\DAI HQC VAN LANG Tran Minh Tim
MOT SO SAN PHAM THU'C PHAM inVG DUNG CONG NGHE LEN MEN LACTIC
SOME FOODS PRODUCED BY APPLYING TECHNOLOGY OF LACTIC FERMENTATION TRAN MINH TAM<') TOM TAT: Vi khudn lactic la mot trong sd nhiing vi khudn co lgi, dong vai trd rdt quan trpng trong qud trinh lin men lactic tgo ra acid lactic vd trong mdi truang len men dd, ndng dp vi khudn lactic tdng lin din 3% ed khd ndng ire che hdu hit cdc loai vi khudn khde, ki ed vi khudn E.eoli Lgi dyng dde tinh nay eon ngu&i da tao ra nhiu son phdm thyc phdm truyin thdng khde nhau diing trong d&i sdng hang ngdy. Bai viet giai thiiu mpt so thyc phdm duac chi biin bdng cdng nghi len men lactic tie mot sd nguyen lieu ndng nghiep nhu siia chua. ba, phomai, nem chua, rau qud mudi ehua...
Tk khoa: len men yim khi; lin men lactic; vi khudn lactic.
ABSTRACT: Laetie bacteria is one of the beneficial bacteria, plays a very important role in the lactic fermentation to produce lactic acid and in that fermentation environment, the concentration of lactic bacteria increases up to 3% and it can manufacture almost all other bacteria, including E.coU. Taking advantages of ths characteristic, people have produced many different traditional food products used in everyday life. This article introduces some foods produced by laetie fermentation technology fi-om some agricultural materials such as yogurt, butter, cheese, sour rolls, pickled vegetables and fruits, elc.
Key words: anaerobic fermentation; lactic fermentation; lactic bacteria.
1. DAT VAN DE
Sy ldn men lactic la qua trinh ldn men yem khi, sin phim tgo ra la acid lactic dudi tic dung ciia vi khuin lactic. Ban chit cua qui trinh nay la su chuyen hda dudng thinh acid pymvic va tiong td bao vi khuin, acid pyruvic khdng bj phan giii siu xa ban ma thu nhin hydro tao thanh acid lactic.
C6H12O6 >CH3CH0HC00H Trong qui trinh phat trien ciia vi khuan lactic, khi ndng do ciia acid lactic dgt ddn 2 - 3 % se lie che eac hoat dpng eua cic loai vi sinh khac, kl c i E.eoli. Chinh vi thd ngudi ta da iing dyng qua tiinh len men lactic dl san xuat nhieu sin phim thyc phim khic nhau dimg yong ddi song hing ngiy. Bai vidt nay se md t i mpt sd
sin pham thuc pham thdng dung ehinh dang dugc su dyng de ban dpc thay ban ehat eua cic san phim iing dung niy [2], [3].
2. NQI DUNG
2.1. Co che chuyen hoa ciia su len men lactk; [I), [7]
Cd hai kidu Idn men lactic:
Ldn men lactic ddng hinh: San phim tao thinh la acid laetie, qui tiinh ldn men phy thudc vao gidng vi khuin su dyng. Su chuyen hda dudng glucose thanh acid lactic xay ra theo ehu trinh Embden - Meyerhof de tao thinh acid pyruvic, sau dd ehuydn thanh acid lactic khdi lugng ldn nhd vi sinh vat. Acid lactic dugc su dyng nhieu tiong cdng nghiep thuc pham, edng nghiep hda hpc va y hge. Vi sinh vit su dyng thdng thudng la hp Lactobacillus va Streptococcus.
