đồ án pectin

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n chuyn mn GVHD: Hong Minh Thc Quyn

Phn I: TNG QUAN TI LIU

I. Gii thiu v vn ang quan tmI.1. Ngun gc pectin

Pectin l cht ph gia thc phm ngy nay thng c dng to

ng, to gel.

Pectin c mt trong qu, c, thn cy. ng vai tr vn chuyn nc

v lu cht cho cc tri cy ang trng thnh. Duy tr hnh dng v s

vng chc ca tri cy. Tin thn ca pectin l protopectin khng tan trongnc v c nhiu trong m tra cy cn xanh, qu trnh chn s km theo s

thy phn protopectin thnh pectin. Sau kt hp vi s demetyl ha di

tc dng ca enzym v s depolymer ha ca pectin thnh pectate v cui

cng l cc loi ng ha tan v acid.

T thi tin s cht pectin l thnh phn trong phu phn n ca

con ngi. Nhng ch mi na th k trc ngnh cng ngh thc phm

mi nhn bit c vai tr quan trng ca ph gia pectin trong vic a dng

cc sn phm thc phm.

Trong cng nghip pectin c thu nhn t dch chit ca cc nguyn

liu thc vt thng l to hay cc qu c mi nh: cam, qut, bi.

Phn ln cc quc gia xem pectin l ph gia qu v v hi c s dng vi

liu lng ph thc vo tng quy trnh cng ngh.

I.2. Ngun nguyn liu cha pectin

Pectin cha nhiu trong cc loi qu ca tri cy: To, mn, cam,

chanh, c rt, sn tr, l, c chua

SVTH: Nguyn Th Hiu Trang :2

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Thnh phn v hm lng ca pectin trong cc loi qu tnh theo % nh

sau:

Tn rau

qu

Tinh bt ng Pectin xenlulozaSaccaroza glucoza fructoza Cng

Khoai ty 17,7 0,6 0,2 0,1 0,9 0,7 1,0Ci bp 0 0,1 2,6 1,6 4,3 0,3 1,2

C rt 0 3,7 2,9 - 6,6 0,4 1,0C chua

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B : Ngi min trung gi qu b l bu r, thuc h bu. B

c th ch bin thnh nhiu mn n ngon, b dng. Cc nh khoa hc

nghin cu v ch ra rng b c lng ln pectin.Vi to : Ngn ng phng ty c cu :"mi ngy vi qu to, th

khng cn bc s" bt c ai, tuy cha bit gi tr dinh dng ca qu to ra

sao, nhng khi nhn thy nhng qu to to trn vi mu sc thm hay

vng ti, u cm thy thch. n khi nm th mt ming to ngi ta

cng thch hn bi mi v chua ngt v thm ca n. Theo chuyn gia dinh

dng v ngoi cng ca qu to cha nhiu pectin. Pectin l cht c tcdng tt cho sc khe.

I.3. Mt s tnh cht ca pectin

I.3.1. Khi nim

-Pectin l hp cht gluxit cao phn t.

-Cc cht pectin ng vai tr quan trng trong qu trnh trao i cht

khi chuyn ha cc cht v trong qu trnh chn ca rau qu.

-Pectin trong rau qu tn ti hai dng: pectin ha tan v pectin khng

ha tan.

I.3.2. Cu to

-Polysaccaride d th, mch thng, l dn xut methyl ca acid pectic.

Acid pectic l mt polymer ca acid D-galacturonic, lin kt vi nhau bng

lin kt 1-4 glucoside. Mi chui gm khong 10000 phn t Galacturonic

to thnh mt phn t pectin M = 10000 -100000 .

Cng thc cu to ca mt chui pectin


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I.3.3. Tnh cht ca pectin-Dng bt mu trng hoc hi vng, hi xm, hi nu.

-C kh nng to gel bn.

-Pectin ha tan: methoxyn polygalacturonic.

-Pectin khng ha tan: Protopectin-l dng kt hp ca pectin-araban.

-Trong cn v dung dch mui th pectin b kt t.

-B ph hy khi un nng nhit cao trong thi gian di lm gim

tnh ng ca sn phm khi c c.

-Pectin tan trong nc to thnh dung dch c tnh keo cao. Keo pectin

c nht v bn rt ln nn gy kh khn trong qu trnh lm trong khi

c c nc qu.

-Trong qu trnh chn, di tc dng ca enzim pectinaza hoc vi s

tham gia ca acid hu c, protopectin b thy phn thnh pectin ha tan

cng lc lin kt gia cc t bo gim.

-Khi qu chn pectin ha tan thnh acid pectic.

-Cc dng pectin trong tri cy tn ti cng mt lc.


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Hiu r c quy lut thay i ca pectin l iu rt quan trng x l v

khng ch n trong qu trnh ch bin.

-Pectin khng tan trong dung dch ethanol.-Tnh cht quan trng ca pectin l c th to ng nng thp(1-

1,5%) khi c mt ng 60-70% v acid 1%.Kh nng to ng ph thuc

vo ngun pectin, mc metoxin ha v phn t lng ca pectin.

