lv che bien tuong tu dau phong

1

MC LC Trang ph ba Li cam oan

Li cm n

MC LC

PHN M U....................................................................................................4

PHN NI DUNG ................................................................................................6 CHNG I: TNG QUAN TI LIU

I.1. S lc v nc tng v bnh du phng .......................................................6

I.1.1. Nc tng.................................................................................................6

I.1.1.1. Nc tng l g?..................................................................................6

I.1.1.2. Vai tr ca nc tng..........................................................................7

I.1.2. Bnh du phng..........................................................................................7

I.1.2.1. Bnh du phng l g?...........................................................................7

I.1.2.2. Thnh phn chnh ca bnh du phng..................................................7

I.1.2.3. Cng dng.............................................................................................8

I.1.2.4. Cch bo qun.......................................................................................8

I.2. Cc quy trnh sn xut nc tng ...................................................................8

I.2.1. Sn xut nc tng bng phng php ha gii .......................................8

I.2.1.1. Quy trnh sn xut .................................................................................9

I.2.1.2. Gii thch quy trnh ..............................................................................10

I.2.1.3. u v nhc im ca phng php ....................................................10

I.2.2. Sn xut nc tng bng phng php ln men.......................................10

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I.2.2.1. Quy trnh sn xut ................................................................................11

I.2.2.2. Gii thch quy trnh ..............................................................................12


I.2.2.4. Gii thiu chng mc Aspergillus Oryaza ............................................13

I.2.3. Sn xut nc tng bng phng php ha gii kt hp ln men.............17

I.2.3.1. Quy trnh sn xut ................................................................................17


I.2.4. Cc phng php khc...............................................................................18

I.3. Tiu chun v nc tng ca B Y T ..........................................................18

I.3.1. Tiu chun v m................................................................................18

I.3.1.1. m trong nc tng l g? ...........................................................18

I.3.1.2. Phn loi hng nc tng da vo m .........................................19

I.3.1.3. nh gi cht lng nc tng da vo m.................................20

I.3.2. Phng php cm quan..............................................................................21

I.4. Cch xc nh m trong nc tng bng phng php Micro Kjeldahl...24 I.4.1. Cc c tnh k thut ca thit b UDK 142................................................24

I.4.2. Ni dung phng php Kjeldahl ...............................................................26 CHNG II: K THUT THC NGHIM.

II.1. Nguyn liu - dng c - ha cht....................................................................28

II.2. Xy dng quy trnh ch bin nc tng .......................................................29

II.2.1. Nui mc ging Aspergillus Oryaza.........................................................29

II.2.1.1. Nguyn liu chnh...............................................................................29

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II.2.1.2. S lm mc ging ..........................................................................30

II.2. 2. Quy trnh lm nc tng .......................................................................31

II.2.2.1. Nguyn liu chnh...............................................................................31

II.2.2.2. S sn xut nc tng..................................................................31

II.3. Xc nh m ca nc tng sau khi sn xut .........................................32

II.3.1. Nguyn tc ...............................................................................................32

II.3.2. Dng c - thit b......................................................................................32

II.3.3. Ha cht ...................................................................................................32

II.3.4. Cch ly mu v chun b mu .................................................................33

II.3.5. Cch tin hnh..........................................................................................33

II.4. Phng php th cm quan phn tch cht lng nc tng ........................37

II.4.1 Chun b....................................................................................................37

II.4.2. Cch tin hnh..........................................................................................37

CHNG III: KT QU THO LUN

III.1. Quy trnh sn xut nc tng bng phng php ln men...........................39

III.1.1. u im..................................................................................................39

III.1.2. Nhc im ............................................................................................39

III.2. Xc nh m ca nc tng sau khi sn xut........................................39

III.3. Phng php cm quan cht lng nc tng.............................................42

PHN KT LUN KIN NGH .......................................................................44 TI LIU THAM KHO .....................................................................................46 PH LC..............................................................................................................47

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PHN M U

I. L do chn ti. Hin nay, vi pht trin nhanh chng ca ngnh cng nghip sn xut gia v

lng, trong c du n khin cho lng b u phng ph thi ngy cng nhiu.

Lng b u phng ny ch c dng lm thc n gia sc, gi th trng nm, ch bin nc tng nhm tn dng ngun nguyn liu r tin v di do ny mt cch hp

l ch bin chng thnh nc tng c hm lng dinh dng cao, dng lm cht iu v, kch thch tiu ha, gip n ngon ming, ng thi cung cp cho c th mt

lng m d hp thu nht nh. Nhng phn ln nc tng c sn xut t bnh du phng iu p dng phng php ha gii. Vi phng php ny, thi gian phn hy nhanh, gi thnh r, mi v c ngi tiu dng a chung, nhng c nhng

nhc im kh khc phc nh: gy nhim cho ngi trc tip sn xut, mi trng

xung quanh. Khng may, HCl khi thy phn Protein trong u cng phn hy lun cht

bo cn st li trong bnh du sinh ra c t 3-MCPD vi hm lng cao c th gy ung th cho ngi tiu dng. Do , c gii php v nc tng an ton hin ang

l mi quan tm hng u ca cc nh khoa hc, nh sn xut, ngi tiu dng. Chnh v th, hn ch 3-MCPD c trong nc tng ngoi vic la chn nguyn liu ti, mi, khng c nm mc, cng cn phi la chn phng php sn xut ph hp nhm

hn ch vic sinh ra nm mc v 3-MCPD m bo an ton v sinh thc phm cho ngi tiu dng. Xut pht t nhng l do trn ti chn ti: "Nghin cu ch bin nc tng t bnh du phng bng phng php ln men truyn thng.

II. Mc tiu ti.

Nghin cu v xy dng quy trnh sn xut nc tng bng phng php ln men truyn thng t bnh du phng.

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III. Nhim v ti.

Nghin cu cc ti liu v nc tng v bnh du phng.

Nghin cu cc quy trnh sn xut nc tng.

Xy dng quy trnh sn xut nc tng bng phng php ln men truyn

thng t bnh du phng.

Kim tra cht lng ca sn phm sau khi ch bin:

Phng php cm quan v: mu sc, trong, mi, v.

