phu gia rau qua

8/8/2019 Phu gia rau qua

1/10

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PHGIA RAU QU

nh ngh aCht phgia thc phm l nh ngch t, hp cht ha h cc a vo trong qu trnh ng gi, ch bin, bo qunthc phm, lm t ngch t lngthc phm ho c boton ch t lngthc phm mkhng lm cho th c ph mmt an ton

Phn lo i ph gia th c ph mHin nay ng i ta chia ch t phgia thc ph m lm 6nhm

Cc ch t bo qun.Cc ch t to mu.Cc ch t to mi.Cc ch t ci to cu trcth c ph m.Cht phgia c nhi u c tnh.

Gi tr thng m i v hm l ng s dng ca cc lo i phgia trn th gi i

Th trng

Chyu l cc polysaccharide nh pectin,carrageenan, alginate, agar v cc lo i gum


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Pectin- C mt trong qu , c, thn cy, ng vai tr v n chuyn

nc v lu ch t cho cc tricy ang trng thnh,

duy tr hnh dngv s vngch c ca tri cy.- Tin thn c a pectin l protopectin, khng tan trongnc v c nhi u trong mtri cy cn xanh.

- Qu trnh chn s km theo s thy phn protopectinthnh pectin, sau kt hp vi s demethyl ha d itcd ng ca enzyme v s depolymer ha c a pectinta thnh pectate v cu i cngl cc lo i ng ha tanv acid.

Pectin c thu nh n t dchchit ca cc nguyn li uthc vt, thng l to hay cc qu c mi.Pectin l m t loi phgia qu v v h i, c s dngvi liu lngph thuc vo t ng quy trnh cng ngh

Cu toPolysaccharide d th, mchthng, l d n xutmethyl c a acid pectic

Pectin

- Acid pectic l 1polymer c a acid D-galcturonic, lin k t vinhau b nglink t 1,4-glucoside.- Mt chui gmkhong 10000 phn t galactoronic t o thnhmt phn t pectinM= 10000-100000.

Pectin- ch s c trng Ch smethoxyl (MI): bi u hin t lmethyl ho, l ph n

trm khi lng nhm methoxyl (-OCH3) trn t ngkh ilngphn t .

MI max = 16,3% MI ca pectin th c vt = 10 12% Ch s ester ha (DE): th hin mc ester ha c a

pectin, l ph n trm vs lng c a cc g c acidgalactoronic c ester ho trn t ng s lng gc acidgalacturonic c trong phn t

Theo % nhmmethoxyl c trong phn t :- HMP (High Methoxyl Pectin): DE > 50% hay MI >7%.- LMP (Low Methoxyl Pectin) : DE 50% hay MI 7%.Theo kh nng ha tan trong n c:- Pectin ha tan: methoxyl polygalacturonic.- Pectin khng ha tan: protopectin l d ng kt hp ca pectin v iaraban (polysaccharide thnht bo).


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Kh nng to gel ph thuc chyu vo 2 y u t: chiu dica chu i pectin v m c methoxyl ha

Pectin- m c to gel

Chiu di c a phn t quy t nh cng c a gel :Nu phn t pectin qu ng n th n s khng t o c gel m c d s

dng vi liu lng cao.Nu phn t pectin qu di th gel t o thnh r t cngMc methoxyl hoquy nh c ch to gel :HMP : to gel b nglin k t hydro iu kin to gel:[ ng] >50%, pH = 3-3,5; [Pectin] = 0,5-1% ngckh nng ht m, v vyn lmgi m mc hydrat ha

ca phn t pectin trong dung d ch.pH acid trung ha b t cc g c COO-, lm gi m tch in ca cc

phn t .V vy cc phnt cth tin li gn nhau to thnh lin k t ni

phn t v to gel. - Lin k t hydro c hnh thnh gi a ccphn t pectin c th hydroxyl hydroxyl, carboxyl carboxyl,hoc hydroxyl carboxyl. Ki u l ink t ny khng b n do ccgel t o thnh s mm do bi tnh linh ng c a cc phn t trong

Cu trcc a gel ph thuc vo hm l ng ng, hamlng acid, hm l ng pectin, lo i pectin v nhi t .