-Pectin ly t ngun gc khc nhau thi kh nng to gel khc nhau.

I.3.4. Gii thiu v sn phm pectin

-Pectin l ph gia thc phm thuc nhm ph gia to gel, to c. Khiu l: Da.

Pectin c amin ha hoc khng:Tn ting Anh l: Pectin

(amidated & non-amidated). Ch s quc t INS l 412.

Pectin: Tn ting Anh l: Pectins. Ch s quc t INS l 440.

-Pectin thng bo qun dng bt mu trng hoc hi vng nht,

m

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Ngy nay trong cng ngh thc phm ph gia thc phm chim mt

phn quan trng. M ph gia to gel, to c li l ph liu quan trng trong

cng ngh ch bin mt, mt ng, ko hoa qu.Ph gia pectin l mt trong nhng ph gia to gel, to c trong cng ngh

ch bin to ra sn phm a dng, phong ph v d bo qun khi vn

chuyn.

Ngun nguyn liu sn xut pectin l cc ph liu trong qu trnh

ch bin nc p tri cy : b cam, chanh, to, v-ci biNh vy gi

thu mua thp v gi tr kinh t cao.Ngun nguyn liu d tm kim v thu mua, do nguyn liu l da dng

cc loi tri cy thch hp nhiu vng nc ta.

Tn dng mt lng ln ph liu nhng phn khng n c hay

nhng phn km gi tr dinh dng m ngi ta khng s dng nhng li

c tc dng v ng dng nhiu.

Bo v mi trng : Vic thu mua cc ph liu khng s dng ca cc

nh my v x l chng em dng l c tc dng ln trong vic bo v

mi trng.

Theo nhu cu ngy nay vic nghin cu v tm cch ch bin cc cht

t ph liu ang l vn c quan tm ln.

y l sn phm cn c t ngi bit n v nghin cu v n cng

cha nhiu, mc d nhu cu tiu th tng i ln. V vy vic tm hiu v

ngun nguyn liu, cc tnh cht bin i v quy trnh cng ngh thch hp

sn xut v ng dng hp l ang l cn thit, ng gp thit thc cho s

phat trin chung ca ngnh cng ngh thc phm trong vic a dng cc sn

phm.


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y cn l mt sn phm m phn ln cc quc gia xem l mt ph

gia qu v v hi c s dng vi liu lng ph thuc vo tng cng

ngh. Cho nn tm hiu r hn v sn phm ph gia ny thun li cho xutkhu.

Mt khc pectin c xem l mt trong nhng ph gia thc phm c

chp nhn nhiu nht v iu ny c chng minh bi hm lng ADI cho

php l "khng xc nh".

IV. Tnh thit thc, li ch v trin vng ca vn

IV.1. ngha khoa hc thc tin ca vic chn ti- ngha v mt kinh t: Vi nguyn liu l ph liu nh b p cam,

chanh, v-ht-ci trng ca bi gi c thu mua r dn n chi ph v mt

sn phm thp.

- ngha v mt x hi : khi chi ph cho mt n v sn phm thp

ng ngha vi gi thnh sn phm khng cao v nh th s c nhiu

ngi dn s dng khi chi ph v chi tiu gim dn dn n chi ph v

gio dc cao. Trnh con ngi trng x hi ngy cng c nng cao.

- ngha v mt sc khe : Pectin c nhiu gi tr trong khu phn n

hng ngy. C nhiu gi tr v phng v cha mt s bnh nh: h

cholesterol trong mu, kch thch bi tit dch v, chng tng cng ng

huyt ngi mc bnh tiu ng.

- ngha trong cng ngh thc phm: Pectin c nhiu ng dng trong

cng ngh ch bin hp rau qu, bnh ko, mt, mt ng.

Trong cng ngh sn xut ko ( ko mm pectin ):pectin c tc dng

lm ng khi ko khi cho vo khi ko dng dung dch 5%. Hm lng

pectin khong 1% so vi khi lng sn phm.


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Trong cng ngh sn xut mt, mt ng: c tc dng nng cao nng

ca mt trong cng on c c.

IV.2. Trin vng ca tiTheo xu th ngy nay ngnh cng nghip thc phm ang c quan

tm v ngy cng pht trin. p ng s pht trin ca ngnh cng

nghp thc phm a dng th cc nguyn liu l ph liu trong cng ngh

ch bin dng thay th hay l vai tr chnh trong sn phm vi hm

lng khng nhiu m khng th thiu ang l cn thit cho ngnh cng

nghip.Ph gia pectin l mt ph liu to gel, to c ngy nay ang c ch

v vy vic tm hiu v nghin cu v n s khng ngng theo thi gian.


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Phn II: NI DUNG CHNH

I.Gi tr v thnh phn dinh dng ca pectin trong nguyn liuTrong mi loi nguyn liu khc nhau tc dng ca pectin i vi c th

ngi cng khc nhau.

I.1. Mt s tc dng chung

- Ko di thi gian tiu ha thc n trong rut, tng hp thu dng cht

trong thc n.

-Gim bo : do to cm gic no bng ko di, gim nng lng n vo,

do gip gim cn ngi bo ph.

