Nghiên Cứu Chiết Xuất Chất Màu Betacyanin Từ Vỏ Quả Thanh Long Hylocereus Spp

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LI CM N

Ti xin by t lng bit n su sc n qu thy c trong khoa Ch bin

ht lng ging dy, truyn t cho chng em nhng kin thc c bn v lnh vc

cng ngh thc phm - l hnh trang qu gi cho em vng bc vo i.

Ti v cng bit n s gip nhit tnh ca qu thy c ph trch B mn

Ha, phng th nghim Ha C bn v phng th nghim Cng ngh Thc phm.

Ti xin chn thnh cm n TS. Hong Th Hu An tn tnh hng dn v

to mi iu kin thun li cho ti trong sut qu trnh thc hin ti.

Xin cm n gia nh v bn b ti lun ng vin, gip v ng gp

nhiu kin qu bu, gip ti hon thin hn ti tt nghip ny.

Nha Trang, thng 7 nm 2010

Sinh vin

NGUYN TH DU

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MC LC

LI CM N ..........................................................................................................i

MC LC ..............................................................................................................ii

DANG MC CC CH VIT TT .....................................................................vi

DANH MC CC BNG ...................................................................................vii

DANH MC CC HNH ....................................................................................vii

M U ................................................................................................................1

Phn 1. TNG QUAN.............................................................................................3

1.1. TNG QUAN V CHT MU THC PHM [4] .........................................3

1.1.1. Tm quan trng ca vic s dng cht mu trong ch bin thc

phm ...............................................................................................................3

1.1.2. Vai tr cht mu thc phm ...................................................................3

1.1.3. Phn loi cht mu thc phm ...............................................................3

1.1.4. Nguyn tc s dng cht mu thc phm...............................................6

1.2. TNG QUAN V THANH LONG ..................................................................6

1.2.1. Tn gi ..................................................................................................6

1.2.2. c im hnh thi.................................................................................7

1.2.3. c im sinh trng.............................................................................7

1.2.4. Phn loi thanh long ..............................................................................9

1.2.5. Tnh hnh sn xut v tiu th thanh long Vit Nam v trn th gii .10

1.3. GII THIU V CHT MU BETACYANIN [4][5]...................................11

1.3.1. Khi nim v cht mu betalain v betacyanin:....................................11

1.3.2. Cu trc ha hc ca cc betalain v betacyanin..................................12

1.3.3. Tnh cht vt l v ha hc ca betacyanin: .........................................13

1.3.4. Chc nng sinh hc v ng dng .........................................................15

1.3.5. Tnh hnh khai thc v ng dng betacyanin t nhin lm cht mu

thc phm......................................................................................................16

1.4. TNG QUAN V CC PHNG PHP CHIT.........................................17

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1.4.1. Cc khi nim c bn v qu trnh chit .................................................17

1.4.2. Cc phng php chit ...........................................................................19

1.4.3. Vi k thut chit hin i dng chit xut cht mu t nhin............20

Phn 2: I TNG V PHNG PHP NGHIN CU ................................23

2.1. I TNG NGHIN CU ........................................................................23

2.1.1. Vt liu nghin cu ................................................................................23

2.1.2. Dng c v thit b .................................................................................23

2.2. PHNG PHP NGHIN CU ...................................................................24

2.2.1. Xc nh thnh phn khi lng ca qu thanh long:..............................24

2.2.2. Xc mt s thnh phn ha hc ca v thanh long..................................24

2.2.3. Quy trnh d kin sn xut betacyanin t v qu thanh long ...................24

2.2.4. Xc nh iu kin thch hp chit betacyanin t v thanh long .............26

2.2.5. La chn quy trnh thch hp chit betacyanin: ......................................30

2.2.6. Nghin cu phng php bo qun dch chit betacyanin.......................30

2.2.7. Th nghim quy trnh chit - nh gi cht lng sn phm .................32

2.2.8. X l s liu...........................................................................................32

Phn 3. KT QU V THO LUN...................................................................33

3.1. Thnh phn khi lng ca qu thanh long.....................................................33

3.2. Mt s thnh phn ha hc ca v thanh long.................................................34

3.3. Xy dng quy trnh chit betacyanin t v qu thanh long..............................34

3.3.1. Chn dung mi chit ..............................................................................34

3.3.2 Chn t l dung mi/nguyn liu .............................................................35

3.3.3. Chn thi gian chit v s ln chit ........................................................36

3.3.4. So snh hiu sut chit ca hai phng php ..........................................40

3.4. Kt qu kho st bn mu ca dch chit betacyanin ..................................42

3.4.1. Khi khng b sung vitamin C .................................................................42

3.4.2.Khi b sung vitamin C.............................................................................44

3.5. Hon thin quy trnh chit sn xut cht mu betacyanin t v qu thanh

long Sn xut th nghim v nh gi cht lng sn phm ...............................45

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3.6. Tnh ton s b gi thnh sn phm. ...............................................................49

KT LUN ...........................................................................................................50

KIN XUT ...............................................................................................51

TI LIU THAM KHO

PHN PH LC

v

DANH MC CC CH VIT TT VIT TT TING ANH TING VIT

A Absorbance hp th

D Dilution factor H s pha long

H Hour gi

H2O Water Nc

HPLC

(hay: LC)

High-Performance Liquid

Chromatography

Sc k lng hiu nng cao

MeCN Acetonitrile Axetonitril

Min Minute Pht

Nm Nanometer Nanomet

Ppm part per million phn triu

R2 Correlation coefficient H s tng quan

Rpm round per minute vng/pht

RT Retention Time Thi gian lu

SD Standard Deviation lch chun

UV-Vis Ultraviolet-Visible T ngoi-kh kin

v/v Volume/volume th tch / th tch

v/w Volume/weight th tch/khi lng

w/v weight/volume khi lng/th tch

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DANH MC CC BNG

Bng 1.1. Liu s dngcho php ca mt s cht mu hu c tng hp ..................4

Bng 1.2. Mt s cht mu t nhin thng dng ......................................................5

Bng 3.1 : Thnh phn khi lng ca qu thanh long ..........................................33

Bng 3.2. Mt vi thnh phn ha hc c bn ca v thanh long ..........................34

Bng 3.3. nh hng ca thi gian v nhit siu m n hiu sut chit

betacyanin t v thanh long ...................................................................................37

Bng 3.4. Kt qu sn xut th nghim dch chit betacyanin c c.....................48

Bng 3.5. Kt qu phn tch mt s ch tiu cht lng quan trng ca sn phm

betacyanin c c ..................................................................................................48

Bng 3.6. c tnh chi ph nguyn vt liu chit betacyanin t 1000 kg v

thanh long..............................................................................................................49

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DANH MC CC HNH

Hnh 1.1. Cy thanh long.........................................................................................9 Hnh 1.2. Cc loi thanh long ...............................................................................10 Hnh 1.3. Mu sc ca cc loi hoa xng rng thay i theo t l betaxanthin v betacyanin.........................................................................................................12 Hnh 1.4. Cu trc phn t acid betalamic v vi betacyanin thng gp...............13 Hnh 1.5. Cc dng sn phm cht mu betacyanin t c ci ng ......................16 Hnh 1.6. S thit b chit SFE..........................................................................21 Hnh 1.7. S thit b chit ASE .........................................................................21 Hnh 2.1. S quy trnh d kin sn xut cht mu betacyanin t v thanh long ph liu ..........................................................................................................25 Hnh 2.2. B tr th nghim xc nh iu kin chit betacyanin t v thanh long ..29 Hnh 2.3. S b tr th nghim chn la quy trnh thch hp chit xut betanin t v thanh long.....................................................................................................30 Hnh 2.4. B tr th nghim nh gi bn mu ca dch chit betacyanin khng b sung vitamin C .......................................................................................31 Hnh 3.1. nh hng ca dung mi n hiu sut chit betacyanin .......................35 Hnh 3.2. nh hng ca t l dung mi/nguyn liu n hiu sut chit betacyanin.......... 36 Hnh 3.3. nh hng ca thi gian v nhit siu m n hiu sut chit betacyanin t v thanh long ...................................................................................37 Hnh 3.4. S ph thuc ca hiu sut chit vo s ln siu m...............................38 Hnh 3.5. S ph thuc ca hiu sut chit vo thi gian ngm chit .....................39 Hnh 3.6. S ph thuc ca hiu sut chit vo s ln ngm chit..........................40 Hnh 3.7. So snh hiu qu chit ca 2 phng php chit.....................................41 Hnh 3.8. bn mu ca betacyanin khi cha b sung vitamin C........................43 Hnh 3.9. bn mu ca betacyanin khi b sung 0,01% (w/v) vitamin C ............43 Hnh 3.10: Mu bo qun nhit phng ...........................................................45 Hnh 3.11. Mu bo qun 40C ............................................................................45 Hnh 3.12. S quy trnh sn xut cht mu betacyanin t v thanh long ..........46 Hnh 3.13. Sn phm betacyanin c c thu c..................................................48

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M U

1. L do thc hin ti

Trong nhng nm gn y, bn cnh cc loi nng sn c ngi tiu dng

trong v ngoi nc bit n t lu nh c ph aklak, bi Phc Trch, nc mm

Ph Quc, vi thiu Lc Ngn, qu thanh long Bnh Thun (Hylocereus spp.) cng

tr thnh mt trong nhng mt hng c nh nc bo h nhn hiu c quyn

trn phm vi c nc v trn th gii.

Hin nay, Vit Nam c xem l mt trong 4 quc gia c sn lng thanh

long nhiu nht th gii. Ch tnh ring Bnh Thun, tng sn lng thanh long t

trn 130 nghn tn/nm vi din tch trng thanh long ln n gn 10 nghn hecta.

Lng thanh long phn ln c xut khu cung ng cho cc th trng chu ,

chu u.

Ngoi vic xut khu qu thanh long ti, tnh Bnh Thun ang xy dng

mt d n sn xut thanh long ng hp xut khu vi cng sut khong 7.000

tn/nm [11]. Khi dy chuyn ny i vo hot ng s thi ra mt khi lng ng

k v thanh long (trn 2000 tn/nm). Nu khng c x l hay tn dng, lng

ph thi ny khng ch gy nhim mi trng m cn l mt s lng ph rt ln v

v thanh long chnh l mt ngun sc t betcyanin t nhin qu gi, c th ng

dng trong cng nghip cht mu thc phm. Chnh v vy, ti Nghin cu

chit xut cht mu betacyanin t v qu thanh long Hylocereus spp. l mt

hng i ng v cn thit hin nay.

Nhng kt qu ca ti ny c th xem l c s ban u nghin cu kh

nng chit xut v ng dng cht mu betacyanin t v qu thanh long trong cng

nghip thc phm.

2. Mc ch v ni dung nghin cu ca ti

Mc ch ca ti ny l xy dng quy trnh thch hp cho php chit

betanin t v qu thanh long Hylocereus spp.

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Ni dung nghin cu ca ti bao gm:

- Nghin cu iu kin thch hp cho php chit betacyanin t v qu thanh

long.

- Kho st bn ca dch chit thu c trong nhng iu kin khc nhau.

T , xut phng php bo qun v kh nng ng dng ca cht mu

betacyanin trong cng nghip thc phm.

Do kin thc v kinh nghim nghin cu ca ti cn hn ch cng nh kh

khn v iu kin thc nghim nn mc d rt c gng ti ny khng trnh khi

nhng thiu st.

Rt mong c s ch bo ca qu thy c cng nh s gp t cc bn sinh

vin ti ny c th c hon thin hn.

