OCHRATOXIN

Mn hc : c t VSV Ging vin: TS. Bi Th Hi Ha ****************************** c t nm mc ochratoxinLp 10-01Nhm 6.

1. Nguyn Th Lng2. Ch Th Huyn3. L Th Thanh Ngn4. Trn Th Hnh5. Nguyn H Nhung6. Nguyn Th Hng

7. Trn Thy Tin8. Nguyn Th Quyn9. Trn Th Hng10. Nguyn Anh Tin11. on Tin Dng

OCHRATOXIN ti thuyt trnh.

KHOA CNG NGH SINH HC ViN I HC M H NI2A/ t vn B/ Tm hiu.I/ S lc mycotoxinC/ Ochratoxin.I/ Khi nim.II/ Lch s pht hin OchratoxinIII/ Tnh cht ha l OchratoxinIV/ C ch tc ng ca OchratoxinV/ Phn loiC.I/ Ochratoxin BC.II/ Ochratoxin CC.III/ Ochratoxin Aa/ Cu tob/ Tnh cht vt lc/ Nm mc tng hpd/ c tnh: + Tc ng nng sn+ Tc ng ln vt nui+ Tc ng ln ng vt th nghim+ Tc ng ln con ngi.e/ gii hn an tonD/ Nhn din OchratoxinE/ Gii php phng tr.

Mc Lc A/ t vn .Theo t chc lng thc v nng nghip Lin Hip Quc (FAO), khong 25% s ng cc th gii c cha mt hm lng Mycotoxin mt mc no .Ty vo a l, kh nng nhim mycotoxin li khc nhau. iu kin nhit i v cn nhit i, nguy c nhim mycotoxin cng cao.c thu khi hu va nn san xut nng nghip Vit Nam tinh trang nhim c t nm mc la kha ph bin. Tm hiu, nh gi ng c t c ngha rt quan trng.

4 B/ Tm hiu.I/ S lc v c t nm mc:/n: c t nm mc hay cn gi l mycotoxins l sn phm chuyn ha th cp t nm mc (). c t nm mc c tinh bn vng nhit cao v khng b tiu dit trong qu trinh ch bin thc n thng thng. c lng thc t c khong 300 loi c t nm mc c hi cho ngi v ng vt. Xut hin: Mycotoxin c th xut hin trc khi thu hoch hoc trong thi gian lu tr, hoc trong thc n hon chnh khi khng c bo qun ng cchNhim c: Cp tnh: S nhim c cp tnh do mycotoxin gy nn rt nhiu t dch bnhv km theo t l t vong rt cao. Nhim liu thp gy ra ri lon chuyn ha.Mn tnh: mycotoxin cn gy nn cc bnh l rt khc nhau. Mycotoxin c th gy c cho cc h thng khc nhau ca cth nh gan ,thn ,h thn kinh ,h tiu ha ca ng vt tiu th cc sn phm nhim cc c t nm mc

Cc cn bnh ngi v ng vt do nm mc gy ra c cc c im sau:y l bnh khng ly. iu tr bng ha hc tr liu t hoc khng hiu qu.Bnh thng bng n theo ma, S bng n ca bnh thng lin quan n thc n c bit.Mc nhim bnh thng chu nh hng ca tui, gii tnh, trng thi dinh dng ca c th.Khi kim tra thc n thy c du hiu ca nm mc. c t nm mc gy c cho gia sc gia cm, lm nh hng n nng sut chn nui v hiu qu kinh t. Chng cn gy c trc tip cho ngi, hoc gin tip.