Xc nh hm lng m ca nc tng sau khi sn xut bng phng

php Kjeldahl. IV. Lch s nghin cu.

c nhiu phng php sn xut nc tng nh: phng php ha gii, phng

php ln men kt hp ha gii c nghin cu p dng trn i tng bnh du phng; vi phng php ln men ch c p dng rng ri trn nguyn liu u nnh,

u phng; cn nguyn liu bnh du phng t c nghin cu.

V. Phng php nghin cu.

Nghin cu ti liu, l thuyt.

Nghin cu thc nghim.

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PHN NI DUNG

CHNG I: TNG QUAN TI LIU I.1. S lc v nc tng v bnh du phng.

I.1.1. Nc tng [11], [13].

I.1.1.1. Nc tng l g?

Nc tng (hay cn gi l nc chm) l mt loi gia v dng nc c hm lng m cao v v mn.

Nc tng l dung dch thy phn ca Protein v gluxit (i vi 1 s loi nc tng sn xut bng phng php ln men), ngoi ra cn c lipit, mui n v mt s thnh phn khc.

Hin nay, nc tng c nhiu loi nhng c th da vo nguyn liu sn xut

chia thnh hai loi ch yu sau:

Nc tng c ngun gc ng vt: xng, lng g, lng vt...

Nc tng c ngun gc thc vt: u nnh, u phng...

Do c im nc tng l dung dch thy phn ca Protein nn v nguyn tc sn xut nc tng loi ny da vo s thy phn Protein ca proteaza (ln men) hoc axit (ha gii).

Phng trnh tng qut chung:

RCO-NHR' + HOH RCOOH + R'NH2

Trong cng nghip, nc tng thng c sn xut t bnh du u phng (b u phng sau khi p du) hoc bnh du u nnh (b u nnh).

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I.1.1.2. Vai tr ca nc tng.

Nc tng khng phi l cht b sung m m ch l nc chm lm tng khu v, ch khng c tc dng b sung dinh dng, khng nn n nhiu.

Theo cc nh y hc, mi ngy c th con ngi cn 60g cht m, nn nc tng khng phi l cht cung cp m chnh.

m thp nht trong nc tng l 10N. Ngi bnh thng, ti a mi ngy

n 10ml nc tng th cht m do n mang li l khng ng k.

I.1.2. Bnh du phng [10], [14].

I.1.2.1. Bnh du phng l g?

Bnh du phng l phn b u phng cn li sau khi p u ly du.

Bnh du ny tn ti dng bnh kh v cha rt t cht bo.

L loi bnh c cha bt mn, rt d nghin nhuyn.

iu c bit l bnh du phng c tnh cht ht nc v n ra thnh bt mn rt thm.

C hai loi bnh du phng:

Bnh du phng c v.

Bnh du phng khng v. Bnh du phng khng v p theo phng php

cng nghip cha Protein th 45,54%, cht bo 6,96%, cht x 5,25%.

Bn cnh nh hng ca v, cht lng bnh du cn ty thuc phng php p

du.

I.1.2.2. Thnh phn chnh ca bnh du phng.

Bnh du phng c hai thnh phn ch yu l:

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Protein.

Cht bo.

Bnh du phng l ngun nguyn liu giu Protein v sinh t nhm B, nhng Protein bnh du phng mt cn i axit amin thit yu (lizin v tryptophan).

I.1.2.3. Cng dng.

Bnh du phng ch yu dng lm nc chm nh: nc tng, nc mm

chay...

Ngoi ra trong thc t, ngi ta cn tn dng ti a lng sn phm ph bnh du phng c cha m ny lm:

Phn bn cho cc loi cy cnh, cy king...

Gi th trng cy v nui nm.

Trong lnh vc chn nui: dng lm thc n cho gia sc v cc loi c...

I.1.2.4. Cch bo qun.

Do bnh du phng cha kh nhiu cht bo v n d b nhim nm mc to c t

(nht l c t afltoxin gy vim gan, st cn, sinh sn km). V th:

Cn d tr bnh du ni cao ro, kh v thong mt.

Ch nn d tr khng qu mt thng vo nhng lc nng m.

I.2. Cc quy trnh sn xut nc tng.

I.2.1. Sn xut nc tng bng phng php ha gii [12], [16], [17].

I.2.1.1. Quy trnh sn xut:

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S I.1. S quy trnh sn xut nc tng theo phng php ha gii

Thanh trng

Lng

NaCl 25%

Mu

NaCl 25%

Lc mn

Ch bin Cht bo qun

ng chai

Nc tng thnh phm

Hng

B

Phi trn Lc ln 2 B

B

Nc

Lc ln 1

Trung ha

Nc

Soa

Bnh du phng

Thy phn Nc

HCl 15-16%

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I.2.1.2. Gii thch quy trnh:

Nguyn liu ngm khong 4-5 gi, em nu nhit 110 1200C vi axit clohidric 15-16% trong 18 24 gi cho si.

ngui hon ton, lc dch thu phn, trung ho axit bng natri hydroxit hoc natri cacbonat n pH t 5 6 (pH thp hn 5 c v chua; pH cao hn 6 c v ng, mi nng). Sau thm mui vo v tip tc c c n hm lng m cn thit (tiu chun m: 10 22g/l).

Cui cng em thanh trng, v chai, bo qun v phn phi tiu th.

I.2.1.3. u v nhc im ca phng php.

a) u im.

Thi gian sn xut ngn.

Mi v c ngi tiu dng a chung.

Gi thnh r.

Chim t mt bng.

b) Nhc im.

C th sinh ra c t 3-MCPD vt mc cho php.

Thit b, dng c phi m bo an ton cho ngi trc tip sn xut.

I.2.2. Sn xut nc tng bng phng php ln men [3], [4], [5], [6], [16], [17].

Phng php ln men l phng php sn xut m di tc dng ca enzym

(men) thu c t mc ging chn lc v nui cy thu phn protit v gluxit ca nguyn liu thc vt.

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p dng thnh cng phng php ln men th yu cu quan trng ch yu l phi la chn mc ging tt cho ph hp. Do mc ging c nhiu loi, nhng lm

ra nc tng ngon th phi chn mc ging Aspergillus Oryaza.

I.2.2.1. Quy trnh sn xut nc tng bng phng php ln men:

S I.2. S quy trnh sn xut nc tng theo phng php ln men

u nnh, u phng

Ngm 4 -5 gi

Hp 1000C

Mc ging Aspergillus Oryaza

Ln men

Nc mui 25%

2-3 thng

Lc

Nc tng

B

Tng c

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I.2.2.2. Gii thch quy trnh:

Quy trnh sn xut nc tng theo phng php ln men gm cc giai on sau:

X l nguyn liu :

u nnh, u phng ngm trong nc.