-Gim hp thu lipid.

- Khng ch tng ng p ngi c bnh tiu ng.

- Chng to bn.


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- Cm mu : pectin c tc dng bo v cc m mch chng hin tng

chy mu.

- St trng : Dung dch pectin 5% c tc dng nh thuc st trngH2O2.

- H cholesterol ton phn trong mu ngi ri loan lipid mu. H

LDL- loi cholesterol khng c li cho tim mch. Ngc li pectin lm tng

HDL- cht c li cho tim mch. Mt ch n hng ngy rt c li cho sc

khe tim mch, gim nh tnh trng tng cao lipid mu, ng mu, gim

bt c liu lng ca cc thuc dng hng ngy ca bnh nhn i thong, cao huyt p hoc cholesterol/ lipid mu cao.

- Nhng ngi c nguy c nhim Hg (i vng, ni dng thuc

nhm g, giy) nn n thc vt c cha nhiu pectin.

Do pectin trong thc vt s kt hp vi Hg, lm gim nng ion Hg trong

mu gp tng tc bi tr Hg.

I.2. Tc dng pectin trong mi loi tri cy

- Trong b : cc nh nghin cu pht hin v ch ra rng

B c lng ln cht pectin v nhiu thnh phn khc .

+ Cht pectin c trong b , khi n cng vi cc loi thc n

loi tinh bt , s nng cao dnh ca cc cht c trong d dy, lm chm

s hp thu cc cht ng vo c th.

+ Cht pectin sau khi hp th y nc trong ng rut s

hnh thnh mt dng cht keo, ko di cht keo ng rut, do m

khng ch s tng trng cao cht m v cht ng trong mu. Nh vy

c tc dng phng cha tt cc bnh cao huyt p, bnh tiu ng.


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+ Cht pectin c trong b c th bo v ng d dy v

rut khi b kch thch bi thc n kh rp, c tc dng phng cha rt tt

bnh lot. N cn c th dnh kt vi cht cholesterol qu tha trong c th,do m h thp c hm lng cholesterol trong mu, c tc dng cha

rt tt bnh x cng ng mch.

- Trong bi : bi gip h cholesterol.

+ Bi cha vitamin C nhng n cn cha nhiu hot cht y

hc khc rt c li. Mt trong nhng cht l pectin mt dng cht x,

gip h bt nng cholesterol. Cc nh nghien cu th trng i HcTexas ( M ) khm ph pectin c cng dng km hm s pht trin ca t

bo ung th. Tuy nhin n sng c li hn ung nc p v chnh trong xc

bi mi c nhiu pectin.

+ Trong ci bi ti cha t 1 2% pectin ( kh ) nhng khi

phi ci bi kh th ch cn 0,5 1% pectin kh.

Quanh v ht bi ti c t 13 16% pectin, khi phi kh v ht bi th

cn 4 20% pectin ( kh ).

- Trong c rt: pectin trong c rt s kt hp vi Hg, lm gim nng

ion Hg trong mu, gip tng tc bi tr ion Hg.

- C chua: pectin c trong c chua lm gim hp thu nng lng kch

thch bi tit dch v, xc tin nhu ng ng rut.

- u : thnh phn pectin c trong u gip ty sch c t ng

rut.

- To: trong to cht c tc dng tt cho sc khe l pectin.

Pectin l mt i phn t do s trng hp cao ca acid D-galacturonic.

Pectin c coi l cht khng c tiu ha khi chng ta n to, nhng khi


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n rut gi th 90% pectin c enzym ca vi khun phn hy thnh acid

formic, acid acetic, acid propionic, butyric, cacbonic

Ngy nay ngi ta cn lu nhiu v cht pectin nh mt cht x thcphm, nhm lm gim bt trm trng tc ng glucoz huyt do n ung

ngi i tho ng. Qu to hay bi cha nhiu pectin s lm chm s

vn chuyn thc n qua d dy, rut dn n iu ny c li cho nhng

ngi n king chng mp.

Tm li qu to c lu nhiu im giu pectin. y l mt cht c li

nhiu mt cho sc khe.II. Tnh cht v sinh ca sn phm

Tnh c hi i vi ngi s dng:

Pectin l mt ph gia thc phm c nhiu ngi chp nhn nht v c

chng minh bi hm lng ADI ( lng ti a n vo hng ngy ) cho php

khng xc nh ngha l khng quy nh ADI c th cho ph gia pectin

v :

- Cc kt qu nghin cu v sinh hc, ha hc, c hc cho thy ph

gia c c tnh khc.

- Tuy lng ph gia cho vo thc phm phi p ng yu cu ca cng

ngh sn xut nhng khng gy tc hi n sc khe ngi tiu th.

Ngha l ph gia pectin khng c c hi g i vi ngi s dng.

Cht lng sn phm thc phm:

Ph gia pectin t b bin i trong qu trnh bo qun do vi sinh vt v y

khng phi l mi trng dinh dng thch hp cho cc vi sinh vt pht

trin. Nhng trong qu trnh bo qun cn ch nhit v m trnh

hin tng mc pht trin.


