Baigiang_CNSXNCGV

BI GING: CNG NGH SN XUT NC CHM GIA V

CHNG I: TNG QUAN V NC CHM GIA V

1.1.Vai tr ca nc chm v gia v i vi i sng con ngi 1.1.1.Gi tr s dng

Gia v c th c hiu l mn n thm vo trong khu phn n nhng c mi v c bit c th gip ta n ngon ming hn, thoi mi hn, thm ch nhng lc c th thy mt bing n, c thm gia v ta c th n thm c nhiu thc n hn. V d nh ngi Vit Nam quen dng nc mm trong cc ba n nh mt iu ht sc t nhin. Thiu nc mm trong ba n, ngi Vit Nam cm thy nh thiu ci g rt quan trng, ba n lc o tr nn nht nho. Hay cng mt cng thc nu n ca mt mn no m c ngi nu ngon, c k nu d. l do ngi nu bit cch nm, nm cho thm vo cc loi gia v mn n tr nn hp dn

Chng ta khng s dng cc loi nc chm hay gia v nh l mt dng thc phm dinh dng nhng thiu nhng loi thc phm ny th qu l cuc sng tht nht nho bit bao. 1.1.2.Gi tr kinh t

Ngun nguyn liu cung cp cho ngnh sn xut nc chm v gia v thng l ph phm ca cc ngnh khc nn lm gim gi thnh sn phm. V d nh sn xut nc chm t kh u nnh, kh lcl ph phm ca ngnh cng ngh ch bin du. Bt ngt (m chnh) c sn xut t mt r l ph phm ca ngnh ng.

Cng ngh sn xut cc loi nc chm v gia v n gin, c th thc hin quy m th cng hay cng nghip u cho cht lng cao nn ngy mt p ng kp thi nhu cu ca ngi dn 1.2. Gii thiu chung v cc loai nc chm gia v 1.2.1. Nc chm

Nc chm l tn gi chung ca tt c cc loi gia v c m v c nng mui tng i cao. Nguyn liu s dng sn xut xut cc loi nc chm l t nguyn liu giu m, ch yu l cc ht c du (u nnh). Ngy nay ngi ta thng sn xut nc chm t kh u nnh, kh lc

Tuy mang nhiu tn khc nhau: magi, x du, nc tng nhng u c sn xut t 2 phng php

Phng php ln men

Phng php ha gii. mi dn tc u c nhng loi nc chm mang c th ring. V d 1.2.2. Tng

Tng l mt sn phm ln men t cc ngun nguyn liu giu glucid v giu m nh l u nnh, go np, go t, bp. Tng thng dng st hay huyn ph do u nnh khng thy phn hon tan.

y l mt dng nc chm c truyn ca Vit Nam v c gi tr dinh dng cao ( cha nhiu aicd amin v glucid cung nh cp nhiu cht bo , sinh t, khong). Nhng a phng lm tng ni ting nh C (H Ni), Bn Yn Nhn (Hng Yn) 1.2.3. Chao

Chao l sn phm ln men t sa u nnh ng c do vi sinh vt tit ra enzyme chuyn ha m (protit), bo (lipit), ng a (glucit) c trong sa u nnh thnh ra nhng phn t n gin nh axit amin, axit bo, cc ng n. Nh vy,chao c mi thm, v bo c bit v l mt sn phm giu cht dinh dng.

Nu so snh vi u ph, chao c gi tr dinh dng cng nh h s tiu ha cao hn nhiu. N c y cht b dng ca sa u nnh, nhng d tiu v cc cht protit, lipit, glucit c phn ha t (hay enzym) ca vi sinh vt chuyn ha ra cc phn t n gin, sn sng c tiu ha v hp th. C th xem chao l mt dng ph mai thc vt

Chao c nhiu dng sn phm khc nhau : chao nc, chao c, chao bnh, chao bt v.v Cc dn tc khc cng sn xut chao nhng c hng v ring do phi trn thm cc gia v v c tn gi khc nh

1.2.4. Nc mm Nc mm l sn phm ln men t cc loi c, l sn phm ca truyn thng ca dn tc Vit Nam.


Nc mm l dung dch acid amin, mui n, cc cht thm c to ra trong qu trnh ln men m nguyn liu l t cc loi c. Cht lng nc mm ph thuc nhiu vo cc loi c khc nhau. Nc mm l mt loi gia v nhng cng l mt loi thc phm c gi tr dinh dng cao.Trong ba n thng ngy ca nhn dn Vit Nam khng th thiu nc mm c.

Phng php ch bin nc mm c truyn Vit Nam c nhc im c bn l chu k sn xut qu di (t 9 thng n 1 nm) v vy khng kinh t.Vi chc nm gn y c nhiu nghin cu trong v ngoi nc nhm rt ngn thi gian ch bin v nng cao cht lng ca sn phm p ng nhu cu ngn cng cao ca nhn dn.

Bn cht ca qu trnh sn xut nc mm gm hai qu trnh :

Qu trnh chuyn ha protein thnh acid amin

Qu trnh to hng 3. Cc loi gia v 3.1. Cc loi gia v dng bt hay vin Chia lm 2 loi: Loi gia v dng s ch: tc l dng kh ca cc loi gia v nh t bt, tiu bt, ht iu hay bt ngt Cn li l cc loi gia v hn hp thng c tn l bt nm, bt canh hay vin sp. Thnh phn ca loi gia v ny l mui, ng, bt ngt, hnh, ti, t ( dng hng hay sy kh) v cc loi gia v khc to nn hng v c th cho tng loi. Ngoi ra ngi ta c th b sung nc chit c c t cc loi tht hay hng tht.

3.2. Cc loi gia v dng st (dng paste)

cc loi gia v thuc nhm ny phn ln l cc loi tng t, m tt.

Tng t: thnh phn chnh l t qu, bt, hnh ti, mui ng, cht iu v

Cc loi tng t ph bin hin nay: tng t mn, tng x mui, tng c


CHNG II:

NGUYN LIU DNG TRONG SN XUT NC CHM GIA V

2.1.THC VT GIU M

1. u nnh Ht u nnh c nhiu hnh dng khc nhau : trn, bu dc, trn di, trn dp, chy di. V mu sc

cng khc nhau : vng xanh, xm, en v cc mu trung gian. Nhng ni chung phn ln l mu vng, loi u nnh c mu vng l mu tt nn thng c a chung.

Ht u nnh c ba b phn : v, t dip, phi. V ht chim khong 8% trng lng ht. Phi chim khong 2% trng lng ht. T dip chim khong 90% trng lng ht.

Ty theo kch thc ca ht thng chia lm ba loi : to, trung bnh v nh.

Loi ht Khi lng ca 1000 ht

To >300g

Trung bnh 150g-300g

Nh


Trong protit u nnh hm lng axit amin khng thay th c :

Thnh phn Hm lng %

Triptofan 1,1%

Leusin 8,4%

Izoleusin 5,8%

Valin 5,8%

Threonin 4,8%

Lizin 6,0%

Methionin 1,4%

Fenylalanin 3,8%

Tr Methionin qu t cn cc axit amin khc ca u nnh c thnh phn gn ging tht. Lipid

Trong lipit ca u nnh c hai loi axit bo : no v khng no. Chim khong 60-70% cht bo ca ht gm c cc loi : axit linoleic 52-65%, axit linolenoic 2-3%, axit

oleic 25-36%.

Cc loi no c : axit panmitic 6-8%, axit stearic 3-5%, axit arachinica 0,4-1% 2. u phng Nguyn liu ch yu sn xut chao t trc ti nay l u nnh. Tuy nhin cng c mt s a phng

rt t c s dng lc lm chao. Dng lc lm chao phi qua khu tch du. y l loi nguyn liu phong ph.

u phng (cy lc) c tn khoa hc l Arachis hypogea. Lc c hai loi : loi 3-4 thng Loi 6-8 thng Ht lc c nhiu hnh dng khc nhau : trn, bu dc. V mu sc cng khc nhau : tm, nu nht, nu v.v Ht lc c ba b phn : v la, t dip v phi. V la rt mng ngoi cng bao ly t dip v phi, khi

sy kh ngui v d tch ra khi t dip. T dip gm hai phin c mu trng sa hoC trng ng. Phi gm c ba thnh phn : phi mm, phi l v phi r. Cn c vo kch thc ca ht lc ngi ta chia ra lm ba loi : Loi to di 1,6-2,0 cm, rng 0,9-1,2cm. Loi trung bnh di 1,2-1,5 cm, rng 0,85-1,1 cm Loi nh di 1,0-1,2cm, rng 0,75-0,85cm. Gi tr dinh dng Thnh phn ho hc:

Thnh phn Hm lng %

protein 20-34%

lipit 40-60%

Hirat cacbon 6,0-22%

Xenlol 2,0-4,5%

Tro 1,8-4,6%.

Trong protein ca lc th globulin l cao nht chim khong 97% hm lng protit, ngoi ra cn c mt hm lng khng ng k cc loi anbumin, prolamin, glutelin.

Trong lipit ca lc c hai loi axit bo no v khng no.


Loi khng no c : Axit olic 50-70%, axit linoleic 13-26%, axit linolenoic 13-26%.

Loi no c : Axit panmelic 6-11%, axit staric 2-6%, axit arachinoic 5-7%. Bt lc t lc tch du : Am 8%, tro 4,8%, protein 48%, lipit 8,0%, hirat cacbon 26,5%. Hm lng acidamin trong bt lc tch du :

Triptofan 0.5%

Lxin 3.5% Izolxin 1.5% Valin 4.0%

Treonin 0.75%

Lizin 1.5%

Methionin 0.6%

Fenylalanin 2.7%

3. Kh u phng, kh u nnh a. Kh u nnh:

Cht bo bng 18% hm lng cht bo trung bnh trong u tng. Do , u tng thng c p ly du trc khi em ch bin nc chm:

p c gii: lng du thu c t 12 14%. p th cng: lng du thu c t 6 10%. u tng sau khi p du, b cn li l kh u tng c dng ch bin nc chm. iu ny tt hn khi dng trc tip u tng sn xut nc chm. V trong u tng c n 18% cht bo. Trong qu trnh ch bin, mt phn cht bo ny chuyn thnh acid bo t do, glycerit, v cc sn phm khc. Cc cht ny lm nh hng n mi, v v cht lng ca sn phm nc chm.

Mt khc, gi thnh ca kh u tng thp hn 30 40% so vi gi thnh u tng. Thnh phn ho hc ca kh u tng theo phn trm cht kh: - m: 10,0%. - Protid: 44,5% .

- Cht bo: 5,0%.

- Glucid: 29,2%.

- Cellulose: 5,8%.

- Tro: 5,5%.

b. Kh lc: Cht bo trung bnh l 50%. Protein ca lc gm: albumin (16,36%), globulin (17,38%), glutelin (16,82%). Trong lc, cn c nhiu vitamin nhm B, v E. Lc sau khi p ly du, b cn li l kh lc. Trong kh lc cn c nhiu cht dinh dng khc cho nn ngi ta thng dng kh lc sn xut nc chm. Thnh phn kh lc p nh my du Vinh theo phn trm cht kh: - m: 10,74%. - Protein: 65,62%.

- Cht bo: 6,5%. - Glucid: 12,1%.

2.2. m t ng vt

2.2.1.Cc loi c Trc y ngi ta thng dng cc loi c ch bin nc mm theo phng php c truyn vi thi gian kh lu, t 6 thng n 1 nm. Hin nay, cc nc trn th gii nh: Lin X, c, Trung Quc c sn xut


dch m thy phn t c theo phng php nhanh. Nguyn liu l cc loi cc nc mn v c nc ngt. Loi c nhiu cht m, t nc cho dch m thy phn ngon hn so vi loi c t m, nhiu nc. Thnh phn ha hc ca mt s loi c nc mn v c nc ngt c ghi trong bng 9 v bng 10.

Bng 9: Thnh phn ha hc mt s c nc mn (g/100g)

Tn c Nc m tng s Cht bo Mui khong

C nc 76,56 1,8 1,30 0,07

C trch 77,02 1,8 4,51 0,08

C cm 75,14 1,8 2,10 0,90

C mi 76,66 1,5 11,10 0,56

C lp 81,84 1,5 1,40 0,60

C chun 76,17 1,6 7,50 1,12

Bng 10: Thnh phn ha hc mt s c nc ngt (g/100g)

Tn c Nc m tng s Cht bo Mui khong

C dic 85 13,0 1,1 0,8

C chp 79 18,1 1,5 1,1

C trm en 77 17,9 3,8 1,2

C m hoa 82 14,5 0,6 1,2

C m trng 86 10,3 1,0 0,7

C lnh canh 76 15,6 2,3 1,3

2.2.2.Cc loi tng, xng, da ca gia sc. Nguyn liu dng ch bin nc chm bng phng php acid, ngoi kh u tng v kh lc ra ngi ta cn dng cc loi ph tng, xng, da ca cc loi gia sc (bng 11). Bng 11: Thnh phn ha hc ca cc loi ph tng, xng v da ca cc loi gia sc (% cht kh)

Thnh phn Loi

Nc Protit Cht bo

Gan 60-80 15 2-20

Mu 79 9 1

No 78 8 12-15

Tim 79 7 7

Xng 42 17-20 10-15

Sn - 17-20 7-10

Da 66 23 7

2.3.Cc loi nguyn liu thc vt khc 1. T

Tn khoa hc : Capsicum annuum L. Thuc h : C ( Solanacceae) c tnh thc vt v cng dng :

t l cy hng nin nhng c th sng c vi ba nm nu chm sc tt. t l mn gia v thng thy trong hu ht cc gia nh ngi Vit Nam cng nh ngi nc ngoi. nc ta ngi min Trung n nhiu t hn ngi min Bc. Hu ht cc mn n u c t, t dng pha vi nc chm, cho v canh c, canh tm, c bit l cc loi thc n c mi tanh. t pha vi bt c ri. C nhiu ngi khi n thiu t khng thy ba n ngon ming. V vy, t trng v c bn khp mi ni. Ngy nay, t l loi hng xut khu cho nhiu nc thu mt lng ngoi t ng k.