'*' PGS.TS. Pho Tdng Bign tap Tgp chi khoa hpc. [email protected] vn. Masd: TCKH22-15-2020
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TAP CHI KHOA HOC BAI HQC VAN LANG Ngudi ta thudng dimg djch thiiy phan tinh bpt vi can siia lam nguyen lieu. Trong qua trinh sin xuat cin duy tri lugng dudng trong mdi tmdng d ndng dp 10-15%. Sau 2-3 ngay ndng dp acid lactic se dgt tdi 90%. Liie nay ndng dp acid eao se kim ham vi khuin phit trien, do dd ngudi ta thudng thdm CaCOs vao mdi tmdng, acid laetie se chuyen thanh mudi, dk cd the duy tri pH d 5,5-6. Qua yinh sinh hda cua su len men lactic dien ra gin gidng nhu qui trinh ldn men mgu: glucose -> pymvat -> laetat. Tuy nhidn, hidu suit sin phim rit eao ldn ddn 90%
lugng dudng sii dyng.
Len men laetie di hmh: San phira tgo thanh eiing la acid laetie, etanol, acid acetic, CO2. Thdng thudng, acid lactic chilm Idioang 40%, acid succinic chilm gin 20%, rugu etylic khoing 10%, acid acetic khoing 10% v i cic chat khic khoing 20%. [8] Qui tiinh Idn men laetie dj hinh khdng cd y nghTa edng nghidp do tgo nhieu san pham cudi nen vipc tach va cd lap cic sin pham khic nhau li rit tdn kem. Vi khuin Idn men lactic di hinh Lactobacillus brevis, Leuconostoe mesenteroides di kem vdi vi khuin len men lactic ddng hinh Lactobacillus plantamm [8]
2.2. Nhirng san phim limg dung len men lactic trong ddi song
2.2.7. Trong cdng nghe sira [5], [6]
Siia ddng vat (siia bd, de, ciru... Ia logt tiiyc pham quy chiia nhidu chit dinh dudng nhu dara, lipit, dudng lacto, chat khoang, vitamm...
nhung yong qua ymh vit thu hdi siia, vgn chuyin, bio quan, cd nhieu logi vi sinh vat xim nhgp, cd thi giy thdi riia; yong so vi sinh vgt niy cd c i vi khuin lactic. Tuy nhidn, khi vi khuin lactic phit yien mgnh se tich ty acid lactic lam cho pH siia cang thip v i se hgn chd, tieu dipt cie logi vi khuan gay thdi r&a khac.
Lgi dyng tinh chat nay, ngudi ta eho len men lactic dung dich sira de bio quan dugc liu, dong thdi tgo ra mdt so sin phira cd gii trj khac nhu: siia chua, kephia, bo, phomat...
1) Sdn xudt sua chua - yaourt: Sira chua die v i yaourt udng Ii sin pham Idn men lactic tii sira bd tuoi hay siia dgng vgt ndi chung hoge sira bgt sau khi da khu chit beo va thanh triing vi khuan gay bdnh bang phucmg phip Pasteur d nhidt dp 80-90°C. N I U nguyen lipu la sira bpt khdng dudng, can cho thdm mgt it dudng dl dgt ndng do « 8-10%. Quy tiinh cdng nghd sin xuat stia ehua tien hanh theo so dd sau:
Hinh 1. So dd quy yinh edng ngh^ sin xuit sii'a chua
TAP CHI KHOA HQC DAI HOC VAN LANG Trin Minh Tim Thuyit minh cong ngh? dqiiymd cdng nghiep:
Giai dogn phoi trpn: Myc dich tgo khdi hdn hgp ddng nhit giup cho qua timh len men sau niy dong ddu. SOa tuoi dd vio bdn cho ehuydn dpng tuin hoin nhd bora hiit - day.
Qui tiinh tuin hoin nay Iam dgng luc, keo hdn hpp bgt sOa, dudng, chit on dinh, bo tidi theo dudng dng. Nhidt do phdi tidn: gift 45^C cd tie dyng cho qui trinh hda tan bpt sua vao nude duge tdt han.
Giai doan gia nhiit: Be nang nhidt do len eho thieh hgp vdi qui yinh ddng hda. Ddng siia eho di dpc tiong dng, qua thilt bi gia nhidt dgng vi, liic nay nhidt dg dugc nang ldn 60'^C.