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III. Cc c tnh k thut v cng ngh ca sn phm

III.1 Phng php sn xut pectin trong cng nghip

Pectin l mt sn phm cacbohydrat c thu nhn t dch chit canhng nguyn liu thc vt, thng l to hay qu c mi. Phn ln cc

quc gia xem pectin l ph gia qu v v hi, c b sung vo trong qu

trnh sn xut ty theo tng quy trnh cng ngh.

III.1.1 S quy trnh cng ngh

Nguyn liu

Ra

Xay nh


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Thy phn

Lc

C c kt ta

Bo qun (dng dung dch) ra sch

Sy kh

Bo qun( dng kh )

III.1.2 Thuyt minh quy trnh

1. Nguyn liu, ra

- Sn phm pectin t tri cy c mi : c chit xut t v chanh, v

cam v v bi. V ca cc loi tri cy ny l sn phm ph ca qu trnh

p nc qu, p du m c cha hm lng pectin cao vi nhng tnh cht

mong mun.


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- Sn phm pectin t to : b to phn thu nhn c t qu trnh p

nc to, l nguyn liu th cho sn phm pectin t to. Nhng sn phm

ny c mu sc ti hn ( mu nu ) so vi pectin t cc loi cy c minhng khc nhau v chc nng.

Nh my thu nhn b to hoc v tri cy c mi t cc nh sn xut nc

tri cy. Trong nhiu trng hp nguyn liu ny c ra v sy c th

vn chuyn v bo qun m khng b h hng.

Nu nguyn liu th, kh th c ly t trong kho. Nhng khi sn xut t

v tri cy t th c s dng ngay v chng h hng rt nhanh.2. Xay nh

Nguyn liu c cho qua my nghin th xay nh.

Yu cu k thut: nguyn liu cng nh cng nh cng d thy phn.

3. Thy phn

Dung dch sau khi xay nh ta em i thy phn bng dung dch acid

citric khan nhit 90 95oC trong thi gian 45 pht vi t l:

B cam: nc: acid citric khan = 100:200:3

Khi dung dch c kh 2% ( hm lng pectin khong 0,7 1% ) kt thc

qu trnh thy phn.

Nu trong qu trnh chit ta ch dng nc th ch chit c mt lng gii

hn pectin.

4. Lc, c c

Sau mt khong thi gian chit pectin cht rn cn li s c tch

ra v dung dch c lc, c c bng cch loi nc. Cht rn c th tch

ra bng thit b lc, thit b ly tm. Dung dch sau c lc li mt ln

na nu cn thit.


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Dung dich sai khi c c n kh 10%. Hn hp c ch trn my

ch c l ry 1 2mm ta c ch phm c cha 4 5% pectin, ch phm

ny s dng ngay khng qu 2h. Bo qun dng dung dch.5. Kt ta, ra sch, sy kh

Hoc l ngay lp tc hoc sau mt khong thi gian pectin bin tnh

cht lng c c s c trn vi cn kt ta pectin. Pectin c th c

de ester ha phn no giai on ny.

Cht kt ta c tch ra khi cn loi cc tp cht v sy. Cn

c dng c th cha cc mui hay kim bin i pectin thnh dngmui mt phn ( Na+, K+, Ca2+, NH4+ ). Cn ( thng dng l isopropanol )

c thu nhn li kt ta thm pectin.

Sau ra li v em i sy.

Trc khi hay sau khi sy pectin c th x l vi NH 3 sn xut

pectin amin ha.

Ch phm sau khi sy c th em i nghin mn li

6. Bo qun

Ch bo qun bnh thng:

- Nhit khng qu 30oC.

- m khng kh 85%.

- Bo qun bng bao PE, PP, l thy tinh khng ht m.

- Thi gian bo qun 6 7 thng

III.2 Quy trnh sn xut ti nh

III.2.1 Cch ch pectin t bi

Trong gia nh sau khi n bi ta c th tn dng ngun pectin quanh

v ht bi.


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Cch lm: ht bi chn b ht ht lp. Nu lng ht qu nhiu th

ch ly khong 20 ht ( ch nc pectin dng trong 1 ngy ) s cn li

em phi hoc sy kh. ng trong ti PE kh sch ( hoc trong l khsch ) dng dn. Ch trnh m v d mc.

Cho ht bi vo cc rt nc si ( nng khong 70 80oC ) ngp ht,

dng a nhiu rng nh lin tc, chng 5 6 pht ri gn ht nc nhy

v cho vo mt cc ring. Tip tc lm nh vy cho n khi ly ht nhy

( s tay vo v ht thy ht nhy ).

Ty theo tng ging bi, qu bi c loi nhiu pectin phi nh htvi nc 5 6 ln mi ht nhy. Loi t pectin ch cn lm 3 ln l c.

III.2.2 Cch dng nc pectin

- Chng to bn, ri lon lipid mu, bnh tim mch: ung 50ml sau khi

n ba chnh 60 pht.

- Gim bo, nga tiu ng: ung 50ml trc khi n ba chnh 5 10

pht.