Hp.

Lm ngui.

Trn vi bt m nui nm mc Aspergillus Oryaza.

m - thy phn :

Thy phn protit u nnh di tc dng ca enzym sinh ra t nm mc.

Nguyn liu mc nm, trn u vi nc mui t trong mi trng m.

thnh khi 35 400C trong 3 4 ngy.

Nu nhit cao qu th phi tri mng ra h nhit xung di 35 400C.

Lc:

Khi mc cho vo thit b c van m y.

Dng nc mui cho vo khi mc, ngp v ngm 8 12 gi.

Rt ly nc tng c m cao.

Li tip tc cho mui vo b, ngm vi gi v rt ra nc tng c m

thp hn.

Thanh trng 90 1000C.

Cho Natri benzoat chng vng mc.

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I.2.2.3. u v nhc im ca phng php.

u im:

t c kh nng sinh ra c t 3-MCPD, Afltoxin.

To ra 3 sn phm: nc tng, tng c v b.

Chng mc Aspergillus Oryaza c hot tnh Amilaza v Proteaza cao lm cho qu trnh ln men n nh.

Nhc im:

Thi gian sn xut ko di 2-3 thng.

Mi v nc tng cha quen vi ngi tiu dng.

Chim mt bng.

Gi thnh tng i cao.

I.2.2.4. Gii thiu chng mc Aspergillus Oryaza:

.

Nm mc Aspergillus Oryaza cn gi l mc tng, si nm c mu vng lc hay vng hoa cau.

Aspergillus Oryaza l nm mc chnh trong qu trnh lm nc tng, nc tng do nm Aspergillus Oryaza ln men ngon hn cc loi nc tng khc. V loi

Hnh I.1. Nm mc Aspergillus Oryaza

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mc ny c kh nng bin tinh bt ca go, np thnh ng lm cho nc tng c v ngt.

y l loi nm s dng lm men ph bin nht trong qu trnh sn xut nc

tng bng phng php ln men hin nay. Ta c th cc loi mc ny bng cc cch sau:

a) Nui cy trong bnh tam gic:

Cch lm mi trng trong bnh tam gic:

Mi trng go:

S I.3. Nui cy trn nguyn liu go t

y nt bng giy ht m

Hp thanh trng 30 - 45 pht

Bnh tam gic (lp dy 1cm)

Bnh tam gic nui mc

Bnh tam gic nui mc sch

Nu

Bp ri

ngui

Go t loi tt

Cm chn u

Cm ngui

Cm ti

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Mi trng ng mnh:

S I.4. Nui cy trn nguyn liu ng mnh

y nt bng giy ht m

Hp thanh trng 1200C, 60 pht

Ngm nc

1-2 gi

Trn u

Ng mnh (0,2 - 0,5mm)

Hn hp ng ngm nc

Ng ti

Khay

Ng ngm nc u

Bnh tam gic (lp dy 1cm)

Bnh tam gic nui mc

Bp ti

Bnh tam gic nui mc sch

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b) Nui cy mc trn khay:

S I.5. Nui cy trn nguyn liu ng mnh

Hp 3-4 gi

3-4 gi

Trn u

Ngm nc

Ng mnh (0,2 - 0,5mm)

Hn hp ng ngm nc

Ng chn u

Khay nh

Ng ngm nc u

Cho ra

Khay ln Lm ti

6-8 gi, 34-350C

Nui 34-36 gi, 34-350C

60 gi ly ra

Trn vi nc mc ging bnh tam gic

trong khay thnh lung, 30-320C

Ri lung thnh lp mng 2-3 cm, t0

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I.2.3. Sn xut nc tng bng phng php ha gii kt hp phng php ln men [15], [16], [17].

Phng php ln men kt hp vi ha gii l phng php ci tin nht da trn s

kt hp hai phng php ln men v ha gii. Phng php ny s dng ging vi sinh vt v enzym proteaza t sn xut trong nc tng nn gi thnh khng tng v mang

li cho ngi tiu dng mt loi nc tng m bo v nng 3-MCPD thp hn mc cho php, mi v c chp nhn. Nhng phng php ny i hi phi s dng

thit b c tin nn rt t nh sn xut s dng phng php ny.

I.2.3.1. Quy trnh sn xut:

Mc ging Aspergillus Oryaza

Axit HCl 15-16%

Trung ha, lc bng Na2CO3

Bnh du phng

Thy phn 1

Thy phn 2

Dch lc

B

Nc tng

Ch phm sinh hc

Ln men, sy kh

iu v, thanh trng, v chai

S I.6. S phng php ln men kt hp vi phng php ha gii

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I.2.3.2. u v nhc im ca phng php:

a) u im:

Thi gian sn xut rt ngn cn 3 ngy.

Nng 3-MCPD mc cho php.

Mi v c ngi tiu dng a chung.

Gi thnh n nh.

b) Nhc im:

Cn thit b c tin v m bo an ton cho ngi trc tip s dng.

I.2.4. Cc phng php khc [15], [16], [17].

Ngoi cc phng php trn, ngi ta cn s dng axit clohidric nng cao cho vo xng ng vt, lng g, lng vt (l nguyn liu giu m). Nn trong qu trnh tip xc, HCl s phn ng vi cht bo trong nguyn liu, ri cho ra amino axit v c t 3-MCPD.

Sau , trung ha bng natri hydroxit v dng mt ng to mu.

Tuy nhin, trong lng g, vt thng cha nhiu cht thch tn (arsenic) v ch l nhng cht cc c i vi h tiu ha, h thn kinh, cha k n qu trnh thy phn

bng axit clohydric, sn phm c 3-MCPD v 1,3 - CDP l iu tt nhin.

Bn cnh , lng khi thu gom v, li rt d bn v khng hp v sinh. V th, nc tng lm t lng g, vt c gi thnh rt r ch t 1.000 n 1.500 ng 1 lt.

I.3. Tiu chun v nc tng ca B Y T.

I.3.1. Tiu chun v m [9], [15], [16].

I.3.1.1. m trong nc tng l g?

19

m trong nc tng l nng Nit ton phn, ni cch khc n l ch s

Protein tnh theo n v g/lt.