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Phn 1. TNG QUAN

1.1. TNG QUAN V CHT MU THC PHM [9][5]

1.1.1. Tm quan trng ca vic s dng cht mu trong ch bin thc phm

Mu sc l mt trong nhng ch tiu cm quan quan trng u tin i vi mi

sn phm thc phm. Quan trng hn ht l mu sc nh hng ti cht lng, mi

v, ngt ca thc phm. Nu gia mu sc v mi v khng c s tng ng, ph

hp ln nhau th ngi tiu dng s khng cm nhn c chnh xc c mi v v

cht lng ca thc phm. Thc vy, trong mt nghin cu ca nh thc phm hc

Johnson vi ti Bo v thc phm nm 1983 chng minh rng v ngt ca

nc gii kht tri du s tng ln 2-12% nu ta tng hm lng ca cht mu ca

loi nc gii kht ny. Do vy, vic s dng cc cht mu trong ch bin thc

phm l iu rt cn thit.

1.1.2. Vai tr cht mu thc phm

Cht mu thc phm mc d khng c ngha nhiu v mt dinh dng,

nhng c nhng chc nng quan trng sau y:

m bo s ng nht v mu sc thc phm t l sn phm ny n l

sn phm khc.

Tng cng mu sc t nhin vn c ca thc phm thu ht ngi tiu

dng.

Lm cho ngi tiu dng ch n mi v t nhin ca thc phm do gia

mu sc v mi v thng c quan h vi nhau.

To mu cho mt s thc phm vn khng mu hay c mu nht (nh cc

loi ko, snack, nc gii kht,...) nhm lm gia tng gi tr cm quan ca chng.

Phc hi li v bn ngoi ca thc phm do cht mu b bin i trong qu

trnh ch bin (Delgado-Vargas et al., 2000).

1.1.3. Phn loi cht mu thc phm

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Cht mu thc phm c chia lm 3 nhm chnh: cht mu t nhin, cht

mu v c , cht mu hu c tng hp, cht mu t nhin.

1.1.3.1. Cht mu v c:

Vo trc th k 20, phn ln cht to mu thc phm u c ngun gc t

cc loi khong vt t nhin c hi.

V d: CuSO4 dng to mu cho cc loi da chua, phn nhm ty trng

bnh m, phomt c nhum mu bng phm mu cha Pb hay HgSO4,....

Tuy nhin, cng vi vic ban hnh nhng quy nh v an ton thc phm ca

Hoa K nm 1960, ngnh cng nghip thc phm dn dn chuyn sang s dng cc

loi cht mu hu c tng hp.

1.1.3.2. Cht mu hu c tng hp: l cc cht mu c tng hp bng

phng php ha hc.

Cc loi cht mu hu c tng hp c chia lm 3 nhm:

Nhm A: gm cc cht khng mang c tnh nhng gy ng c tch ly.

Bng 1.1. Liu s dngcho php ca mt s cht mu hu c tng hp

Loi cht mu Liu lng s dng (mg/kg trng lng)

Amarant (K hiu CI.16185)

Vng mt tri (K hiu CI.15985)

Tartrazin (K hiu CI.19140)

0 - 0,15

0 - 5,00

0 - 7,50

Nhm B: gm 5 loi mu l -caroten tng hp, xanh l VRS (k hiu

CI.42090), Erythrozin (k hiu CI.45430), Indigocarmin (k hiu CI.73015), xanh

lc sng FCF.

Nhm C: bao gm tt c cc loi mu hu c tng hp khc nhau cha c

nghin cu hoc nghin cu khng r rng.

Cht mu hu c tng hp c u im l to ra nhiu mu sc phong ph, r

tin, v tin li trong vic ch bin thc phm. Tuy nhin, hin nay mt s cht mu

hu c tng hp (c bit l thuc nhum azo) b hn ch s dng do ngi ta nghi

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ngi v nhng nh hng khng tt ca n i vi sc khe con ngi. Chng hn,

mt s nghin cu gn y pht hin nhng enzyme trong rut non c kh nng xc

tc cho phn ng kh cc phm mu azo sinh ra cc tc nhn gy ung th. Do

, vic s dng chng cn phi c tun th nhng quy nh ht sc cht ch v

nghim ngt.

1.1.3.3. Cht mu t nhin: l cc loi cht mu hu c c chit tch t

ng vt hay thc vt.

Bng 1.2. Mt s cht mu t nhin thng dng

Cht mu t nhin Ngun t nhin Athocyanin V nho, elderberries,

Betalain C ci ng, cy rau dn tm, v qu thanh long... Carotenoid - Annato (Bixin) - Canthaxanthin - .Apocarotenal

Ht iu Nm rm, loi gip xc, c Cam, rau xanh

Chlorophyll Cc loi rau xanh Riboflavin Sa

Caramel ng saccharose Cc loi khc - Turmeric - Crocetin, Crocin

Cy ngh Cy ngh ty

Nhng cht mu t nhin c con ngi bit n v s dng t lu to

mu cho thc phm. u im ca cht mu t nhin l to ra mu rt p cho thc

phm, ng thi chng li c mi, v gn ging nh ngun t nhin ca chng. Tuy

nhin, so vi cht mu tng hp, cht mu t nhin thng km bn v c gi thnh

cao do vic thu hi tch chit chng t nh cc ngun t nhin kh tn km. Do

vy, vic s dng chng hin nay cn cha rng ri lm.

Tuy vy, nh c an ton cao v mt s cht mu t nhin cn c tc dng

tt i vi sc khe (nh c kh nng chng oxy ha, tng cng sc khng ca

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c th,) nn ngi tiu dng ngy cng c xu hng a chung nhng loi thc

phm dng cht mu t nhin. V vy, trong nhng nm gn y, ngnh cng

nghip sn xut cht mu t nhin trn th gii ang pht trin nhanh chng v tr

thnh mt trong nhng lnh vc kinh doanh y tim nng [6], [8].

1.1.4. Nguyn tc s dng cht mu thc phm

V nguyn tc, b sung cht mu nhm phc hi mu vn c ca mt s thc

phm b tn tht trong qu trnh ch bin. Khng c dng cht mu che y

khuyt im ca thc phm hoc ngi tiu dng nhm ln v s c mt khng

thc ca mt vi thnh phn cht lng trong thc phm.

Trc khi quyt nh s dng cht mu thc phm b sung vo mt sn phm

thc phm no chng ta cn quan tm cc yu t sau:

Trng thi ca cht mu: ngi tiu dng vn a dng cht mu dng

lng hn l dng bt.

S chuyn mu mi nh th no: thng phi trn nhiu mu vi nhau

to ra mu mong mun ph hp vi thc phm ca mnh.

Thnh phn cc cht cha trong thc phm cn phi trn cht mu: s

c mt ca protein, nc, tanin hay cht bo s nh hng ti trong hay vn c

ca cht mu phi trn vo trong thc phm .

pH: s n nh cng nh s chuyn mu ca cht mu u c th b nh

hng ca pH ca mi trng thc phm.

iu kin ch bin: c bit l thi gian v nhit nh hng ti cht

lng cht mu phi trn vo.

iu kin bao gi: quyt nh n mc xm nhp ca khng kh v

nh sng vo thc phm, do c th lm bin i cht mu.

iu kin bo qun v thi gian s dng: Cht mu s dng ch bn di

nhng iu kin bo qun thch hp v trong mt thi hn nht nh.

1.2. TNG QUAN V THANH LONG

1.2.1. Tn gi

Tn Vit Nam: Thanh long

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H: Xng rng

Tn ting Anh: Pitaya (hay Pitahaya)

Tn khoa hc : Hylocereus spp.

1.2.2. c im hnh thi

- Thanh long thuc loi thn leo trn, di n 10 m, phn nhnh nhiu, bm

vo cc gi th nh cc r ph rt pht trin.

- Thn v cnh u mu xanh lc, c 3 cnh dp, mp c gai nh, ngn (2 - 4

gai mi mt thn).

- Hoa rt to, mc n c trn cnh, ng knh c th n 30 cm, mu trng

hay trng ng. Hoa c nhiu l i v cnh, dnh vi nhau to thnh ng. Hoa c rt

nhiu nh.

- Tri mu ti, hng hay vng vng, mng nc, c nhiu gai mm do

nhng l hoa cn li, ng knh khong 10 cm. V tri rt d bc. Phn tht mu

trng hng cha nhiu ht nh li ti mu en.

1.2.3. c im sinh trng

Thanh long l loi cy thuc h xng rng, chu nng hn, d trng. Mt s

a phng trong nc cng trng loi cy ny nhng xem ra thanh long ph hp

hn c vi vng t Bnh Thun.

Vo cui thng 3 m lch hng nm, thanh long ra hoa, n thng 5, nhng

cy ra hoa sm c qu chn v ko di n cui thng 8.

Thanh long ra hoa ng lot theo tng la, sau khi th phn s hnh thnh tri.

Trong vng 10 ngy u, tri pht trin chm sau tng rt nhanh v kch thc

v trng lng. Trong 2 giai on 1618 ngy v 2834 ngy sau khi n, s gia

tng trng lng v ng knh ca tri rt nhanh v c bit l trong giai on sau

nn nng dn c tp qun gi tri trn cy tri c trng lng cao hn. Nu trong

giai on ny ti nc nhiu qu hoc tri ma ln s gy hin tng nt qu.

Trong khi chn cng ca tri gim hn. cng ca tri gim rt nhanh t ngy

th 16 n ngy th 25 sau khi hoa n v sau cng tip tc gim nhng chm

hn.

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Theo s phn nhm tri theo cng h hp th thanh long l loi tri c

cng h hp thp khi chn (70100 mg CO2/kg/gi). Cng h hp ca tri

cao khi tri cn xanh v gim dn khi chn. Vi c im v cng h hp trn

th trong iu kin thch hp v nhit , m v phng tr nm bnh sau thu

hoch tt, thanh long c th bo qun trong 40 ngy. Ngoi ra, thanh long thuc

nhm tri khng c nh h hp khi chn. V vy, khc vi cc loi tri cy khc

nh chui, xoi c th hi tri khi cn xanh v sau chn th thanh long phi thu

hoch ng lc tri chn; khi s cho cht lng tri tt hn.

chua ca tri gim rt nhanh t ngy th 22 n ngy th 28 sau khi n hoa

v tip tc gim nhng khng ng k (t 1,5% xung 0,04%). Brix (ch

ngt ca tri) tng t ngy th 25 (12%) sau khi hoa n v cao nht ngy th 28

v ngy th 43 (14%). tiu th th trng trong nc, nng dn thch tri trn

cy lu hn v ngi tiu dng thch tri c v ngt hn.

Trong giai on 16 22 ngy sau khi n hoa, s chuyn mu xy ra chm

nhng bt u ngy th 22 mu bt u xut hin, hon ton vo ngy th 25

v sau sm vo ngy th 31.

Qu thanh long c hnh dng ging qu su ho nhng thon v di, qu ca n c

3 dng, trn qu c nhiu tai. Qu c cha rt nhiu ht ging nh ht vng en

nm ln ln trong rut, thnh phn ch yu l celluloza, khi n vo khng tiu ha.

Khi b qu ra c mi thm du. Qu c th ch bin thnh nc ung hay ru

vang v c th phi hp vi cc loi khc lm nc ung hn hp. Hoa thanh long

c th n c hoc ngm vo nc ung ging ch.

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Hnh 1.1. Cy thanh long

1.2.4. Phn loi thanh long

Thanh long c cc loi sau:

- Hylocereus undatus thuc chi Hylocereus: c rut trng vi v hng hay .

Loi ny c trng rng ri cc tnh Bnh Thun, Long An, Tin Giang

- Hylocereus polyrhizus (hay Hylocereus costaricensis) thuc chi Hylocereus:

c rut vi v hng hay . Loi ny c lai to t ging thanh long rut trng

Bnh Thun vi ging rut nhp t Colombia..

- Selenicereus megalanthus thuc chi Selenicereus: c rut trng vi v vng.