Chia l 2 loi: t cay (ht chili) v t ngt (sweet chili)


Yu cu k thut: -loi t cay, chn , khng b dp ng thm en (cay phn li)

2. C CHUA

C chua c c l mt trong nhng sn phm chnh ca ngnh cng nghip hp rau qu. C chua c c c s dng nh mt bn ch phm, dng sn xut mt s dng hp rau, qu, tht c v dng nu cc mn n trong gia nh. Sn xut c chua c c bng cch c c tht qu, theo mc c long khc nhau, sau khi loi b v, ht v nghin nh. C chua c c thng c phn loi theo kh thnh phm, ph bin Nga c cc dng sau :

- Pure c chua, c kh 12,15 v 20% ; - C chua c c va phi : c kh 30, 35 v 40% ; - C chua c c mc cao : c kh 50 70 % ; - Bt c chua : c kh 88 95 % ;

3. TI Ting Anh: Garlic Tn khoa hc: Allium L. Thuc h loa kn

Ti l mt mn gia v c bit trong ba n ca cc gia nh. Trong ti c cha cht alixin, c tnh dit khun nh mt cht khng sinh nn ngi thng dng ti nh l mt v thuc phng tr bnh thng hn, l t cng nh bnh bch cu.

Khi y hi n mt c ti, hay gi nh xoa vo bng cng lm gim c chng y hi. Khi b cm cm, nhai mt vi c ti, nu bit ung ru th ung mt ly nh cng vi ti cng cm thy d chu sau chc lt.

Trong 100kg ti cha 60-200g tinh du, thnh phn ch yu ca tinh du l allixin. Cht ny c tc dng dit khun rt mnh, n cng c tc dng chng oxy ha Trong ti cn c cc glycoside alliin, vitamin C, cc vitamin B1, B2, B6, cc cht phytosterol, inulin. 4. HNH

Tn khoa hc : Allium fistulosum L. Tn ting Anh : catawissa, onion Tn i thng, bch thng c ngha l: thng l rng, bch l trng. V dc cy hnh ( l hnh) rng t

cung n ngn, gi hnh ( c hnh) c mu trng, nn c tn l bch.


c tnh thc vt v cng dng: Chia lm 3 loi: Hnh l (hnh hoa)

Hnh c (hnh tm) Hnh ty

Hnh l v hnh c c th l t 1 ging hnh hay 2 ging hnh khc nhau T 1 ging: nu thy phn l bn c gi th bn thc phn cho l pht trin tt (70-75ngy), nu khng

th ptrin bnh thng sinh c (90 ngy) Trong hnh ty c nhiu hp cht bay hi cha lu hunh c tc dng khng sinh mnh.

Trong 100g hnh c cha : 18-33mg vitamin C, 50 mg vitamin B2, 4 mg -caroten, acid citric, acid tartric, ng glucose, fructose v cc flavonoid. Tinh du hnh c tc dng khng sinh, ng ch l Alixin cng nh hot cht ca ti: Ngoi hnh ta, hin nay nc ta cn trng nhiu hnh ty (Alium cepa L.) lm thc phm v xut

khu. 5. TIU

Ting Anh : Black pepper Tn khoa hc: piper nigrum L. Thuc h: H Tiu ( Piperaceae )

c tnh thc vt v cng dng : L loi cy leo, thn mm do, c th mc di n 10 m. Thn tiu khi gi cng ho g, thn non dng

tho mc. Qu tiu thuc loi qu mng, khng c cung, ch cha mt ht. Qu lc cn non c mu lc. Khi gi c mu en nhn nheo.

Tiu l mt loi gia v rt c a chung khp mi ni trn th gii. Ht tiu c v cay, c mi thm hp dn nn c s dng lm gia v cho nhiu mn n. Ht tiu thng phm ( tiu en hay tiu trng ) c cha t 12 14% nc v 86 88% cht kh. Cc cht kh trong ht tiu gm c :

tiu en : 95,49% cht hu c. : 4,51% cht khong. tiu trng : 98,38% cht hu c. : 1,62% cht khong. Thnh phn ho hc ca ht tiu c th c tm tt trong bng sau :


Cht Tiu en ( % )

Tiu trng ( % )

T l % ca tiu trng/tiu en

Cht khong Cht m Cellulose

Cht ng bt Cht bo Tinh du Piperin

Nha

4,51

11,67

16,49

42,45

8,10

1,56

9,20

1,58

1,62

11,71

6,35

62,30

9,21

1,86

8,59

1,19

36

97

39

146

116

119

94

78

Nh ht tiu c thnh phn ho hc nh vy nn khng nhng ch dng lm gia v nc ta m cn c nhiu nc a chung. Hin nay nc ta xut khu hng nm hng chc ngn tn ht tiu thu c ngun ngoi t ng k. 6. NGH Tn khc : ut kim, khng hong Tn khoa hc : Curcuma longa L,( Curcuma domestica Lour ). Thuc h : Gng

c tnh thc vt v cng dng :

ngh khai thc ly c, dng lm cht mu thc phm (mu vng). C v ng, thm Bt c ri c thng dng An , Bng La t, v c Vit Nam. Ngh tham gia vo 15% trong thnh phn bt c ri. 7. S

Tn khc: c s Tn khoa hc: Cymbopogon nardus Rendl. (s); Cymbopogon flexuosus ( citratus) Stapf. ( s hnh) Thuc h: Ho Tho ( Gramineae) c tnh thc vt v cng dng :

S c dng lm gia v trong mn n hng ngy. Nhm s cho tinh du c thnh phn ch yu l xitrala, l loi tinh du c mi chanh rt r. V vy ta thng dng s nu nc tm, nc xng khi b cm, du s c trn vo x phng thnh x phng s tm c mi thm d chu. Tinh du s dng lm thuc gip tiu ho, ui mui, dng lm cng nghip nc hoa, cht thm.

S c trong cc mn: c, mui s, lu thi Rn rt s tinh du s.

Nc Nc dng trong sn xut nc tng cng l mt ngun nguyn liu nn nh hng rt nhiu n sn

phm Yu cu cm quan:

Trong sut.

Khng mu.

Khng c mi v l.


Khng cha cc vi sinh vt gy bnh. Ngoi ra, nc dng sn xut nc chm cn phi tha mn thm cc ch tiu ha hc nh:

Thnh phn Hm lng %

cng 8-17o

Cht khong, hu c


Acid sorbic, benzoic thng t tan trong nc, du nn t dng hn. Cc loi natri benzoat, kali sorbat l dng d tan trong nc 2. Ha cht dng thy phn 3. Ha cht dng trung ha


CChhnngg 33:: CNG NGH SN XUT CC LOI NC CHM

3.1.SN XUT NC TNG THEO PHNG PHP HO GII

3.1.1 QUY TRNH CNG NGH SN XUT :

Nguyn liu sn xut nc tng theo phng php ha gii l cc nguyn liu giu prtit nh kh u tng (44%), kh lc (55 60%), kh vng(48%), kh da (20,7%), cc loi ha cht ( axt HCl, NaOH, Na2CO3), mui n v nc. Sn xut nc tng theo phng php ha gii da trn c s phn gii prott c trong nguyn liu thc vt hay ng vt giu m thnh cc amino axt di tc dng ca axt HCl nhit cao. Sn xut gm 6 giai on sau: x l nguyn liu, phi liu, thy phn, trung ha, lc, c c.

3.1.2. X l nguyn liu: Mc ch: lm sch v tch cc tp cht (t, , rm, rc..). Sau em i nghin nh bng my

nghin hoc xay nh bng my xay ti khi ht c kch thc 0,5 1 mm. [1] Mc ch nghin nh l tng qu trnh tip xc ca HCl vi nguyn liu thu phn cc mi lin

kt peptide c d dng, ng thi tng hiu sut v lm gim thi gian thy phn. i vi nguyn liu l xt nu dng cc phi hon tan vi nc mi s dng, nn dng Na2CO3.

Mt khc, HCl thng mi nng m c 21 22 Baum c pha long ra vi nc c nng

khong 10 11 Baum.[2]

Phi liu: phi liu nguyn liu s dng c chnh xc phi cn c vo khi lng m ton phn trong nguyn liu m tnh ton. V d: thnh phn protein ca kh u tng l 45%. Hm lng Nit l 45/6,26 = 7,2%

3.1.3. Thy phn: y l qu trnh rt quan trng trong sn xut nc chm bng phng php ha gii. Trong qu trnh thy phn thng ly tr s acid amin ln nht t c lm im cui thi gian phn gii hon ton gi l hiu sut phn gii. i vi kh u tng hiu sut phn gii thng l 65%.

nhit cao, HCl thy phn protein thnh pepton, polypeptide, cui cng l acid amin. ng thi vi s thy phn protein cc cht khc cng b phn gii theo.

Tinh bt b thy phn thnh ng mantoza ri cui cng thnh gluco: 2(C6H10O5)n + nH2O n C12H22O11 + nH2O 2n C6H12O6 tinh bt mantoza glucoza Xenllul phn thnh pentoza v cui cng thnh fulfuran. (C5H8O4)n + nH2O n C5H10O5 - 3H2O C4H3OCHO xenlulo pentoza fulfuran

Cht bo phn ly thnh glyxerin v cc axt bo C3H5 (COOR)3 + 3 H2O C3H5 (OH)3 + 3 RCOOH Glyxerin axt bo

Mun thy phn protein hon ton th cc thng s ca qu trnh thy phn cn ch l nhit , nng HCl, thi gian thy phn.

TUONG LAMSticky Notecau 5: neu muc dich va giai thich cac qua trinh trong quy trinh sx nuoc tuong theo phuong phap hoa giai


a. Nhit thy phn: c nh hng rt ln nn phi chn nhit thch hp. p lc cao nhit l

125 1300C. i vi p lc thng, nhit l 105 1120C. p lc thy phn cng cao th thi gian thy phn cng ngn. Tuy nhin, khng nn duy tr nhit v p sut thy phn qu cao s lm cho protein c trong nguyn liu phn hu mnh lm gim hm lng acid amin v sn phm ph to thnh nhiu. Trong

iu kin cng ngh dng ni thy phn kn v chu acid th nhit thy phn tt nht l 125 130 0C, p

sut 2,5 kg/cm2. Trong iu kin thy phn th cng chum vi th nhit thy phn ti u l 105 112

0C.

b. Nng acid: cng rt quan trng. Ty theo thit b thy phn m nng acid khc nhau. Nu dng thit b kn th nng acid c th ti 25%, cn dng chum, vi th nng acid thp. Trong ni kn c th sc hi nc trc tip vo lm tng p lc thy phn, ng thi lng hi nc cng lm cho nc trong dung dch thy phn tng ln ln v nng acid gim. Nu thy phn bng chum, vi th dng la gia nhit bn ngoi lm cho nc trong dung dch thy phn b bay hi, nng acid tng. Ngoi ra, nng acid qu cao lm acid amin b phn hy, acid bay hi gy tn tht v gy c hi cho ngi cng nhn sn xut. Nu nng acid thp, tc nhn xc tc yu, thi gian phn hy ko di , thy phn khng trit lm tn nc v nng lng. Trong chum, vi nng acid tt nht l 16%.

c. Thi gian thy phn:

Vi phng php lm th cng trong chum, vi thi gian thy phn tt nht l 18 24 gi (k t khi

si). Nu thy phn trong thit b kn, nhit thy phn l 125 1300C, p lc cao th thi gian thy phn l

6 12 gi. Xc nh im kt thc qu trnh thy phn bng cch th phn ng mu ca protid.? Dng giy th anilin axtt theo di hi fulfuran bay ra quyt nh thi gian thy phn. a giy th anilin axetat vo khng thy ng mu thm l c. Lm giy th anilin axetat bng cch dung 1 phn t gam (1M) axt axetic ha ln vi 1 phn t gam anilin ta s c dung dch anilin axetat, nhng giy lc vo dung dch ny ta s c giy th aniline axetat

3.1.4. Trung ha:

Sau khi thy phn, lm ngui n 50 600C ri dng NaOH hoc Na2CO3 nhm trung ha lng HCl cn d li v iu chnh pH ca nc chm n pH thch hp. Qu trnh ny cn to ra mt lng mui n trong nc chm. Phng trnh trung ha:

Na2CO3 + HCl NaCl + CO2 + H2O

hoc NaOH + HCl NaCl + H2O

pH thch hp nht l 5,0 5,5. mi trng acid yu, nc mm s c hng v thm ngon. Nu pH > 7,0 nc chm c v ng, mi nng kh chu. Nu pH < 4,0 nc chm c v chua. y l im mu cht ca phng php sn xut tu v yu.

3.1.5. Lc: Mc ch: tch dch m thy phn ra khi b (cc cht khng ha tan v cc h keo). V sn phm sau

khi thy phn gm hn hp acid amin, b en, mui khong. Nu sn xut c gii th dng my p khung bn hoc my lc ly tm. Nu s dng th cng th lc bng tm vi hoc ti lc. Nc lc ln mt c nc 1. B cn li cho nc nng vo ngm khong mt m ri lc li c nc 2.

3.1.6. Phi trn :

Thm mui vi liu lng 120 150 g/l v phi trn hay pha u nc I v nc II vi t l nht nh thu c hm lng m ton phn ph hp vi tiu chun qui nh.

3.1.7. Thanh trng:

Mc ch: lm tng thm mu sc hng v cho sn phm, ng thi tiu dit vi sinh vt cn trong sn phm ko di thi gian bo qun.

TUONG LAMSticky Notecau 11: trinh bay phuong phap xac dinh thoi diem ket thuc qua trinh thuy phan trong sx nuoc tuong theo phuong phap hoa giai.


Thanh trng 75 800C trong 20 pht. Sau thm ha cht chng mc nhm ko di thi gian bo qun.

Thng dng C6H5COONa vi nng 0,07 0,1%. nng ny, C6H5COONa c tc dng bo qun tt, khng ch c s pht trin ca nm mc, nm men ng thi khng c hi i vi c th con ngi.

3.1.8. Hon thin sn phm: Chai thy tinh ng sn phm phi c ra sch thanh trng tiu dit vi sinh vt bm trn chai v

loi b cc loi bi bn bm trong chai. Sn phm c rt vo chai theo dung tch qui nh. Sau ng nt, dn nhn. Sau giai on ny sn phm c a vo kho bo qun v chun b xut xng a ra th trng tiu th.