I.3.1.2. Phn loi hng nc tng da vo m.

Theo ti liu Nc chm, yu cu k thut ca Tiu chun Vit Nam (TCVN 1763-86), vic phn chia hng nc tng tu theo phng php sn xut v cht lng m nc tng c chia thnh 3 hng I, II v III. Trong , cc ch tiu ho hc ca nc tng:

TCVN(1763-86) Hm lng Nit tng s

(g/l) Phn hng

12N I

10N II Nc tng

N

20

C s sn xut Ch s m

( N hoc g Protein/100ml ) Phn hng Phn b, tiu th

12-18N I TPHCM, Ty Nam B Mekng

10-14N II Min Trung, min Bc

18-22N I Min Nam

14-16N II Min Nam Tng Thnh

10-12N III Min Nam

4,32N

Hay 2,7g Protein/100ml I Min Nam

Nht Ca v Nh Ca N32,4

Hay 1,6g Protein/100ml II Min Nam

> 6,5 N I Min Nam Ch Vn

5,6 N II Min Nam

Theo quy nh ca B Y t, sn phm nc tng ca cc c s sn xut trong

nc phi t m ton phn thp nht l 10N v buc phi ghi trn nhn.

iu c bit: Trong khi cc n v nc ngoi hoc lin doanh (nh Magi, Chinsu, Ch Vn) li c php ghi nhn l hm lng Protein. I.3.1.3. nh gi cht lng nc tng da vo m.

m cng cao th mi thm c trng ca bnh du, u nnh, u phngcng

thm, thi gian bo qun cng lu.

Bng I.2. Ch tiu m ca cc c s sn xut

21

Sn phm c m cng cao th cha th khng nh l ngon, v theo nhn xt ca cc nh sn xut: nc tng ngon thng c m t 18-25N, nhng loi tiu th mnh nht li t 14-18N. Nc tng c mt trn th trng Vit Nam thng c

ch s t 10-22 N.

Sn phm c m qu cao t 27N tr ln thng c mi hc, v mn lm t mi ca thc phm, mt i v c trng ca mn n. Do vy, khng cn phi b sung

lng Protein cho loi gia v ny.

Mt s loi nc tng c m t 25-26N, thi gian bo qun nc tng trung bnh sau khi m np 3-6 thng trong iu kin thong mt, kh ro.

Vi nhng sn phm nc tng c m thp, th ch s mui m formol

cng thp, khng iu kin bo qun sn phm. Do vy, sau mt thi gian s dng

d sn sinh NH3 lm phn hu cc cht dinh dng, si bt khng tan, gy ri lon tiu ho.

I.3.2. Phng php cm quan [7]. Phng php cm quan (hay trc quan) l quan st, nh gi cht lng sn phm,

hng ha bng cc gic quan: nhn, s, nim, ngi, nghephng php ny c ng dng rng ri vi nhng sn phm hng ha m mt phn quan trng cht lng ca

n ph thuc vo c trng v thm m, v mu sc, hng v. Nhng c trng ny,

vi phng php ha - c - l, nhiu khi khng gii p c.

Tuy l cm gic nhng hin nay, phng php ny c nh gi cao, coi ngang

hng vi cc phng php hin i khc v n va t tn km, va khng km chnh

xc.

Thit b quan trng nht ca phng php ny l ngi th.

Do phng php cm quan tr thnh phng php chnh thc, khng th

thiu trong vic nh gi cht lng sn phm. C nhiu phng php nh gi cm

22

quan khc nhau, ty theo tng trng hp c th. nc ta, cht lng sn phm thc

phm c nh gi theo phng php cho im theo tiu chun Vit Nam (TCVN-3215 -79). Khi phn tch cm quan cho im cc sn phm thc phm, tiu chun Vit Nam s dng h 20 im c xy dng trn mt thang im thng nht c 6 bc t 0-6. Trong , im 5 l cao nht cho mt ch tiu v gim dn theo bc, 6 bc nh gi phi tng ng vi tng ni dung m t sau:

Tn ch tiu

im s

Yu cu ch tiu ca tng sn phm

5 Sn phm mu nu nht n nu, khng c vng mc, khng c

mu khc l.

4 Sn phm c mu nu hi sm, khng c vng mc, khng c

mu khc l.

3 Sn phm mu nu en sm, khng c vng mc, c pha mu

thc phm t, khng c mu khc l.

2 Sn phm c mu en, khng c vng mc, c pha mu thc

phm nhiu.

1 Sn phm c mu khc l, c vng mc ni ln nhiu.

Mu sc

0 Sn phm khng t cc yu cu trn.

5 Dng lng, khng c cn en di y chai, khng c tinh th

mui l. trong

4 Dng lng, c ng cn en di y chai t, khng c tinh th

mui l.

Bng I.3. Bng phn cp cht lng sn phm

23

3 Dng lng, c ng cn en di y chai nhiu, khng c

tinh th mui l.

2 Dng sn st do ng cn qu nhiu, khng c tinh th mui l.

1 Dng st, c tinh th mui nh.

0 Khng m bo cc yu cu trn.

5 Sn phm c mi c trng, khng c mi khc l.

4 Sn phm t c hoc khng c mi c trng.

3 Sn phm c mi hi chua, hi kht.

2 Sn phm c mi chua, kht nhiu.

1 Sn phm c mi l.

Mi

0 Sn phm khng m bo cc yu cu trn.

5 Sn phm c v mn, c v chua c trng, khng c v cht,

ng v v l khc.

4 Sn phm c v hi mm, c v chua c trng, khng c v cht,

ng, v l khc.

3 Sn phm c v mm nhiu, hi chua, khng c v cht, ng v

v khc.

2 Sn phm khng c v mn, qu chua, c v ng, khng c v

cht, v l khc.

1 Sn phm khng mn, qu chua, c v ng, cht, v l khc.

V


24

Sn phm c nh gi bng tng im trung bnh chung theo phng php Duncan khng c h s quan trng K. Nu tng im trung bnh chung cha c h s K t t 11,2 - 20 im l t.

I.4. Cch xc nh m trong nc tng bng phng php Micro Kjeldahl [1], [2], [8].

I.4.1. Cc c tnh k thut ca thit b UDK 142:

Ch thch:

1. ng dn c bo v bi lp Plastic. 5. Khay thu hi.

2. ng nghim. 6. B phn p.

3. ng Teflon. 7. Gi bnh.