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1.2.5. Tnh hnh sn xut v tiu th thanh long Vit Nam v trn th gii

Vit Nam c nh gi l mt trong 4 quc gia c tri thanh long nhiu nht

th gii. Hin nay nc ta c hai vng trng thanh long xut khu chnh ca c

nc l Ch Go (Tin Giang) v Bnh Thun, trong Bnh Thun l tnh ng

u c nc v tri thanh long c v sn lng, din tch, nng sut v cht lng.

Tng din tch trng thanh long ca hai vng ny l 14 nghn hecta, chim trn 90%

tng din tch c nc.

Nhng nm gn y thanh long lun l loi tri cy c kim ngch xut khu n

nh. Thanh long l mt trong 40 mt hng xut khu li th ca quc gia c

Chnh Ph ph duyt. Do c im kh hu thun li, thanh long Bnh Thun c

Thanh long rut trng v vng Thanh long rut trng v .

Thanh long rut v hng Thanh long rut v

Hnh 1.2. Cc loi thanh long

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th t nng sut ti 25 tn/hecta. Ch tnh ring Bnh Thun, nm 2006 tng sn

lng tri thanh long t 130 nghn tn, trong xut khu t 23 nghn tn thu v

kim ngch gn 14 triu USD. Hin nay, Bnh Thun pht trin din tch thanh

long ln n gn 10 nghn hecta.

Hin nay trn th trng th gii c 4 loi thanh long: v rut trng, v

rut , v hng rut v v vng rut trng. Vit Nam xut khu nhiu nht loi

thanh long v rut trng. Gn y trng c v xut thm loi thanh long v

rut .

Thanh long nc ta c xut khu sang trn 20 th trng trong cc th

trng ln l i Loan, Trung Quc, Hng Kng, Singapore, Malaysia, Thi Lan

v mt s nc chu u. Th trng chu u d mi thm nhp nhng c trin

vng pht trin, nht l cc nc H Lan, Php, c, Anh. tng v m rng

cng nh xm nhp vo nhiu th trng hn na th Vit Nam xy dng d n

GAP. D n thanh long GAP ang hp tc vi cc h trng, nh xut khu v cc

c quan nh nc n lc t chng nhn EuroGAP v xy dng chin lc qung

b y mnh xut khu cng nh cng c thng hiu thanh long cht lng cao

ca Vit Nam.

Bn cnh vic xut khu qu thanh long ti, tnh Bnh Thun ang xy dng

mt d n sn xut thanh long ng hp xut khu vi cng sut khong 7.000

tn/nm [11]. Khi dy chuyn ny i vo hot ng s thi ra mt khi lng ng

k v thanh long (trn 2000 tn/nm). V vy, song song vi vic pht trin cc sn

phm ch bin t thanh long, vn nghin cu thu hi cht mu betacyanin c

trong v thanh long nhm ng dng trong cng nghip thc phm l rt cn thit.

1.3. GII THIU V CHT MU BETACYANIN [9][8]

1.3.1. Khi nim v cht mu betalain v betacyanin:

Betalain l tn gi chung ca mt nhm sc t t nhin tan trong nc, c mu

t vng ti n da cam, ti, sm, hng cho n mu -tm trong hoa, tri,

l v c ca nhiu loi thc vt khc nhau (hoa xng rng, v thanh long, hoa

giy, rau v c dn).

12

Betalain bao gm 2 nhm sc t chnh:

- Betaxanthin: l nhm sc t betalain c mu vng - cam

- Betacyanin: l nhm sc t betalain c mu - tm

Ty thuc t l gia 2 nhm sc t ny m cc b phn thc vt s c mu

vng chanh, vng cam, cam, , tm hay tm (Hnh 1.3)

Hnh 1.3. Mu sc ca cc loi hoa xng rng thay i

theo t l betaxanthin v betacyanin

1.3.2. Cu trc ha hc ca cc betalain v betacyanin

Cc betalain c th xem l dn xut ca acid betalamic, trong u

dihydropyridin c gn vi mt nhm chc cha Nit thng qua nhm chc vinyl

(Miller et al., 1968). (Hnh 1.4).

Betacyanin n gin nht l betanidin c cu to t mt n v phn t acid

betalamic lin kt vi mt phn t cyclo-DOPA (Wyler v Dreiding, 1961) (Hnh

1.4).

a s cc betacyanin khc c to thnh do phn ng glucosyl ha mt trong

hai nhm chc OH t do ca vng cyclo-DOPA ca betanidin, trong thng

gp nht l s glucosyl ha v tr 5. Dn xut betacyanin quan trng v thng

gp nht trong t nhin l betacyanin (tc betanidin-5-O--glycosidase, c cng

thc phn t C24H26N2O13 v khi lng mol M = 551,48) (Hnh 1.4).

Sau y s gii thiu mt s tnh cht l-ha c bn ca betacyanin.

13

Betanidin

Hnh 1.4. Cu trc phn t acid betalamic v vi betacyanin thng gp

1.3.3. Tnh cht vt l v ha hc ca betacyanin:

S tn ti ca h thng 6 ni i lin hp trong betacyanin dn n nhng tnh

cht l ha c trng ca hp cht ny.

1.3.3.1. S hp th nh sng v mu sc:

Cc phn t betacyanin c kh nng hp th bc x kh kin trong vng t

534 - 554 nm, to nn mu n -tm.

1.3.3.2. Tnh tan:

Do phn t cha nhiu nhm chc phn cc (- OH, - COOH, - NH) , cc sc

t betacyanin u d tan trong nc hay dung dch etanol-nc,..

1.3.3.3. Tnh khng bn:

- nh hng ca pH:

Cc betacyanin km bn trong mi trng kim hay mi trng c hot

nc cao do b thy phn thnh acid betalamic (c mu vng) v amin (khng

mu):

14

Acid betalamic hnh thnh c th tip tc b phn hy v mt mu:

V d:

Trong mi trng kim betcyanin b thy phn gii phng glucose v

betanidin. Mu sc ca betanin thay i theo pH nh sau:

pH = 3,5 - 7,0: mu xanh l - (max = 537 nm). y l vng pH m betanin

bn mu nht

pH < 3,5: mu tm-xanh l (max = 535 nm pH = 2)

pH > 7: mu tm-l m (max = 544 nm pH = 9).

Mi trng kim mnh c th lm betcyanin b thy phn thnh betanidin

(mu ) hay thnh betaxanthin (mu vng). Tuy nhin, phn ng thy phn

betacynin c tnh thun nghch. Khi thm acid ascorbic, isoascorbic,

metaphosphoric hoc acid gluconic vo dung dch betanin b thy phn th

betcyanin c ti to tr li v dung dch s c mu sc nh ban u (Elbe v ctv.,

1981; Bilyk v Howard, 1982)

- nh hng ca nh sng, nhit, oxy khng kh, m:

Betacyanin b phn hy di tc dng ca nh sng. Nhit cng cao th tc

phn hy cng mnh. Do , betacyanin thng ch dng to mu cho cc

thc phm bo qun lnh nh kem, sa chua, thc ung t sa,(Pasch v ctv.,

1975).

Betcyanin cng rt d b oxy ha khi c mt trong cc sn phm c hm lng

nc cao hoc cha cc ion kim loi (V d: Fe hay Cu). Cc cht chng oxy ha

nh acid ascorbic v vic bao gi cc sn phm c cha betacyanin mt cch thch

Phn ng sm mu

Phn hy tip tc

15

hp c th lm chm qu trnh ny li. Tuy nhin, betacynin khng b bin i khi

thanh trng sn phm c cha hm lng ng cao.

1.3.4. Chc nng sinh hc v ng dng

1.3.4.1. Tc dng to mu:

Nh bit, cc betalain/betacyanin mang li s a dng, phong ph v mu

sc cho hoa ca nhiu loi thc vt. Nh vy, to nn sc hp dn i vi cc loi

cn trng, gip cho qu trnh th phn v pht tn ht ca thc vt c d dng

(Clement v Mabry, 1996).

Nh c mu rt p, cc betalain c dng lm cht mu trong cng nghip

thc phm. vng Trung v Nam M t lu ngi dn a phng t lu s

dng dch chit t qu thanh long mu tm (Hylocereus polyrhizus) lm cht to

mu cho thc phm (Stintzing v ctv., 2002). c bit, betcyanin (cht mu c m

s E162) c ng dng to mu cho nhiu loi thc phm khc nhau nh tht,

xc xch, tht mui, kem lnh, yaourt, cc loi nc gii kht, cc loi mt, ko, cc

sn phm t c chua,

Trong qu trnh bo qun, thnh phn betalain/betacyanin trong cc dch chit

s dn dn b phn hy do nh hng ca pH, nhit v hot nc. Do , cc

thc phm cha cht mu betalain dn dn b phai mu hay mt mu ty theo iu

kin bo qun. Do , cc betalain/betacyanin c th c thm vo thc phm hay

dc phm lm ch th mu cho bit ti hay mi ca cc sn phm ny.

Khi mu ca betalain b chuyn thnh mu nu hay mt mu c ngha l cc sn

phm trn c bo qun khng ng cch v cht lng b bin i.

1.3.4.2. Tc dng dc hc:

Nhng nghin cu gn y cho thy c ci ng l mt trong 10 loi rau

qu c tc dng oxy ha mnh nht (Hanvorsen v ctv., 2002; Ou v ctv., 2002) v

dch chit c ci ng c th c s dng nh l mt phng thuc ngn nga

ung th v chng x va ng mch. iu ny c gii thch l do c ci ng

cha mt hm lng kh ln betacyanin (300-600 mg/kg). Betacyanin c tc dng

nh l mt cht chng oxy ha nh kh nng bt gi cc gc t do c th lm t

16

bin t bo v gy ra nhng ri lon trong s trao i cht. Tc dng chng oxy ha

rt tt ca betacyanin cng c gii thch bi kh nng hp th tt betacyanin bi

thnh rut non v s gn kt d dng ca betacyanin vi mng t bo do s c mt

ca nhm nh chc cationic (-N+H).

1.3.5. Tnh hnh khai thc v ng dng betacyanin t nhin lm cht mu thc

phm

Ngun betacyanin t nhin ch yu c khai thc thng mi hin nay l c

ci ng (Beta vulgaris). Dch chit betacyanin t ngun nguyn liu ny cha

khong 95% betacyanin. Ngoi ra, cng c mt hm lng nh sc t betaxanthin

(mu vng), tuy nhin mu ny b mu tm ca betacyanin lt t [8]. Ngoi cht

mu betacyanin, dch chit c ci ng cn c cha cc ng, mui hoc cc

protein t nhin. Do vy, sau khi c c, sn phm th c tinh ch loi b cc

tp cht ny. Ngoi ra, cc acid thc phm (v d: acid citric, lactic, L-ascorbic) c

th c thm vo lm tc nhn khng ch pH v cht n nh. Sn phm

betacyanin thng mi c th di dng dch chit c c hay dng bt kh

(bng cch trn cht mang thch hp vi dch chit c c ri sy phun). Cc sn

phm betacyanin th v tinh ch v ang c s dng rng ri lm ph gia to

mu vi sn lng hng nm EU c lc ln n gn 4000 tn v ang c xu

hng ngy cng gia tng.

Hnh 1.5. Cc dng sn phm cht mu betacyanin t c ci ng

Hin nay cng c mt s nghin cu sinh tng hp betacyanin bng phng

php nui cy m so t bo c ci ng (Mukundan v ctv., 1998, 2001; Akita v

ctv., 2002). Tuy vy, sn phm cht mu thu c c gi thnh qu cao nn khng

th ng dng thng mi.

17

Do dch chit c ci ng c mi t v nng nitrite v nitrate cao nn

khng hp dn ngi tiu dng1 nn gn y xut hin xu hng nghin cu

chit betacyanin t v thanh long thay th cho c ci ng [9][8][7]. Kt qu

nghin cu cho thy y cng l ngun betacyanin tim nng, c th khai thc ng

dng lm cht mu thc phm.