MT S MYCOTOXIN IN HNHTn c tTn tinh hng sc kheAflatoxin- c t ph bin nht.- Tn ti trong mt s loi ht ng cc (la mch, bp, k, yn mch, go, la ming, la m), sa, tht, trng, ni tng, ng, hoa qu kh, gia v.- Gy ung th. - c ch min dch.Tc ng ln nhiu h chuyn ha( gan, thn, mt), h ni tit, h xng - Gim kh nng tit sa, trng v sc khng gia sc, gia cm.Ochratoxin A-Tn ti trong tht, trng, ni tng, ru, cafe, ng cc, hoa qu kh, nc p nho.- Gy ung th. Gy t bin v qui thai- c ch min dch- Kch thch peroxy ha lipid. nh hng n thn kinhPatulin-Nc tri cy, ru to, cc sn phm t to.- Gy ung th- c ch min dch, gy xng, vim lot nim mc rutVomitoxin,Zearalenone, Fumonisin-Thng tn ti trong ng v cc sn phm t ng.- Gy ung th. Gy t bin v qui thai.Ri lon sinh sn- c ch min dch. Kch thch peroxy ha lipid. nh hng n thn kinhC/ OCHRATOXIN.I/ Khi nim:c t Ochratoxin, l mt sn phm chuyn ho th cp ca mt s loinm mc.Ochratoxin c mt trong khp cc loi nng sn thc phm: ng cc, tho dc, bia,c ph... trong cc sn phm c ngun gc ng vt do b ly nhim trc. Ochratoxins c bit n l sn phm ca cc loi nm Aspergillus v Penicillium v thng c tm thy trong a dng cc sn phm lng thc v thc n chn nui.

Hnh 1. Penicillium verrucosum Hnh 2. Aspergillus

II/ Lch s pht hin OchratoxinOchratoxin A ln u tin c tm thy nm mc A. ochraceus vng Nam Phi bi Scott( 1965) trn ht la min b nhim A.ochraceus. c tm thy Ochratoxin thng xuyn trong tht. Anh, chng c tm thy trong u nnh, bp bt, ca cao. M.Nakajima nm 1997 ghi nhn t l chim 30% hm lng OTA t 0.1 17,4 g/kg 47 mu caf c nhp vo Nht Bn t cc nc Phi , v 1 s nc ASIAN.Ti VN, Nghin cu tin hnh trn 123 mu ng ca 2 x Cn T v Lng Tm huyn Qun B tnh H Giang. Kt qu cho thy: trong 123 mu ng c phn tch c ti 50 mu (40,7 %) pht hin cOchratoxin A, trong s c 2 mu (1,6 %) vt mc d lng theo quy nh ca B Y tCho ti nay pht hin c 7 loi Ochratoxin khc nhau.

III/ Tnh cht ha l OchratoxinOchratoxin l c t tinh th khng mu, t tan trong nc, tan trong cc dung mi hu c, nh benzen, chloroform.. Dng mui d tan trong nc. Dng axit tan trong dung mi phn cc (chloroform, methenol).Ochratoxin rt bn vng vi cc x l nhit v ha cht. Hin ti, p2 hay dng l s dng kh quyn iu chnh, tng CO 2 = 30% c ch hon ton s to thnh OTA.

Ochratoxin pht hunh quang v hp th UV cc i ti 365nm. Cc Ochratoxin rt a m, thng c trong c cht vi m >16%. c t c sn sinh nhiu nht nhit t 20-25oC. S sn sinh Ochratoxin ph thuc chng nm mc, hot tnh ca nc trong ht, c cht, nhit .

OTA pht hunh quang xanhCon ng xm nhpThc n Gan,thn,c,m mRut, d dyNc tiu, phnIV/ C ch tc ng ca OchratoxinOchratoxin gy c ch s vn chuyn ca ribonucleic axit (tRNA) v cc axitamin. Ochratoxin cn c ch vi khun, nm men v phenylalanine-tRNA gan. Tc ng lm c ch s tng hp protein trong t bo v c th.S c ch min dch ca ochratoxin c biu hin lm gim thc bo v cch t bo lympho. c ch tng t nh trn cc amino axit synlaza tRNAtng ng OTA gy c ch hydroxylase phenylalanine, 1 na phenylalanine caOTA l 1 phn hydroxyl ha tyrosin gy bnh cc t bo gan trong c thOchratoxin c ch s tng hp RNA lm nh hng n cc protein trong vngtun hon. Tc ng n cc t bo mng ty th v gy ra cc hiu ngkhc nhau trn ti th. Kch thch s hnh thnh DNA trong thn, gan v l lch. CcDNA ny l cc si n b ph v.

