pht, hiu sut l 91,16 %.

- L ba kh : 25 g, nng KOH l 0,3M , th tch dung mi l200 ml, nhit l 750C, thi gian l 150 pht, hiu sut l 50,01 %.

Bng dung mi NaOH vi iu kin :- V ba kh : 25 g, nng KOH l 0,6M , th tch dung mi l

200 ml, nhit l 750C, thi gian l 150 pht, hiu sut l 85,33 %.

- L ba kh : 25 g, nng KOH l 0,4M , th tch dung mi l200 ml, nhit l 850C,thi gian l 150 pht, hiu sut l 47,00 %.

3/ xc nh cmui HCK to thnh bng ph hng ngoi

(IR), NMR, xc nh hm lng mui bng sc k lng cao p(HPLC) . Hm lng mui HCK trong sn phm v qu chuyn ho

l 91,16% ng vi thi gian lu l 3,91 pht, trong l l 50,03%.

Kin ngh

1/ Axit(-)-HCA c tnh nng chng bo ph hiu qu c cung

cp ch yu di dng cc mui. V vy, chng ta nn tip tc nghin

cu theo hng iu ch v ng dng cc mui ca (-)-HCA dng


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mui kp tng hiu qu trong sn xut dc liu hay thc phm

chc nng vi mc ch gim cn.

2/ Nghin cu xy dng quy trnh chit tch (-)-HCA t v qu

ba theo quy m cng nghip sn xut thc phm gim cn cha

(-)- HCA ti Vit Nam.

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