1.4. TNG QUAN V CC PHNG PHP CHIT [1][2][4]

1.4.1. Cc khi nim c bn v qu trnh chit

Chit l qu trnh chuyn cht cn chit rt trong nguyn liu vo dung mi

v c thc hin bng khuch tn phn t v khuch tn i lu.

a) Khuch tn phn t: l s chuyn vt cht cn chit rt t pha ny sang pha

khc do s chuyn ng nhit hn lon trong mi trng tnh.

Khuch tn phn t theo nh lut Fick I: dxdCDS

dtdm

trong :

dtdm : tc ha tan cht cn chit

S : din tch tip xc gia cht cn chit v dung mi

dxdC : gradient nng

D: h s khuch tn phn t, ph thuc vo nhit (T), nht ca dung

mi () v bn knh phn t cht cn chit (r) theo cng thc Einstein:

rkTD6

(k: hng s Boltzmann)

Nh vy, tc khuch tn phn t cng mnh khi chnh lch nng cht

cn chit gia 2 pha tip xc nhau, din tch b mt tip xc gi nguyn liu v

dung mi cng ln, nhit cng cao v kch thc phn t cht cn chit cng

nh.

1 Hin nay, c th hn ch nhc im ny bng k thut siu lc v ln men dch chit c ci ng vi s c mt ca Candida utilis trong iu kin k kh (Adams et al., 1976).

18

b) Khuch tn i lu: l s vn chuyn vt cht t mi trng ny sang mi

trng khc trong dng chuyn ng ca cht lng ch chy xoy. Khuch tn

i lu l hnh thi di chuyn vt cht trong dung dch phm vi nh.

Khuch tn i lu theo nh lut Sucarep: dCSBdtdm ..

trong : dm, dt, dC v S c ngha ging nh cng thc khuch tn phn t trn;

B: hng s tc khuch tn i lu.

Trong khuch tn phn t s di chuyn vt cht nh vo ng nng ca

chuyn ng nhit phn t. Trong khuch tn i lu di chuyn vt cht nh vo

nng lng bn ngoi dn ti. Khuch tn phn t v khuch tn i lu c gi l

khuch tn nng v ng lc ca qu trnh khuch tn u l do chnh lch nng

.

1.4.1.2. Cc yu t nh hng ti qu trnh chit

Trong qu trnh chit, t c vn tc chit v hiu sut chit cao, cn cn

lu cc yu t sau:

a) Chnh lch nng cht cn chit trong nguyn liu v dung mi phi

cao qu trnh khuch tn cc phn t cn chit cng mnh.

- Mun vy, c th li dng nguyn l chit ngc dng to ra s chnh

lch nng ln (trong chit lin tc) hay thay mi dung mi chit nhiu ln (trong

chit gin on).

- T l dung mi/nguyn liu phi ln. Tuy nhin ch ln mc hp l

nht nh: nu t l ny qu ln s lm cho nng cht cn chit trong dung dch

chit rt uc thp, gy kh khn v hiu qu kinh t km (tn nng lng v thi

gian ui dung mi)

b) Hnh thi, tnh cht v cu to ca t chc nguyn liu:

- Mc ph v cu trc t bo cng nhiu th s tip xc gia cht cn chit v

dung mi cng tng nn rt ngn thi gian chit v chit trit hn.

- Kch thc cng nh th din tch tip xc gia nguyn liu v dung mi cng

tng, hiu sut chit tng. Tuy nhin cng ch nn nh ti mc nht nh v qu nh

19

nguyn liu d b vn li cc ht mn lng ng trn cc lp nguyn liu. Mt khc,

nguyn liu qu nh s b cun vo dch chit gy kh khn cho qu trnh x l dch

chit sau khi chit.

- Tnh cht ca nguyn liu cng nh hng ln n hiu sut chit. Khi chit

bng dung mi hu c, m nguyn liu gim th tc chit tng ln.

c) nh hng ca thi gian v nhit chit

- Thi gian cng di th lng cht khuch tn tng, nhng thi gian phi c

gii hn. Khi t c mc trch ly cao nht nu ko di thi gian th s khng

mang li hiu qu kinh t.

- Nhit c tc dng tng tc khuch tn v gim nht, do phn t

cht ha tan chuyn ng d dng khi khuch tn gia cc phn t dung mi. Tuy

nhin, nhit tng c gii hn, v nhit qu cao s c th phn hy phn t cn

chit v gy kh khn cho qu trnh cng ngh.

c) Dung mi chit

Dung mi chit cn tha mn cc iu kin sau:

- ha tan cht cn chit bt k t l no.

- c nhit si thp d dng tch dung mi ra khi dch chit.

- c thnh phn ha hc n nh, khng phn ng ph vi nguyn liu.

- khng c hi , khng nh hng sc khe v cht lng sn phm.

- kh chy n, an ton cho qu trnh sn xut.

- khng n mn thit b.

- r tin, d kim, c kh nng s dng trong sn xut.

Tuy nhin hin nay cha c loi dung mi no p ng y nhng iu kin

trn. Do , ty trng hp chit c th chn dung mi cho hp l.

1.4.2. Cc phng php chit

Da vo cch tin hnh, c th chia thnh cc phng php chit sau:

1.4.2.1. Chit gin on:

Theo phng php ny ta ngm nguyn liu vo dung mi. Sau mt thi gian

nht nh, khi gia dung mi v nguyn liu t nng cht cn thit mc

20

cn bng, tin hnh dung mi c ra, thay dung mi mi vo. C nh th cho n

khi chit ht cht cn chit. Phng php ny c u im l n gin, d thc hin.

Nhc im l tn cng, tn thi gian cng nh tn dung mi chit nn khng kinh

t, khng ph hp vi quy m sn xut ln.

1.4.2.2. Chit bn lin tc

Nguyn l ca phng php ny l dng nhiu thit b chit gin on b tr

thnh mt h thng lin hp tun hon nhm mc ch gim thi gian chit, t tn

cng hn, tit kim c nhiu dung mi hn. i vi phng php ny qu trnh

chit thc hin theo nguyn tc dung mi i t ni c nng cht chit cao n

nng cht chit thp.

1.4.2.3. Chit lin tc

Nguyn l l ngm dung mi trong dng chuyn ng cng chiu hay ngc

chiu ca dung mi. u im ca phng php ny l cho hiu qu kinh t cao,

thch hp cho sn xut cng sut ln, p dng cho quy m cng nghip. Tuy nhin,

nhc im l thit b kh phc tp, chi ph u t ln.

1.4.3. Vi k thut chit hin i dng chit xut cht mu t nhin

1.4.3.1. Chit nh siu m (Ultrasound-assisted extraction):

Nguyn liu c trn vi dung mi thch hp ri chit bng siu m. Nhiu

nghin cu cho thy rng siu m c kh nng ph v mng t bo ca nguyn liu,

do gip cho xm nhp ca dung mi vo bn trong t bo d dng hn. Ngoi ra,

siu m cn c tc dng khuy trn mnh dung mi, do gia tng s tip xc ca

dung mi vi cht cn chit v ci thin ng k hiu sut chit.

1.4.3.2. Chit siu ti hn (SFE: Supercritical Fluid Extraction):

y l phng php chit c quan tm nhiu nht hin nay trong lnh vc

chit cc hp cht c hot tnh sinh hc t nguyn liu t nhin nhm ng dng

trong cng nghip dc phm v thc phm. Phng php ny cho php t ng

ha qu trnh chit v hn ch vic s dng cc dung mi hu c c hi. Dung mi

chit l mt cht lng trng thi siu ti hn2. trng thi ny, cht lng c

2 tc l nhit v p sut cao hn im ti hn ca n

21

nhng tnh cht c bit nh c tnh chu nn cao, khuch tn nhanh, nht v sc

cng b mt thp Do , n c kh nng khuch tn mnh vo nn nguyn liu

tt hn nhiu so vi cc dung mi thng thng, v th lm tng hiu sut chit ln

nhiu ln. Trong phng php ny, thng dng CO2 trng thi siu ti hn lm

dung mi chit (i khi trn vi vi % dung mi phn cc no nh etanol,

metanol, 2-propanol lm tng kh nng ha tan carotenoit ca CO2) do n cho

php chit nhanh, chn lc, khng lm oxy ha carotenoit v an ton trong vn

hnh.

1.4.3.3.Chit dung mi tng tc (ASE: Accelerated Solvent Extraction) hay

chit di p sut cao (PFE : Pressurized Fluid Extraction):

y cng l mt phng php chit mi, cho php chit rt nhanh, t ng

ha, hiu qu v tit kim dung mi. Nguyn tc ca n tng t nh phng php

chit Soxhlet c in, ngoi tr vic qu trnh chit c thc hin nhit v p

sut cao (nhng vn di im ti hn ca dung mi s dng). Trong phng php

ASE, nguyn liu cn chit c xay nh, lm kh (thng l ng kh), ri nhi

vo mt ng chit (extraction cell). ng chit ny c t trong l duy tr nhit

thch hp (c th iu chnh t 40 2000C). Dung mi c bm vo ng chit

v gi p sut 10 -20 MPa trong vi pht (static time), sau dch chit c y

vo mt bnh hng bng mt th tch dung mi mi (flush volume). Qu trnh c

lp li vi ln (cycles). Cui cng, ton b dch chit c y ra bng mt dng

kh tr (N2)

Hnh 1.6. S thit b chit SFE Hnh 1.7. S thit b chit ASE

22

ti ny s nghin cu v so snh hiu qu chit cht mu betcyanin t v

qu thanh long rut trng (Hylocereus undatus) trng Vit Nam bng phng

php ngm chit gin on v phng php siu m. T , chn la quy trnh

thch hp cho vic chit betacyanin t ngun nguyn liu ny.

Ngoi ra, ti cn kho st bn mu ca dch chit betacyanin thu c

trong mt s iu kin bo qun khc nhau v xut phng php thch hp cho

vic ng dng v bo qun cc loi thc phm b sung cht mu ny.

23

Phn 2.

I TNG V PHNG PHP NGHIN CU

2.1. I TNG NGHIN CU

2.1.1. Vt liu nghin cu

2.1.1.1. Nguyn liu chnh:

Trong nghin cu ny, nguyn liu dng chit betacyanin l v qu thanh

long rut trng (Hylocereus undatus). Qu thanh long (chn nhng qu va chn, v

c mu hng m) c mua ch Vnh Hi (Nha Trang).

2.1.1.2. Ha cht

- Etanol tuyt i

- Nc ct 1 ln

- Na2SO4 khan

- Acid ascorbic

Tt c ha cht u thuc loi tinh khit phn tch (PA)

2.1.2. Dng c v thit b

2.1.2.1. Dng c

Bnh nn, phu lc thy tinh, ng nghim, ng ong, bnh nh mc, pipet,

bng y t, giy bc.

2.1.2.2. Thit b

- Cn k thut 1 g (Vit Nam)

- Cn phn tch 1 mg (Shimadzu, Nht)

- Cn phn tch 0,1 mg (Satorius, Nht)

- T sy 10C (Memert , c)

- B siu m Elmasonic S300H (Elma, c)

- Thit b c quay RV 10 Control (IKA, c)

- Quang k UV-Vis Genesys 20 (Thermo, USA)

24

2.2. PHNG PHP NGHIN CU

2.2.1. Xc nh thnh phn khi lng ca qu thanh long

Qu thanh long c ra sch v lau kh nc. Sau , xc nh thnh phn

khi lng ca thanh long nh sau:

- Cn qu thanh long c khi lng l mQ

- Tch v. Ct b nhng phn khng c mu (cung, u, tai) v co b lp

mu trng nhy bn trong (st phn rut qu), em cn phn cn li, c khi

lng l mV

- Phn rut em cn ta c khi lng l mR

- Phn b i cng c em cn c khi lng mB

Thnh phn khi lng ca qu thanh long c tnh nh sau:

% V = %100.Q

V

mm ; % Rut = %100.

Q

R

mm ; % B i = %100.