3.2. SN XUT NC TNG THEO PHNG PHP LN MEN

3.2.1. VI SINH VT TRONG SN XUT NC TNG:

Trong sn xut cng nghip, iu cn thit phi to c ging vi sinh vt thun chng. Ging vi sinh vt a vo sn xut phi m bo cc iu kin sau:

- C nh hng tt n s to hng. - C hot lc protease cao. - Sc pht trin mnh v chng tp khun tt - Khng c cha c t aflatoxin. Ging nm mc dng trong sn xut nc chm c th l Aspergillus oryzae, A. soyae, A. terriol,

A.mellieus, A. niger, A. ochracus Cc ging nm mc ny c nhn ging v gi ging trong ng nghim c thnh phn nh sau:

ng : 40g Nc chit u : 1000ml Thch : 25g

pH : 5,5 6,0 Hoc c th dng mi trng thch malt thng thng. Nc malt 70 Balling: 1000 ml Thch: 25 g T ng nghim ta s nhn ging trung gian cc bnh tam gic vi mi trng go hoc bp mnh

c hp chn. Nui 28 300C trong 3 4 ngy. (nc chit u: ra sch 300g gi , cho vo 1000ml nc, un si 30 pht, cht ly nc, b sung thm nc cho 1000ml)

3.2.2. SN XUT MC GING:

Sn xut nc tng cng nghip s dng cc loi nm mc thun chng. Cc nghin cu v tng cho thy nm mc c ngha quan trng nht trong sn xut nc tng l nm nc Aspergillus oryzae. Chnh v th trong cng nghip ng dng ch yu nm mc Aspergillus oryzae thun chng, khi pht trin trong khi nui mc c mu vng. Nm mc Aspergillus oryzae c cc loi enzyme : amylase, protease v cc enzyme oxy ha kh nh glucooxydase. iu kin sinh trng ca loi nm mc ny nh sau :

m , % 45 55

pH mi trng 5,5 6,5

m khng kh ,% 85 95

Nhit nui , 0C 27 30

Thi gian , gi 30 36

TUONG LAMSticky Notecau 9: trinh bay ve vi sinh vat trong sx nuoc cham


i vi chng thuc Aspergillus oryzae dng sn xut tri qua 2 giai on sau: Giai on sn xut nm mc ging : Mc ch ca giai on ny l to c lng ging cho sn xut vi lng bo t cao nht. ng

thi ging nm mc phi oc thun khit v chng loi. Giai on ny tin hnh lm ba bc : Nui cy ging trong ng thch nghing hay gi ging trong ng nghim. Nui cy trong bnh tam gic (nhn ging nh). Nui cy trong sng, nia.

Quy trnh sn xut mc ging:

Nui cy trong mi trng thch nghing : ng ging nm mc A. ozyrae ly t c quan nghin cu hay qun l sn xut mang v khng c dung trc tip m phi cy truyn sang cc ng thch nghing khc.

Ly ng thch nghing c ging cy truyn sang ng thch nghing khc.cc ng ny va c dng bo qun gingva c dng vo trong sn xut, ng ging phi tuyt i m bo thun khit khng c ln bt k mt loi vi sinh vt no khc. Mi trng thch nghing nui cy nm mc cn phi y cc cht dinh dng. Mi trng gm thch ( lm mi trng tr nn rn) v cc cht dinh dng (nc dinh dng). Cch lm mi trng thch nghing:

- nc nm vng: go t hay go np vo sch, ngm nc 8 12 h, vt ra em hp nh xi. Go np hp 1 1,5 h, go t nu cm khng c nho hay kh. Nu xong cm hay xi c W: 48 55%. Bp ti, ngui 400C, cy mc ging A.ozyrae vo, t l 1-2%. Trn u ri ra sang thnh lp 2 -2,5cm. ph trn lp vi t, nui 30 320C, m 85 100%, t: 36 - 42 h. sau ly mc ra lm nt, cho nc un si ngui 65 -700C. c 1 kg nguyn liu cho 2,5 3 lt nc, khuy u, gi 55 -600C trong 3 5 gi ng ha, th iot khng cn xanh th em lc. ly nc trong gi l nc nm vng, iu chnh nng ng 8 10% (5 60 Bome)

- nc malt: cn 250 g malt hoc thc mm nghin nh, trn vo 1 lt nc un si ngui 65

0C,khuy u gi 55 -580C, t: 4 5h ng ha, th iot. Lc iu chnh nng ng 7%( 7

0 Baling)

- ly nc nm vng, hoc nc malt hoc mi loi, them 2- 3% thch, un cch thy, lc, vo cc ng nghim, hp thanh trng 1200C trong 30 pht

- dng que cy ly bo t A.ozyrae t ng ging gc cy sang cc mt thch nghing khc, nui 30 -32

0C 5 -6 ngy. ng ging gi 4 -50C 2 -3 thng, nu bo qun t0 phng th dung trong khong 20

30 ngy sau cy li

Nui cy nm mc trong bnh tam gic (nhn ging nh): Nui cy nm mc trong bnh tam gic l phng php nhn ging trong khu sn xut, t y s nhn

ging trong khay, mnh hoc cc dng c cn thit khc.

Thng s dng cc bnh tam gic c dung tch 0,3 0,5 hoc 1,0 lt c c rng giai on ny. C th dng go t loi tt khng mc, khng mt. Tin hnh nu cm nh bnh thng, lm sao ht cm chn u

khng b nho v ng thi khng qu kh. m khong 45 48%. Ly ra, ngui ri bp ri ra tng ht, cho vo bnh tam gic thnh mt lp dy 1 cm v em kh trng 1 at trong 45 - 60 pht.

Sau khi chun b c mi trng trong bnh thy tinh, ta tin hnh gieo cy vi sinh vt. Trc tin cn phi chun b ly 5ml nc v trng vo trong cc ng nghim. Sau nc v trng cho bo t ha vo trong nc, ng thi cy truyn chng sang bnh tam gic. Trung bnh c mt ging c th cy truyn thnh

2 3 bnh tam gic, c dung tch khong 1 lt. Lc u cho ging phn b u trong mi trng v tin hnh nui chng nhit thch ng 30 320C.

Nui khong 5 6 ngy l c. Mc ging phi c nhiu bo t vng lc hoc vng nu.

TUONG LAMSticky Notecau 7: trinh bay quy trinh sx moc giong

TUONG LAMSticky Notecau 12: trinh bay moi truong trong binh tam giac trong sx moc giong

TUONG LAMSticky Notemoi truong nuoi cay giong trong ong thach nghieng


Yu cu c bn trong giai on ny l lm sao m bo to nhiu bo t v pht trin mnh khe. Trng hp no thy bnh b nhim phi loi b ngay.

Nhn ging mc trn mnh, sng ( nhn ging ln ) : y l giai on cui cng trong qu trnh nhn ging mc. Mi trng dng nhn ging trong giai

on ny l ng mnh. Cng c th dng mt s dng mi trng khc thay th c.

Ng mnh trn nc yn cho ngm nc khong 3 4 gi. Nu dng go th thi gian hp nhanh hn.

Nguyn liu sau khi hp xong phi chn u khng c bt hoc qu kh. m cn li 45 50% l va.

Sau khi hp nguyn liu xong, tin hnh lm ngui nhanh n 36 38 0C th tin hnh trn mc ging vo

vi t l 0,5 1% hoc cao hn. tin hnh cho u ta c th tin hnh mt lng mi trng em thanh trng trc vi mc ging, sau t lng ny em trn u vo khi mi trng. Hoc ta c th dng nc v trng cho vo bnh tam gic nh cho tht u ri em trn vi mi trng thanh trng.

Sau khi trn em ri ra mnh, khay thnh khi c chiu dy 0,3m mi trng b kh th khay, mnh

c t vo phng iu ha nhit 30 320C, m 85 100%. Thi gian khong 6 8 gi. Sau 3 4

gi, trn u mt ln iu ha nhit v khng kh, sau 6 8 gi tin hnh tri mng ra vi lp dy 1,5

2 cm. Sau khi nui 34 36 gi nhit trong khi bt u gim cn phi iu chnh nhit ln 34 350C duy tr s hnh thnh bo t ca nm mc.

Thi gian nui trn khay, mnh thng ko di 60 gi, nu thy mc hnh thnh bo t chm c th ko

di thi gian 70 72 gi. Sau khi nui ging xong c th s dng mc ny sn xut hoc sy kh ti m 8% em bo qun dng dn hoc cung cp cho cc ni sn xut. Ch qu trnh sy khng c nng nhit ln qu 400C. Sau khi sy xong cho mc ging vo cc bc nylon chng m. Ch lm sao trnh nhim bo t ca cc loi khc.

Bo qun ging mc ni kh ro, trnh nh nng. Cng c th bo qun lnh 4 50C. Ta c th bo

qun ging mc trong khong 1 2 thng. 3.2.3. QUY TRNH CNG NGH SN XUT NC TNG:

3.2.4. X l nguyn liu: Nghin nh:

i vi nguyn liu giu protein phi nghin nh khi trn nc thm u; khi hp chn u trnh tnh trng nguyn liu ngoi chn trong sng. Ngoi ra cn lm tng din tch tc dng ca enzyme v din tch pht trin ca nm mc. i vi nguyn liu l tinh bt nh bt m, bt ng nn rang trc khi dng lm cho protein c trong tinh bt b bin tnh v h ha b phn.

3.2.5.. Phi liu:

Kh u 90% v 10% bt ng hoc bt m, thm 60 70% nc so vi tng nguyn liu v cho nc ngm sau mt gi ri hp.

Mc ch: phi trn bt m, ng s dng tinh bt lm thc n cho mc sinh trng v pht trin mnh, nh c s pht trin mnh nn ln p c cc loi tp mc khc xm nhp v pht trin, gip cho thy phn cao hn. Trn nc c tc dng lm cho nguyn liu c m thch hp vi s pht trin ca nm mc.

3.2.6. Hp chn: Mc ch: lm cho nguyn liu chn thnh mt mi trng thch hp vi s pht trin nm mc v sau ny cc enzyme d dng thy phn. ng thi thanh trng mi trng qui trnh ln mc c thun ging. Khi hp chn cn ch nhit hp v thi gian hp. i vi nguyn liu c phi trn nh trn th p

lc l 0,7 0,9 kg/cm2, thi gian 1 1,5 gi l thch hp. Nguyn liu sau hp yu cu phi chn u, khng kh, khng nt, khng c mu nu sm, c mi thm ca u tng. 3.2.7. Lm ngui v trn ging:


Nguyn liu hp cn c cho qua my nh ti v dng qut thi ngui n 36 380C ri trn 0,5 1% nm mc so vi khi lng nguyn liu. Sau a vo thit b nui mc.

3.2.8. Nui mc: Mc ch: nhm lm cho mc pht trin u trn mi trng cy hnh thnh cc h enzim c kh nng thy phn protein v thy phn tinh bt cao nht. Cn ch 3 yu t: nhit , m v khng kh. Trong nhit ng vai tr quan trng nht. Trong qu trnh nui mc nhit c quan h trc tip n sinh sn ca mc. Thc tin sn xut nhiu

nm cho thy nui mc nhit phng nui cy t 28 300C v hm lng nc trong khi nguyn liu

nui mc l 27 37% s cho hot tnh enzyme protease v enzyme ng ho cao nht. y l 2 loi enzyme ng vai tr quyt nh nhng thnh phn ch yu ca nc chm.

3.2.9. Ln men: (hoc thy phn) Mc ch: to pH thch hp cho enzyme protease ca nm mc chuyn ha protein c trong nguyn liu thnh acid amin. ng thi enzyme amylase c trong nm mc chuyn ha tinh bt thnh ng ho tan. Cn ch 3 yu t nhit , thi gian, v lng nc cho nguyn liu khi ln men. a. Lng nc cho vo nguyn liu khi ln men:

Mc ch: lm tng nhit v gi nhit ca sn phm (mc thng c hm m t 27 30%) thc y tc dng phn gii v ci tin hng v ca nc chm cho ph hp vi th hiu ngi tiu dng. V nc t lm cho nc chm c mu m v c mi h cng, nhiu th thi gian ln men s ko di.

Thng lng nc trn vo 30 40% so vi nguyn liu tng ng 60 70% so vi mc. Khi trn

nc ta cho thm 5 10% mui so vi nc trn vo hn ch cc vi khun gy chua, thi hot ng. Khng dng nhiu mui v c th c ch qu trnh ln men. b. Nhit ln men: Nhit ln men to iu kin cho enzim ca mc xc tc qu trnh phn hy tinh bt v protein thnh ng v cc acid amin.

Thng gi nhit t 54 580C trong sut qu trnh ln men. gi c nhit ny v ma ng phi gia nhit. cc nc c kh hu lnh phi gia nhit gin tip bng hi nc gi nhit. Vit Nam dng m nm mc h hp to nhit lm cho enzym protease hot ng. c. Thi gian ln men: Ty loi nguyn liu, lng nc trn vo v iu kin nhit ln men m thi gian ln men c th di

hay ngn. Vi iu kin nu trn thi gian ln men t 64 72 gi. C th cn c vo s tng hay gim ca Nit formol quyt nh thi gian ln men. 3.2.10. Trch ly:

Mc ch: dng mui c nng 20 25% nhit 600C ho tan m v ng thy phn qu trnh trc. ng thi to mi v phng thi, v sau ngm rt nc chm ra.

Sau khi ln men xong phi nhanh chng cho mui vo v cho vi lng chnh xc ri khuy u

ngm trong thi gian 6 8 gi ha tan cht m v cc cht b dng khc. Sau thi gian ngm cn thit

rt nc ra c nc I. B cn li ngm thm ln na vi mui nng 20 25% khong 4 6 gi, li rt ra c nc II hoc nc III. Phi trn nhn c thnh phm nh qui nh. Thanh trng v bo qun: Mc ch: lm tng thm mu sc hng v cho sn phm, ng thi tiu dit vi sinh vt cn trong sn phm ko di thi gian bo qun.

Thanh trng 75 800C trong 20 pht. Sau thm ha cht chng mc nhm ko di thi gian bo

qun. Thng dng natrium benzoate vi nng 0,07 0,1%. nng ny, natrium benzoate c tc dng bo qun tt, khng ch c s pht trin ca nm mc, nm men ng thi khng c hi i vi c th con ngi.