4. Vnh chn an ton.

Hnh I.2. Thit b chng ct m bng phng php Micro Kjeldahl

1

2

3

6 7

4

5

25

* Gm cc b phn:

1. Thit b chng ct kiu UDK 142.

2. ng nghim (42mm x 300mm).

3. Bnh Erlenmeyer (250ml) thu sn phm chng ct.

4. Km ht thi hi nng trong ng nghim t b phn chng ct.

5. ng dn kt ni vi vi nc.

6. ng dn c thit b cm bin nm ngang cha vt liu v o thi nhng cht cn lng.

7. ng dn phng in.

8. Bn phm.

9. Thit b vn hnh bng tay.

* Cc phm chc nng:

ESC : Tr li mn hnh hoc danh mc nm ngang pha trn mn hnh.

: Xem lin tip mn hnh khi la chn danh mc hoc tng thm gi tr cn

xem.

: Xem lin tip mn hnh khi la chn danh mc hoc gim gi tr cn xem.

: Thc hin lnh khi la chn danh mc hoc iu chnh mn hnh.

Vic chng ct hi nc c thc hin trong phng th nghim. Khi chng ct

phn on nhng cht lng khng tan, hoc nhng cht rn tun theo nh lut ca

Daton v p sut ring phn i vi mt hn hp kh. Thit b ny c s dng chng ct phn nh trong ha hc t nhng hn hp, hay nhng cn bng ion trong

dung dch. Sau phn ng khi ta thm axit hoc baz vo. C th, l vic nh lng m tng s bng phng php Kjeldahl. Mc khc, phng php Kjeldahl cn c

26

s dng nhiu trong vic xc nh Nit v hm lng Protein trong thc phm. Thit b ny rt d s dng v cho kt qu chnh xc cao.

H thng chng ct hi nc t ng l mt thit b in t c iu khin bi b

vi x l, cho php thay i thi gian chng ct v s bc hi nc. Vic chng ct din ra nhanh hay chm l ph thuc vo mu phn tch. C ngha l khi tin hnh xc nh

hm lng Protein bng phng php Kjeldahl th thi gian chng ct c th c gim bt t 2-3 pht, trong khi nhng trng hp khc th c th ko di n 30

pht hoc lu hn na.

I.4.2. Ni dung phng php Kjeldahl. a) Mc ch :

nh lng Nit tng s trong nguyn liu nh: bt u nnh, bt xng, bt c, nc tng, nc mm

b) Nguyn l : Di tc dng ca H2SO4 m c nhit cao v c cht xc tc, cc hp cht

hu c c cha Nit b phn hy v b oxi ho n CO2 v H2O, Nit chuyn thnh Amoniac (NH3) v tip tc kt hp vi H2SO4 to thnh mui Amoni sunfat.

c) M t:

y l qu trnh nh lng Nit tng s theo phng php Kjeldahl c thc hin theo 3 bc sau:

Bc 1 : V c ho nguyn liu:

Protein tc dng vi axit Sunfuric m c nhit cao trong mi trng c cht xc tc.

R-CH(NH2)-COOH + H2SO4 CO2 + H2O + NH3 + SO2

2NH3 + 2H+ 2 +4NH

27

2 +4NH + duSO 24 (NH4)2SO4

Bc 2 : Ct m: (NH4)2SO4 + 2NaOH Na2SO4 + 2NH3 + 2H2O

2NH3 + H2SO4 (NH4)2SO4 + H2SO4 d Bc 3 : Chun lng H2SO4 cn tha bng NaOH:

T lng NaOH tiu tn trong chun vi ln th tht (mu l dung dch m v c ho) v ln th khng (mu l nc ct), chng ta tnh ra c hm lng Nit tng s trong mu nguyn liu.

d) Cng thc tnh m ton phn: * Hm lng Nit tng s: i vi mu rn (%):

m

KVVX

100*0014,0**)( 211

=

i vi mu long (g/l):

101000*20*0014,0**)( 21

1KVV

X

=

Trong :

V1 : th tch ca dung dch NaOH 0,1N dng cho php th trng (ml). V2 : th tch ca dung dch NaOH 0,1N dng chun mu tht (ml). 10 : th tch mu th pha long (ml). m : khi lng mu th (g). K: h s iu chnh NaOH (K=1). 20 : l pha long mu th.

0,0014 : s gam Nit tng ng vi 1ml NaOH 0,1N. 1000 : h s tnh ra g/l.

100 : h s tnh ra phn trm. * Hm lng Protein (%): X2 = 6,25* X1

28

CHNG II: K THUT THC NGHIM

II.1. Nguyn liu - dng c - ha cht.

II.1.1. Nguyn liu:

Bnh du phng loi tt, cn nguyn vn, khng nhim mc en v c mi thm c trng c mua t ch Kim Bin Si Gn.

Go, np phi chn loi tt, loi b sn, t, ht h, thc, tru c mua Ch Tn Tch thnh ph Cao Lnh.

L chui ra sch, lau kh.

Mc ging Aspergillus Oryaza.

II.1.2. Dng c

Nhit k cn, cc thy tinh 500ml.

H snh loi va c np y.

R nh, nia hoc xng ln.

1 ci thau va.

a tre di 1,5m.

Ni hp.

Mt ci bao b, mt ci gi, ....

Cn phn tch c chnh xc 0,0001g.

Bnh cu c nhnh, dung tch 250ml.

Bnh tam gic, dung tch 250ml v 50ml.

H thng sinh hn.

29

Bp un c chc nng kim sot nhit.

Buret 25ml.

Pipet 10ml v cc dng c thng thng khc trong phng th nghim.

II.1.3. Ha cht:

Mui n (NaCl).

Nc ct.

Hn hp xc tc K2SO4/CuSO4 (t l 10:1) theo khi lng.

H2SO4 m c, dung dch H2SO4 0,1N.

Dung dch NaOH 30%, dung dch NaOH 0,1N.

Cht ch th: Phenolphtalein 1% v ch th hn hp (Metyl : Metyl xanh).

II.2. Xy dng quy trnh ch bin nc tng.

II.2.1. Nui mc ging Aspergillus Oryaza:

II.2.1.1. Nguyn liu chnh:

Go, np (0,5kg).

L chui sch.