Q

B

mm

2.2.2. Xc mt s thnh phn ha hc ca v thanh long

a) Xc nh hm lng nc: sy 105 1100C n khi lng khng i

(Ph lc 1)

b) Xc nh hm lng betacyanin tng s trong v thanh long: chit

betacyanin bng nc ct v o hp th ca dung dch 538 nm dng H2O lm

dung dch so snh (Ph lc 2).

2.2.3. Quy trnh d kin sn xut betacyanin t v qu thanh long

Trn c s kt qu ca mt s nghin cu lin quan, chng ti xut quy

trnh d kin sn xut cht mu betacyanin t v thanh long nh sau:

25

Hnh 2.1. S quy trnh d kin sn xut cht mu betacyanin

t v thanh long ph liu

iu kin chit thch hp: - Dung mi - T l dung mi/nguyn liu - Thi gian chit - Nhit chit - S ln chit thch hp - Phng php chit

Bt mu betacyanin

Trn vi dung dch maltodextrin

X l thch hp

Lc

Chit

V thanh long ph thi

Dch chit betacyanin

C ui dung mi (p sut thp; < 400C)

Sy phun

Dch chit betacyanin th c c

Tinh ch EtOH - CHCl3 3/1 (v/v)

26

Gii thch quy trnh

* V thanh long em ct b cc phn khng c mu (cung, u, tai) v no

b phn khng mu bn trong. Sau , ct thnh ming nh, bo qun lnh (- 200C)

n khi chit .

* Chit xut cht mu betacyanin trong v qu thanh long bng dng mi v

phng php chit thch hp (t l dung mi/nguyn liu, thi gian, nhit v s

ln chit c chn sao cho t hiu sut chit cao hp l)

* Lc ly dch chit.

* C ui dung mi di p sut thp: trnh s phn hy betacyanin, tin

hnh c c dch chit nhit khng qu 400C .

* Sau khi ui dung mi, thu c dch chit th cha betacyanin c c

* Sau khi c ui ht dung mi, tinh ch betacyanin bng cch chit

betacyanin sang cloroform, sau kt tinh betacyanin bng cch thm etanol 3/1

(v/v) v 40C qua m. Gn v ra tinh th betacyanin bng etanol lnh [9]

* Ha tan betacyanin tinh th trong nc v b sung maltodextrin (t l thch

hp)

* Sy phun hn hp betacyanin-maltodextrin thu bt mu betacyanin.

2.2.4. Xc nh iu kin thch hp chit betacyanin t v thanh long

V qu thanh long ti c ct thnh ming nh (2 - 3 mm), sau trn u,

cn chnh xc thnh nhiu mu nh (1 2 g) ri cho vo cc ng nghim, bt kn,

bo qun -200C n khi chit.

Betacyanin km bn nhit nn ch nghin cu chit bng phng php ngm

chit ( nhit phng, trong bng ti) v phng php siu m.

xc nh iu kin chit betacyanin bng phng php chit nh siu m

v ngm chit, tin hnh cc l th nghim sau:

2.2.4.1. Chn dung mi chit (L TN1):

C nh t l dung mi trn nguyn liu l 5/1(w/v). Tin hnh chit 1 ln

bng phng php siu m (5 min, 300C).

27

Dung mi chit s dng l dung dch etanol-nc, trong t l etanol trong

dung dch (X1) thay i ln lt t 0 100% (v/v):

X1 = 0; 20; 40; 60; 80; 100 % (v/v)

Dch chit sau c pha long bng etanol tuyt i ri o quang 538 nm

xc nh hiu sut chit betacyanin theo cng thc:

%H = (lng betacyanin chit c/ lng betacyanin tng s).100%

2.2.4.2. Chn t l dung mi/ nguyn liu (L TN2):

Dng dung mi chit thch hp chn. Tin hnh chit 1 ln bng phng

php siu m (5 min, 300C), trong t l dung mi/nguyn liu (X2) thay i

nh sau:

X2 = 5/1; 10/1; 15/1; 20/1; 25/1; 30/1 (v/w)

Betacyanin km bn nhit nn ch nghin cu chit bng phng php ngm

chit ( nhit phng, trong bng ti) v phng php siu m. Do thi gian chit

v s ln chit ph thuc vo phng php chit nn cn nghin cu nh hng s

thay i hiu sut chit theo thi gian chit v s ln chit bng hai phng php

chit chn.

2.2.4.3. Chn thi gian chit (L TN3):

a) Phng php siu m:

Dng dung mi v t l dung mi/nguyn liu thch hp xc nh. Tin

hnh chit 1 ln. y ta kho st thm yu t na l nhit siu m.

Nhit v thi gian siu m thch hp c xc nh phng php quy hoch

thc nghim ton phn 2 yu t theo m hnh cu trc c tm 22+ 3 (gm 4 th

nghim bin v 3 th nghim tm), trong :

Thi gian: X3 = 5 35 (min); Nhit : T = 30 80 (0C)

Hm mc tiu (Y) l hiu sut betacyanin chit c (xc nh bng phng

php o quang).

Phng trnh hi quy thc nghim theo m hnh bc hai c xc nh bng

phm mm EXCEL:

Y = b0 + b1X3 + b2T + b3X3.T + b4X32 + b5T2

28

Dng chun Student loi b cc h s khng c ngha v chun Fisher

kim nh tnh tng thch ca phng trnh hi quy vi thc nghim ( tin cy

95%). Sau , xc nh cc thng s ti u bng phn mm Maple 7.0.

b) Phng php ngm chit:

Dng dung mi v t l dung mi/nguyn liu thch hp xc nh. Tin

hnh chit 1 ln, trong thi gian ngm chit (X3) thay i nh sau:

X3 = 2; 4; 6; 8; 10; 12 (h)

2.2.4.4. Chn s ln chit (L TN4):

Dng dung mi, t l dung mi/nguyn liu, thi gian chit (v nhit chit

thch hp, nu chit bng phng php siu m), trong thay i s ln chit (X4)

nh sau:

X4 = 1; 2; 3; 4 (ln)

S b tr th nghim xc nh iu kin thch hp chit betacyanin t v

thanh long bng phng php siu m v phng php ngm chit c trnh by

hnh 2.2.

29

Ngm chit (X1 opt ; X2 opt ; X4 = 1)

S ln chit (X4 opt)

X3 = t/gian (h) 2 4 6 4 8 10 12

Dch chit betacyanin

Tnh hiu sut thu hi betacyanin

T l dung mi/nguyn liu thch hp (X2 opt)

X2 = Dmi/N.Liu (v/w) 5/1 10/1 15/1 20/1 25/1 30/1

Siu m (X2 = 5/1 v/w; X3 = 5 min; X4 =1 ln)

Dch chit betacyanin


% Etanol thch hp (X1 opt)

Siu m (X1 opt; X3 = 5 min, X4 = 1 ln)

X1 = % etanol (v/v) 0 20 40 80 100 60

L TN 2

L TN 1

L TN3 Siu m (X1 opt ; X2opt; X4=1)

X3 = 5 35 (min) T = 30 80 (0C) Quy hoch thc nghim yu t ton phn

Dch chit betacyanin


Thi gian (nhit ) chit thch hp (X3 opt; Topt )

X4 = s ln chit 1 2 3 4 4

Dch chit betacyanin


L TN4 Siu m (Topt) /Ngm chit (X1 opt; X2 opt ; X3 opt )

Hnh 2.2. B tr th nghim xc nh iu kin chit betacyanin t v thanh long

30

2.2.5. La chn quy trnh thch hp chit betacyanin

Sau khi xc nh c iu kin chit thch hp chit betacyanin t v

thanh long bng phng php siu m v ngm chit, tin hnh chit th nghim

trong cc iu kin trn. So snh hiu sut chit thu c. T , chn quy trnh

chit thch hp nht (Hnh 2.3.)

Hnh 2.3. S b tr th nghim chn la quy trnh thch hp

chit xut betanin t v thanh long

2.2.6. Nghin cu phng php bo qun dch chit betacyanin

Tin hnh kho st bn mu ca dch chit betacyanin theo thi gian bo

qun trong cc trng hp sau:

Dch chit betacyanin

V thanh long x l

Tnh hiu sut chit So snh

Quy trnh chit thch hp

Siu m (iu kin thch hp)

Lc

Ngm trong dung mi thch hp

Ngm chit (iu kin thch hp)

31

2.2.6.1. Khng b sung vitamin C:

Dch chit c bo qun v nh gi bn mu trong 2 iu kin:

- nhit phng, di nh sng t nhin

- Bo qun 40C, trong ti

Hnh 2.4. B tr th nghim nh gi bn mu ca dch chit betacyanin

khng b sung vitamin C

Tin hnh: Cho vo 6 bnh nn mi bnh 20 ml dch chit betacyanin trong

etanol, bt kn li (dng giy bc v mng polyetylen). Sau , 3 bnh nhit

phng (nh sng t nhin), 3 bnh cn li gi trong ngn mt t lnh (40C). C sau

24 h tin hnh quan st v o hp th ca dung dch bc sng 538 nm (dng

etanol lm dung dch so snh).

Xc nh %betacyanin cn li theo cng thc:

%betacyanin cn li = (lng betacyanin cn li/lng betacyanin ban u).100%

Dch chit betacyanin

- Bo qun nhit phng - nh sng t nhin

Bo qun lnh (40 C), trong ti

o quang - Quan st

1 2 3 4 5 7 6 Thi gian (ngy):

nh gi bn mu

32

2.2.6.2. Khi b sung vitamin C

Tin hnh th nghim tng t nh trn nhng cc dch chit betacyanin c

b sung 0,1% (w/v) vitamin C.

Cc dch chit ny c bo qun trong 3 iu kin:

- nhit phng, di nh sng t nhin

- nhit phng, trong ti

- Bo qun 40C, trong ti

So snh bn mu ca dch chit betacyanin trong cc iu kin bo qun

ni trn. T , xc nh phng php thch hp cho vic bo qun v ng dng

dch chit betacyanin thu c.

2.2.7. Th nghim quy trnh chit - nh gi cht lng sn phm

Sau khi chn c quy trnh thch hp chit betacyanin t v qu thanh

long, tin hnh sn xut th nghim betacyanin vi quy m phng th nghim. Sn

phm th nghim c em phn tch nh gi cht lng sn phm.

- Xc nh d lng Pb: phng php quang ph hp th nguyn t (ph lc 3)

- Xc nh hm lng betacyanin tng s trong sn phm: phng php o

quang UV-Vis (ph lc 2)

2.2.8. X l s liu

Cc kt qu nghin cu u l trung bnh cng ca 3 ln xc nh song song.

X l s liu bng phn mm MS Excel 2003.

V th hai chiu bng phn mm Excel v th ba chiu bng phn mm

Maple 7.0.

33

Phn 3. KT QU V THO LUN

3.1. Thnh phn khi lng ca qu thanh long

Kt qu xc nh thnh phn khi lng ca qu thanh long c trnh by

bng 3.1.

Bng 3.1. Thnh phn khi lng ca qu thanh long

V Rut Phn b i Mu Khi lng

(g) T l (%)

Khi lng (g)

T l (%)

Khi lng (g)

T l (%)

1 150 25,0 400 67,0 50 0,1

2 170 26,2 420 64,6 60 0,1

3 145 23,6 410 66,7 60 0,1

Trung bnh - 24,9 - 66,1 - 0,1

Kt qu trn cho thy :

- Phn n c trong qu thanh long chim t l ln (khong 66% trng

lng qu). y cng l thnh phn c ch nht, c dng n ti hay ch bin

thnh cc dng sn phm khc nhau.

- Phn v c cha betacyanin cng chim t l kh ln (gn 25% trng lng

qu). Nu phn v ny b thi b trong dy chuyn ch bin cc sn phm thanh

long ng hp th s sinh ra mt lng ph liu rt ln, gy nhim mi trng. Do

vy, vic tn dng ngun ph liu ny chit xut cht mu betacyanin l iu c

ngha thc tin v gip nng cao hiu qu kinh t ca qu trnh sn xut thanh

long ng hp.