- Chng chy mu ( mu rng, mu cam, rong kinh, a kinh ) mi ln

dng 20ml cch nhau 20 pht trn mt ln trong gi u.

Ch : sau khi ch 3h, nu khng dng ht nn cho vo t

lnh. Bo qun trong 48h, lc ny pectin s ng li nh

thch trng.

IV. Cc vn khc

IV.1 Tc dng dc l ca pectin

Trong cng nghip dc phm, pectin c dng ch thuc ung,

thuc tim (bp, di da ) cm mu trc v sau khi phu thut rng,

hm, mt, tai, mi, hng, ph khoa. Cha chy mu ng tiu ha, tit


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niu. Dung dch pectin 50% cn c s dng nh thuc st trng H 2O2

(nc oxy gi) trong phu thut rng hm mt, tai mi hng ( khng gy

xt li cm mu tt). Thm bng nht vo ch nh rng cm mu. Trnth trng hin c bit dc Hacmophobin (c) v Arthemapectin (Php).

IV.2 nh hng ca pectin trong ch bin dch p

-Trong cng nghip sn xut ru vang vic x l dch qu c coi l

bc khi u c vai tr quan trng i vi vic n nh cht lng nguyn

liu. dch ln men c cht lng tt, vn tp trung x l l lm gim

hm lng pectin cht gy c v nht ca dch ln men v vang thnhphm.

Vi mc ch nng cao hiu sut thu hi dng qu, vic s dng enzym

pectinaza l rt cn thit v s c mt ca pectin v ng lm cho qu khi

nghin c tnh keo ha, nn khi p dch qu kh thot ra.

Pectin c trong thnh phn dch ln men v trong ru vang s lm tng

nht, gim tc lc, ko di thi gian ch bin v nh hng n gi tr

cm quan ca sn phm.

- Trong ch bin nc qu c c :

Trc khi c c ngi ta cn lng, lc v loi tr n mc ti a pectin c

trong nc qu sn phm khi b c v khng b ng c khi c c.

- Trong ch bin nc qu khng tht qu:

Vic n nh trong ca nc qu trong sut qu trnh bo qun l rt cn

thit v khi bo qun nc qu c th b c tr li v c khi kt ta. Nc

qu b c l do nhng phn t keo cn li trong nc qu kt t vi nhau.

Hin tng c do keo l v c s bin i ca cht mu, tanin, protit v c

c pectin. V vy trong qu trnh ch bin cn phi un nng nhit cao


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(80 85oC ) cho cc cht keo v pectin ng t. Nhng khng th un

cao hn v nu cao qu th c th gy cho nc qu c v kh chu v nu

thp hn th qu trnh ng t ko di.

Phn III: NG DNG

I. Cc ng dng ca pectin trong cc lnh vc

I.1. Trong cng ngh thc phm

-Pectin l tc nhn to gel quan trng nht c s dng to ra cutrc gen cho thc phm, ch yu l nhng thc phm c ngun gc t rau

qu. Kh nng to gel ca n cn c s dng nhng thc phm cn s

n nh ca nhiu ph gia, hoc trong sn phm cui, hoc mt giai on

tc thi trong qui trnh sn xut.

- Tcdng to gel ca pectin c s dng ch yu nhng loi thc

phm cn c hnh dng tht t nhin.

I.1.2. Mt tri cy v mt ng

- Vai tr quan trng ca pectinl nhm to ra mt cu truc cho mt

ng v mt tri cy nhng sn phm ny khi vn chuyn vn khng

thay i cu trc, to ra mi v ngon cho sn phm, v gim n ti a s

phn r.

Qu trnh sn xut mt ng v mt tri cy phi m bo ti ra s

phn b ng u ca cc phn t trong pha lin tc ngay t khi qu trnh

khuy trn ngng li. Hm lng pectin s dng trong mt v mt ng

thng trong khong t 0,1 - 0,4 %.


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- Pectin c kh nng to gel nhanh c gi tr c bit trong sn xut

mt v yu cu tt nht khi chng khng b tc ng trong sut qu trnh

to gel. chnh l l do pectin to gel chm c s dng vo cc khuvo hp, ng np, dn nhn, xp chng phi c thc hin khi qu trnh

to gel din ra.

- Qu trnh to gel ca pectin c th c th c to ra trong mt qui

trnh lnh bng 2 cch. Trn syrup ng pectin ( c pH = 2,9 ) c hm

lng cht kh ha tan t 60 - 65 %, pH = 3,8 - 4,2, vi dch acid tri cy

t c pH = 3.- Trn dung dch pectin c pH = 2,9 v lng cht kh ha tan l 25%

vi syrup ng thu c hn hp mi c hm lng cht kh 23%.

- LMP:(To gel bng lin kt vi ion Ca2+). Thng c ng dng

trong mt tri cy c hm lng cht kh ha tan < 55%. Loi LMP c

chn da trn hm lng cht kh v pH trong sn phm c hm lng cht

kh rt thp v d nh: Mt tri cy khng ng cho ngi b bnh tiu

ng. LMP kh to lin kt vi nc v carragenan thch hp hn.

Trong mt s trng hp ngi ta c th s dng c pectin v carragenan.