Giai dogn ddng hda: La giai dogn diing ip suit cao dd pha vd cic hgt beo, phin tin ehit beo vao tiong nguydn lieu v i phin tin eac chat khae nhau, tgo hdn hgp dong nhit. Tilp tue dua ddng sfta di qua thilt bj ddng hda d nhi^t do 60"C, ap suit ddng hda l i 200 bar, dugc tgo bdi bam pitidng.
Giai dogn thanh triing I: Tan dyng ngudn nhidt sau ddng hda dd thanh triing so bd tiudc khi cho vao bon ageing, de tieu diet mpt phin vi sinh vgt, ngan can sy phat tiiln ciia cac vi sinh vgt tiong giai dogn niy. Thdi gian thanh triing khoing 1 phut d nhidt dp 60''C.
Giai dogn ldm lgnh: Mue dich dua khdi sii'a ve nhipt dd thip d l ngung su hogt ddng eua cie vi sinh vit cdn sdt lgi tmdc khi dua vao bdn Ageing. Ddng sfta dugc cho qua thilt bi tiao doi nhidt dgng vi cd nude lgnh di ben ngoai v i nhipt dd ddng siia dugc hg xudng edn S^C. Sau dd ddng siia dugc bam vio bon Ageing, tgi day dong siia duge dl yen trong khoang 1-2 gid.
Nhidt dp tiong hhn Ageing la 5°C.
Giai dognh thanh triing II: Nhim myc dich tieu di^t cac vi sinh vit edn sdt lgi sau tiianh triing I. Ddng siia dugc nang nhipt dp len 95''C, thdi gian thanh trimg la 1 phiit.
Giai dogn ddng hoa IL Sau khoang thdi gian dai trong bdn Ageing, cic chit trong khoi siia bit dau cd sy phin ldp. Dl khdi sira trd lgi
trang thai dong nhit, ddng sira dugc dua qua thidt bi ddng hda lin thii 2. Qui trinh niy se phin nhd cic hgt beo, phan tan eae chit vio nhau.
Ap suit ddng hda la 200 bar. Nhidt dp ddng hda li 95°C. Sau khi ddng hda lin 2, ddng siia lai dugc ha nhidt do xudng cho thich hgp vdi dilu kidn phat tridn cua vi khuin lactic, tao dilu kien eho qui trinh ldn men dugc tdt nhit (d t° 43 °C)
Giai dogn chudn bi lin men: Bon raen dugc phdi ydn vdi him lugng chit khd la 12%.
Thinh phan tiong bon men nhu sau: 50 kg bpt sua giy, pha nude cho din khi thi tich hdn hgp dgt 500 lit. Mgt gdi men 50g. Loai men d day su dyng la gi&ig vi khuin Lactobacillus btilgaricus (hinh que) vi Streptococus ihermophilus (hinh ciu);
gioigriay lliudcdiut^ji^^axcia^ hp I^ctolisctenace^
Dudng lactose chuyin hda thinh acid laetie.
CnHaOii.HzO —•4CHJ-CHOH-C0OH Nhiet dp d bdn men khoing 43°C. Bdn men duge chuin bi tmdc khoing 4—5 gid. Sau thdi gian nay, pH tiong bdn dat khoing 4,4-4,5 thi bom sang bdn ciy men. Sua sau khi ra khdi thidt bj nhidt, nhipt dugc hg xudng cdn 43°C, siia dugc chuyin vao bdn cay men, cimg liic men tir bdn men dugc bora sang bdn ciy men.
Lugng men bom sang ehidm 5% tdng khdi lugng sin phim. Tgi diy, dudng lactose tiep tuc dugc Idn men de biln thanh acid lactic.
Giai dogn u: Nhim rauc dich tgo du thdi gian dl qui tiinh Idn men duge hoin thanh va dn dinh chit lugng Idn men. Sua tir bdn ciy men dugc bom sang bdn ii, nhidt dp tgi bdn ii Ii 43°C.