V/ Phn loi

RR1R2OchratoxinAHClHOchratoxinBHHHOchratoxinCC2H5ClHOchratoxinAmethylesterCH3ClHOchratoxinBethylesterC2H5HHOchratoxinBmethylesterCH3HH4-HydroxyochratoxinAHClOH

C.I/ OCHRATOXIN B

C.II/ OCHRATOXIN C

C22H22ClNO6Bng tnh cht l ha ca 3 loi Ochratoxin in hnhochratoxinKhi lng phn tmax hp thu(nm)im nng chy ( 0 C ) A/s hunh quangOTA403330169Xanh lcOTB369320221Xanh lamOTC431330-Xanh lamC.III/ OCHRATOXIN Aa/ Cu to:Ochratoxin A hay cn c gi l OTA hoc OA CTPT: C20H18ClNO6 . Cng thc danh php theo IUPAC: L-phenylalanine- N-[( 5chloro-3,4-dihydro-8-hydroxy-3methyl-1-oxo-1h-2-benzopyran-7-yl)carbonyl]-(R)- isocoumarin.Khi lng phn t l 403.822Da.

Hnh 3. Cu to OTA

16b/ Tnh cht vt l.OTA l hp cht khng mu, kt tinh. Tan trong dung mi phn cc v trong dung dch bicabonat, tan hn ch trong nc. Ph hp th116-332nm. OTA c im nng chy 94-96 0C.Ph hng ngoi trong cloroform cho cc peak c di 3380, 1723,1678, 1655 cm-1OTA c tnh axit yu pKa14.2-4.4 v pKa2 7.0-7.3.OTA pht hunh quang xanh khi dng thit b TLC chiu tia UV 366nmc/ Nm mc tng hp OchratoxinAspergillus sectionPenicilliumCircumdatiFlaviNigriA.cretensisA.alliaceus.A.carbonariusP.nordicumA.flocculosusPetromycesalbertensisA.lacticoffeatusP.verrucosumA.melleusA.nigerP.chrysogenumA.ochraceusA.sclerotionigeP.brevicompactumA.persiiP.crustosumA.petrakiiP.olsoniiA.pseudoelegansP.oxalicumA.roseoglobulosusA.sulphureusA.sulphureusA.westerdijkiaeTable1.OTAproducingfungi.

(SpeciesacceptedbyFrisvadandco-authorsarelistedinTable1.)

c/ Nm mc tng hp OchratoxinHnh 4. A. caboniusc im:Xut hin trong tri cy trng thnh. khng cao vi nh nng mt tri. Pht trin tt nht 15-20 C, hot nc 0.95-0.98 aw.c/ Nm mc tng hp Ochratoxin

Hnh 5. A. ochraceusc im :- C nhiu trong caf - Pht trin tt nht 25-30 C, v hot nc 0.98 aw (substrate water activity).

c/ Nm mc tng hp OchratoxinHnh 6. P. verrucosumc im: Pht trin tt nht 24Cv hot nc 0.950.99aw C th sn xut OTA nhit thp l 5 C d/ c tnhOchratoxin A ( OTA) c tnh c cao nht. Do nhm hydroxyl phenol c tch ra d dng. OTA thng gy ra nhim c mn tnh hn cp tnh.d.1/ Tc ng ti nng sn:Ngay t khi gieo trng, tt c cc loi ng cc u b nhim nm mc. Loi nm mc ny c tn l Fusarium.

Hnh 7. Fusarium

Hnh 8. Ng nhim nm mc FoodproductsContaminationlevelsBeans0.250.92g/KgCocoabeans0.3514.8g/KgCorn0.110.15g/KgDriedfigs