I.1.2. Trong ko mm pectin

- Hm lng pectin dng sn xut ko mm hoa qu l 1% so vi

sn phm.

- Khi dng pectin phi a pectin dng dung dch 5 %, vo cui giai

on nu, phi nu nhit thp, m ca khi ko l 25 %, to iu

kin thun li cho pectin ng t tt hn.


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- To hnh khi ko pectin tin hnh nhit cao hn cc loi ko

khc v nhit ng t vi khi ko c pectin cao hn, c th to hnh

bng cch rt khun hoc rt mng.- i vi ko pectin c th dng t l nguyn liu nh sau so vi khi

lng sn phm.

+ ng Saccharose : 50 - 65 %

+ Mt tinh bt : 20 - 25 %

+ Pectin : 1 - 1,5 %

+ Acid citric hoc Acid lactic : 1 - 1,5 %- S thy phn cht to ng, s chuyn ha ng ph thuc vo:

+ Nhit .

+ Thi gian tc ng nhit cao.

+ pH mi trng.

I.1.3. Tm tt ng dng ca pectin

- Tnh cht pectin v kh nng ng dng:

Phn t pectin di v d vng vo nhau, dung dch c nht

pectin c kh nng to c. Pectin c th ci thin cu trc nc ung c

hm lng ng thp.

Nu hm lng ng ln c b sung vo gim

hydrate ha ca cc phn t pectin cc phn t s li hnh thnh mng li

gel. Mt trai cy c hm lng ng cao ph thuc vo pectin to hnh.

- V nhm acid kh yu , s thay i pH s thay i kh nng tich in

ca chui pectin, phn t c th lin kt vi nhau iu kin acid. Cn c

c ng v acid trong sn xut mt ng.


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Nhm acid ca pectin c th phn ng vi ion Ca2+ to lin kt vi 2

nhm COO- hnh thnh gel khng cn ng . LMP c s dng l

mt tri cy c hm lng ng thp v nhiu sn phm ch bin t tricy.

- Phn t pectin c th lin kt vi mt protin tch in (+), chng

khng b ng li khi gia nhit. Gip pectin sa trong Yoghut khng b

ng t v nhit c th tit trng UHT.

I.2. Kh nng to ng ca pectin

- Kh nng ti ng t ca pectin ph thuc vo kh nng lm rachng, do chng c gi tr khc nhau trong sn xut bnh ko, pectin

c ly t to, v cam, chanh, c ci ng th c gi tr ng t cao nht,

pectin ca mn, me, o, to gel km bn hn.

- Kh nng to gel ca pectin qu thay i theo qu trnh pht trin

ca cy, chn ca qu cng nh khi bo qun v ch bin chng.

- Ga tr chnh ca pectin trong sn xut ko l kh nng to ng ca

chng.

- Cc pectin v acid pectinic c cc nhm hydroxyl ( -OH) nn c kh

nng hydrate ha cao.

- Cc phn t pectin mang i tch m nn chng coa kh nng y ln

nhau, do lm gin mch v lm tng nht ca dung dch.

- V vy khi lm gim tch in v hydrate ha s lm cho cc

phn t pectin xch li gn nhau v tng tc vi nhau to nn mt mng

li 3 chiu rn cha pha lng bn trong.

- Tnh cht to ng ca pectin c xc nh ph thuc ch yu vo

cc yu t sau:


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+ Chiu di mch phn t pectin: Chiu di mch phn t

pectin quyt nh cng ca gel.

Nu phn t pectin qu ngn th n s khng to c gel mcd s dng vi liu lng cao.

Nu phn t pectin qu di th gel to thnh c cng.

+ Mc methoxyl ha qui nh c ch to gel.

HMP: To gel bng lin kt hydro.

iu kin to gel: [ng] > 50%, pH = 3 - 3,5 ; [pectin] = 0,5 -1%. ng

c kh nng ht m v vy n lm gim mt hydrate ha ca phn tpectin trong dung dch, pH acid trung ha bi gc COO- lm gim tch

in ca cc phn t.

V vy cc phn t c th tin li gn nhau to thnh lin kt ni

phn t v to gel. Lin kt hydro c hnh thnh gia cc phn t pectin

c th hydroxyl-hydroxyl, carboxyl-carboxyl hoc hydroxyl-carboxyl. Kiu

lin kt ny khng bn do cc gel ti thnh s mm do bi tnh linh

ng ca cc phn t trong khi gel. Cu trc ca gel ph thuc vo hm

lng ng, hm lng acid, hm lng pectin, hoc pectin v nhit 30

- 35 0c ng thm vo pectin l sacharose. Do cn duy tr pH acid

khi un nu s gy ra qu trnh nghch o ng sachrose. Tuy nhin cng

khng nn dng qua nhiu acid v pH qu thp s gy ra nghch o mt

lng ln sacharose gy kt tinh glucose v ho gel nhanh to nn cc vn

ct. Khi dung lng pectin vt qu lng thch hp s gy ra gel qua

cng. Do khi dng mt nguyn liu c cha nhiu pectin cn tin hnh

phn gii bt chng bng cch un nu lu hn.