Thdi gian li la 4-5 gid. Sau thdi gian niy, pH ciia hdn hop dgt khoang 4,7-4,8. Qua trinh ii kdt thuc. Sfta duge cho qua thilt bj lira Ignh.
Giai dogn lam lgnh: Nhidt dp ha xudng 15"C dl hgn ehi qui trinh ldn men va tiiuan lgi cho qui tiinh rdt. Trong qui tiinh niy pH ciia khdi siia tidp tyc giam xudng edn 4,3-4,4. Diy la dilm dimg mong muon. Khdi siia dugc tru lgi yong bdn sau qui trinh lam lgnh. Tir bdn rdt se didu chinh lgi luu lugng sfta cho qua timh ddng gdi va sau dd dugc dua vao bdn rdt. Hai
TAP CHl KHOA HOC DAI HQC VAN LANG bdn rdt dugc dat cgnh nhau cd the chira sira eho hai me niu lidn tidp.
Giai dogn ddng gdi. ddn nhan: Sua tu bdn rdt dugc bom sang may ddng gdi, miy ddng gdi se thyc hidn qua yinh rdt san pham va ddng gdi ty ddng.
Tren day la toin bd quy yinh sin xuat siia chua ydn diy ehuydn thidt bj ty dgng hoin chinh cua md hinh cdng nghidp. Dd lam sfta ehua tiong didu kien gia dinh chung ta ed thd lim nhu sau: Tmdc hdt dung djeh sfta tuai hoac sua bdt gay pha thinh dung dieh rdi dun sdi thanh triing vi dd ngudi din khoang 45°C v i ciy vi khuin lairtk vao. Cdtiid ding diing gidng gdc Lactobacteraim bidgaicuni, Lactdxx^rium acidopMin, Lactobacillus btdgcoicus. hog:: Streptococus lactic...
hoac cd the sir dung ngay mgt thia sua chua Vinamilk cho vio khuiy ddu rdi rdt vio cde dd Idn raen yong didu kidn yem khi (bing each day kin) Idioang 6-8 gid. Lugng acid lactic dugc hinh thanh lam cho dung dich sua ddng die vi cd vj chua thanh, miii thom rit die trung. Sin phim dupe bio quin trong tu lgnh (t" = 7-0"C) sau 1-2 ngiy dem su: dyng. Siia chua li sin phira rit bd, chfta duge ragt sd benh dudng mdt, suy nhuge co the, chuyen hda tidu hda rit tdt.
2) Sira chua Kephia: Kephia li sin phim eiia su ldn men laetie sua ddng vat (sua bd, de, triu, ciru...) nhd h? vi khuin hdnhppcdlror^hgt Ksfim. Nhung vi Idiuin nay bao ^ n : Lactdxxillus cxMxtsicus, S^vptococudaOic. nam men, vi khuan khac nhu Aerobacler. Klebsiella... [8]. Qui yinh ldn men tgo sin pham cung tuong ty nhu sin xuit yaourt nhung sin phim cd thinh phin va huong vi rat die trung ed chiia 0,6-0,8%
mgu, 0,6-0,9% acid lactic v i 50% CO;. So vdi sua chua yaourt, siia chua Kephia cd vj thom die bipt vi him lugng dinh dudng eao ban, la logi san phim tidu bieu eho su len men hdn hgp.
3) Sdn xudt Ba: Bo la san phim ldn men lactic td chit beo ciia siia. Chit beo sau khi tich bing phuang phap iy tim, logi acid va
thanh yiing Pasteur, dl ngupi din 30°C, sau do eiy gidng vi khuin tiiuin khilt vi cho ldn men.
Kit thiic qui yinh Idn men, ta tiiu duge sin phin d dgng kem ed vj ehua, tham. Kem dugc danh nhuydn, trpn diu cho ddng nhat va tich bdt nude se duge thanh phim la bo. Cd thd thdm 10% mudi dl cd bo man. San phim duge bao quin d nhiet do lanh.
