TRNG I HC CNG NGH NG NAIKHOA THC PHM MI TRNG V IU DNG

TIU LUN MN HCHA SINH THC PHM

TN TIPECTIN NG DNG TRONG THC PHM

Gio vin hng dn: H Th Ngc NhungSinh vin thc hin: Nguyn Minh Ln

Bin Ha, thng 11 nm 2014

Danh sch nhm

STTHo tnMSSVLp

1Nguyn Vn c130367113DTP2

2Nguyn Trn Tun Ti130392213DTP2

3Nguyn i D130391313DTP2

4Bi Vn Phc130369213DTP2

5Vy Minh Trung130350913DTP2

6Nguyn Minh Ln130391213DTP2

iNhn xt ca gio vin: Gio vin hng dn. K tn.

Th.s. H Th Ngc Nhung

iiLi m u

Nhng nm gn y trong xu th pht trin chung khi i sng ngy cng c nng cao cng s tng cng giao lu vi nn kinh t khc trn th gii. Nhu cu v thay th hng ngoi nhp m bn cnh sc khe ang l vn c quan tm, ch trng. gii quyt vn trn vic chn sn phm t ngun nguyn liu ph bin t nhiu vng. M sn phm chng ta ang tm hiu li l ph phm ca cc nguyn liu trong nh my. Ph phm chnh l b p cc qu trnh p nc qu nh: b p nc to, cam, chanh, qut, bi Pectin l sn phm ph gia thc phm thuc nhm ph gia to ng, to gel trong qu trnh ch bin v bo qun mt, mt ng, ko pectin t hoa qu m bi vit ni n. Pectin l sn phm ph gia c nghin cu bng phng php pectat-canxi trong ph gia c nhiu hu ch nh gip thc phm an ton v dinh dng, c hi la chn thc phm nhiu hn, gi thnh thc phm.

iii

CHNG I : TNG QUANI.Gii thiu v pectin I.1. Khi nim v pectinPectin l mt hp cht t nhin c nhiu trong mng t bo ca cc loi thc vt bt cao, phn b ch yu cc b phn nh qu, c, thn. Trong mng t bo, pectin c mt phin gia ( vi hm lng cao nht ) v vch t bo s cp. Pectin l polysaccharide phc tp c cha t nht 65% acid galacturonic c lin kt vi nhau bng lin kt -1,4-glycoside, trong mt s gc COOH c methoxyl ha CH3O.

Hnh 1.1. Acid D-galacturonic-n v cu to ch yu ca pectinpectin l mt thut ng ch mt nhm cc cht sau:-Protopectin : l pectin trng thi t nhin ( trong vch t bo thc vt v phin gia ), mc methyl ha rt cao, khng ha tan, Protopectin c nhiu trong qu xanh.- Acid pectinic: mc methyl ha trung bnh, tan, mui pectinnate- Pectin: mc methyl ha trung bnh, tan, bn cht l cht keo,c kh nng tao gel, to nh, to c v n nh.- Acid pectin: mc methyl ha rt thp,tan,mui l pectateNgi ta rt hay ln ln gia pectin v acid pectinic nn tht ra trong thc t pectin l tn gi chung ca c hai cht ny.I.2. Ngun gc pectin v cu to pectinI.2.1. Ngun gcPectin l cht ph gia thc phm ngy nay thng c dng to ng,tao 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 trong nc 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 dopolymer ha ca pectin thnh pectate v cui cng l cc loi ng ha tan v acidT thi tin s cht pectin l thnh phn trong phu phn n ca con ngi. nhng ch mi na th k trc nghnh 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 mui 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 thuc vo tng quy trnh cng ngh.I.2.2. Cu to ca pectinPectin l mt polysaccharide tn ti ph bin trong thc vt, l thnh phn tham gia xy dng cu trc t bo thc vt. thc vt pectin tn ti ch yu 2 dng l pectin ha tan v protopectin khng ha tan. Di tc dng ca acid, enzyme protopectinaza hoc khi gia nhit th protopectin chuyn thnh pectin.

Trong mng t bo, pectin c mt phin gia ( c hm lng cao nht ) v vch t bo s cp

Hnh 1.3. Pectin trong cu to ca thnh t bo thc vtPectin l hp cht cao phn t polygalactoronic c n phn t l galactoronic v ru metylic. Trng lng phn t t 20.000 - 200.000 vC. Hm lng pectin 1% trong dung dch c nht cao, nu b sung 60 % ng v iu chnh pHmi trngt 3,1-3,4 sn phm s to ng.

Cu to phn t pectin l mt dn sut ca acid pectic, acid pectic l mt polymer ca acid D-galacturonic lin kt vi nhau bng lin kt 1-4-glycozide.