II.2.1.2. S lm mc ging:

30

S II.1. Quy trnh lm mc Aspergillus Oryaza

Vt ra

Cho ra

3 ngy

2 ngy

Go + np

i sch

Ngm nc 4-5 gi

Xng

Hp 2 gi

Xng go, np chn u

Lm ti

Thau

ngui

L chui lp dy 1,5-2cm

Nia y l chui khc kn li

Bao b

M bao b

Mc vng, , xanh lc

Ly mc ra

Phi nng

Lm nhuyn

31

II.2. 2. Quy trnh lm nc tng bng phng php ln men:

II.2.2.1. Nguyn liu chnh:

Bnh du phng (1,5 kg).

Mc ging Aspergillus Oryaza.

II.2.2.2. S sn xut nc tng:

S II.2. Quy trnh lm nc tng bng phng php ln men

H snh c np y

cho ln men 50-600C

Nc mui 25%

3 thng

em lc

Nc tng I

Nc tng II

Ch bin

Nc tng thnh phm

B

Ln 1

Ln 2

Nghin

Ly hn hp mc

Bnh du phng

Phn loi kch c

Ngm nc 4-5 gi

Chn u Hp 5-6 gi

Thau

Nia Ngui

Trn mc lm trn

y l chui kn li

Bao b

3 ngy

Mc pht trin u

M bao b

32

II.3. Xc nh m trong nc tng sau khi sn xut.

II.3.1. Nguyn tc:

Mu c v c ha bng axit Sunfuric m c, Nit c trong mu th chuyn

thnh Amoni sunfat. Dng kim mnh y Amoniac ra khi Amoni sunfat trong h

thng ct m to thnh Amoni hydroxyt ri nh lng bng axit.

II.3.2. Dng c - thit b:

Cn phn tch c chnh xc 0,0001g.

Bnh cu c nhnh, dung tch 250ml.

Bnh tam gic, dung tch 250ml v 50ml.

H thng sinh hn.

Bp un c chc nng kim sot nhit.

Buret 25ml, Pipet 10ml v cc dng c thng thng khc trong phng th nghim.

II.3.3. Ha cht:

II.3.3.1. Hn hp xc tc K2SO4/CuSO4 (t l 10:1 theo khi lng)

Cn 10g K2SO4 v 1g CuSO4, nghin nhuyn ri trn u.

II.3.3.2. Axit H2SO4 m c trong phng th nghim.

II.3.3.3. Dung dch H2SO4 0,1N:

Dng Pipet ht 2,8ml H2SO4 m c cho vo bnh nh mc 1000ml, nh mc ti vch.

II.3.3.4. Dung dch NaOH 30%:

33

Cn 150g NaOH rn ha tan bng nc ct n 500ml trong bnh nh mc, nh mc ti vch.

II.3.3.5. Dung dch NaOH 0,1N:

Ha tan 2g NaOH rn pha thnh 500ml trong bnh nh mc, nh mc ti vch.

II.3.3.6. Phenolphtalein 1%:

Cn 1g phenolphtalein pha trong Etanol 600 trong bnh nh mc 100ml, nh mc ti vch.

II.3.3.7. Hn hp ch th:

Cn 0,1g Metyl v 0,05g Metyl xanh pha trong Etanol 600 trong bnh nh mc 100ml, nh mc ti vch.

II.3.4. Cch ly mu v chun b mu:

i vi nc tng nn lc u hn hp trc khi ly mu i phn tch.

Khi ly mu phi bo qun trong cc dng c thch hp, sch, kn, trong cc iu kin khng lm nh hng ti cht lng mu.

Chun b 2 mu:

Mu 1: cha qua ch bin (lc b b ly nc tng).

Mu 2: qua ch bin (sau khi lc xong, em nu si khong 1000C, sau cho gia v v cht bo qun).

II.3.5. Cch tin hnh:

Gm 3 giai on c th sau:

II.3.5.1. Giai on v c ha mu:

Lc u mu nc tng, ly 5ml nc tng bng Pipet sch cho vo bnh nh mc 100ml, nh mc bng nc ct cho ti vch, lc u.

34

Ht 20ml dung dch pha long bng pipet cho vo bnh cu c nhnh, cho 2g xc tc vo v 5ml H2SO4 m c, y np kn li 30 pht.

Dng nt cao su c gn h thng sinh hn y ln bnh ph mu, t ln bp un ri

dn lung kh CO2 v SO2 i qua dung dch NaOH c trnh gy nhim mi trng xung quanh.

Tin hnh un nh, sau tng nhit dn, nhng ch nhit un phi nh hn 1000C.

Trong qu trnh un, thy mu khng trng th ngng un, ngui cho thm 0,5g xc tc v 3ml H2SO4 m c vo v tip tc un.

Tin hnh un cho n khi dung dch c mu xanh trong, mt trong bnh khng

hon ton trong sch m c cn en th ngng un, ngui.

Hnh II.1. Thit b ph mu Hnh II.2. Dung dch nc tng sau khi ph mu.

35

II.3.5.2. Giai on chng ct mu:

Dng pipet ht 20ml H2SO4 0,1N cho vo bnh tam gic (bnh hnh nn hay elen) hng ca b ct m v nh t t 3 git ch th hn hp vo bnh tam gic. Nhng u

di ng sinh hn ca b ct m ngp vo dung dch trong bnh tam gic trnh mt m.

Cho mu v c ha vo bnh chng ct (bnh cu c nhnh), dng nc ct trng bnh cu cha mu v c ha nhiu ln cho n khi nc trng ht phn ng vi axit

(th bng giy qu). Cho 5 git phenolphtalein 1% v 35ml dung dch NaOH 30%, trng nc ct cho sch kim phiu.

Nu dung dch trong bnh cha c mu hng m th tip tc thm 5-10ml dung dch NaOH 30% n khi dung dch c mu hng m. Thm nc ct n khong 2/3 th tch ca bnh v kha phiu li. Gi mt t nc ct trn phiu cao khong 2cm

trnh NH3 bay ln.

Tin hnh ct n khi bnh hng c khong 250ml th dng (th u ng sinh hn bng giy qu nu khng c phn ng kim th qu trnh ct kt thc).

H bnh hng xung ng sinh hn khng chm mt nc v dng nc ct ra sch u ng sinh hn cho chy vo bnh hng.

Hnh II.3. Dung dch bnh hng.

Hnh II.4. Thit b chng ct mu khi gn bnh hng.