4) Sdn xudt Fomai (phomai): Fomat li san phim ldn men lactic tu sfta, tao ddng ty tii protein sua (cazein). San pham chiia nhidu dinh dudng, dugc cic nude chau Au ua chuong. Qui tiinh sin xuit bao gom cae giai dogn sau:
Giai dogn ddng ty Cazein: Sua sau khi thanh yiing, cho men Renin vd vi khudn laetie vdo de kit tua sica. Vi khuin lactic tidn hinh qui yinh ldn men tgo ra acid lactic, lam cho pH giam tao didu kidn cho men Renin hogt dpng mgnh, Cazein de dang kdt tiia. Ngoii ra. Renin cdn thuy phin mdt phan Cazein ddng ty dugc gpi li Fomat.
Giai dogn ep. nen tdch huyit thanh: Huydt thanh sua khdng ddng ty cd miu vang dugc tieh ra sau khi ep tii 20-24 gid d nhidt dg 35-50"C.
Thdi gian nay su len men laetie van tidp tye.
Giai dogn mudi Fomat: Khdi Fomat sau khi da tich huydt thanh dugc chuyin vao bd nude mudi ndng dp 24% yong vai ngay dd ning eao chat lugng vi miii vi Fomat ddng thdi kim ham vi sinh vit gay hgi khdng phat triln duge.
Giai ^xm ii chin: Fomat dugc chimin vio him ldn men d t° 18-22°C, do im 80-90%. Giai doan nay, su len men lactic yeu din, vi khuin propiomc boat ddng manh len men va tgo ra acid propionic, acid acetic vi CO2, Ca 2 logi acid nay lim cho Fomat ed vj chua, hang die bipt Qua frinh u chin dl dong khoang 2-2,5 thing, Udn be mat khdi Fomat cd nhung Id hong do CO3 sinh ra. Giai dogn nay Cazdn tidp tue phan giai chim dudi tic dyng eiia men Renin vi vi khuan lactic tgo thinh pepton. acid amin va mgt Iupng nhd NH? Sin phim tilp tye li chin dwm va bio quin d t° lanh. NIU dimg nguyen l i ^ 1^ x^orrm thd, quy trinh sin xuat dieo so dd sau:
TAP CHi KHOA HQC DAI HOC VAN LANG Trin Minh Tam
' '
Phdi trdn^ ^ ^ San phim ^ ^ >
Niu
Dong gdi
*
De ngupiHinh 2. So dS quy trinh san xuit phomai tho Thuyit minh quy trinh cdng nghi: Tat c i
nguyen lieu eho vio ndi nau, cho cinh khuiy chgy vdi vin tde 750 vdng/phut trong 1 phiit.
Sau do chuyen sang 1500 vdng/phiit trong 30 giiy, rdi chuyen vd tde do 750 vdng/phiit vdi myc dieh la dl tgo hdn hgp ddng nhit. Sau khi toe dp ehuydn ve 750 vdng/phiit thi md hai dot, ip suit chan khdng dk ning nhidt dg ldn 85°C.
Giu nhidt dg 85''C, quay diu tiong 1 phut va dd ra xd de tidp tyc nau me khac. Sin pham de ngudi din nhipt dp khoang 50°C thi chuyin
sang ddng gdi. Phomai dupe dua qua may ddng gdi va din nhan tu ddng.
2.2.2. Trong cong nghe che btiti thU (nem chua) [6]
Nem chua la san phim ldn men lactic tir thit heo tuoi cd trdn thdm dudng va gia vj cin thilt. Bin chit eua qui yinh la su tgo thanh acid lactic trong thit nhd vi khuan laetobaeillus va microcoeus. Qui yinh ldn men cang lau sin phim cang ehua. Vi the, tuy theo ky thuit va thdi gian ldn men khie nhau v i sin pham tgo ra cd ehit lugng khic nhau.