- Phn b i chim t l rt nh (khong 0,1%). Phn ny c th tn dng

ch bin thnh phn vi sinh.

Nh vy, c th ni thanh long l mt loi qu rt c ch: tt c thnh phn

ca n u c th dng ch bin thnh nhng sn phm c gi tr kinh t. Tuy

nhin, thc hin c iu ny th song song vi vic pht trin cc vng thanh

34

long nguyn liu cn xy dng cc c s ch bin cho php tn dng mt cch hiu

qu tt c cc thnh phn ny.

3.2. Mt s thnh phn ha hc ca v thanh long

Bng 3.2. Mt vi thnh phn ha hc c bn ca v thanh long

Thnh phn Hm lng Nc (%) 89

Betacyanin tng s (mg/kg TL ti) 109

Qua kt qu trn ta thy:

- V qu thanh long cha hm lng nc kh cao (khong 89%), do rt

d b h thi. V th, v sau khi bc tch nn tin hnh chit betacyanin ngay

trnh nh hng n cht lng sn phm cht mu thu c.

- Hm lng betacyanin trong v qu thanh long Hylocereus undatus hi

thp so vi trong vi trong c ci ng3 (bng khong 1/6 - 1/3). Nh vy, gi

thnh betacyanin t nhin chit t v thanh long s cao hn khi chit t c ci

ng. Tuy nhin, nhc im ny c th c b tr nh s gim bt chi ph kh

mi t kh chu v nng nitrat v nitrit kh cao ca dch chit c ci ng.

3.3. Xy dng quy trnh chit betacyanin t v qu thanh long

3.3.1. Chn dung mi chit

Bn cht ca dung mi nh hng n nhiu n hiu sut chit betacyanin.

Kt qu thu c khi tin hnh chit betacyanin t v qu thanh long bng

phng php siu m (Bng PL4.1. v hnh 3.1) cho thy:

- Khi tng nng etanol trong dung dch nc t 0 - 40% th hiu sut chit

betacyanin tng ln. Nhng sau , tip tc tng nng etanol (60 - 100%) th

hiu sut chit li gim i.

- Vi dung mi etanol 40% th hiu sut chit betacyanin ln nht. Do ,

dung dch etanol-nc 40% (v/v) c chn lm dung mi chit.

3 cha 300 600 mg/kg [7]

35

Chn t l etanol/nc

17,43 20,18

38,53

27,5222,94

12,84

0

10

20

30

40

50

0 20 40 60 80 100

T l etanol/nc (% v/v)

Hi

u s

ut

ch

it (

%)

Hnh 3.1. nh hng ca dung mi n hiu sut chit betacyanin

3.3.2 Chn t l dung mi/nguyn liu

Kt qu kho st nh hng ca t l dung mi/ nguyn liu n hiu sut

chit betacyanin t nguyn liu v thanh long ti (Hnh 3.2) cho thy:

- Khi t l dung mi nguyn liu ny nh hn 20/1(v/w) th hiu sut chit

tng ln khi tng t l dung mi/ nguyn liu. Tuy nhin, khi tip tc tng t l dung

mi/nguyn liu th hiu sut chit gn nh khng thay i. iu ny c th gii

thch nh sau: Vi t l dung mi/ nguyn liu nh hn 20/1 (v/w), lng dung mi

cha ngp ht nguyn liu, do hiu sut chit kh thp (ch khong gn 40%).

Khi t l ny t n ngng gi tr trn, ton b khi nguyn liu ngp ht trong

dung mi ln hiu sut chit tng ng k.

- Vi t l dung mi/nguyn liu t 25/1 (v/w) tr ln, ton b khi nguyn

liu c tip xc hon ton vi dung mi v di tc ng ca sng siu m th

gn nh ton b betacyanin trong nguyn liu s c chuyn vo trong dung mi,

do hiu sut gn nh l khng thay i.

Mc d khi t l dung mi/ nguyn liu ln hn 20/1 (v/w) th hiu sut chit

tng ln nhng khng ng k, trong khi phi tn nhiu chi ph dung mi cng

36

nh chi ph nng lng v thi gian cho vic ui dung mi. Do , t l dung mi

nguyn liu thch hp nht c chn l 20/1 (v/w)

Chn t l dung mi/nguyn liu

19,20

32,28

39,39

49,1252,92 53,43

0,00

10,00

20,00

30,00

40,00

50,00

60,00

5/1 10/1 15/1 20/1 25/1 30/1

DMi/N.Liu (v/w)

Hi

u s

ut

chi

t (%

)

Hnh 3.2. nh hng ca t l dung mi/nguyn liu n

hiu sut chit betacyanin

3.3.3. Chn thi gian chit v s ln chit

3.3.3.1. Chit bng phng php siu m

a) Xc nh thi gian v nhit siu m

Kt qu nghin cu s ph thuc ca hiu sut chit (Y%) vo thi gian

chit (X3, min) v nhit siu m (T, 0C) c th hin trn bng 3.3. v hnh 3.3.

T kt qu ny, xc nh c phng trnh hi quy nh sau:

Y = - 110,77 + 6,70T 0,03T.X3 0,06T2+ 0,05X32 (R2 = 0,9893)

Dng phn mm Maple 7.0 xc nh c nhit v thi gian siu m ti

u chit betacyanin t v thanh long l:

T = 470C ; X3 = 35 min

Do , chng ti chn thi gian chit l 35 min ng vi nhit siu m l

450C.

37

Bng 3.3. nh hng ca thi gian v nhit siu m n

hiu sut chit betacyanin t v thanh long

Thi gian X3 (min)

Nhit T (0C)

Hiu sut chit Y (%)

5 30 35,29

5 80 46,76

35 30 64,94

35 80 33,45

20 55 70,55

20 55 67,65

20 55 73,78

Hnh 3.3. nh hng ca thi gian v nhit siu m n hiu sut chit

betacyanin t v thanh long

b) Xc nh s ln chit bng phng php siu m

S thay i hiu sut chit vo s ln chit bng phng php siu m c

th hin trn bng PL4.4 v hnh 3.4.

38

Xc nh s ln chit bng phng php siu m

62,98

83,1799,19 100

0

20

40

60

80

100

120

1 2 3 4S ln chit

Hi

u su

t c

hit

(%)

Hnh 3.4. S ph thuc ca hiu sut chit vo s ln siu m

Kt qu ny cho thy khi tng s ln chit t 1 n 3 ln th hiu sut chit

tng nhanh. Nhng tip tc tng s ln chit ln 4 ln th hiu sut tng khng ng

k. Nguyn nhn l do sau 3 ln siu m th di tc dng ca sng siu m cc t

bo cha cht mu b ph v gn hon ton v betacyanin c chit gn nh trit

. Do vy, nu tip tc chit th hiu sut chit gn nh khng tng. Do vy,

gim chi ph sn xut, chng ti chn s ln siu m l 3 ln.

3.3.3.2. Chit bng phng php ngm chit

a) Xc nh thi gian ngm chit

Qua th biu din s thay i hiu sut chit betacyanin vo thi gian

ngm chit (Hnh 3.5 v bng PL4.5) ta thy:

- Khi tng thi gian chit t 2 6 h th hiu sut chit tng mnh (t 21,79

n 45,71%). Nhng vi thi gian chit di hn th hiu sut chit li gim i. S

gim hiu sut chit trong trng hp ny c th gii thch bi s thy phn

betacyanin (mu tm ) thnh betanidin (mu ) hay acid betalamic (mu vng)

khi betacyanin tip xc vi mi trng c nng nc cao (60%) trong thi

gian di.

39

Vi thi gian ngm chit l 6h th hm lng betacyanin thu c l cao

nht. Do , thi gian ngm chit c chn l 6 h.

Xc nh thi gian ngm chit

21,79

41,7945,71

40,66 37,5633,7

0

10

20

30

40

50

2 4 6 8 10 12Thi gian chit (h)

Hi

u su

t c

hit

(%)

Hnh 3.5. S ph thuc ca hiu sut chit vo thi gian ngm chit

b) Xc nh s ln ngm chit

Kt qu kho st s thay i hiu sut chit theo s ln ngm chit (Hnh 3.6

v bng PL4.6) cho thy: khi tng s ln chit t 1 n 3 ln th hiu sut chit tng

ln (67,47 n 98,04%), nhng sau (sau 4 ln chit) th hiu sut tng rt t.

Nguyn nhn l sau 3 ln chit hm lng betacyanin cn li trong nguyn liu rt

t (khong 2% so vi hm lng cht mu tng s ban u), do gradient nng

gia b mt phn cch pha rn (nguyn liu) vi dung mi rt nh, dn n tc

chit khng ng k. Nh vy, gim chi ph sn xut ta chn s ln chit l 3 ln.

40

Chn s ln ngm chit

67,47

83,7398,04 100,00

0,00

20,00

40,00

60,00

80,00

100,00

120,00

1 2 3 4S ln ngm chit

Hi

u s

ut

chi

t (%

)

Hnh 3.6. S ph thuc ca hiu sut chit vo s ln ngm chit

Tm li, iu kin thch hp chit betacyanin t v thanh long nh sau:

- Dung mi chit: dung dch nc cha 40% etanol (v/v)

- T l dung mi/nguyn liu: 20/1 (v/w)

- S ln chit: 3 ln

- Thi gian chit:

35 min/ln chit 450C (nu chit nh siu m)

6 h/ln chit nhit phng (nu dng phng php ngm chit)

3.3.4. So snh hiu sut chit ca hai phng php

Sau khi xc nh iu kin thch hp chit betacyanin t v thanh long bng

2 phng php nu trn, tin hnh chit th nghim cc mu ln (khong 40 g)

bng cc phng php trn.

Kt qu so snh hiu qu chit ca cc phng php trn c trnh by trn

hnh 3.7 v bng PL4.7.

41

So snh 2 phng php chit

98,04 96,26

60,00

70,00

80,00

90,00

100,00

Siu m Ngm chit

Phng php chit

Hi

u su

t c

hit

(%)

Hnh 3.7. So snh hiu qu chit ca 2 phng php chit

Kt qu trn cho thy:

Phng php siu m cho hiu sut chit cao hn phng php ngm chit.

Tuy nhin, s chnh lch khng ng k. Do vy, ty theo iu kin, quy m sn

xut hay mc ch nghin cu m ta la chn phng php chit ph hp.

Phng php siu m:

* u im: cho php chit nhanh, tit kim thi gian

* Nhc im: tn chi ph u t trang thit b, in nng

Phng php ngm chit:

* u im: khng tn chi ph u t trang thit b v in nng

* Nhc im: mt nhiu thi gian

Tuy nhin, c 2 phng php chit trn u ch ph hp vi quy m nh

(nghin cu phng th nghim hay sn xut nh). Do vy, vic nghin cu thit k

cc h thng chit bn lin tc hay lin tc thch hp cho vic chit nhng hp cht

km bn nhit nh betacyanin l iu cn thit c th p dng quy trnh chit

trn trong thc t.

42

Ngoi ra, cng cn nghin cu chn dung mi chit c nhit si thp hn

c kh nng chit betacyanin nhm gip trnh s phn hy betacyanin do ko di

thi gian c ui dung mi.

Trong nghin cu ny, rt ngn thi gian chit, chng ti s dng phng

php chit nh siu m.

3.4. Kt qu kho st bn mu ca dch chit betacyanin

3.4.1. Khi khng b sung vitamin C

Hnh 3.8 (trang 44) trnh by kt qu kho st bn mu ca dch chit

betacyanin trong cc iu kin bo qun khc nhau:

- Mu 1-sng: Bo qun nhit phng, di nh sng t nhin

- Mu 2-0-ti: Bo qun lnh (40C), trong ti

Qua quan st bng mt cho thy: khi bo qun nhit phng c nh sng

th mu mt dn, thay vo l mu vng nht v dn dn mt mu hon ton.