Hon thin sn phm:


Chai thy tinh ng sn phm phi c ra sch thanh trng tiu dit vi sinh vt bm trn chai v loi b cc loi bi bn bm trong chai. Sn phm c rt vo chai theo dung tch quy nh. Sau ng nt, dn nhn. Sau giai on ny sn phm c a vo kho bo qun v chun b xut xng a ra th trng tiu th.


3.3. Cng ngh sn xut tng

3.3.1. Vi sinh vt dng trong sn xut tng

(xem phn 3.2.1,3.2.2)

3.3.2. Qui trnh sn xut tng

Tng l sn phm ln men t cc ngun nguyn liu giu glucid v giu m. y l mt dng nc chm c truyn ca VN. Nhng a phng lm tng ngon ni ting phi k n l tng Bn (Hng Yn), tng C (H ng), tng Nam n (ngh An)

Gi tr dinh dng ca tng: Ngun nguyn liu ch yu l u nnh v cc loi ht cha glucid. Do trong qu trnh chuyn ho

trong tng, hm lng cht dinh dng ng ch nht l aa v ng n Ngoi ra trong qu trnh chuyn ho cn to thm cc aicd hu c, cung cp cho tng mi v thm

ngon c trng. Bn cht sinh ho ca qu trnh sn xut tng l 2 qu trnh thu phn ch yu: Qu trnh thu phn protein v qu trnh thu phn tinh bt. Ngoi ra cn c qu trnh to thnh ru,

cc este to hng v c trng cho tng

Nc 1kg :6,7ltN

Ngm (8-10h)

Hp chn

Nui mc

U mc

U tng

Ng tng

Ln men ph

Nguyn liu

(go t)

Sn phm

tng

Rang vng

(45-60p)

Nghin

Ngm 6,7 ngy

Lc

u nnh

Dch bt u

Nc u

Nc

Mc

ging

trung

gian

Nc

Mui

TUONG LAMSticky Notecau 14: quy trinh sx nuoc tuong bang phuong phap len men


Cc cng on sn xut tng chia lm 3 giai on: lm mc tng, lm nc u ng tng v ngu (ln men ph).

3.3.3.X l mc sn xut a. Nguyn liu chnh Trong sn xut tng,2 loi nguyn liu ch yu l nguyn liu giu tinh bt nh go, bt m, bp v

nguyn liu giu m l u nnh. T l: NL giu glucid/NL giu m=4 Go: ngm 8-10 h (nc lnh) hay 4-5h(nc nng) ri ro em hp chn Ng mnh: xay c 0,5-1,5mm ngm vi nc (t l 1:1) trong 8-12h ri hp Bt m: ngm vi nc (50-70% nc) trong 2h ri hp Go t v ng hp 2 ln, tg 3-4h Nu dng thm du nnh th hp u nnh ging nh lm nc chm ln men. Yu cu k thut sau khi hp: nguyn liu hp xong phi chn u, khng nho t hay kh qu, W=40-

50%

3.3.4. Lm nc u: Nguyn liu s dng l u nnh, khi lng chim khong 1/3 khi lng nguyn liu chnh Cng on ny phi tinh ton lm sao cho n khp vi cng an nui mc khi mc nui xong th cng

l nc u ngm dt yu cu. Rang u: Mc ich: lm bin tnh protein ng thi tng mu, mi cho sn phm sau ny u nnh c nht sch c rc, ngm trong nc khong 15 pht ro v rang trn cho (T cho t

170-200oC, tg t 45-60 pht)

Yu cu k thut: ht u rang c mu vng nu, gin thm, W=1-1,5% u rang xong c xat tch v, nghin mn thun tin cho s chuyn ha cht m sau ny. Ngm u: Ngm nc u l mt qu trnh ln men t nhin kh phc tp, n quyt nh mi v c trng ca tng

c truyn khi ta ngm dng k thut, ng gi. c bit nc u c pH=5,5 th ngoi vic rt ph hp vi qu trnh xc tc chuyn ha ca hh ez amilase, protease v 1 s ez khc khi ng tng, cn c tc dng bo qun. V theo thc nghim, nu khong c b sung nc ngm u trong qu trnh ng tng d sinh hin tng ni vng trng

Tin hnh C th tin hnh ngm u trong chum, vi t l l 1 kg u: 6,7 lt nc, thm khong 150g mui/lt c

ch VSV pht trin, thi gian ngm 6-7 ngy, nhit ngm thp 25-28oC Nc u lu ngy b thi- chua, co th do rang u khng u, rang cn non C th rt ngn thi gian lm nc u bng cch cy thm mc, nhit 55-60oC trong 14-15h

Lm ngui v cy ging Nguyn liu hp xng c lm ti ri c lm ngui ti 35-40 th cy mc ging trung gian vo vi

lng 0,5-1% so vi kl nguyn liu, sau a qua khu nui mc Nui mc:

Mc ch: thu c nhiu ez amilase v protease c hot lc cao chuyn ha nguyn liu thnh tng Nguyn liu sau khi c cy mc ging th c a vo thit b nui mc c gii hay ti ra nong, mnh

tre (nui mc th cng) sau cho vo phng nui mc 12 gi sau khi cy mc, ht go bt u c trng m, dn mng nc. Trong thi gian ny, nhu cu oxi

cho mc khng cn nhiu, c th ng v mc tng pht trin tt, c ch c tp khun. T gi th 16 tr i, nguyn liu xut hin t trng (khun ty) v nhit bt u tng .Nhit phng

trong khong 38-32, W=85-95% Gi th 24, nguyn liu bt u kt bnh, phi bp ti vo o u nguyn liu. Nhit phng tt nht

cho mc pht trin lc ny l 30-32 d, W=90-95%


T gi th 32, c th nang nhit phng v gim m (W=75-80%) nhm ngn cn mt s tp mc . Khi mc gi, bo t chuyn sang mu vng hoa cau, W=30-32% Mc ch: ca bp ti nguyn liu khi b kt bnh: iu ha nhit v m trong thit b nuoi mc Cc thm oxi cho khi mc Kim tra pht hin hin tng nhim tp hay b chn cc b.

U mc: Mc ch: to iu kin cho ez thy phn hot ng, ch yu l thy phn tinh bt thnh ng

Khi mc sau khi nui khong 32 hay hn th c trn vi nc (60oC), khong 10-12% so vi nguyn liu t t m 50-60%, bp nhanh v trong 8-10h, nhit ln n 50-55oC v gi n nh trong 2 ngy. Mc ch l ez xc tc qu trnh thy phn tinh bt v m

U tng Mc ch: to iu kin cho ez thy phn protein ca bt u nnh.

Tin hnh: Ly dch bt u ngm v t nc ngm (15-20%kl khi mc) cng phi thm nc lc theo t l

nc/NL=1,2/1 trn u gi nhit 50-60oC trong 36 h th em i ng tng. Nc dng vi t l cao qu s d lm tng b chua.

B sung dch bt u ngm v t nc ngm (15-20%kl khi mc) cng phi thm nc lc theo t l nc/NL=1,2/1 cho vo khi mc li dng ez c trong khi mc thy phn protein, lm tang v ngt m cho tng, rt ngn thi gian. 3.3.5. Ng tng, ngu v bo qun.

Ng tng ngu l giai on cui cng trong qu trnh lm tng. Sau khi tng, cho nc ngm du, mui n v b sng thm nc nh nhuyn v ngu trong 10 ngy

th sn phm c mi thm r rt ca tng thnh phm. Nhit ng tng v lm ngu thch hp l 30-35oC. Tng c th bo qun t nhin trong 1 vi nm nu ch bin tt. Hin tng tng b ni vng trn mt ch gp khi tng nhit qu thp (di 45oC), hay do tng

b chua do nhim mc. Tng thnh phm:

Tng nc thng c th gp hin tng Vng chua-mi khng tt, km ngt-mu xu-c b, chua sinh hi (ci tng ni ln) Chua nt-khng nhuyn-km ngt, mi v khng tt-mu km-nht trn mt-sinh hi Ni chung l do s h hng ca cc khu v c bit l v sinh trong khau bao gi, bo qun Tng thiu mui dsinh vng chua, c th vt b vng, thm mui, a v pH 5,5 bng NaHCO3 Tng sinh hi l do nhim qu nhu vi khun k kh hay cha tg ngu.


3.4. CNG NGH SN XUT MAGI

3.4.1.Qui trnh sn xut 3.4.2. X l xng cc loi: nguyn liu l cc loi xng ng vt chn hay cn sng, khng hi thi, tt nht l ng vt mi git m, ra sch b m. Phn loi xng c ch hm thch hp: - xng cng: xng ng - xng mm: b vai, sn, sn. 3.4.3. Hm: cho xng vo thit b hm c p sut, cu to c 2 phn: phn gi li d cha xng c dt trong ni hm p lc. Sau khi hm, gi xng c b phn ko nhc ra khi ni, dch m s li trong ni. Ap sut hm: 2 3 kg/cm2 Thi gian hm xng: cng 3 5 h, mm: 2 3 h.

2.3.Tch m: nc xp c m 10 11 g/l, trc khi thu phn cn tch b m bi m s to mi i kht khi thu phn v sn phm d hng. u tin dch xp ngui, a phn m s ni ln, ng thnh lp, d tch b. Mt phn m ln trong nc xp, dng phng php x phng ho tch ra. Nhit x phng ho 60 -700C, thi gian 15

3.4.4 Thu phn: Lng NaOH dng khi thu phn ph thuc lng nit-protit. Lng nit-protit ca nc xp thng 10-11g/l. lng NaOH cho vo cho 100 lt l 4,5kg, thi gian thu phn 12 -16 h, nhit thu phn ;100 1100C.

3.4.5: Trung ho: trung ho bng HCl n pH 6,5 -6,8, khi thu phn nhit tng cao v vy cn lm ngui n 800C trc trng ho.

3.4.6. lc, thanh trng, bo qun: dch sau trung ho thm 12 -13% mui ri em lc, tch b x phng, cc cn bn, c c nhit 1000C thu sn phm c m 20 g/l- mu nu sng, trong mi thm ngon, v ngt m , ngon ming, giu axt amin.

3.5. Cng ngh sn xut chao

3.5.1. Vi sinh vt dng trong sn xut chao

T khi bit nguyn nhn ch yu ca qu trnh to thnh chao l do vi sinh vt cc nh nghin cu tin hnh phn lp chn la ging thun chng.Ngay t nhng nm 1927 n nm 1967 Wai phn lp t cc mu chao sn xut nh, 1 loi Actinormucor elegans, M.hiemalis, M. silvaticus, M. siubtilis. Sau ny Vng cng xc nh nh vy. Nm 1967 Vin cng nghip thc phm khi nghin cu vi sinh vt pht trin trn bnh du lm chao ti phng th nghim cng pht hin l mc Mucor, ng thi cng c c vi khun v m t cc loi vi khun u thuc dng S trn bong.

Vic la chn ging a chao vo sn xut qui m cng nghip tr thnh mt yu cu cp thit i vi nhng nh nghin cu.Trong cc ti liu ni v sn phm ny, hu nh nht tr tiu chun i vi mt chng vi sinh vt c s dng sn xut chao nh sau: - To ra c enzim c hot tnh thy phn m cao. - Lm cho chao c mu sc, hng v ph hp vi phong v c trng ca n, khng c mi kh chu li hp dn, cu trc ca cc si nm phi cht, dy, to c mt lp mng vng chc trn mt bnh u gi c hnh dng ban u sau mt qu trnh x l cng ngh.

Vit Nam, Vin cng nghip thc phm la chn mt chng mi thuc loi Mucor k hiu Rc c s dng vo sn xut cng nghip nm 1971 ti nh my m, bnh Hi Chu H Ni. Trn th gii thng s dng 4 loi mc sau y: Actinomucor elegans, M. hiemalis, M.silvaticus, M.subtiliscinus v cho rng Actinomcor elegans


Thc t nghin cu chng ti thy nu s dng tng hp c hai loi vi khun v mc th chc chn chao s c v bo ngy, mi khng nng v phm cht cao hn.

3.5.2. Qui trnh sn xut chao

p mui

Nui mc

Hoa u

u ph chao

p

Cho gia sc n

Cy mc

Cht

Ln men Chao nc

Ru

Dch sa u

Nc

CaSO4 Kt ta

un si

Mui n

Mc bt

bo t


3.5.3. Sn xut u h lm chao

u nnh

V loi b rm rc v sn

Na2CO3 v H2O

Ngm

i v

Nc Xay t

Dch sa u th

Cht ph bt,Na2CO3

Lc th B 1

Ra b

Nc

Cht

Nc

Cho gia sc

Hoa u

p Bnh u

ph

Thc n gia

sc

B 2

Dch sa

Lc tinh

Sa u

un si

Kt ta Nc chua

Nc chua

B 3


3.5.4. Nui mc

C th ni trong ton b cng ngh sn xut chao, khu nui mc ng vai tr ht sc quan trng, n quyt nh phn ln phm cht ca sn phm chao. Mc pht trin tt, men c tch ly nhiu v c hot lc thy phn proteaza cao th hiu sut thy phn m s cao, cc axit amin to thnh trong bnh chao s nhiu. Mt khc, mc tt, pht trin u s l mt ci mng bao ly bnh chao lm cho n thm vng chc. V vy ta phi ht sc quan tm khu ny. cho mc pht trin u v tt trong sn xut ta cn ch hai im di y: -Khng bnh u tp nhim cc vi sinh vt khc. -To cc iu kin sng thch hp cho mc sinh trng v pht trin. trnh tp nhim, bnh u trc khi cy ging phi chn nc si 100oC trong 1 pht, nhm dit cc tp khun xm nhp vo bnh u ngay t lc u to iu kin thun li cho mc chao pht trin. Mc chao l mt loi vi sinh vt ,l mt c th sng ,v vy ta phi nm c quy lut trao i gia c th v mi trng , l iu kin c bn nm c hot ng ca b my sng ny.Khi ni vi sinh vt mt t nhin tnh cht qu gi ca n ,Saponicop nhn xt mt cch chnh xc rng: Trong trng hp ny ng hn khng phi li cho c th v n b thoi ha m nn li cho nh thc nghim v khng cho n nhng iu kin nui cy thch hp. ` Lng ging c phun cy vo bnh u theo t l 100Kg u dng 0,5 Kg ging bt bo t , 500 Kg dng 1 Kg , 1000 Kg dng 1,2 Kg . Nu khng cy ging bng my th lng ging s dng phi nhn vi h s 0,2 0,3 mi . Sau khi cy xong , phi bo m cc iu kin sinh trng v pht trin ca chng : Nhit ca phng lun lun gi trong khong 28-30 0C, hm m nhng gi u l 90% , 10-16 gi sau khi thy xut hin cc khun ty mu trng trn mt bnh u phi a hm m ln 95% , ni chung hm m cng ln cng tt , v trong giai on ny mc rt cn m . i vi kh hu nc ta , kinh nghim trong sn xut thng iu chnh hm m ca bu khng kh xung quanh bnh u nui mc bng cch : 5 gi u ph x mn t ln cc gi mc , sau 12 gi nhng nc khn 1 ln , 28-30 gi sau b khn m gim m trnh tnh trng ko di thi gian nui , ng thi khng ch c hm lng men cho ph hp vi yu cu cng ngh sn xut . Khng ch hm m thch hp vi iu kin sinh trng v pht trin ca mc l vn ht sc phc tp . Phi nm vng ba yu t c lin quan mt thit vi nhau diu chnh cho ph hp .