Thit heo tirai (95%1 Rita sach
*
Xav nhuven
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i Trpn gia vj (mudi, toi,
bdt nggt, dudng)
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Trpn diu1 Bi heo f5%l |
1 Lam sach 1
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1 Ludc chin | V
1 Thai nhd |
»
1 . . ^•. • 1
Tgo hinh Bo sung them gia vi
Bao gdi f LSn men San phim
Hinh 3. Quy trinh cdng nghd sin xuit nem chua
Md td edng ngh$: Thit heo diing dl san xuit tiinh Iam nhuydn thit cd thd dimg raiy xay hoac phii la heo tuoi vira md, gilt, cd mau hdng, khdng
dung thit cii, qua dem, mau sam, cd miii la. Qua
gii nhuydn. Bi heo sau khi ludc chin, can loai md tiigt ky va thai nhd thanh sgi vi hong khd yudc khi
TAP CHI KHOA HOC PAi HQC VAN LANG trdn vdi thjt heo nhuydn. Trong qua trinh trdn deu cd thd bd sung them gia vi. Toin bd nguydn lieu dugc tgo thanh vidn, dai hogc trdn nhu khuc gid va gdi chat bing la vdng (cd tie dyng gift nhiet thich hgp cho len raen). Sau dd gdi bing 2-3 Idp li chudi, bugc chat tao dilu kien ydm khi hoin toan.
Vi khuin lactic boat dpng mgnh din, acid lactic tich ty ngay cang nhieu lam eho thit cd mui thom va vi chua. Khi thay mat nera khd, min va ed miii thom die tnmg Ii cd tiid diing dugc. Tiiy theo khiu vi in chua mi ed the dl len men them 1-2 ngay nua. Ndu nera khdng cd do dai, nhao, mat nem udt, nhay li nem bi hdng.
2.2.3. Trong che bien rau, qud (dua, cd mudi chua, kim chi...) [5]
I) Mudi chua bdp edi (quy md cong nghiip):
Bap cii mudi chua li mdt phuang phap de bao quan lau tiidng qua vide ehd bidn thinh sin phim khae. Ngudi ta chpn bap cii ed dp chin ky thugt chic, trpng lugng tnmg binh it hon 0,7kg. Bap cii li logi rau chiia nhieu vitamin C (26-60 mg%) ndn tiong qui tiinh Idn men dd tdn thit. Khdng sii dyng .nhung b ^ cii cdn non, bi dip hoac siu benh...
Tmdc khi mudi chua, can bd hdt nhftng la xanh bdn ngoii, li hdng, li benh. Cd till su dung c i ldi vi cd nhidu chit dinh duong. Dd ting vi mudi ehua hip eai, ngudi ta cho them c i rdt thii nhd vi li nguyet qui (khoing 30%). Dd ting nhanh qui trinh tgo acid lactic cd thd cho thdm vao bip cii mpt lugng eitrat natri (0,4-0,7%).Thung dd mudi ehua la nhimg thiing gd hoic sanh cd thi tieh 100- 2001. Thung gd trudc khi mudi ndn nia nude ndng sgnh se hoic ngim nude mdt thdi gian de sgch hit chit chit Bip eai cho vio thimg nen chit timg Idp cho mudi vio (nen chgt dd tgo didu kidn yem kiii tot), Iupng mudi tdng cpng eho vao khoing 2 - 2,5%. Vi sinh vgt lactic se phit tridn va bio vd dugc vitamin C. Giai dOgn dau ciia qua trinh Xen men se cd nhieu khi sinh ra vi thd tich bip cai tang ldn 2-3%, sau do se giim xudng, tuy viy eiing khdng nen nen chit qua, djch bao se mit di do bi trao ra ngoii, can phii ldn trdn mgt Idp la bip cai rdi d§y vii man. Diing v^t n$ng de idn trdn cho bip
cii nen chgt. Nhiet dp len men tdt nhat cho qua trinh mudi chua khoang 20°C, len men uong 10 ngay. Niu nhidt do tir 10-12t, tiidi gian ldn men lau hon. 6 nhia 15"C qui Uinh ldn men ngimg lgi khi him luong acid lactic trong san [rfiam dgt 1%.