Trong khi , nu bo qun lnh (40C) trong ti th mu c nht dn nhng

khng ng k. iu ny chng t betacyanin b phn hy mnh khi bo qun

iu kin thng nhng kh bn nhit thp trong ti.

Kt qu o cng mu ca dch chit betacyanin cng khng nh kt

lun trn mt cch nh lng: sau 1 tun bo qun iu kin thng betacyanin

b phn hy gn ht (khong 87%), trong khi mc phn hy ny ch

khong 17% nu bo qun 40C trong bng ti. iu ny c gii thch bi s

tng tc thy phn betacyanin di tc dng ca nh sng v nhit, to thnh

betanidin, acid betalamic hay cc sn phm cp thp khc.

43

bn mu ca betacyanin khi khng b sung vitammin C

100,00

53,33

24,3320,67

16,67 15,00 13,33 12,67

100,00 96,67

86,67 86,33 85,33 85,00 83,33 83,00

0,00

20,00

40,00

60,00

80,00

100,00

0 1 2 3 4 5 6 7 8Thi gian (ngy)

%B

etac

yani

n c

n l

i

Mu 1-0-sng

Mu 2-0-ti

Hnh 3.8. bn mu ca betacyanin khi cha b sung vitamin C

bn mu ca betacyanin khi b sung 0,01% vitamin C

100,00

76,00

51,00

24,33 20,0015,00 13,33 12,67

100,00 96,6786,67 86,33 85,33 85,00 83,33 83,00

0,00

20,00

40,00

60,00

80,00

100,00

0 1 2 3 4 5 6 7 8Thi gian (ngy)

%B

etac

yani

n c

n l

i

Mu 1-sng

Mu 1-ti

Mu 2-ti

Hnh 3.9. bn mu ca betacyanin khi b sung 0,01% (w/v) vitamin C

44

3.4.2. Khi b sung vitamin C Hnh 3.9 (trang 44) trnh by kt qu kho st bn mu ca dch chit

betacyanin c b sung 0,01% (w/v) vitamin C trong cc iu kin bo qun sau:

- Mu 1-sng: Bo qun nhit phng, di nh sng t nhin

- Mu 1-ti: Bo qun nhit phng, trong ti

- Mu 2-ti: Bo qun lnh (40C), trong ti

Kt qu cho thy:

- cc mu bo qun nhit phng: mu nht i, sau chuyn sang

vng v mt mu i nhanh chng, tng ng vi s suy gim hm lng betacyanin

rt nhanh. S suy gim ny c chm hn i vi mu bo qun trong ti nhng

khng ng k. Nh vy, nh sng cng nh hng ti bn mu ca betacyanin

nhng khng ng k.

Ngoi ra, so vi mu cng bo qun nhit phng nhng khng b sung

vitamin C th s suy gim hm lng betacyanin c chm hn mt t. Nh vy, vi

hm lng vitamin C b sung l 0,01% (w/v) th tc dng km hm tc phn hy

ca betacyanin khng nhiu.

- i vi mu bo qun lnh: mu gn nh khng thay i v hm lng

betacyanin gim i khng ng k. S gim hm lng betacyanin cng tng t

nh mu bo qun cng nhit nhng khng c vitamin C.

Tm li, nhng kt qu kho st trn cho thy :

- Nhit v nh sng lm tng tc phn hy betacyanin, tuy nhin nhit

l yu t quan trng, nh hng nhiu n tc qu trnh phn hu ni trn.

- Vitamin C c tc dng lm chm tc phn hy betacyanin. Tuy nhin,

tc dng ny cha nhiu nng vitamin C 0,01% (w/v). Do vy, cn nghin cu

xc nh nng vitamin C thch hp hn hay la chn tc nhn acid hu c khc

c kh nng km hm tt hn s phn hy betacynin.

45

Hnh 3.10. Mu bo qun nhit phng

Hnh 3.11. Mu bo qun 40C

Nhng kt qu trn c th c ng dng vo qu trnh tch chit v bo

qun betacyanin:

- Khi chit nn tin hnh nhit thp nht c th c v b sung viatmin

C hay acid hu c c kh nng km hm s phn hy betacyanin

- Betacyanin b phn hy kh chm khi bo qun lnh ( 40C). Do vy, ch

nn s dng betacyanin to mu cho cc thc phm c bo qun lnh (chng

hn kem, b, phomat, sa chua, cc loi ung lnh)

3.5. Hon thin quy trnh chit sn xut cht mu betacyanin t v qu thanh

long Sn xut th nghim v nh gi cht lng sn phm

T nhng kho st trn y, c th xut quy trnh sn xut cht mu

betacyanin t v thanh long nh sau:

46

Hnh 3.12. S quy trnh sn xut cht mu betacyanin

t v thanh long

- Dung mi: etanol 40% (v/v) + vitamin C 0,01% (w/v) - Dmi/N.Liu: 20/1 (v/w) - Phng php chit:

Siu m: 35 min/ln chit; 450C ( hay: Ngm chit, t0phng; 6 h/ln) - Chit 3 ln (trong ti)

Bt mu betacyanin

Trn vi dung dch maltodextrin

X l thch hp

Lc

Chit

V thanh long ph thi

Dch chit betacyanin

C ui dung mi (p sut thp; < 400C)

Sy phun

Dch chit betacyanin th c c

Tinh ch

47

Thuyt minh quy trnh

* V thanh long em ct b cc phn khng c mu (cung, u, tai) v no

b phn khng mu bn trong. Sau , ct thnh ming nh, bo qun lnh (- 200C)

n khi chit.

* Khi chit c 1 kg v thanh long ti th thm vo 20 lt etanol 40% (v/v)

cha 0,01% (w/v) vitamin C. Tin hnh chit betacyanin bng cch siu m trong

35 pht 450C (hay ngm nhit phng trong 6 h). Sau thi gian trn, gn ly

dch chit v lp li qu trnh trn thm 2 ln na vi phn b cn li. Tt c cc

thao tc trn u thc hin trong bng ti.

* Cc dch chit betacyanin sau c gp li, lc ht chn khng loi b

cc tp cht l lng.

* Dch chit sau c em c ui dung mi bng thit b c quay di p

sut thp (tc quay: 150 vng/pht, nhit khng qu 400C) trnh s phn

hy betacyanin. Khi c c ch gim p sut t t xung 100 mbar, sau tip

tc gim dn xung 40 mbar trnh s si tro qu mnh ca dch chit gy tht

thot cht mu.

* Sau khi ui dung mi, thu c dch chit th cha betacyanin c c

* Dch chit beacyanin c c c th c tinh ch bng cch chit betacyanin

sang cloroform. Sau , kt tinh betacyanin bng cch thm etanol 3/1 (v/v) v

40C qua m. Gn v ra tinh th betacyanin bng etanol lnh [9]

* Ha tan betacyanin tinh th trong nc v b sung maltodextrin (t l thch

hp)

* Sy phun hn hp betacyanin-maltodextrin thu bt mu betacyanin.

* Tt c cc thao tc trn nn thc hin trong bng ti.

Tuy nhin, do hn ch v thi gian, kinh ph v trang thit b nghin cu (thit

b sy phun b hng) nn chng ti ch c th thu c sn phm betacyanin di

dng dch chit th c c.

48

Bng 3.4. Kt qu sn xut th nghim dch chit betacyanin c c

Mu Lng mu (g) Dch betacyanin

c c thu c (g) Hiu sut thu nhn

betacyanin c c (%)

1 40,000 4,006 10,02

2 40,000 4,052 10,13

3 40,000 3,882 9,71

T.Bnh 40,000 3,980 10,01

Kt qu phn tch mt s ch tiu quan trng ca sn phm betacyanin c c

c trnh by trong bng sau:

Bng 3.5. Kt qu phn tch mt s ch tiu cht lng quan trng ca sn

phm betacyanin c c

Ch tiu Kt qu Betacyanin tng s (mg/kg) 948

Pb (mg/kg) 0,17

T kt qu phn tch hm lng betacyanin tng s trong sn phm, tnh

c hiu sut thu hi betacyanin ca ton b quy trnh nh sau:

Hiu sut thu hi betacyanin (%) = %54,86109

%100.40

1000.1000

98,3*948

Hnh 3.13. Sn phm betacyanin c c thu c

49

Kt lun:

Quy trnh chit xy dng cho php thu nhn betacyanin c c vi hiu sut

kh cao (86,54%). Sn phm thu c c hm lng betacyanin khong 948 mg/kg

v d lng Pb di mc cho php 0,17mg/kg. Do vy, sn phm c th xem l t

yu cu cht lng.

3.6. Tnh ton s b gi thnh sn phm.

Bng 3.6. c tnh chi ph nguyn vt liu chit betacyanin

t 1000 kg v thanh long

Nguyn vt liu Lng s dng n gi Thnh tin Etanol tuyt i 8.000 lt 53.000 424.000

Vitamin C 2 00g 110.000 220.000

Ngy lao ng 2 ngy 50.000 100.000

in 5 kWh 2.000 10.000

Nc 3 m3 5.000 15.000

Tng: 769.000

Lng sn phm betacyanin c c thu c

M = 1000.000.3,98/40 = 99,5 kg

Chi ph sn xut 1 kg sn phm l 7.729

Nhn xt: sn xut ra 1kg sn phm betacyanin c c th chi ph cho

qu rnh sn xut l 7.729

50

KT LUN T nhng kt qu nghin cu trn y, c th i n nhng kt lun sau:

1/ Hm lng betacyanin trong v thanh long Hylocereus undatus trng Vit

Nam vo khong 109 mg/kg, hi thp hn hm lng betacyanin trong c ci

ng (bng khong 1/6 1/3 ln).

2/ iu kin thch hp cho php chit betacyanin t v thanh long quy m nh

l: chit bng phng php siu m (35 min/ln chit 450C) hay bng phng

php ngm chit (6 h/ln chit, nhit phng) s dng dung mi chit l etanol

40% (v/v) trn vi vitamin C 0,01% (w/v). T l dung mi trn nguyn liu l 20/1

(w/v), s ln chit l 3 ln.

3/ Dch chit betacyanin phn hy nhanh khi bo qun nhit phng nhng

kh bn khi bo qun nhit thp (40C). Do vy, nn s dng cht mu ny cho

mc ch to mu cho cc thc phm bo qun lnh.

4/ Sn phm dch chit betacyanin sn xut th nghim cha hm lng

betacyanin khong 948 mg/kg vi d lng Pb di ngng cho php (khng qu 2

mg/kg). Sn phm thu c c th s dng lm cht mu thc phm.

51

KIN XUT

1/ Cn nghin cu thit k v ng dng cc h thng chit bn lin tc hay lin

tc thch hp cho vic chit nhng hp cht km bn nhit nh betacyanin c th

p dng quy trnh chit trn trong thc t.

2/ Cn nghin cu chn dung mi chit c nhit si thp hn, thch hp cho

vic chit betacyanin nhm gip cho khu c c dch chit c nhanh chng, d

dng hn, trnh s phn hy betacyanin do ko di thi gian c ui dung mi.

3/ Cn nghin cu phng php tinh ch loi b cc tp cht trong sn phm

betacyanin trnh nh hng n cht lng thc phm c to mu.

4/ Cn nghin cu su hn v bn mu ca betacyanin di dng cc dng

sn phm c hot nc khc nhau (dng kh, dng dch c c) v nhng nhit

, bn cht v nng cht bo qun khc nhau) chn c iu kin chit v

bo qun betacyanin tt nht.