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Khi s dng mt lng c nh bt c mt loi pectin no pH, nhit

cng thp v hm lng ng cao th gel to thnh cng nhanh.

LMP: To gel bng lin kt vi ion Ca2+.+ S c mt ca cc thnh phn hu c v v c.

- S trng hp ca phn t pectin c th xy ra di tc dng ca men

khi bo qun pure v tc dng ca nhit v ha hc khi gia cng nguyn

liu cha pectin. Nu nguyn liu chu tc dng ca acid, baz v nhit

cng nhiu th cng khng c li cho s trng hp pectin v s thu c

pectin c phn t lng b.Chiu di phn t pectin quyt nh cng ca gel, ch c pectin c

khi lng phn t khng b hn 10000 mi c kh nng to gel, nu chiu

dau qu thp th n khng to gel c mt d dng vi liu lng cao.

- Khi pectin c cng khi lng phn t th kh nng to gel ph thuc

vo mc este ha cc gc ca mach galacturonic ti cc nhm metoxyl (-

OCH3).

+ Nhm metoxyl tng t 8 -11 % th bn ng t ca n

tng, ngc li kh nng ng t gim.

+ Pectin c t 9,5 -11% nhm(-OCH3) mi trng pH = 3 v

hm lng ng 35 % kh nng ng t tt.

+ Khi hm lng metoxyl gim xung 5% v thp hn khi

pectin vn gi c kh nng ng t to ng chm, i hi thay i hm

lng ng cng nh pectin v acid.

+ Nu pectin c hm lng t 3,5 -6 % nhm metoxyl khi c

s tham gia ca cc mui kim loi nhiu ha tr nh Ca2+ v trn 35%

ng th n s to ra ng t bn vng.


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_ Vai tr ca Ca2+ v ion kim loi khc trong vic to gel l: Cac phn

t acid pectic tc dng tng h ln nhau nh cc nhm carboxyl t do, cc

nhm ny lin kt li nh cc ion Ca2+thnh khung bn vng nh sau:

High Methoxyl pectin

Low methoxyl pectin+ Dng cation v anion c nh hng n bn ng t cc

cation Ca2+

, Al3+

lm tng bn gel cn cation ha tr I nh Na+

iukin xc nh c tc dng ngc li.

- Trong thnh phn ca phn t pectin c th c nhm acetyl CH3CO,

hm lng nhm CH3CO c trong pectin, este ha cao khng qu 0,8% th

khng nh hng n kh nng to ng ca pectin, song cao hn th kh

nng ng t gim.

I.3. Vai tr cc cu t trong vic to gel pectin

I.3.1. Pectin

- Nng ca cc phn t pectin trong dung dch cng ln th s lin

kt gia cc phn t xy ra cng nhanh v s ng t c to ra cng bn.


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-Nhng khng phi tt c lng pectin u tham gia vo vic to ng

t chnh v vy bn gel khng phi xc nh theo s lng nhiu t m

xc nh theo chiu di mch phn t v mc metoxyl ha.- Pectin cht lng tt s to ra si ch di v chc trong qu trnh ng

t lm cho keo n hi do keo long cng kh bn.

-Nu pectin to ng t yu do cc si ch c to ra ngn hn, mng

li gi pha lng ca keo km hn do s oong t s yu v c kh nng

a n s ra nt ( v nh nc ).

I.3.2 Nc:- m ca khi keo tng th qu trnh to keo t cng nhanh ( v tng

tc nh hng ca cc phn t pectin do nht ca dung dch phn

tn gim)

- Thi gian to ng ca khi ko ph thuc vo m, m cng

cao thi gian to ng cng gim.

I.3.3. ng

-Vai tr ca ng trong vic to ng l kh nc, gim solvat ha

ca cc phn t pectin, ph thuc vo s lng v cht lng pectin m

dng lng ng khc nhau.

- Hm lng pectin cng cao, cht lng ca n cng tt th i hi

hm lng ng trong s tao ng cng nhiu nhng nu ly lng ng

khng tng ng vi pectin.

+ Cao qu so vi pectin th bn ng t gim v gim tc

to ng.

+ Qu t ng th gel to ra s qu cng.


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- Khi dng pectin c cht lng tt, nng ca nso trong dung dch

l 0,6 1% th hm lng ng cn t ti 65%.

I.3.4 Acid :- Yu cu ca acid trong vic to gel pectin :

+ Acid cho vo phi c mc phn ly cao hn acid pectit nh

vy n s ngn cn s phn ly ca acid pectit do o cc mixen pectit mt

in tch cng du, chng c ni li thnh si di.

+ Khi cho acid vo th ion hydro thay th ion kim loi trong

nhm cacboxyl ca phn t pectin sau khi ty c acid pectit ra khimui ca n.

V mui ca acid khng tham gia vo qu trnh to ng m ch c acid

pectit to ra ng t do khi thm acid vo s lm tng tc to ng t.

+Acid tactric c tnh hot ng ln nht v acid citric hot

ng yu nht trong nhng acid dng sn xut ko. Nng ti thiu

ca ion hydro to ra ng t l 3,46.