Q nhiet dp tii^ hon nfta, qua trinh len men cd the keo dii 2-3 tiling. Qua trinh ldn men lactic ngimg lgi khi him lugng acid lactic dat tdi 1,5-2,4%.
Huong vj ngon nhat khi him lugng lactic li 0,8- 1,2%. Bap eii mudi chua dugc bao quan d nhipt dp 0-2°C, cd till bio quan ngay ei trong thiing muoi ehua va gift bap cii ludn ludn ngap nude dd khdng tdn thit lugng vitamin C. Cd tiid dimg nong dp mudi dd bao quin: Bio quin tii 3-4 thing —> nong do mudi la 1,5-2%, bio quin tu 6 thing - > nong do mudi Ii 2-2,5%. Cd dil bao quan thanh phim bing each ddng vao nhung bao bi kin, Ig thiiy tinh, tui polyetylen va phai thanh trimg tot Dd ed b ^ cii mudi ehua chit lugng tdt, ngudi ta sii dyng vi khuin cd gidng tinh khilt dd Idn men lactic. Nhiing gidng niy thudng cho vio d dgng nude chua.
Nude ehua dugc sin xuit bing each sir dyng cic gidng vi khuan gay chua khdng tgo ra khi nhu Bacterium brassieae fermentati vi Sach brassieae fermentati. Nude chua nay ddng d chai. De ed nude ehua, ngudi ta sii dung nude djch bio cua bap eai va nudcludc cua chiing dd lira mdi trudng.
Dich bao liy d eie thiing mudi b ^ eai da mudi sau 3-4 ngay. NIU liy qua mugn se khdng thich hgp vi nd it chit dmh duong (dudng) ^n trong qua trinh muoi chua cic logi vi sinh vgt lactic da sii dyng het NIU nude dieh bio khdng du ed till eho thdm nude (ty Ip l/l) v i eho them dudng ( 1 % so vdi lugng nude djch bao da pha loang nude niy lpc qua vai dun sdi dk thanh yimg khoing 1 gid. Trong khi sdi vdt bgt tgo ra; Nude bip eai luge tiiu dugc khi him nhir b ^ eai vdi nude (liy 20-25 kg bip eai vi 1001 nude) khi bip cii mlm, lgc liy nude sic va cho vao djch bao. Mdi midng sii dyng dl lam nude chua phai thanh yimg bing hoi nude ndng yong tiidi gian 30-40 phiit d nhipt dg 105- 1 lO^C. Sau khi cho vao tiiimg va lam ngupi din 35°C va cho vao 1% gidng vi khuin tinh khilt, lie
TAP CHI KHOA HQC DAI HQC V A N LANG Trin Minh Tim ddu, dd trong 3 ngay vi giu d nhipt dp mdi tmdng
la 25-3tf'C. Nude ehua thu dugc cd vi chua thanh, diu sinh. NIU xuit hidn mang trdn mat la khdng sir dyng dugc vi da cd vi khuin lg xuit hidn. Sau khi di ed gidng vi khuan tinh khilt phit trien, ngudi ta trpn vdi raen cho vao tiiiing (1% nude chua ciia vi khuin va 0,25% nera).
2) Muoi chua dua ehupt: Day la mgt hang ma cac nude rat ua tiu'ch, la mat hing xuit khau cd the bio quin vi dung duge lau. Chgn nhiing qui cd kich thudc vira phii, khdng to, vd mdng mau xanh tham, mat qua ed gai, thit qui phii dac, hgt be va cdn non. Khdng sir dung nhiing qua chin ving.