TI LIU THAM KHO

Ting Vit

[1]. Hong Minh Chu (2003), C s ha hc phn tch, nh xut bn KHKT

[2]. Nguyn Th Cc (2003), Nghin cu th nghim chit rt cht mu t rut

b , lun vn tt nghip trng i Hc Nha Trang

[3]. V ng (1998), C s l thuyt cc qu trnh ha hc, nh xt bn gio

dc

[4]. Nguyn Th Hng Giang(2004), Nghin cu th nghim chit rt cht mu

thc phm t ru tqu b bng dung mi cn, lun vn tt nghip trng

i Hc Nha Trang

[5]. Trn Kim Quy(1987), K thut cc cht mu, nh xut bn TPHCM

Ting Anh

[6]. Alison, D., Paul, C. (2000), Colouring our foods in the last and next

millennium, J. Food Sci. & Tech., 35, p.5-22.

[7]. Harivaindaran, K.V., Rebecca, O.P.S; Chandran, S. (2008), Study of Optimal

Temperature, pH and Stability of Dragon Fruit (Hylocereus polyrhizus) Peel for

Use as Potential Natural Colorant, Pakistan J. Bio. Sci., 11 (18), 2259 2263.

[8]. Henriette M.C.A., Andr N.S., Arthur C.R.S., Knya C.B. M., Maria I. R.A.

(2007), Betacyanin Stability During Processing and Storage of a

Microencapsulated Red Beet Extract, American J. Food Tech., Vol 2 (4), 307-312.

[9]. Lim Tze Han (2004), Betacyanins from Hylocereus undatus as natural food

colorants, Thesis of Master Science, National University of Singapore.

[10]. Lima,E.C., Krug, F. J., Arruda, M.A.Z. (1998), Direct determination in sweet

fruit-flavoured powder drinks by electrothermal atomic absorption

spectrometry, J. Spectrochimica Acta, Part B 53, p.601-611.

Internet

[11]. http://www.socongthuong.binhthuan.gov.vn/Detail_project.asp?ProId=3

[12]. http://en.wikipedia.org/wiki/Betalain

PHN PH LC

Ph lc 1 Phng php xc nh hm lng nc ca v qu thanh long

a) Nguyn tc :

Dng nhit cao lm bay hi nc ht trong mu phn tch.

Da vo hiu khi lng ca mu trc v sau khi sy tnh hm lng

nc c trong mu phn tch.

b) Tin hnh:

- Chun b cc sy : em cc i ra ro, sau sy 1051100C trong vng 30

pht. ngui trong bnh ht m ri em cn.

- Chun b mu: Nguyn liu c bm nh ri cn chnh xc khong 2 g cho vo 3

cc sy ( c xac nh khi lng trn). Dng a thy tinh nh trn mu vi

Na2SO4 khan n lc thy thnh dng bt ri. Cn cc c cha mu v a (khi

lng G1). a cc c cha mu v a sy 60700C trong vng 2 h, sau nng

nhit ln 1051100C v sy trong vng 2 h (thnh thong trn u). Ly mu ra,

ngui trong bnh ht m v em cn (khi lng G2). Lp li qu trnh sy vi

ln n khi chnh lch khi lng gia 2 ln cn lin tip khng qu 0,2 mg. Ghi

khi lng cui cng (G2).

Hm lng nc trong nguyn liu tinh theo cng thc:

%H2O = %100.21 GGG

G: khi lng mu;

G1: khi lng mu trc khi sy;

G2: khi lng mu sau khi sy

Ph lc 2. Phng php xc nh hm lng betacyanin tng s [6]

a) Nguyn tc: Chit betacyanin t mu phn tch bng dung mi thch hp. o

hp th ca dch chit betacyanin trong etanol 538 nm v xc nh hm lng

betacyanin bng nh lut Lambert-Beer.

a) Tin hnh

Mu rn:

Cn chnh xc khong 1-2 g mu phn tch ct nh. Thm 20 mL nc ct.

Siu m trong 5 min, nhit phng. Lc ly dch chit, phn b tip tc chit

n lc dch chit khng c mu. Gp cc dch chit li cho vo bnh nh mc th

tch D mL, thm nc ct n vch. o hp th ca dung dch 538 nm, cuvet 1

cm trn quang k UV- Vis, dng nc ct lm dung dch so snh (Nu dung dch

c qu th pha long vi h s F).

Hm lng betacyanin tng s trong mu phn tch tnh theo cng thc:

Gd

FDMAkgmgBetacyanin..

..1000/

Mu dung dch :

Ly chnh xc V mL mu dch chit cho vo bnh nh mc D mL. nh mc

n vch bng nc ct. o hp th ca dung dch 538 nm, cuvet 1 cm trn

quang k UV- Vis, dng nc ct lm dung dch so snh.

Nng betacyanin trong dung dch phn tch tnh theo cng thc :

d

FMALmgBetacyanin.

.1000/

trong :

A: hp th ; D: th tch bnh nh mc (mL)

F: pha long ; M: phn t lng betacyanin (M = 550 g/mol)

: h s hp th ca betacyanin trong H2O ( = 60000 L/mol.cm)

d: b dy cuvet (d = 1cm); G: khi lng mu (g)

Ph lc 3. Xc nh hm lng Pb trong dch chit betacyanin c c [7]

(Phng php quang ph hp th nguyn t -AAS)

Tin hnh :

a) Chun b dung dch chun:

Ha tan 0,7992 g Pb(NO3)2 (Johnson & Mathey) trong 1 lt dung dch HNO3

1,0% (v/v) thu c dung dch chun gc Pb 1000 mg/L.

T dung dch chun gc Pb, pha ch cc dung dch chun lm vic c nng

trong khong 0,00 20,0 mg/L (dng dung dch HNO3 0,2% (v/v) pha

long).

b) Dng ng chun :

Ht 20,0 L dung dch chun v 10 L dung dch iu chnh cha Pd 0,05%

w/v + Mg(NO3)2 0,03% w/v ln lt cho vo ng nguyn t ha THGA

(transversely heated graphite atomizer).

Tin hnh nguyn t ha theo chng trnh nhit nh sau :

Bc Nhit (0C)

Thi gian nng nhit (s)

Thi gian nng nhit (s)

Tc dng ca Argon (mL/min)

1 150 5 25 250

2 180 5 25 250

3 600 5 5 250

4 1000 5 20 250

5 1800 0 5 0

6 2400 1 4 250

Ghi hp th ca cc dung dch 283,3 nm s dng n pht x khng

in cc EDLI.

Dng ng chun: A = a.C +b

c) Phn tch mu :

Cn chnh xc 4 g mu (cn phn tch 0,1 mg), ha tan trong mt t nc ct

v acid ha bng HNO3 0,2%(v/v) ri nh mc ln 50 mL.

Ht 20,0 L dung dch mu phn tch v 10 L dung dch iu chnh cha Pd

0,05% w/v + Mg(NO3)2 0,03% w/v cho vo ng nguyn t ha THGA (transversely

heated graphite atomizer).

Tin hnh nguyn t ha theo chng trnh nhit nh trn. o hp th Ax

ca dung dch.

T ng chun, tnh c nng Pb trong mu theo cng thc :

450.

)( (mg/kg) Pb

abAx

Ph lc 4 Bng PL4.1. nh hng ca bn cht dung mi n hiu sut chit

T l etanol/nc (%,v/v)

Lng mu G (gam)

hp th (A)

Betacyanin chit c (mg/g)

Hiu sut chit (%)

0 1,0733 0,217 0,019 17,43

20 0,9877 0,242 0,022 20,18

40 1,0244 0,470 0,042 38,53

60 0,9585 0,315 0,030 27,52

80 1,0376 0,286 0,025 22,94

100 0,9777 0,150 0,014 12,84

Bng PL4.2. nh hng ca t l dung mi/nguyn liu

n hiu sut chit betacyanin

D.Mi/Ng.liu (v/w)

Lng mu G (gam)

hp th (A)


Hiu sut chit (%)

5/1 0,9853 0,450 0,021 19,20

10/1 0,9898 0,380 0,035 32,28

15/1 1,0247 0,320 0,043 39,39

20/1 1,0272 0,300 0,054 49,12

25/1 1,0328 0,260 0,058 52,92

30/1 1,0859 0,230 0,058 53,43

Bng PL4.3. S ph thuc ca hiu sut chit betacyanin vo s ln siu m

S ln siu m

Lng mu G (gam)

hp th (A)

Betacyanin chit tng cng (mg/g)

Hiu sut chit (%)

1 1,0457 0,393 0,069 62,98

2 1,0457 0,126 0,091 83,17

3 1,0457 0,010 0,108 99,19

4 1,0457 0,005 0,109 100,00

Bng PL4.4. nh hng ca thi gian ngm chit n hiu sut chit

betacyanin

Thi gian (h)

Lng mu G (gam)

hp th (A)


Hiu sut chit (%)

2 1,0113 0,131 0,024 21,79

4 1,0585 0,263 0,046 41,79

6 1,0413 0,283 0,050 45,71

8 0,9928 0,240 0,044 40,66

10 1,0568 0,236 0,041 37,56

12 1,088 0,218 0,037 33,70

Bng PL4.5. S ph thuc ca hiu sut chit betacyanin vo s ln ngm chit

S ln chit

Lng mu G (gam)

hp th (A)

Betacyanin chit tng cng (mg/g)

Hiu sut chit (%)

1 1,0775 0,448 0,076 67,47

2 1,0775 0,108 0,095 83,73

3 1,0775 0,095 0,111 98,04

4 1,0775 0,013 0,113 100,00

Bng PL4.7. S ph thuc ca hiu sut chit vo phng php chit

Phng php chit

Lng mu G (gam)

hp th (A)


Hiu sut chit (%)

Siu m 40,023 0,162 0,107 98,04

Ngm chit 40,005 0,159 0,105 96,26

Bng PL4.8. Kt qu kho st bn mu ca betacyanin

khi khng b sung vitamin C

Mu 1 (t0phng, c nh sng)

Mu 2 (40C, trong ti) Thi

gian (ngy) hp

th (A) Betacyanin

(mg/L) % Betacyanin

cn li hp th (A)

Betacyanin (mg/L)

% Betacyanin cn li

0 0,300 2,750 100,00 0,300 2,750 100,00

1 0,160 1,467 53,33 0,290 2,658 96,67

2 0,073 0,669 24,33 0,260 2,383 86,67

3 0,062 0,568 20,67 0,259 2,374 86,33

4 0,050 0,458 16,67 0,256 2,347 85,33

5 0,045 0,413 15,00 0,255 2,338 85,00

6 0,040 0,367 13,33 0,250 2,292 83,33

7 0,038 0,348 12,67 0,249 2,283 83,00

Bng PL4.9. Kt qu kho st bn mu ca betacyanin

khi b sung vitamin C

Mu 1 (t0phng, c nh sng)

Mu 2 (t0phng, trong ti)

Mu 3 (40C, trong ti)

Thi gian

(ngy) hp th (A)

BtC (mg/L)

% BtC cn li

hp th (A)

BtC (mg/L)

% BtC cn li

hp th (A)

BtC (mg/L)

% BtC cn li

0 0,300 2,75 100,00 0,30 2,75 100,00 0,300 2,75 100,00

1 0,228 2,09 76,00 0,229 2,10 76,33 0,290 2,66 96,67

2 0,153 1,40 51,00 0,154 1,41 51,33 0,260 2,38 86,67

3 0,073 0,67 24,33 0,074 0,68 24,67 0,259 2,37 86,33

4 0,060 0,55 20,00 0,062 0,57 20,67 0,256 2,35 85,33

5 0,045 0,41 15,00 0,058 0,53 19,33 0,255 2,34 85,00

6 0,040 0,37 13,33 0,050 0,46 16,67 0,250 2,29 83,33

7 0,038 0,35 12,67 0,040 0,37 13,33 0,249 2,28 83,00

Documents

Nghiên Cứu Chiết Xuất Chất Màu Betacyanin Từ Vỏ Quả Thanh Long Hylocereus Spp