- Hm m ca bnh u sau khi p .

- Hm m ca phng nui mc .

- Hm m ca khng kh .

c bit nhng thng hanh kh m ca khng kh c khi xung ti 60 70 % phi tng cng m , nhng thng m t phi ty theo thi gian sinh trng ca mc m khng ch hm m ca phng nui cho thch hp . Ni chung m ca khng kh thp mc s cn ci ,nu cao , nui s khng ng thi gian quy nh , mc s lu gi lm cho cc khu trong dy chuyn sn xut khng nhp nhng . Nui mc ng k thut sau 36-42 gi mc c hot lc thy phn t cao nht l 2,8-3,5 n v protea l con s hp l. Nhng gi cui ca thi gian nui phi gim m xung 80-85% cho mc khng pht trin na v mc qu tt, khun ty di trn 2,5cm c hm lng men rt cao s thy phn protein qu mnh, lm cho chao nng mi khng ph hp vi th hiu ca ngi tiu dng. Ngc li mc cng khng c cn ci v nh vy s khng men thy phn protein ca bnh u lm cho chao c v sng.


Trong qu trnh nui mc, khi thy mc chuyn t mu trng sang mu hung nu l phi kt thc giai on nui. Khc vi nui mc ging, khng dc gi v khng ly bo t, m phi kt thc ng lc mc cn non va phi v cng gi hot lc cng gim. Kinh nghim khi thy mc tt (thng khun ty di trn 2cm) nn chuyn t mu trng sang hung nu r rt, mc xu (thng khun ty di khong 1cm cm gic nhn khng thy m mng) nn kt thc lc chuyn mu cha r rt ngha l lc mc cn trng ng. lm tt khu ny, trong sn xut phi b tr ngi theo di, xc nh hot lc ca mc, kt thc thi gian nui mc c chnh xc, mt khc thng qua vic xc nh hot lc ny, gip ta bit c s thoi ha ca ging kp thi thay i. C th ni hng v ca sn phm phn ln l do vic kt thc thi gian nui mc quyt nh. Trong qu trnh nui mc khi mc b tp nhim vi khun hoc loi mc lc gi to thnh mt thm mu en nh nh ni, khi kim tra hot lc s rt cao, nhng sn phm d nng mi, thm ch cn c mi mm tm, khng hp khu v. m bo c cc yu cu k thut trong qu trnh nui mc, kt cu phng nui mc cng chim a v kh quan trng. Ty theo kh u v iu kin nguyn vt liu ca tng a phng, cu trc ca phng c khc nhau nhng ti thiu phi t cc yu cu sau : - C thit b gia nhit bng in hoc bng hi p lc ( khng dng than) v thit b tng m khi cn thit. Trn nh c qut iu ha n m cc im trong nh khng chnh lch qu 2oC nht l cc gc.

- Phng c cu trc nh th no gim s tn tht n m mc thp nht v d dng iu chnh. C ni theo di n m pha ngoi trnh ngi ra vo gy tp nhim.

- Nn nh nghing, thot nc d dng, xung quanh tng lt gch men hoc nh xi mng nhn bo m v sinh.

` i vi cc phng mc thng gi t nhin 100kg u nui mc cn c dung tch 6-7 m3, trn din tch 2m2. Mt phng ch nn nui khong 1000kg u. Trng hp thng gi cng bc th 100kg ch cn dung tch 5-6m

3 trn din tch 2m2. Mt phng ch nn nui 1500kg. Trong phng c trang b n t ngoi thng

xuyn c th dit trng sau mi ln kt thc mt t nui mc. Mt tun l dit trng bng focmon mt ln, khng nn t lu hunh gy h hi cc dng c in bng ng. Phi v sinh nghim ngt dng c nh ca mi khi b tp nhim, thm ch phi ngh sn xut trnh h hi cc t sau. Mt phng nui mc tt nht nn gia nhit bng in va v sinh gn gng, gi thnh li h. Tnh ra mt phng nui 600-700kg u ch cn mt h gia nhit c cng sut 5KW l v trong sut qu trnh nui mt t ch s dng 40KW in i vi cc tnh pha bc, cc tnh pha nam th thp hn.

p mui hoc ngm trong trong dung dch ru v mui. Mui l l loi dit trng nh , trong mi trng c mui oxi t tan, do vi sinh vt him kh khng c iu kin sinh sng . Nhng dng mui vi liu lng qu cao ion Cl- s kt hp vi protit ca u cc mi ni peptit li lm cho men phn hy cht m khng th xc tc s thy phn protit ca u dn ti chao b sng .Lng mui p thch hp vi chao nc l 130-150 g/kg u , thi gian p 24 gi, c nhiu cng trnh nghin cu chng minh rng men c nh ngay trn b mt ca cc khun ty ca nm mc bng nhng mi ni ion v n d dng c y ra khi gp cc mui c kh nng phn gii thnh cc ion nh NaCl . Do vy vi lng mui p nh trn khng nh hng g lm i vi s thy phn protit ca men m chnh nh mui c kh nng trn cng vi tnh p sut thm thu cao ca n to iu kin cho men thm su vo trong bnh u tin hnh cc phn ng thy phn protit ca bnh u sau ny . Khi p mui xp mt lt u , rc mt lp mui u , c nh vy cho n lp u cui cng th ph mt lp mui kn mt u ( bo m lng mui quy nh ) khng h mt ming u no , v nu h s b nhim khun gy hu qu thi ra khi ln men . Mui dng p phi sch s khng ln t , sn , rm rc , tt nht nn dng loi mui tinh .


Ngoi cch p mui c th dng phng php nhng mui , nhng bnh u ln mc vo dung dch mui c nng 300-320 g/lt lin tc 6-7 gi th nhc ln kh 24 gi cho vo thit b ln men. Dng phng php ny c th c gii ha d dng. i vi chao ngm ngay gi nui mc vo dung dch ru v mui (mui 130 g /lit , ru 12o) trong 18 gi . Vi thi gian ny lng mui gia trung tm v ngoi bnh u chnh lch khng ng k. T l nc ngm so vi u 3 :1. Nc ngm phi c s dng li ti 11 ln v sau mt ln ngm , dung dch cn li khong 8o ru v 80-85 gam mui trong mt lt. Nhng im cn ch trong qu trnh ngm . - Ngm ln u phi ly cc bnh u trong gi mui mc ra , xp vo thng ngm cho dung dch ru v mui vo theo t l 1 u 1 nc , ln hai 1 u 2 nc , ln 3 ngm c gi nui mc theo t l 1:3 nh ni trn.

Trng hp khng sn xut theo dy chuyn c gii th mi ln ngm xong loi b nc ngay , phng php tin hnh nh ln u. - Sau khi ln ngm phi xc nh li hm lng mui v ru trong dch ngm.

Cng thc tnh ton b sung ru nh sau : x1 n1 = x2 n2

Trong : x1 = lng cn b sung ( lt ). x2 = lng ru s dng ( lt ). n1 = cn trc khi pha . n2 = ru cn pha. Th d, cn pha 100 lt ru 120 khi c cn 950. Tnh lng cn pha ? Theo cng thc ta c :

x1 = 1

22

n

nx

x1 = 95

12100 o = 12.6 lt

Trng hp khi cn pha ru b sung sn xut chao bnh ta vn c th dng cng thc trn tnh ton .

Thit b ngm hoc p mui phi dng loi thp khng b n mn bi mui v ru (inox) lm b hoc s dng cc loi chum snh. thun tin trong sn xut , nn c ng ng dn hi , dn nc n tng b , chun v y c van tho nc . i vi x nghip sn xut qui m ln kch thc ca thit b ngm v p mui phi ph hp vi cc gi nui mc. Ton b cc thit b ngm hoc p mui t trong bung c ca knh , c li chng rui mui , nn nh nghing thot nc d dng , nh lun lun kh ro sau mi ln c ra.

3.5.5. Ln men

C th ni y l mt cng on khng km phn quan trng so vi cng on nui mc. Trong cng on ny men s thc hin mt chui phn ng sinh ha khc nhau, to cho chao c mt phong v c bit v c gi tr dinh dng cao. lm tt cng on ln men, cn c mt s khi nim v ln men


Men ( emzim) l mt cht xc tc khc vi xc tc phi sinh hc, c tc dng lm tng qu trnh ha hc. Hin nay ngi ta bit hn 800 men u l nhng protein c cha nhng nhm ngoi hu c tng i n gin ( nhng coemzim) hay nhng kim loi phc hp rt quan trng i vi nhng hot ng xc tc ca n.

C s ca phn ng enxim l tc dng thun nghch gia c cht v enzim vi s to thnh phc cht. Phc cht ny b phn gii tip theo s to thnh nhng sn phm ca phn ng v ti to enzim ban u. Do cc enzim vn l protein, hot tnh ca n c th b gim hoc hon ton mt i vi bt k tc dng no gy ra s bin i protein nh: un nng, tc dng ca acid, baz m c vv

Nguyn nhn nh hng ca s km hm ( c ch) ca cc phn ng emzim nh sau. - c ch c cht Tc phn ng emzim lc u tng vi s tng nng c cht theo nh lut Michaelis, nhng khi t c tr s ti a th tc gim, khi tng lin tc nng c cht. Nng c cht m phn ng emzim l ti a gi l nng thch hp nht ca c cht. - nh hng ca nng cc ion hidro n tc phn ng ca enzim. Trong mi trng ang xy ra cc phn ng ca enzim, khi thay i nng ca ion hidro th s dn n s thay i ca tc phn ng men. Thng s ph thuc ca tc phn ng men vo pH c biu th bng ng cong vi im cc i hay i khi vi vi im, nng ion H+ lc tc phn ng ti a c gi l nng thch hp nht, pH thch hp nht. - nh hng ca nhit n tc phn ng ca emzim

Tc phn ng enzim tng vi s tng ca nhit , tuy nhin s tng ch ch c thy trong khong nhit rt hp. Mi men c nhit c trng ring, khi nhit t n mc , tc phn ng ca enzim s gim. S ph thuc ca tc phn ng emzim vo nhit c biu th bng ng cong c mt cc i.

Nhit m tc phn ng cc i gi l nhit thch hp nht. Sau nhit thch hp nht tc phn ng s gim l do phn t protein ca men bin tnh bi nhit, do ko theo s gim nng ca men. Mi men c nhit thch hp ring l do s khc bit trong cu to phn t ca cc protein ca emzim.

Mt khc emzim c ngun gc t nhin khng c tri li c loi cn c tc dng khng sinh mnh nh glucooxida, mt loi emzim m mc chao ca chng ta c th sn sinh ra, n khng thuc nhm emzim thy phn m l emzim oxy ha kh glucooxida c kh nng kt hp vi oxy rt mnh khi c mt glucose,qu trnh xy ra nh sau.

C6H12O6 + O2 + H2O glucooxida C6H12O7 + H2O2

Di tc dng ca catala mt men hay i cng vi glucooxida, H2O2 s b kh thnh H2O v O2 H2O2 catala H2O + O2

Nh vy trong mt h kn vi mt lng oxy c hn v mt lng tha gluco, th di tc dng ca h men glucooxida- Catala s b tch ( kt hp ) ht v to thnh acid gluconic theo phng trnh.

2C6H12O6 + O2 glucooxida -catala 2C6H12O7

C l nh kh nng ny m n c tnh khng sinh mnh v c hot ph rng Men protein ca mc chao l mt hn hp men, trong c mt s emzim thuc nhm endopeptida, v mt s thuc nhm exopetida. Endopetida tc dng vo cu peptid trong phn t polypeptid ca protid cho peptid c trng lng phn t thp hn, cc phn t peptid ny tip tc b exopetida tc dng v tr nhm amin hay cacboxin to thnh cc acid amin pht huy ht tc dng ca men trong qu trnh ln men sn xut chao, ta phi to mi iu kin ti thch cho n nh nhit , m, pH mi trng vv... V vy sau khi p mui xong mun sn xut chao nc phi gi sch mui. xp vo thit b ln men ( chum snh, thng inox, l nha, thu thy tinh vv ) cho ru 12o cn vo theo t l 1kg u cho 0,5- 0,6lt ru ni chung ngp bnh u l va. y np tht kn a vo phng ln men.


i vi sn xut chao dng bnh, sau khi ngm, vt bnh u ra, bao gi bng giy bc hoc giy trng parafin, gn kn vo cho vo ti polietylen dn kn ln na, a vo phng ln men. Trng hp nu sn xut mt s lng ln c th a c gi nui mc ( trnh by phn trn) vo thng inox gn kn ri ln men. Nhit ln men khi trn mt bnh u l 35-36oC do vy nhit ca bung ln men phi lun gi nhit 37-38 oC. Thi gian ln men v nhit ln men c quan h mt thit vi nhau. Nhit ln hn 40 oC th thi gian ln men s ngn nhng sn phm d b h hng tri li nhit h hn 35 oC th thi gian ln men s ko di, tn km thit b, nh ca v.v Trong qu trnh ln men, theo di m chun focmon ( k hiu NF ) bit kh nng chuyn ha protid thnh cc acid amin t do, kp thi kt thc giai on ln men. Thi im kt thc giai on ln men, cng chnh l lc NF t gi tr cc i v bt u i xung. Nu ko di na th m hu c chuyn sang m thi, gy h hi sn phm. Thng khi kt thc giai on ln men vo khong 0,65%-0,9%, ln hn 1.2 thng sn phm nng mi. i vi chao nc khi ln men cc thng dung tch 20 lt khong 11-12 ngy cn cc h snh 20 lt l 14-15 ngy cc thu thy tinh 1 lt khong 9-10 ngy, cc l nha 1 lit 10-11 ngy. i vi chao bnh khi bao gi tng bnh mt ln men khong 6-7 ngy, cn i vi cc thng 20 lt thng 9-10 ngy. Khi va ln men xong chao n cha thc ngon phi nhit bnh thng khong 1 tun l sn phm ngu n mi ngon. i vi chao bnh sau giai on ln men nng cn c giai on ln men lnh hay ln men ph, y l giai on n nh sn phm, khu ny cng quan trng nh ln men nng, c tc dng lm tng phm cht sn phm v hng v. ( nhit ln men ph thch hp v kinh t nht l 5-10oC) di 0oC c mi tht i, cao hn chao khng nhun nhuyn n khng ngon khong 7 ngy s b h hng. Giai on ln men lnh ca chao bnh th to hng l ch yu cn s thy pn protid ca u coi nh khng ng k. Chao khi ln men xong c mi v c trng hp dn vi nhng ai tng quen n n. Hng v ny do 4 nhm chnh sau y to nn : acid amin v amoniac sn phm ca s thy phn protid, cc acid bo sn phm ca s thy phn lipid, metylaxeton sn phm ca s oxy ha cc acid bo v cc cht nhm cacboxila nh cc acid hu c, este, andehit v.vtrong qu trnh ln men cc cht to hng c tng hp li mt cch y lm cho hng chao c mi thm c o sau thi gian ln men. Sn phm sau khi ln men xong i vi chao nc c th gi nhit bnh thng c 1-5 thng, chao bnh gi nhit bnh thngc 4-5 thng, chao bnh gi nhit d 10oC c khong 8-10 thng.