Hnh 1.4. Cu to ca pectinHp cht pectin c c trng bi 2 ch s quan trng l ch s methoxyl MI biu hin cho phn trm khi lng nhm methoxyl OCH3c trong phn t pectin v ch s este ha DE th hin mc este ha ca cc phn t acid galactoronic trong phn t pectin.Da trn mc methoxy ha v este ha, trong thng mi chia pectin thnh 2 loi: pectin c methoxyl ha cao v pectin c methoxyl ha thp. Pectin methoxyl ha cao (High Methoxyl Pectin HMP): DE >50 % hay MI > 7%. Cht ny c th lm tng nht cho sn phm. Mun to ng cn phi c iu kin pH = 3,1 3,4 v nng ng trn 60 %.

Hnh 1.5 Hight Methoxyl Pectin

- Pectin methoxyl ha thp (Low Methoxyl Pectin LMP): DE < 50 % hay MI < 7%. c sn xut bng cch gim nhm methoxyl trong phn t pectin. Pectin methoxy thp c th to ng trongmi trngkhng c ng. Chng thng c dng lm mng bao bc cc sn phm.

Hnh 1.6 Low Methoxyl Pectin

Nhng nghin cu mi v cu trc phn t pectin cho thy pectin c hai vng cu to chnh l vng sun thng ( smooth regions ) chim khong 60 90% khi lng, v vng rm ( hairy regions ) chim 10 40% khi lngTrong qu trnh bo qun c th b tch nc hoc lo ha. Qu trnh to ng ph thuc vo nhiu yu t: ngun pectin, mc methoxy ha cng cao th kh nng to ng cng cao. Khi s dng cn phi ha tan pectin vo nc, khi pectin ht nc th mi s dng cng on cui ch bin.Cc pectin u l nhng cht keo ho nc nn c kh nng hydrat ha cao nh s gn cc phn t nc vo nhm hydroxyl ca chui polymethyl galacturonic. Ngoi ra, trong phn t pectin c mang in tch m nn chng c kh nng y ln nhau c kh nng lm gin mch v lm tng nht ca dung dch. Khi lm gim tch in v hydrat ha s lm cho si pectin xch li gn nhau v tng tc vi nhau to nn mt mng li ba chiu rn cha pha lng bn trong.I.3. Phn loi pectin v cc ch s c trngI.3.1. Phn loi*Hip hi ha hc M ( American Chemical Society ) phn loi cc hp cht pectin thnh 3 loi: - Acid pectic - Acid pectinic - Pectin (Polygalacturonate)* Da trn mc este ha, trong thng mi chia pectin thnh 2 loi: Pectin methoxyl ha cao (High Methoxyl Pectin HMP): DE > 50%. Pectin methoxyl ha thp (Low Methoxyl Pectin LMP): DE < 50 %. I.3.2. Ch s c trngPectin c c trng bi cc ch s sau: ch s mrthoxyl (MI): ch s methyl ha, l phn trm khi lng nhm methoxyl (-OCH3) trn tng khi lng phn t. S methyl ha hon ton tng ng vi ch s methoxyl bng 16,3% cn cc pectin tch ra t thc vt thng c ch s methoxyl t 10% n 12%. Ch s ester ha (DE): th hin mc ester ha ca pectin, l t l phn trm v s lng ca cc gc acid galatoronic c ester ha trn tng s lng gc acid galaturonic c trong phn t.I.3.1 Tnh cht ca pectin a. Kh nng to gel c tnh quan trng ca pectin l c kh nng to gel, v vy n c ng dng ph bin trong cng ngh sn xut mt, ko gm, ko do. Kh nng to gel ca pectin ty thuc ngun pectin, mc methoxyl ha v phn t lng ca pectin. b. Cc tnh cht khc Pectin l mt cht c kh nng hydrat ha cao, pectin c thb kt ta vi ru, axeton, ete hoc benzen. Dung dch pectin c tnh keo cao, nht v bn ca keo ln. Pectin tinh ch c dng cht bt trng hoc hi vng hoc mu xm nht, v tan trong nc. M hiu quc t ca pectin l E440. I.3.2 S phn b pectin trong t nhin Pectin c nhiu trong c, qu, l v thn cy. Hm lng pectin trong cc loi rau qu l khc nhau. I.3.3 ng dng ca pectin Trong thc phm S dng nh mt tc nhn to gel, s dng nh mt cht n nh keo, s dng trong h nh tng Trong Y dc Pectin l mt loi cht x ha tan c tc dng gim cholesterol trong mu, cha cc bnh ng rut. Dung dch pectin 5% cn c s dng nh thuc st trng H202I.4. Ngun nguyn liu cha pectinPectin cha nhiu trong cc trong cc loi qu ca tri cy: to, mn, cam, chanh, c rt, sn tr, l, c chua, b