36

II.3.5.3. Giai on chun mu:

* Mu v c ha:

Ly bnh hng (bnh tam gic) ra chun lng axit d trong bnh bng NaOH 0,1N nng chnh xc. Ht 5ml dung dch trong bnh tam gic em chun .

Cho dung dch NaOH 0,1N vo Buret, nh mc ti vch 0. Nh t t dung dch NaOH 0,1N vo bnh tam gic n khi dung dch chuyn t mu tm sang mu xanh l

m th dng chun .

* Mu trng (mu nc ct): Tng t v s dng cng lng thuc th nh trn.

Hnh II.5. Dung dch trong bnh chng ct mu. Hnh II.6. Thit b ang

tin hnh chng ct mu.

Hnh II.7. Dung dch em chun . Hnh II.8. Dung dch

sau khi chun .

37

II.3.5.4. Tnh kt qu:

a) Hm lng Nit tng s tnh bng g/l: 10

1000*20*0014,0**)( 211

KVVX

=

b) Hm lng Protein tnh theo %: 25,6*12 XX =

II.4. Phng php th cm quan phn tch cht lng nc tng.

II.4.1. Chun b:

Dng c v iu kin th cm quan theo TCVN 3215 79

Lc k chai ng mu th, m nt chai rt ra 15-20ml nc tng vo mt cc thy tinh khng mu, kh, sch c dung tch 50ml xc nh ch tiu cm quan.

II.4.2. Cch tin hnh:

II.4.2.1. Xc nh mu sc:

Khi nhn xt mu sc phi t cc nh mu th ni sng, trn nn trng. Mt

ngi quan st phi cng pha ngun sng chiu vo mu th.

II.4.2.2. Xc nh trong:

t cc ng mu th gia ngun sng v mt ngi quan st, lc nh cc xc

nh trong.

II.4.2.3. Xc nh mi:

Sau khi rt nc tng t chai mu ra cc phi 5-10 pht mi xc nh mi. Cn tin hnh ni thong, khng c mi l d nh hng n vic nhn xt mi ca mu th.

II.4.2.4. Xc nh v:

Trc khi xc nh v ca nc tng phi sc ming bng nc l un si

ngui, khng c ht thuc l, ung nc tr trc khi xc nh v.

38

Sau khi dng mu nc tng xc nh cc ch tiu cm quan, khng c tr li chai ng mu th v cng khng c dng xc nh cc ch tiu ha hc.

Hi ng cm quan gm 10 thnh vin vi cc ch tiu v mu sc, trong, mi,

v.

Ta t:

Mu 1: mu cha qua ch bin (lc b b ly nc tng).

Mu 2: mu qua ch bin (sau khi lc xong, em nu si khong 1000C, sau cho gia v v cht bo qun).

Tin hnh cm quan hai mu trn.

39

CHNG III: KT QU THO LUN III.1. Quy trnh sn xut nc tng bng phng php ln men.

III.1.1. u im:

To ra sn phm nc tng sch khng c 3-MCPD m bo an ton sc khe cho ngi tiu dng.

Khng s dng cc ha cht c hi.

S dng mc ging Aspergillus Oryaza lm t nguyn liu go, np.

III.1.2. Nhc im:

Cn c lu, h sch.

Thi gian sn xut di 3 thng mi cho sn phm.

Mi v cha quen vi ngi tiu dng.

Cn mc ging Aspergillus Oryaza, nhng vic lm mc rt kh.

III.2. Xc nh m ca nc tng sn xut c.

Trc khi tin hnh xc nh m ta chun b 2 mu:



Kt qu:

40

Th tch dung dch NaOH 0,1N (ml) Mu

Ln 1 Ln 2 Ln 3 NaOHV

1 7,45 7,44 7,43 7,44

2 7,60 7,59 7,58 7,59

Th tch dung dch NaOH 0,1N (ml) Mu

Ln 1 Ln 2 Ln 3 NaOHV

1 10,95 10,94 10,93 10,94

2 11,04 11,03 11,03 11,03

Bng III.1. Th tch dung dch NaOH 0,1N dng chun mu trng.

Bng III.2. Th tch dung dch NaOH 0,1N dng chun mu v c ha.

41

Mu

Mu

trng

(V1)

ml

Mu v

c ha

(V2)

ml

V1-V2

ml

Hm lng

Nit

tng s

g/l

Hm lng

Protein

%

1 10,94

7,44 3,50 9,80 61,25

2 11,03

7,59

3,44 9,64 60,25

Kt lun: Nc tng qua ch bin c hm lng Nit tng s v hm lng

Protein nh hn nc tng cha qua ch bin khng nhiu, do nc tng qua ch bin c b sung thm gia v, cht bo qun nhng khng nh hng nhiu n m.

Tuy nc tng qua ch bin c hm lng Nit t hn nhng vn gi c mi v thm ngon c trng ca nc tng, l v mn v v ngt ca ng. Cn nc tng cha qua ch bin c hm lng m cao hn mt t, c mi v c trng ring

ca nc tng, nhng c v mn l khng m nh nc tng qua ch bin.

Bng III.3. Hm lng Nit v Protein trong nc tng

42

Kt lun: Da theo TCVN 1763-86, nc tng sn xut c phn hng loi III, v c m v hm lng Protein (theo bng I.1 trang 16).

Hm lng Nit tng s v hm lng Protein ca mu 2 tht thot khng nhiu so

vi mu 1, v mu 2 qua ch bin c b sung thm gia v, cht bo qun, nhng

khng nh hng nhiu n m.

III.3. Phng php cm quan cht lng nc tng:

Trc khi tin hnh cm quan ta chun b:

Dng c theo TCVN 3215-79

Mu phn tch: 2 mu.



Kt qu:

Theo tiu chun Vit Nam 1763-86

Mu Hm lng Nit tng s(g/l) Hm lng Protein(%) Phn hng

1 9,80 61,25 III

2 9,64 60,25 III

Bng III.4. So snh vi tiu chun ca Vit Nam

43

Mu 1 Mu 2 Tn

ch

tiu

TB

khng

c K

H s

quan

trng K

TB

c K

TB

khng

c K

H s

quan

trng K

TB

c K

Mu

sc 4,7 0,5 2,35 4,9 0,5 2,45

trong 4,0 1,5 6 4,4 1,5 6,6

Mi 3,3 0,5 1,65 3,2 0,5 1,6

V 2,8 1,5 4,2 3,5 1,5 5,25

Tng

im 14,8 4 14,15 16,0 4 15,90

Kt lun: Nc tng qua ch bin th thu c sn phm c cht lng khng khc nhiu so vi sn phm cha qua ch bin. Bi v, nc tng cha qua ch

bin c mu nu m, mi c trng ca nc tng, v mn l hi kh nim. Cn nc tng qua ch bin c: mu nu nht, mi c trng, v mn, ngt d n.