30 50% ng thm vo pectin l sucrose. Do cnduy tr pH acid khi un nu sgy ra qu trnh ngh cho ng sucrose, ng n cn s kt tinh ca ngsucrose. Tuy nhin c ng khng nn dng qu nhi u acidv pH qu th p s gy ra ngh ch o mt lng lnsucrose gy k t tinh glucose v ho gel nhanh t o nncc vn c c. Khi dng l ng pectin v t qu lngthch h p sgy ra gel qua c ngdo khi dngm tnguyn li u c ch a nhiu pectin c n tin hnh phngii bt chng b ng cch un lu h n.

Khi s dng mt lng c nh bt cmt loi pectinno pH, nhi t cng gi m v hm l ng ng cngcao th gel t o thnh cng nhanh.

Pectin- m c to gel

Khi s dng mt lng c nh bt cmt loi pectinno pH, nhi t cng gi m v hm l ng ng cngcao th gel t o thnh cng nhanh.

LMP : to gel b nglink t vi ion Ca2+. iu kin to gel: khi c m t Ca2+, ngay c nng 70

Tc to gelIon ha tr II ng (%)pHiu kin to gel

DE

Tc d ng c a DE c a pectin ln s to gel

Mt tri cy vm t ng :-Vai tr c a pectin l nh m to r a m t cu trcchom tng- Qu trnh s n xut mt ng vm t tricy ph i m boto r a s phn b ng u ca cc phnt trong pha lintc ngay t khiqu trnh khu y trn ngng li. Hm l ngpectin s dng trong m t v m t ng thng trongkhong t 0,1 0,4%.- Pectin c kh nng to gel nhanh c gi tr c bit trongsn xut mt v yu c u ca s n phm ph i c to gel,to c trc khi ng h p. Cn m t ng tricy t t nhtkhi chng khng b tc ng trong su t qu trnh t o gel. l l do pectin t o gel ch m c s dng, v cc khu vohp, ng n p, dn nhn, x p chngph i c thc hintrc khi qu tr nht o gel din ra.

Pectin- m c to gel


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- Qu trnh t o gel c a pectin c th c to ra trongmt quy trnh l nh bng 2 cch :

Trn syrup ng pectin c hm l ngch t kh hatan t 60 65%, pH = 3,8 -4,2 v i dch acid tri cy t c pH = 3,0.

Trn dung d ch pectin c pH = 2,9 v l ngch t khha tan l 25% v i syrup ng thu c hn hpmi c hm l ngch t kh 23%.

- L MP thng c ng dng trong m t t r icy chm lngch t kh ha tan < 55%. Lo i LMP cchn da trnhml ngch t kh vpH trong s nphm. Trong nh ng s n phm c hm l ngch t khrt thp, v d nhmt tri cy khng ngcho ng ib bnhtiu ng, LMP kh t o lin kt vi ncv Carrageenan thch h p hn. Trong m t s trnghp ngi ta c th s dng c pectin v carragenan

Pectin- m c to gel

Gip protein s a trong yoghurt khng

b ng tvnhit cthtittrng UHT

Phn t pectin c th lin k t v i 1protein tch in (+) chngkhng b ng li khi gia nhiet

LMP c s dng lm m t tricy c hm l ng ng thp vnhiu sn phm ch bin t tricy

Nhm acid c a pectin c th phn ngv i ion Ca 2+ to lin k t v i 2nhm COO - hnh thnh gelkhng c n ng

Cn c c ng v acid trong s nxut mt ng

V nhm acid kh y u, s thay i pHs thay i kh nng tch in cachui pectin. Pectin c th lin k tv i nhau iu kin acid

Mt tri cy c ng cao ph thucvo pectin to hnh

Nu hm l ng ng l n c bsung vo gim hydrate haca cc phn t pectin, cc phn t sli hnh thnh m ng l i gel

Pectin c th ci thin c u trc n cung c hm l ng ng ngthp.