Hnh 1.5 Pectin c trong rau, c, qu

Bng 1.1: Thnh phn v hm lng ca pectin trong cc loi qu tnh theo %

Tn rau quTinh btngPectinXenluloza

SaccarozaGlucozaFructozaCng

Khoai ty17.70.60.20.10.90.71.0

Ci bp00.12.61.64.30.31.2

C rt03.72.96.60.41.0

C chua50%, pH = 3 3,5 ; [Pectin] = 0,5 -1 %. ng c kh nng ht m v vy n lm gim mc hydrate ha ca phn t pectin trong dung dch, pH axit trung ha bi gc COO- lm gim tch in ca 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 to 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 axit, hm lng pectin, hoc pectin v nhit 30 35oC ng thm vo pectin l sacharose. Do cn duy tr pH axit khi un nu s gy ra qu trnh nghch o ng sacharose. Tuy nhin cng khng nn dng qu nhiu axit v pH qu thp s gy ra nghch o mt lng ln sacharose gy kt tinh glucozo v ha gel nhanh to nn cc vn cc. Khi dung lng pectin vt qu lng thch hp s gy ra gel qu cng. Do khi dng 1 nguyn liu c cha nhiu pectin cn tin hnh phn gii chng bng cch un nu lu hn.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 axit, bazo 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 di qu thp th n khng to gel c mc 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 mch galaturonic 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 ( -COH3) mi trng pH=3 v hm lng ng 35% kh nng ng t tt.Khi hm lng methoxyl gim xung 5% v thp hn th pectin vn gi c kh nng ng t to ng chm, i hi thay i hm lng ng cng nh pectin v axit.Nu pectin c hm lng 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 to ra ng t bn vng. Vai tr ca Ca2+ v ion kim loi khc trong vic to gel l: Cc phn t axit pectit tc dng tng h ln nhau nh cc nhm cacboxyl t do, cc nhm ny lin kt li nh cc ion Ca2+ thnh khung bn vng nh nhau

Hnh 2.4. Hight Methoxyl Pectin

Hnh 2.5. Low Methoxyl Pectin

Dng cation v anion c nh hng n bn ng t cation Ca2+Al3+ lm tng bn gel cn cation ha tr I nh Na+ iu kin xc nh c tc dng ngc li. Trong thnh phn phn t pectin c th c nhm axetyl 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, xong cao hn th kh nng ng t gimI.3 Vai tr cc cu t trong vic to gel pectin I.3.1 Pectin Nng cc phn t pectin trong dung dch cng ln th lin kt gia cc phn t xy ra cng nhanh v s ng t to ra cng bn. 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 ng 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 keo ph thuc vo m, m cng cao thi gian to ng cng gim.I.3.3 ngVai 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 to 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. Khi dng pectin c cht lng tt, nng ca n trong dung dch l 0,6 1% th hm lng ng cn t ti 65%I.3.4 Axit Yu cu ca axit trong vic to gel pectin: Axit cho vo phi c mc phn ly cao hn axit pectit nh vy n s ngn cn s phn ly ca axit pectit do cc mixen pectit mt in tch cng du, chng c ni li thnh cc si di. Khi cho axit vo th ion Hydro thay th ion kim loi trong nhm cacboxyl ca phn t pectin sau khi ty c axit pectit ra khi mui ca n. V mui ca axit khng tham gia vo qu trnh to ng m ch c axit pectit to ra ng t do khi thm axit vo s lm tng tc ng t. Axit tactric c tnh hot ng ln nht v axit citric hot ng yu nht trong nhng axit 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 ng t ca dung dch cng cao, khi ca mui ca axit pectit c thay th hon ton bi ion Hydro mt cch nhanh chng v chuyn chng v axit pectit. Sau tip tc tng nng ion Hydro th s khng c hiu qu na. Hm lng ca axit dng to ng khng nhng ph thuc vo tnh cht ca axit 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 ng t nu pectin c kh nng ng t yu th nng ca axit nn tng nhng ch nn tng trong mt gii hn nht nh hm lng axit cao lm tng hm lng ng chuyn ha do tng tnh ho 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 axit a vo.II. Ch tiu nh gi cht lng sn phmII.1 Tnh cht v tinh sch ca pectin s dng trong ch binTiu chun:FAO: Food and Nutrition paper 1992FCC: Food chemical codexEEC: Eropean Ecconomic ComnutityCc tp cht cha trong pectin c quy nh vi hm lng nh sau:Cc 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/kgMax: 50mg/kgMax: 50mg/kgSodiummethy 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: 3ng, ppm: 50Km, ppm: 25ng v km, ppm: 50Kim loi nng nh (Pb), ppm:Max: 20II.2 Quy nh s dngPectin 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 t chc JECFA ( Jount Food 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 bin n khi b sung vo qu trnh ch bin vi nhiu mc ch khc nhau iu c tc dng khng tt i vi c th ngi cho 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 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 nghnh ch bin nc qu v ru vang.

Ti liu tham kho1. Nguyn Vn Tip_Qach nh_Ng M Vn_2001_K thut sn xut hp rau qu_NXB Thanh Nin.2. Trng cao ng lng thc_thc phm_Gao 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/thuvien/ten/28 TCN 56 htm.