Dua chupt sau khi thu hai 1 ngay phi! chi bien ngay kieh thudc va dd dudng ciia dua chudt cd inh hudng cd anh hudng rit ldn den chit lugng ciia sin phim, nhftng qua be ed hira lugng dudng nhidu hon, lugng celluloza it hon so vdi nhimg logi cd qui to. Do dd mudi chua nhiing logi be cd pham chit se cao hon, va sy hao hyt ciia dua chudt be se it hon khi bio quan. De tiln hanh muoi chua dua chudt, tnrdc hit phai lua chpn kp, qua diing tidu chuin , sau do dem nia sgch dat eit bin, xdp vio thimg cung vdi cae phdi Ioai nhu thia la, nguypt qui, tdi, dt, ca rot dk tgo miii thom, ngon. Tdi cho vio de sit triing. Cic logi gia vi kd trdn cho vio vdi lieu lugng tii 3-8 kg cac logi/ lOOkg dua chudt Ndng dp muoi trong dung dieh tii 6-8%. Dua chupt cang to, nong dp nude muoi cang eao. Bao quin dua chugt mull d nhidt do 15-20"C trong 1- TAI LIEU THAM KHAO
[I] Biii Ai, Ky thudt lin men thyc phdm cd truyen Viet Nam vd cdc nuac trong vimg, ebook.
[2] Kilu Huu Anh (2014), Gidotrinh Vi sinh vol hpe thuc phdm,l>ixb Giao due Vi^l^am.
[3] Biln Van Minh (Chu bien, 2008), Kilu Hftu Anh, Pham Ngpc Lan, Dd Thi Bich Thuy, Gido trinh di$n tie Vi sinh vgt hpc Cong nghiip. Hue.
[4] Nguydn Thj Minh Phuong (2008), Bdo Qudn Chi Biin Rau Qud Thyc Phdm, Nxb Hi Npi.
[5] Trin Minh Tim (2006), Bdo qudn vd chi biin ndng sdn sau thu hogch, Nxb Ndng nghiep.
[6] T i ^ Minh Tim (2012), Cdng nghi vi sinh iing dyng, Nxb Ndng n^ipp.
[7] Dong Thi Thanh Thu (2004), Gido trinh sinh hda ca bdn. Dgi hpc Qude gia Thinh phd Hd Chi Minh.
[8] Trin Linh Thudc (2007), Phuang phdp phdn tich vi sinh vol trong nu&c, tiiyc pham va mT phim, Nxb Giio dye.
Ngay nhgn bai: 02-6-2020. Ngay bien tgp xong: 07-7-2020. Duyet ^ n g : 24-7-2020 2 ngiy cho vi khuin lactic jdiat tridn mgnh. Khi ndng dp lactic 03-0,4% tfii ed till ehuydn vao kho lgnh de lam chim qua trinh len men. Sau thdi gian nay ndng do acid lactic dat 0,6-1,4% thi dem bio quin d -l^C din +WC hoac diing acid sorbie dk bio quin.
3) Mudi chua ca chua: Caeh mudi chua cung tuang ty nhu cieh mudi dua chudt Cd till diing nguydn lieu ci ehua xanh, uong hoac chin. Ndng do muoi diing tii 7-9%. Ca chua chin rit mem, cho ndn chi nen mudi Uong nhftng thimg cd nhd cd thd tich tdi da 50 lit ddi vdi ca ehua xanh vi uong ed the diing fliiing cd thi tich ldn hon 50 lit Qui trinh Idn men ciing tiln hinh trong kho lanh hay trong him rait gjdng nhu dua chudt Thdi gian ldn men tu 25-50 ngay vi bio quan d nhiet do O-l^C.
3. KET L U ^
Trong qui yinh sinh sdng vi phit yidn ciia cic vi sinh vat, ed nhiiu logi giy hgi nhung cung cd logi cd lgi. Vi khuin lactic Ii mpt trong sd nhirng vi khuin cd lgi, ddng vai yd rit quan trgng trong qui yinh ldn raen lactic tgo ra acid laetie v i tiong radi trudng ldn men do ndng do vi khuan lactic tang ldn cd khi ning tie cbd hiu bet cae loai vi khuin khic, vi thd lgi dyng tinh chit nay, nhieu sin pham thyc phim da duge sin xuat phye vy eho con ngudi va da yd thanh nhung sin phim tmydn thdng quen thuge ciia chiing ta ngiy nay.
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