Phn t pectin di v d v ng vonhau dung d ch c nh t pectin c kh nng to c

Kh nng ng d ngTnh ch t ca pectin

Carrageenan Tn g i khc:

Irish moss gelose (t Chondrus spp.); Eucheuman (t Eucheuma spp.); Iridophycan (t Iridaea spp.); Hypnean (t Hypnea spp.); Furcellaran or Danish agar (t Furcellaria fastigiata ); INS No. 407.

Ngu n g c:- c chit xut t loi to c ngu n gc t Ireland,mc dc theo b bin Anh, Php, Ty Ban Nha, Island.- Chit xut Carrageenan b ng n oc nng d i iu kinkh kim, sau o cho k t ta hay c c.

Cu to :- Carrageenan l m t hn hp ph c tp ca t nh t 5 loipolymer: , , , , - carrageenan, c u to t cc g c D-galactose v 3,6-anhydro D-galctose. Cc g c ny k t hpvi nhau b ng lin k t -1,4 v -1,3 lun phin nhau. Ccgc D-galactose c sulfate ha v i t lcao. Cc lo icarrageenan khc nhau v mc sulfate ha.


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Carrageenan

- Mch polysaccharide c a cc carrageenanc c u trcxo n kp.Mi vngxo n do 3 n gc disaccharide t o nn.- Cc polysaccharide ph bin ca carrageenan l kappa-, iota- vlambda- carrageenan:Kappa-carrageenan l m t loi polymer c a D-galactose- 4-sulfate v3,6-anhydro D-galctose.Iota-carrageenan c ng c c u to tng t Kappa-carrageenan,ngoi tr 3,6-anhydro-galactose b sulfate ha C s 2.Lambda-carrageenan c monomer h u ht l cc D-galactose- 2-sulfate (lin k t 1,3) v D-galactose-2,6-disulfate (lin k t 1,4).

Carrageenan Mu v nu carrageenan khi c x l bngkim schuy n thnh kappa v iota- carrageenan

AginateNgu n g c :

- Alginate l lo i polymer sinh h c bin phong ph nh t thgii v lloi poymer sinh h c nhi u th hai trn th giisau cellulose. Ngu n alginate ch yu c tm th y thnh t bo v gian bo c a to nu bin (thu c hRhaeophyceae). Cc phn t alginate t o ra cho th c vtmm do v bn cn thit cho cc loi th c vt bindo alginate cc gian bo t o thnh m t mng li .

Cu to :- L mu i ca acid alginic.Cc lo i alginate th ng g p nh : Natri alginate, Kali alginate, calci alginate.A- cid alginic l m t polymer do acid D-mannuronic (M)vacid L-guluronic (L) lin k t vi nhau b ng lin k t 1,4. C 3dng lin k t c thgp trong 1 phn t alginate (M-M-M),(G-G-G), (M-G-M).


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Aginate

T lM/G khc nhau nhngloi t o nu vngay c trnmt loi vo nh ng ma khc nhau trong n m. S khcnhau ny c nh hng n tnhch t dung d ch c a ccloi alginate. Th ng t lM/G ca cc loi t o nu daong trong kho ng 1:0.5 n 1:3.

Aginate

Aginate trong rau qu

Kali alginate:CTPT : (C6H7KO6)n.KLPT : 10.000-600.000 D ng s i, b t, h t. C mu t tr ng n nu h i vng.Tan ch m trong n c t o dung d ch s t, khng tan trong ethanol v

ether.Natri alginate:CTPT : (C6H7NaO6)n.

KLPT : 10.000-600.000 C tnh tan nh kali alginate .Calci alginate :CTPT : (C6 H7 Ca1/2 O6)n.KLPT : 10.000-600.000 Khng tan trong n c v ether, tan t trong ethanol, tan ch m trong

dung d ch c a polyphosphate, Na2CO3.

C d ng s i, dng b t hay d ng tinh th . Khng mu ho chi vng. C mi v v c trngnh


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Ka

Na

Ca

Gum arabic

Tn g i khc:Gum arabic ( Acacia senegal ), gum arabic ( Acacia seyal ),Acacia gum, arabic gum, INS No. 414

Ngu n g c:- Gum arabic l nh a c ly t thn v cnh c a cyAcacia senegal, Acacia seyal

Cu to:- L hn hp ca nhi u polysaccharide c quan h gn g inh L-arabinose, L-ramnose, D-galactose, D-glucuronicacid. Chu i chnh c a n l cc g c -D-galactose lin k tvi nhau b ng lin k t 1,3.- Khi lng phn t : M = 250000 1000000 D.- Gum arabic ch a nh ng phn t polysaccharide di v imui Ca, Mg, K c a chng.