3.5.6. Cc s c k thut

Hai hin tng ph bin nht thng xy ra trong sn xut chao l: hin tng ng v nng mi nh mm tm. 1. Hin tng ng Chao c v ng thng th hin r nht chao bnh v qu trnh ln men dng m t khng phi dng nc nn cht gy ng khng chit rt ra c. Tuy nhin khng phi chao nc khng c , nguyn nhn nh sau: - Mc xu nui khng t yu cu. Khi mc pht trin km, cn ci do hm lng men tch t trong mc t. Khng lm trn nhim v thy phn protid thnh cc acid amin t do, c mt phn protid cn dng peptid trung gian. Cc peptid ny lm cho chao c v ng, v ng cng r khi hm lng acid glutamic trong sn phm thp di 3,0g/kg.

Hin tng ny cng c gii thch. nhng sn phm ngm li nc ngm nhiu ln thng t gp ng. V vy trong nc ngm sau mi ln ngm c tch t li t men do c men b sung trong trng hp men ca mc thiu.


- ng do nhim khun gy ng Thng khi thy nhim vi khun gy ng bnh chao c mi kh chu , quan st bnh u khi ln mc thy bnh u nht, c mng nhy mu vang nh dim sinh hoc hng nu, khi ln men xong bnh chao vn cn mu sc nh vy. Nhng vi khun ny tit ra cc cht c ch hot ca men proteaza lm ngng tr cc phn ng to thnh cc acid amin t do nht l s to thnh acid glutamic + ng do CaSO4 dng qu nhiu trong khi kt ta. Dch sa u khi b chua, hm lng acid lactic trong sa u tng ln khi kt t cho CaSO4 qu d, s to thnh lactic canxi, cng lm cho chao b ng thm ch cn nng cht. + ng trong chnh cht ng trong sa u ca ht u khi dng lm chao. Trong ht u nnh c mt cht gy ng (Gerhard- c) cht ny th hin rt r nhng ht u lu ngy, bo qun khng tt, tc chng ra khi ht u rt phc tp. + ng do mt s acid amin gy nn Trong chao c metionin ( loi acid amin rt cn thit di vi c th con ngi ) c v ng nh tre, mng vu v.v.. l hin tng bnh thng ca chao, ch khi thy c v ng kh chu mi chnh l cc nguyn nhn ni trn . 2. Nng mi. Bnh thng bnh chao c mu vng c mi thm hp dn, c trng. Nhng khi c mu en, hoc xm th thng km theo mi nng nh mm tm v cm quan c v t t, ng khng hp dn. Nguyn nhn ch yu l: + Chao b nhim loi nm mc u en. V cha c iu kin trong nghin cu v sn xut chng ti quen gi tn chng l mc u en. Nhim loi mc ny khi kim tra hot lc ca mc s thy cao hn bnh thng nhiu, theo di quan st mc pht trin rt mnh khun ty di, khi non cng c mu trng nhng lc gi c mu en nh nh ni. Sau 3 ngy ln men, bnh chao c mu en loang l v mi rt nng nh mm tm khng hp khu v. Chao thng b tp nhim hai mc ny nhng ngy thi tit qu m. + Khi ra mc cn non hoc mc qu tt Ni chung khi nui mc thy mc qu tt, hot lc cao cng xy ra hin tng nng mi v hm lng men qu cao, thy phn qu mnh. Khc phc hin tng ny phi gim m v phi mc gi mi cho ra, c ngha l mc phi chuyn t mu trng sang mu nu r rt. + Bn u p m qu cao Hin tng ny hay xy ra khi kt ta cn non khng th p ht nc hoc kt ta t yu cu nhng p khng ht nc, m ca bnh u cn cao, d tp nhim vi khun, mc khng pht trin c ( khng phi nhim vi khun u hng m ty loi ) kim tra hot lc thy t tr s cao, cng d dn ti nng mi. Cc nguyn nhn gy ng v nng mi trnh by trn chng ta phi trnh v c th trnh c, nu thc hin ng cc iu kin k thut quy nh trong quy trnh cng ngh. i vi thit b ln men, c nhiu loi : thu thy tinh, l nha, h snh, h nan tre c qut sn, thng imox v.v.. nhng ni chung nn dng cc thng Inox c kch thc di rng cao=351831 centimet thng c mp parafin m bo kn. Loi thng ny ph hp vi iu kin sn xut cng nghip cng nh sc khe ca cng nhn, thi gian ln men va phi, hng t, phm cht sn phm tt, v sinh c ra d dng, bn cho ngi tiu dng tng bnh mt cng rt thun tin. Khi gia cng cn ch kht gia np v thn thng .


3.6. Mt s sn phm ln men c truyn t u nnh

3.6.1 Miso

sn xut cc loi miso c cc phng php khc nhau, nhng nhng im c bn ca qu trnh sn xut ging nhau, bao gm vic lm sch v nu u nnh, chun b Koji, hn hp u nnh mui, Koji v ging, ln men trong iu kin ym kh, trn v bao gi sn phm.

Go xay u nnh

Ra Loi tp cht

Ngm Ra

Lm ngui n 350C

Hp

Cy ging

Koji (go ln mc)

Nui 50 gi 27-280C

Ngm

Gn nc

Hp (1150C trong 20 pht)

Lm ngui (hm m 57,2%)

NaCl Ging

Trn

Ln men 7 ngy 280C, 2 thng 330C

ngu (2 tun nhit phng)

Nho trn

Bao gi

Miso


2). Chun b Koji a. Phng php lm koji ni chung

T Koji (Tamiya 1958) l ch vit tt ca Kabi-tacki c ngha l hoa ca mc. Koji l mt ngun enzim chuyn ha bt thnh ng c th ln men c v chuyn ha protein thnh peptit v axit amino. Nhng nm mc c dng lm Koji hu nh thuc ging Aspergillus, ch yu l Asp.Oryzac v Asp.Sojac. Cc mc khc i khi cng c dng nh: mc Rhizopus c dng lm amilo-koji, mt s loi mc en thuc Asp.Niger.

cc nh my lm Koji hin i ngi ta s dng cc thit b hin i v chm sc cn thn to ra Koji tt. Chng l ging thun khit ca mt loi mc hoc nhiu loi c hn hp mt cch ch nh, bo t ca chng c kh nng ny mm nhanh v cao (ti 98-99%).

Phng php lm Koji thun khit bt u bng cch nui mt chng Asp.Oryzae c la chn trn mi trng thch nghing. Bo t t nhng ng thch nghing sau khi nui ngy c dng cy cho 1-1,5kg go lm m v hp v trng. Ngi ta thng cho thm 2% tro ca mt s cy nht nh b sung cc nguyn t him. Vic cho thm tro g l mt bc quan trng v n to ra t l RNA/DNA ca mc cao hn. T l cao ca RNA/DNA lm cho bo t c kh nng ny mm v sinh lc ln hn.

Go cy ging c nui dng 300C, thi gian nui khong 4-5 ngy. Bo t c lm kh 50

0C v bo qun 150C bn. thun khit ca ging c xc nh mt cch chnh xc. Ty theo tng sn phm m Koji gm mt

loi hoc nhiu loi mc hn hp vi nhau theo mt t l hn hp nht nh. Cng ty theo tng sn phm m nguyn liu v yu cu ca Koji cng khc nhau. Th d trong sn xut miso go, koji c lm t go, khi mc pht trin go kt li thnh bnh rn v s c thu hoch

Ngay khi nh bo t ca mc va c to thnh cha chuyn sang mu xanh. giai on ny cc men amila thy phn bt c to thnh cc i. i vi koji lm sin (mt loi nc chm ca Nht) c nui trn hn hp bt m rang v u nnh. Khi kt thc koji c mu xanh.

Nhng mc dng lm koji c nghin cu mt cch hon chnh. Cc chng ny to ra mt s

enzim khc nhau bao gm - amila, protea (gm 3 loi : mt loi hot ng pH kim, mt hot ng pH

axit v mt hot ng pH trung tnh) mulea, sunfata, fotfata, transglicozida, peptida, axila ribonucl depolimera, mononucleotit fotfata, adenin deamina v purin nucleosida.

b. Sn xut koji lm miso

Koji c lm t go xay, ngm trong nc lnh (khong 15 C) qua m cho ti khi hm m khong

35%. Loi nc tha, nu p lc thng trong 40 60 pht, lm ngui n 35 C, cy ging vi t l 0,1%

(dng chng Asp.oryzac). Trong cc nh my hin i, vic lm lnh v cy ging c tin hnh theo phng php lin tc. Go

cy ging c chuyn bng nhng bng chuyn n phng nui koji, phng ny c th trn hoc hnh ch nht.

Nhng phng hnh ch nht c th ti 2,1m chiu cao, 4,5m chiu rng v 9m chiu di. Trong nhng phng php c, koji c nui trn nhng khay bng g. Trong qu trnh pht trin ca koji, nhit , m ca khng kh l nhng nhn t c bit quan trng v phi c kim tra cht ch. Do vic ln men c tin hnh trong cc phng ln c th b nhim vi khun. S sinh trng ca vi khun c c trng bi s tng nhit, lm tng nc t do trn ht go, iu ny li kch thch cho vi khun sinh trng nhanh.

S nhim trng c ngn cn bng cch thanh trng, bng hi, bng cch lc khng kh, bng n t ngoi lm gim cc khun lc c trong khng kh. Mt iu quan trng l khi gi m cho ht go, khng c c nc t do trn b mt ca ht. Trong qu trnh lm koji, go c o nhiu ln. Khi o nhng ht


di y phi c o ln trn v ph v nhng tng mc duy tr nhit , m v khng kh ng u trong sut qu trnh pht trin ca mc.

mc sinh trng tt, m c duy tr khong 90%. Phi thng kh nhiu cung cp y oxy v loi CO2.

Trong khong 40 48 gi, go c ph hon ton bng nhng si t trng. Kt thc giai on vo lc koji cn trng lc ny koji c mi d chu, khng c mi mc, c v ngt khi koji go s c ly ra khi phng nui, c lm lnh v ri c hn hp vi mui, vi u nnh hp chn, lm ngui, vi nm men tin hnh giai on ln men 2.

3. X l u nnh

ng thi vi vic sn xut koji, u nnh c chun b ln men. Mc d cc loi u nnh khc nhau u dng c nhng cc nh sn xut a loi u c mu vng sng, v ht mng v mn, rn ht mu vng nht hoc trng, hm lng protein cao, hp th nc ng u v chn nhanh, u c kch thc ln. Miso lm vi loi u s l mt sn phm ng nht v mu sc v nht.

Ht c nht sch, ra, ngm nc qua m, lng nc hp th khong 1,2 ln trng lng ht. i vi miso , u c nu di p lc 4 6kG/cm2 cho ti khi chng hon ton mm c th dng ngn tay bp nhuyn. Nhng i vi miso trng hoc vng u khng cn nu p lc, nhit v thi gian nu c nh hng n mu sc v hng v ca sn phm cui cng. Cc nhn t khc cng c nh hng quyt nh n hng v, mu sc, l t l ca u nnh, go, koji, lng mui v thi gian ln men.

4. Phi trn cc nguyn liu

Sau khi lm ngui, u c trn vi koji, go, mui v nc c cha ging. nhn c m mong mun, khong 10% nc c cho vo cng vi ging. Trc kia ngi ta dng ging l miso ca ln ln men trc c cha hn hp nm men v vi khun bn vng vi mui c la chn mt cch t nhin, chng c kh nng sinh trng di nhng iu kin ym kh. Nhng loi quan trng nht l nm men Sac. Rouxii v mt s chng vi khun sinh axit lactic. Thc t cc loi nm men khc nh Torulopsis sp cng c th c. Trong nhng nm gn y ngi ta s dng ging thun khit, iu d lm gim nh hng ca nm men v vi khun di. Cc hp phn c trn trong thit b knh v chng quyt loi, mu sc, hng v ca sn phm cui cng. Miso trng c t l go nhiu hn u nnh. Hng v chnh ca miso hon ton do u nnh quyt nh, cn v ngt l do ng to ra bi cc enzim ca koji go. Miso trng cha t mui (4 8%) do ln men nhanh hn, nhng sn phm kh bo qun. Miso cha 11 13% mui, miso cha 48 52% nc. Nu di 48% nc miso qu rn v nu qu 55% nc sn phm tr nn nho qu. Hm m cng c nh hng n thi gian ln men.