Nng ca ion hydro cng cao th kh nng to ngt ca dung dch

cng cao, khi ca mui ca acid pectit c thay th hon ton bng ion

hydro mt cch nhanh chng v chuyn chng v acid pectit. Sau tip

tc tng nng ion hydro th s khng c hiu qu na.

- Hm lng ca acid dng to ng khng nhng ph thuc vo

tnh cht ca acid m cn ph thuc vo s lng v cht lng ca pectin,

hm lng ng.

+ Hm lng ion hydro cng cao th hm lng pectin dng

cng t trong vic to ra ng t.


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Nu pectin c kh nng ng t yu th nng ca acid nn tng nhng

ch trong mt gii hn nht nh.

Hm lng acid cao lm tng hm lng ng chuyn ha do tng tnhho nc ca sn phm.

+ Pectin c cht lng tt th pH thch hp cho mi trng

ng t l 3 3,2.

- Hm lng ng t l nghch vi hm lng acid a vo.

II. Ch tiu nh gi cht lng sn phm

II.1 Tnh cht v tinh sch ca pectin s dng trong ch bin- Tin chun: FAO: ( Food and Nutrition paper 1992 )

FCC: ( Food chemical codex )

EEC: ( Eropean Ecconomic Comnutity )

Cc tp cht cha trong pectin c quy nh vi hm lng nh sau:

- Cht d bay hi:

max : 12%

max : 12%

max : 12%

- Tro khng tan trong acid:

max : 1%

max : 1%

max : 1%

- Sulfur dioxyde:

max : 50mg/kg

max : 50mg/kg

max : 50mg/kg


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- Sodiummethy sulfate:

max : 0,1%

- Methanol, ethanol v isopropanol:max : 1%

max : 1%

max : 1%

- Hm lng Nitrogen:

max : 2,5%

max : 0,5%- Hm lng galacturonic acid:

min : 65%

min : 65%

- Tng Anhydro galacturonides:

min : 65%

- Mc amin ha:

max : 25%

- Arsenic, ppm:

max : 3

- ng, ppm: 50

- Km, ppm: 25

- ng v km, ppm: 50

- Kim loi nng nh (Pb), ppm:

max : 20

II.2 Quy nh s dng


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Pectin c xem l mt trong nhng ph gia thc phm v c chp

nhn nhiu nht v iu ny c chng minh bi hm lng ADI cho

php khng xc nh c ban hnh bi cc t chc JECFA ( JountFood Experts committee ), SCF ( Scientisic committee for food ), lin

minh chu u v GRAS ( Genrally Regarded ).

Phn IV: KT LUN

Qua ti ny gip ta hiu r hn v tc dng ca ph gia pectin

vi c th ngi v ng dng trong cng ngh thc phm cng nh quy

trnh sn xut ph gia pectin trong cng nghip v ch bin ti nh.a s ph gia m ta c bit n khi b sung vo qu trnh ch bin

vi nhiu mc ch khc nhau du c tc dng khng tt i vi c th

ngi d tnh cht c hi rt nh. Nhng ph gia pectin th ngc li d b

sung vo trong qu trnh ch bin vi hm lng bao nhiu cng khng nh

hng xu n sc khe con ngi.

Bn cnh pectin cn c tc dng dc l i vi c th con ngi

m ph gia khc khng c tc dng .

Nhng d pectin c tc dng tt, ng dng nhiu n u th mt khc n

cng c tc dng khng tt, l tc dng xu trong ngnh ch bin nc

qu v ru vang.


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TI LIU THAM KHO

1. Nguyn Vn Tip _ Quch nh _ Ng M Vn _K thut sn xut

hp rau qu_ NXB Thanh Nin.

2.Trng cao ng lng thc - thc phm _Gio trnh sn xut bnh ko

_ Nng 1998.

3.http://www.google.com.vn/search?

q=pectin&hl=vi&lr=&cr=countryVN&start=10&sa=N

4. http://ww.h2vn.com/community/index.php?topic=656msg3306

5. http://ww.freewe btoun.com/tammmx/thu vien/ten/28 TCN 56 htm

6.http://www.skhcn.vinhlong.gov.vn/ThongTin/tabid/59/categoryId/62/itemI

d/741/Default.aspx - 40k -


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MC LC

Phn I: TNG QUAN TI LIU

I Gii thiu v vn ang quan tm................................Trang

II Hin trng ca vn .....................................................Trang

III L do chn ti...........................................................Trang

IV. Tnh cht thit thc, li ch v trin vng ca ti....Trang

Phn II: NI DUNG CHNH

I. Gi tr v thnh phn dinh dng ca sn phm.............Trang

II. Tnh cht v sinh ca sn phm.....................................Trang

III. Cc c tnh k thut v cng ngh ca sn phm.......Trang

IV. Cc vn khc...........................................................Trang


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Phn III: NG DNG

I. Cc ng dng ca pectin trong cc lnh vc...................Trang

II. Ch tiu nh gi cht lng sn phm..........................TrangPhn IV: KT LUN

TI LIU THAM KHO

MC LC

đồ án pectin

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