Guar gum Tn g i khc:

Gum cyamopsis, b t guar; INS No. 412.Ngu n g c:- C trong thnh ph n ni nh ca h t Cyamopsis tetragonolobus,

thuc hLeguminosae, v i lng g n 35% c trng ch yu An , Pakistan va M (Texas). B t guar gum ch a 10-15% m, 5-6% protein; 2,5% x ; 0,5-0,8% tro.

- Thu nh n gum b ng cch r a vi ethanol hay isopropanol; hay hatan trong n c si, sau lc, c c v s y.

- Cu to:- L galactomanan g m 1 m ch chnh do cc g c D-mannose k t hpli vi nhau b ng lin k t -1,4 v cc g c D- galactose n i vi D-mannose c a m ch chnh b ng lin k t -1,6. T lgalactose :mannose l 2 : 1.

_ Khi lng phn t : M = 220000.\ Tnh ch t: - Mu tr ng, trng h i vng. - Dng b t, gn nh khng mi. - Hydrate ha trong n c lnh to dung d ch c nht cao.


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Xanthangum- L mt polysacchride ngo i bo, c sn xut bng cch

len men trn canh tr ng tinh khi t ca carbohydrate v iXanthomonas campestris , tinh s ch bngcchx l

ethanol ho c isopropanol, s y vnghin.Cu to:- Cha D-glucose v D-mannose l cc ng hexose ch

yu, ngoi ra cn c acid D-glucuronic v acid pyruvic.Cc D-glucose lin k t vi nhau qua lin k t -1,4 v do c c u to gingnh phn t cellulose. M t nhnhgm 3 trisaccharide trong c 1 acid glucuronic gia2 phn t ng mannose v nhnh ny n i vi miphn t ng glucose v tr s 3.

- c sn xut di dng mui Na+, K+ v Ca2+, dungdch c a n trung tnh.

Tnh ch t:- Dng bt mu kem.- Tan trong n c, khng tan trong ethanol.

Hm l ng cho php s dng ph gia t o gel,

to c theo quy nh c a b y tVit Nam

10.000N c chm dng sa( n c stmayonne, s t salad)

8.000N c chm dng st( t ngc chua,t ng t, n c chmc kem)

6.000Rau c ngm d m, du, n c mui.20.000Mt, mt c c, mt hoa qu

Propylen glycolalginate405

GMPRau c x l bmtCalci alginate404

2.500N c qup thanh trngpasteur nghp hoc ng chaiKali alginate402

20.000N c qup thanh trngpasteur nghp hoc ng chaiNatri alginate401

Hm l ngti a (ppm)

Loi th c phmTnph giaKhi u

GMPNectar qu c c(dng lnghoc dngrn)

GMPN c quc c(dng lnghoc dngrn)

Guar gum412


GMPN c quc c(dng lnghoc dngrn)Locust bean gum410

GMPNectar qu thanh trngpasteur nghp hoc ng chai

GMPN c qup thanh trngpasteur nghp hoc ng chai

Carrageenan vmui Na +, K+,

NH 4+ ca n(baogm c

Furcellaran)

407



GMPRau c ng lnh

Thchtrng(Agar)406


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Gum arabic414

3.000Nectar qu thanh trngpasteur nghp hoc ng chai

5.000N c qup thanh trngpasteur nghp hoc ng chai

Xanthan gum415

2.000N c qup thanh trngpasteur nghp hoc ng chaiTragacathgum413



Karayagum416



3.000Nectar qu thanh trngpasteur nghp hoc ng chai

5.000N c qup thanh trngpasteur nghp hoc ng chai

Natri carboxylcellulose

466

3.000Nectar qu c c(dng lnghoc dngrn)


Pectin440



Gellan gum418



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