Cc mu nc tng do chng ti t sn xut ch t cht lng mc trung bnh, bi v chng ti cha c kinh nghim v vn ny.

Bng III.5. Kt qu cm quan

44

PHN KT LUN KIN NGH

I. Kt lun:

Nhng kt qu nghin cu t c ca ti:

Lm mc ging Aspergillus Oryaza t go, np.

Tin hnh thc nghim trn 1,5kg bnh du phng th cho ra 3 lt nc tng.

Thc nghim 3 thng cho ra 2 mu nc tng. Hin 2 mu ny c chng ti tin hnh cm quan v phn tch hm lng m tng s, hm lng Protein

nh gi cht lng sn phm. Kt qu cho thy:

Hm lng Nit tng s: 9,64 - 9,80g/l.

Hm lng Protein: 60,25 - 61,25%.

Phn tch cm quan t 14,15 - 16,00 im ph hp vi TCVN 3215-79.

Tin hnh phn tch cm quan 2 mu: mu 1 (cha qua ch bin), mu 2 ( qua ch bin). Kt qu sn phm qua ch bin c cht lng khng khc nhiu so vi sn phm cha qua ch bin.

Thc nghim xc nh m 2 mu th thy mu 2 tht thot khng nhiu so

vi mu 1.

Cc mu nc tng do chng ti t sn xut ch t cht lng mc trung bnh, bi v chng ti cha c kinh nghim v vn ny.

II. Kin ngh:

Mc d phng php sn xut nc tng bng phng php ln men t bnh du phng s to ra sn phm ngon, sch v m bo sc khe cho ngi tiu dng.

Trong qu trnh sn xut nc tng c s dng mc ging Aspergillus Oryaza, nhng vic lm mc ging rt kh. Nn y, hn ch ca chng ti l cha mua c mc

45

ging Aspergillus Oryaza c nui cy sn ca Vin Khoa hc cng ngh Thnh Ph H Ch Minh.

Do chng ti ch s dng phng php th cng xc nh m trong nc

tng nn kt qu t c khng chnh xc tuyt i.

V vy, chng ti c kin ngh cho hng tip theo nh sau:

Nghin cu thm v vic sn xut mc ging.

Nn lin h vi Vin Khoa hc cng ngh Thnh Ph H Ch Minh mua mc ging.

Nu c thi gian nn so snh nc tng sn xut t mc t lm vi nc tng

lm bng mc ging ca Vin Khoa hc cng ngh Thnh Ph H Ch Minh.

So snh m xc nh theo phng php th cng vi phng php xc nh

bng my bit thm v chnh xc.

46

TI LIU THAM KHO. 1. Phm Th Trn Chu (1987), Thc hnh ha sinh, NXB GD.

2. Nguyn Th Hin V Thy Th (2003), Ha sinh nng nghip, NXB HSP.

3. Nguyn c Lng (2004), Cng ngh enzym, NXB HQG TPHCM.

4. Nguyn c Lng, Cng ngh vi sinh vt - thc phm ln men truyn thng

(tp 3), NXB H K Thut TPHCM.

5. Nguyn c Lng, Cng ngh sinh hc, NXB H k thut TPHCM.

6. Nguyn Xun Thnh, Gio trnh vi sinh vt hc cng nghip, NXB GD.

7. Trung tm 3 - tng cc tiu chun o lng cht lng TPHCM (www.quatest3.com.vn).

8. HouBenWeyl (1979), Cc phng php phn tch ha hc hu c (tp1,2), NXB Khoa Hc v K Thut H Ni.

9. http://www.asimco.com.vn

10. http://www.dost-bentre.gov.vn

11. http://giaoanviolet.vn

12. http://www.hoahocvietnam.vn

13. http://www.H2.vn

14. http://www.medinethochiminhcity.gov.vn

15. http://sem.net

16. http://www.tiengiang.gov.vn

17. http://vietsciences.vn

47

PH LC

PHIU CHO IM CM QUAN NC TNG

Bng im chi tit:

im cm quan Tn ch

tiu

im s

Yu cu ch tiu ca tng sn phm

Mu 1 Mu 2

Nhn xt

5 Sn phm mu nu nht n nu,

khng c vng mc, khng c mu

khc l.

4 Sn phm c mu nu hi sm, khng c vng mc, khng c mu khc l.

3 Sn phm mu nu en sm, khng c vng mc, c pha mu thc phm t,

khng c mu khc l.

2 Sn phm c mu en, khng c vng

mc, c pha mu thc phm nhiu.

1 Sn phm c mu khc l, c vng

mc ni ln nhiu.

Mu

sc


5 Dng lng, khng c cn en di y chai, khng c tinh th mui l.

trong

4 Dng lng, c ng cn en di

y chai t, khng c tinh th mui l.

48

3 Dng lng, c ng cn en di y chai nhiu, khng c tinh th

mui l.

2 Dng sn st do ng cn qu nhiu,

khng c tinh th mui l.

1 Dng st, c tinh th mui nh.

0 Khng m bo cc yu cu trn.

5 Sn phm c mi c trng, khng c

mi khc l.

4 Sn phm t c hoc khng c mi c

trng.

3 Sn phm c mi hi chua, hi kht.

2 Sn phm c mi chua, kht nhiu.

1 Sn phm c mi l.

Mi

0 Sn phm khng m bo cc yu cu

trn.

5 Sn phm c v mn, c v chua c

trng, khng c v cht, ng v v l

khc.

V

4

Sn phm c v hi mm, c v chua c trng, khng c v cht, ng, v

l khc.

49

3 Sn phm c v mm nhiu, hi chua,

khng c v cht, ng v v khc.

2

Sn phm khng c v mn, qu chua, c v ng, khng c v cht, v l

khc.

1 Sn phm khng mn, qu chua, c v

ng, cht, v l khc.


Cao Lnh, ngy..thngnm 2009 Ngi cm quan

lv che bien tuong tu dau phong

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