5. Ln men

Sau khi trn, hn hp c chuyn sang nhng thng lm bng g hoc b tng ln men. Hin nay trong cc nh my hin i cc thng ln men bng g c dung tch t 4 tn tr ln c s dng nhiu hn v:

- Chng c th di chuyn bng cn cu do d cho vo hoc ly ra khi bung ln men. - Do di chuyn c nn v sinh d dng.

Trong giai on ln men c nhiu s thay i v ha hc xy ra do cc enzim ca koji v ca cc vi sinh vt tham gia trong qu trnh lm miso gy ra, ch yu l cc enzim thy phn protein, gluxit v lipit trong nguyn liu.

a. Di tc dng ca cc enzim amila, gluxit c chuyn ha thnh cc loi ng: gluc (76%), izomanto (5%), fruct v arabin (3,5%), manninotri (3,0%), galact (2,2%), xil (2,1%) v pan (2,1%). T l gia ng kh (RS) v ng tng s (TS) ca miso t khong 75% sau 20 ngy ln men.

b. Protein ca u nnh di tc dng phn hy ca cc enzim , protein c chuyn ha thnh cc axit amin v cc peptit c trng lng phn t thp. Kh nng thy phn ca cc enzim c biu th bng t s gia


Nfomon/Nton phn(tc thy phn) v Nha tan/Nton phn (tc ha tan). Cc tr s ny t ti cc i khong 30% v 60%. Sau 50 ngy ln men, tt c cc axit amin tr axit glutamic, axit axpactic v prolin u tng ln trong giai on u ca thi k ln men (qung 25 30 ngy). Lng acginin t do gim sau 50 ngy ln men, c l do hot ng ca cc vi khun lactic. Axit glutamic v axit axpactic t do tng dn sau 90 n 120 ngy ln men. Tc gii phng ca cc axit amin ny gn 20%.

Cc peptit c trng lng phn t thp c to thnh rt sm sau gim dn , cc chui peptit c t 3 n 4 axit amin t cc i vo ngy th 2 hoc ngy th 3.

Cc peptit c trng lng phn t ln (gm 13 20 axit amin ) tng dn trong thi gian ln men, nhng ngy th 50 ch chim khong 5% N ton phn.

c. Lipit chim khong 5 6%, ch yu l cc triglixerit, diglixerit, monoglixerit v cc axit bo. Trong cc axit bo c cc axit bo cha no nh oleic, linoleic, linolenic v axit bo no nh panmitic. Cc axit ny tng dn cho ti ngy th 10 sau gim dn.

Nhit ln men c tin hnh 30 - 38 C. Thi gian ln men khc nhau i vi cc loi miso. Miso

vng nht cn t nht mt thng, miso cn ba thng, loi miso sm mu hn c nng mui cao c th tin hnh t 3 12 thng, loi ny c th bo qun c lu khng cn lnh do c nng mui cao c ch c cc tp khun.

Trong giai on ln men, miso c chuyn t thng ln men ny sang thng khc t nht 2 ln. Mi ln chuyn nh vy c o trn k lm hon thin cc iu kin ln men.

Miso ln men ngu trong 1 tun nhit thng sau em gi bn.

3.6.2 Tempeh

Temp (tempeh) l mt loi thc phm c truyn ca ngi Indonexia lm t u nnh ln men. Temp khng ging vi cc sn phm ln men ca Nht Bn v Trung Quc ch:

N khng n thun l cht iu v m c dng nh mt loi thc phm chnh. Khng s dng mc Asp m dng loi mc Rhizopus. Qu trnh sn xut c tin hnh trong mt thi gian rt ngn. Phn ln temp lm t u nnh v c gi l temp koenx. Ngoi ra mt s t ni cn sn xut

temp t ci da gi l temp Brongkek. Temp khng phi ch l mn n dn tc ca ngi Indonexia m n c ngi phng Ty quan tm n nhiu v gi tr dinh dng v hng v hp dn ca n.

Temp khi rn bng du thc vt n rt ngon v ph hp vi khu v ca ngi phng Ty. Nui chut vi khu phn c 20% temp chut t trng lng trung bnh l 203g, trong khi nui bng khu phn c 20% u tng chut ch t 189g v khi nui vi 20% sa loi b 201g. Temp l mt loi thc phm c gi tr dinh dng v d tiu ho. Gn y ngi ta thy rng Rhi. oligosporus to ra nhn t khng khun, khi ln men temp. Cht ny c bit chng li s hot ng ca mt s vi khun gram dng bao gm c vi khun ym kh v vi khun hiu kh. Hot ng ca n khng b nh hng ca enzyme pepsin hoc protea ca Rhi. oligosporus, b nh hng t bi enzyme tripsin v peptida, nhng b mt hot tnh nhanh chng bi prona.

Ngi ta bit rng cht khng sinh ngoi vic lm hn ch n mc ti thiu s nhim trng cn c tc dng kch thch sinh trng ng vt, c bit l nhng ng vt m khu phn n thiu mt trong cc loi vitamin hoc protein, hoc mt s nhn t sinh trng no . Vic nghin cu nhng cht khng khun to ra bi Rhi. oligosporus em li s hiu bit r rt hn v gi tr tht s ca temp trong khu phn ca ngi Indonexia v c l c nhng thc phm ln men khc ca ngi phng ng. Ngoi ra nhng cht khng khun ny c tc dng hn ch n mc ti thiu s nhim vi khun khi ln men temp.


I. QUI TRNH SN XUT TEMP

Nam Dng thng l sn xut temp bng th cng. Phng php sn xut gm cc bc chnh:

- u nnh ngm qua m. - Loi v. - Nu khong 30. - Tri u nu chn trn nhng khay tre lm ngui v lm kh. - Cy ging bng cch trn vi temp ca ln trc hoc bng dch bo t ca nm mc. - Gi trong l chui thnh nhng gi nh c kch thc 1x5x10cm. - Nui nhit phng trong 1-2 ngy.

u em ngm trong nc cho ti khi d dng tch v bng tay. hn ch cc cht tan trong nc trong qu trnh nu, c ni ngi ta x l vi mt lng nc ti thiu va ngm u, hoc l phun vi mt th tch nc ngm nht nh trc khi hp. Nhng Smith v cng s (1964) thy rng khi p dng phng php ny mc t pht trin v to nhiu bo t. Sn phm cng c mi kh chu.

Sau ny ngi ta thy rng chnh nhng cht ho tan trong nc v bn vng vi nhit ca u tng c ch s to ra enzim proteolilic ca Rhi. oligosporus ( Wang v Hesselline 1965).

u tch v un si trong nc trong 30, sau gn nc v tri cho kh b mt. mnh u nnh tch v bng my cng thch hp lm temp c cht lng tt, v mnh u cng hp th nc tt, thi gian ngm c th gim i.

u sau khi lm ngui em cy ging. Theo phng php c truyn ngi ta dng nhng bnh temp ca nhng ln ln men trc lm ging. Trong phng php sn xut tin tin ngi ta cy ging bng dch bo t.

u cy ging c gi trong l chui v gi ln men nhit phng trong mt ngy. Rhi. oligosporus khng i hi nhiu khng kh nh nhiu loi mc khc, trong thc t nhiu khng kh qu c th gy ra s to thnh bo t, iu ny khng thch hp cho sn xut temp. Trong thi gian ln men ht u c ph mt lp t trng v c mi v d chu, nhit ca ht u tng ln vt qu nhit phng, nhng ri nhit s gim dn do s sinh trng ca mc yu i.Do s pht trin ca mc v tc dng ca cc enzim c mt s thay i xy ra trong qu trnh ln men. Trc ht cc cht ho tan tng t 13 n 28%. N ho tan cng tng t 0.5 n 2%. Tuy nhin N ton phn t thay i, pH tng t 5 n 7.6, x tng t 3.7 u tng tch v n 5.85% temp. Trong s cc acid bo th 40% acid linolenic b mc s dng Niaxin, riboflavin, pantoteric, pantoenic acid v vitamin B6 ca u tng tng sau khi ln men, nhng tanin gim nh.

Thi gian ln men khong t 20-24 gi. Cc nh nghin cu coi temp c cht lng tt khi pH= 6.5 v cc cht ha tan khong 21%.

Do s pht trin ca t mc, cc ht u lin kt vi nhau thnh bnh- Bnh ny c hng v thm ngon v phi c tiu th hng ngy. Theo thi quen ca ngi Indonexia temp c ct thnh nhng lt mng ngm trong nc mui v rn trong du da hoc dng nu sp.

Nu khng s dng ngay phi c bin phi c cc bin php bo qun nu khng do s hot ng ca cc enzim NH3 c to thnh sn phm s c mi kh chu. C th ko di thi gian bo qun bng nhiu cch khc nhau.

Phng php bo qun n gin nht l ct temp thnh lt ri phi kh di nh mt tri. Mt phng php bo qun thch hp nht l trc tin lm mt hot tnh ca mc v enzim bng cch

lm ti temp, sau lm lnh. Temp c cho vo hp bao kn v ngay lp tc bo qun -290C, bng cch ny c th gi c 10

tun v cht lng vn tt. Sau ny ngi ta nghin cu mt phng php ci tin lm temp : u hp chn v cy ging em bo qun trong t lnh 5-60C hoc lnh ng (-100C) khi no dng mi em ra ln men. i vi u trong t lnh khi ln men ch cn 21-22 gi, nhng i vi u lnh ng cn 36-38


gi. Phng php ny c li r rt v n cho php chun b mt lng ln ri bo qun ln men dn theo yu cu.

Trong sn xut ngi ta t hiu sut 72,6 gr temp t 100 g u tng.

3.6.3 Natto

Trc kia natto c sn xut bng cch ly rm bc ly u tng hp chn ri t vo ni m p. Vi khun natto c sn trong rm s sinh sn trong u tng ch ti khi c ngi ta ko thnh si.

Ngy nay do phn lp c cc vi khun thun khit v nghin cu y cc c tnh sinh hc ca chng, ngi ta dng ging nui cy thun khit cy tn u tng sau nui trong nhng phng c thit b hin i t ng iu chnh nhit v m.

X l nguyn liu. u tin u tng c a vo my chn loi b ht nhng ht lp, ht su, ct si v rc ri.

Nht hin nay cc hng bun u tng m nhim cng vic ny. u la chn v phn loi em ra sch ct bn cn bm trn v u ri em ngm. Thi gian ngm l thuc vo nhit 0 50C cn 24 30 ting, 10 150C cn 16 -20 ting, 20 250C cn 8 12 ting. u sau khi ngm ht mt lng nc khong 1,2 1,5 ln trng lng ca ht.

Nc ngm hp quy cch l nc mm (nc c t mui canxi v mui magie) hm lng Fe di 5ppm nu khng u s b en.

Hin nay hu ht cc nh sn xut u dng ni p lc hp nguyn liu. p lc hp 1-1,5 kg/cm2 thi gian trong khong 20 30 pht. Cy v nui vi khun Natto.

Vi khun Natto do cc c s chuyn lm ging lm bn ra th trng. ging c th lm di 2 dng: dung dch v bt, nhng loi no cng c t 100 triu n 1 t vi khun Natto. Thng c 60kg nguyn liu dng 5g ging sau khi pha long vi 3 -5l nc v trng.

Khi nhit ca u hp vo khong 800C th cy ging ri nh lng v cho vo thng cha ln men.

Dng c ng natto c lm bng rm, mn ca, giy polietilen. Rm r v mn ca gy tr ngi v v sinh, nhng nhiu ngi tiu dng li thch loi ny v n c tnh cht truyn thng, do hin nay nhiu nh sn xut vn dng nhng th ny sau khi nu kh trng. Ln men.

Trc y natto c ln men trong cc phng xy bng tng cch nhit v iu chnh nhit bng than hoc in. Ngy nay phng ln men c xy bng nhng cht liu cch nhit t v trang b bng cc thit b iu ho nhit v m trong phng mt cch hon ton t ng. Vi khun natto bm trn u tng nhit thch hp (khong 400C) s sinh trng v pht trin. Giai on u do nhit ln men cha to ra ngoi nn phi iu chnh h thng nhit nhit phng khng gim xung di 400C. sau khong 4 6 gi cng vi s pht trin ca vi khun natto, nhit ca sn phm cng nh nhit trong phng u tng ln. Lc ny nhit trong phng khong 42 450C v nhit ca sn phm s tng dn ti 50 530C. Gi nhit ny chng vi ting ri iu chnh cho nhit ca sn phm h xung ngang vi nhit phng.

Trong vng 11 18 gi qu trnh ln men s hnh thnh cng vi s sinh trng ca vi khun natto, cc enzim c tng hp nn. nhit thch hp cc enzim pht huy tc dng lm thay i thnh phn ca u tng. Trong qu trnh ln men cho ti khi kt thc, hm lng cc cht bo tng ln t 21,4 n 24,6%. Kt thc qu trnh ln men gn 60% protein b phn gii thnh cc hp cht nito ho tan, cn t l axut amin ch trn di 10%.


Quy trnh ch to natto c th tm tt nh trong s 19.

Ni chung trong vng 16 gi thi gian m ngi ta cho rng natto ln men xong, s to thnh NH3 s tng ln, c th ngi thy mi ca ammoniac.

u tng

Chn, ra

Ngm

Lm ro nc

Hp chn

u tng hp chn Vi khun Natto

Cy ging

Bao gi

nh lng

Lm lnh, bo qun

Ln men

Natto


Cc axit hu c cng c to thnh trong qu trnh ln men v chng c lin quan nhiu n hng v ca sn phm. hai axit c nhiu trong natto l axit axetic v axit lactic. Cc axit proionic, sucxinic, butinic tng t gi th 9 cho ti khi kt thc ln men.

Trong natto i khi thy c v ng v mi kh chu. V ng l ca cc peptit c cha izoloxin phn cui nito.

Thnh phn ch yu ca cc mi kh chu l axit izovalerianic, cn mi hi ca natto th lin quan n amoniac. Ngoi ra kokuda cn phn tch t natto hp cht gi l tetrametin pirazin. Cht ny c tnh thng hoa mnh v vi nng cao mi ca n rt ging mi natto, ng d on n l mt trong cc thnh phn to nn mi natto.

- Bo qun

Natto ln men xong c lm lnh xung 100C trong phng lnh ri em bn ngay. Nu khng tiu th ngay phi bo qun trong phng lnh t 2-70C .

Ngi ta cng thng bo qun natto di dng natto kh. em ngm natto vo trong nc mui c hoc rc mui n ln khong 15-20 ting. sau tri mt

lp mng em hong kh bng nh nng mt tri. Trng hp sy kh bng nhit th cho lung khng kh nng c nhit trn di 100C v m 20% i qua tun hon lm kh n m di 8%. Nu nhit lm kh vt qu 600C th hng v v mu sc ca natto s xu i.


CHNG 4: CNG NGH SN XUT M CHNH V CC SN PHM GIA V 4.1. CNG NGH SN XUT M CHNH 4.1.1. GII THIU V M CHNH

M chnh l mui mono natri ca axt L- glutamic thng gp di dng bt hoc tinh th mu trng ngm mt phn t nc. Axt glutamic l cht iu v c gi tr trong cng nghip thc phm v trong cc ba n gia nh.

1.Vai tr ca m chnh:

- l cht iu v trong ch bin thc phm

- ng vai tr quan trng trong c ch chuyn ho cht b dng trong c th ngi Lng glutamat c trong c th ngi dng t do v lin kt khong 2 kg, trong lng glutamat t do l 10 g, gm c:

- C bp - No

- Gan

6,0 g

2,3 g

0,7 g

- Thn - Mu

0,7 g

0,04 g

- cc nghin cu khoa hc ch ra rng lng glutamat t nhin c trong thc phm v glutamat c ngun gc t m chnh u ging nhau. Chng c h thng rut hp th v tiu ho nh nhau. Mt khi c tiu ho, c th khng phn bit c u l glutamat t thc phm hay t m chnh. - Vo nm 1987, hi ng chuyn gia v ph gia thc phm ca FAO v WHO xc nhn m chnh l an ton, khng cn thit phi qui nh c th lng m chnh s dng hng ngy. - Tuy vy m chnh khng th thay th tht, c, trng . . .Do ty thuc vo s kho lo ca ngi ni tr m s dng m chnh mt cch thch hp nht trong ba n gia nh. Thnh phn nguyn liu giu protit

Tn nguyn liu T l protit (%) T l axit glutamic (%)

Bt m 12-15 30-36

u xanh 23,2 21

u h lan 22,4 18.5

u tm 22.4 18.5

Ng 10 31.3

Lc 27.5 18

Kh lc 50-60 20.7-24.1

Tht c 16.5-19 12

Tht g 20.3-22.4 13-14

Tht tru, b 18-21 13-14

Nhng 23.1 13-14

2.TNH CHT CA M CHNH 2.1.Tnh cht l hc:

- m chnh l loi bt trng hoc tinh th hnh kim ng nh, c tinh khit 99%, tinh th c mu trong sut, d tan trong nc, khng tan trong cn.

- Hng s vt l:

Trng lng phn t: 187

Nhit nng chy: 1950C

pH = 6,8 7,2


ho tan: nhit tng th ho tan tng: 25

0C ho tan 74 g/ 100 ml nc 60

0C ho tan 112 g/ 100 ml nc

2.2.Tnh cht ho hc:

- cng thc ho hc: C5H8NO4Na

- cng thc cu to: H2O.NaOOC CH CH2 CH2 COOH

NH2

- phn ng mt nc: khi nhit ln hn 800C glutamat natri b mt nc:

- phn ng phn hu nhit cao: nung glutamat natri nhit cao > 3500C:

C5H8 NO4Na + O2 Na2CO3 + H2O + CO2 + NO2

2.3.Lch s m chnh Lch s ca m chnh c hn 100 nm. Vo nm 1860, nh khoa hc Ritthaussen Hamburg (c)

xc nh thnh phn cc protein ng vt, c bit l thnh phn cc axt amin, trong c mt axt amin c tn axt glutamic v mui natri ca n gi l glutamat natri, sau l Woff, ng l nh ho hc xc nh c s khc nhau v trng lng phn t v cu trc ca cc axt amin.

Lch s m chnh c th cm mc u tin l ngy chng thanh nin Tokyo c tn Ikeda theo hc ti vin i hc Tokyo, tt nghip c nhn ho nm 1889. Tt nghip xong, Ikeda i dy trng trung hc ri sang c tu nghip.May mn, ng c lm vic vi Woff, tham gia nghin cu ho hc protein. Chnh thi gian ny Ikeda hc c cch nhn bit v tch tng axt amin ring r.

Tr li Nht Bn, ng lm vic ti khoa ho thuc vin i hc Hong Gia Tky. nh, trong ba n gia nh, v ng thng thm rong bin khi ch bin cc mn n. v vy m v ca thc n ngt hn, c v tht hp dn.

Ti phng th nghim ring ca mnh, Ikeda tm hiu xem trong rong bin c cht g m lm thc n m v tht. Ong khng ng cc th nghim tm hot cht trong rong bin ca mnh s m ng cho mt ngnh cng nghip hng mnh th k 20.

T rong bin ng tch c axt glutamic ri chuyn thnh natri glutamat. Ikeda cng bn hn vn lp cng ty sn xut glutamat natri m ng t tn cho thng phm ny l Ajinomoto theo ting Nht l tinh cht ca v ngon.

Ngy 21 thng 4 nm 1909, Ikeda ng k bn quyn sng ch s 9440 ti Anh quc vi tn gi: cht to v.

Thc ra ngi ta bit axt glutamic trc khi bit mui natri glutamat l mt cht iu v. Tn glutamic xut pht t thut ng gluten ca bt m. Tch gluten, thu phn n bng axt, cui cng thu c mt lng ln axt amin, trong axt glutamic chim 80%.

Nm 1920, b mt v cng ngh sn xut m chnh cng c khm ph. T nm 1920 n 1930, hng V Tinh sn xut 200 tn cn Nht sn xut 4000 tn mt nm.

Nm 1968, cng ty Ajinomoto ca Nht Bn mi hon thin qu trnh sn xut m chnh thng phm bng phng php tng hp da vo cht ch yu l acrylonitril (CH2=CH-CN).

Ngy nay, vic sn xut axt glutamic ri chuyn thnh MSG khng phi t gluten ca bt m hoc t rong bin m dng cng ngh vi sinh. T tinh bt cng vi ging vi sinh vt v ngun nit to thnh axt glutamic ri chuyn thnh MSG.

2.4.Tnh hnh sn xut m chnh trn th gii v Vit Nam


Ngy nay sn phm m chnh c sn xut hon ton bng phng php ln men trn khp th gii Ti Nht:

1961: 15000 tn

1966: 67000 tn

1967: 72000 tn

1989: 106000 tn

Sn lng m chnh ca cc nc trn th gii nm 1989 nh sau:

i Loan: 146000 Nht: 106000 Trung Quc: 90000 Hn Quc: 63000 Php: 40000

Y : 14000

Peru: 5500

Idonexia: 44000

Philipin: 12100

Malaixia: 500

Vit Nam: 1980 Ty Ban Nha: 3300

Mexico: 2750

Gn y vi s pht trin ca khoa hc, ngi ta dng mt nucleotit c bit to thnh m chnh . Trong t nhin c 2 loi nucleotit to nn hng v l 5-inosin monophotphat (IMP) v 5-guanosin monophotphat (GMP).

T nm 1960, cng ty Ajimonoto bt u sn xut IMP v GMP v sau cc hng sn xut m chnh khc cng lm c iu ny. Thm ch cng ty Merck M to ra sn phm Mertaste gm 50% IMP v 50% GMP. Ngi ta tha nhn mt hn hp gm 8% Mertaste v 92% MSG to nn hng v mnh hn khong 20 ln so vi ch dng MSG n l. Nhu cu v m chnh trn th gii khng ngng tng ln. Vic sn xut m chnh theo phng php thu phn protein lc, u v la m khng cn ph hp na. Ngi ta thi nhau tm phng php mi: tng hp ho hc, tng hp ho hc kt hp vi sinh hc v tng hp sinh hc. Trong phng php cui cng c tha nhn c hiu qu nht v t phin phc nht.

II. CC PHNG PHP SN XUT M CHNH M chnh d c sn xut theo phng php no cng phi tun theo mt s tiu chun sau:

- Tinh th MSG cha khng t hn 99% MSG tinh khit

- W 0,5%

- NaCl 0,5%

- Cc tp cht cn li khng c cha asen, kim loi v hp cht Canxi. Hin nay trn th gii c 4 phng php sn xut m chnh:

- Phng php tng hp ho hc: s dng cc phn ng tng hp ho hc tng hp nn axit glutamic v cc aminoaxit khc t cc kh thi ca cng nghip du ho hay cc ngnh khc. V d: Nht nm 1932 tng hp c 300 tn axit glutamic, prolin v.vt cracking duho, t furfurol tng hp v prolin, lizin. u im: phng php ny c th s dng ngun nguyn liu khng phi thc phm sn xut ra v tn dng ph liu ca ngnh cng nghip du ho. Nhc im: ch thc hin nhng nc c cng nghip du ho pht trin v yu cu k thut cao. Mc khc sn xut bng con ng ny to ra mt hn hp khng quay cc D, L- axit glutamic, vic tch L-axit glutamic ra li kh khn nn lm gia tng gi thnh sn phm. Do nhc im nh vy nn phng php ny t c ng dng cc nc.


-Phng php thy phn protit. Phng php ny s dng cc tc nhn l ho cht hoc ezym thu phn nguyn liu protit to ra mt hn hp cc axit amin. T tch axit glutamic v sn xut m chnh. Vi d gluten thu phn bng HCl 1500C to ra cc a.a. lc c c v gi nhit thp to cc ht tinh th hydroclorat glutamic natri. Nhng ht tinh th ny c lc ring sau c ho tan trong nc dng Na2CO3 trung ho ti pH=3,2 (pH ng in) tinh th axit glutamic s kt tinh v c tch ring bng phng php ly tm. Sau pha long v kt tinh ln 2 vi dung dch Na2CO3 pH= 5,7-7,0. Than hot tnh v Na2S c thm vo kh mu v kt ta tp cht. Sau lc, c c chn khng, thu c dch c c MSG, ly tm tch nc, sy kh, to tinh th MSG tinh khit. -Phng php ln men s dng 1 s vi sinh vt c kh nng sinh tng hp ra cc aa t ngun gluxit v m v c. Phng php ny c ngun gc t Nht Bn nm 1956. s dng chng Micrococcus glutamicus sn xut glutmate t mi trng c cha glucoza v amoniac. Sau mt s vi sinh vt khc cng c s dng nh Brevi bacterium v Micro bacterium.

Tt c cc loi vi sinh vt ny c mt s c im sau: + T bo c hnh cu hoc hnh que ngn. + Vi khun Gram (+). + H hp hiu kh. + Khng to bo t. + Khng chuyn ng c khng c tin mao + Sinh trng v pht trin cn biotin. + Tch t mt lng ln glutamic t hydrat cacbon v NH4

+ trong mi trng c sc khng kh.

- Phng php kt hp. y l phng php kt hp gia tng hp ho hc v vi sinh hc. Phng php vi sinh vt tng hp nn axt amin t cc ngun m v c v gluxit mt nhiu thi gian, do ngi ta li dng cc phn ng tng hp to ra nhng cht c cu to gn ging axit amin, t li dng vi sinh vt tip tc to ra axit amin

4.1.2. SN XUT M CHNH THEO PHNG PHP THY PHN 1. qui trnh sn xut 2. gii thch qui trnh 2.1.X l nguyn liu - ch bin keo protit ca u:

u ngm nghin sng ry sa u lng bt dch protit gia nhit lm ngui

lc ht ct vn sy Keo thnh phm Cc loi u sau khi ngm nc trng n qua nghin ph v t bo, gii phng cc phn t tinh bt.sau qua ry tch cc cht khng ho tan nh xenlulo, hemixellulo, dch sa bt qua qua h thng lng, tinh bt lng xung y cn li l dch protit. Tin hnh gia nhit 80 1000C. Keo protein sau khi ng t cho qua lc ht chn khng tch nc c keo m c m 70 75% Sau khi lc qua h thng dao ct ra tng ming nh cho qua sy bo qun keo c lu. Sy xong hm m ca keo cn 12 13% 2.2.Thu phn nguyn liu: Thu phn protein thnh axt amin nh HCl Mun tng nhanh qu trnh thu phn phi s dng cc cht xc tc mnh nh cc axt c hot tnh cao. Bng cc th nghim cho thy hot tnh ca cc axt so vi HCl nh sau:

Axt HCl H2SO4 HNO3 HCOOH CH3COOH

Hot tnh 1 0.51 0.23 0.07 0.06


Trong sn xut hay s dng HCl do cng lc xc tac cao v do trung ho to NaCl. Tuy nhin n c hi v n mn thit b v d bay hi gy c hi cho ngi sn xut nn khi s dng phi m bo chng n mn v kn.

2.3.Lc: hn hp sau thu phn gm cc axt amin , b en ch yu l hydrat cacbon, mui v c khng tan, dn xut tinh bt, xenlulo, mui khong, HCl v cc thnh phn khc, lc tch axt amin ho tan ra khi b en. Dung dch sau thu phn c nng 13 -180Be, ngui n 500C ri tin hnh lc. 2.4.C c: loi i phn ln nc v HCl dung dch t n trng thi bo ho nhit c c, h nhit n trng thi qu bo ho cho cc axt amin dng mui hydro clorua kt tinh. 2.5.Lm lnh kt tinh: dng mi trng HCl 20% gim ho tan v h thp nhit ca dung dch tinh th kt tinh.

Loi nguyn liu Thi gian kt tinh (ngy) Thi gian gim nhit (ngy)

Keo u 17 21 7

Kh lc 17 21 7

Gluten bt m 5 - 7 2 - 3

2.6.Ht lc: lc tch tinh th hydro clorua axt glutamic v mt s axt amin kt tinh khc ra khi cc cht ho tan v tp cht khc. 2.7.Ty ra: sau khi ht lc cn 1 phn nc ci bm xung quanh tinh th lm tr ngi cho qu trnh ch to axt glutamic nn cn ra sch. Li dng tnh cht ho tan ca hydro clorua axt glutamic so vi hydro clorua axt amin trong mi trng HCl c ra. Dng HCl 31% ra bo m: - ho tan bt cc hydro clorua axt amin khc - khng ho tan v lm hao ht hydro c

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