TLTK-Báo-cáo-thực-tập-Bánh-Kẹo

7/22/2019 TLTK-Bo-co-thc-tp-Bnh-Ko

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BO CO THC HNH

CNG NGH SN XUTNG BNH KO


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Bo co thc hnh ng bnh ko GVHD: HXun Hng

DHTP2 nhm 5 t1 http://www.ebook.edu.vn Trang 1

LI MU

Bnh l mt loi thc phm rt phbin v tin dng. Bnh v cng nghsn xut

bnh xut hin trt lu v ngy cng pht trin. u tin l nhng sn phm thcng

cht lng khng cao, thit b th s, thi gian bo qun rt ngn. Nhng cng ngh sn

xut bnh dn c ci tin, nng cao v pht trin rc r nhngy nay. Trong li sng

cng nghip bn rn th cc sn phm n lin, trong c cc loi bnh, trthnh mt trong

nhng thnh phm khng ththiu trong i sng hng ngy.

Bnh biscuit l mt trong nhng thc phm quan trng trong cuc sng p ng c

nhu cu thc phm truyn thng v vn ho ca con ngi, l mt hng rt a dng v

phong ph, rt tin cho vic s dng, c gi tr dinh dng cao. K thut sn xut bnh

biscuit tuy khng phc tp nhng i hi phi c kin thc, kthut v kinh nghim cao.

nc ta cng ngh sn xut bnh biscuit ang c tin bng kt gi tr cao v dinh

dng, phong ph v chng loi v m thut v to hnh dng c ngi tiu dng yu

thch.

Trong bi bo co thc hnh cng nghsn xut ng, bnh, ko ny chng em s

ni tng quan vsn phm bnh biscuit vani, tng quan vnguyn liu, quy trnh sn xutv cch tin hnh cc th nghim.

Cm n c HXun Hng gip chng em nh hng c hng i ng n,

phng php thc hin c hiu qu. Tuy nhin, do lng kin thc cn hn hp, thi gian

thc hnh c hn nn chc chn sc nhiu thiu st. V vy, knh mong sgp ca c

chng em thy nhng chsai, thiu st bsung vn kin thc cho mnh.

Nhm thc hin


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Lm biscuit ngon l mt nghthut, v lch s chng nhn iu . Trong sut

thkXVII v XVIII ti chu u, nng l mt nghc kim sot mt cch cn thn,

qun l thng qua mt lot cc phng hi hoc cc hip hi chuyn nghip. trthnh

mt ngi lm bnh, phi hon thnh mt nm hc ngh- lm vic thng qua cc cp bc

ca ngi hc vic, ngi lam thu, v cui cng l ngi thy lm bnh. Khng chvy, s

lng v cht lng ca biscuit cng c theo di mt cch cn thn.

Khi cng nghci tin trong sut cuc Cch mng cng nghip trong thkXIX,

gi ng v bt m gim xung. Cc tc nhn ha hc lm nbnh nhNaHCO3, tr

thnh sn c v di do, c sdng trong cng thc bnh. iu th vl mc d thi gian

tri qua nhng cc thnh phn thit yu ca biscuit vn khng thay i - nh bt m

mm (cha hm lng protein t hn bt mdng lm bnh m) ng, cht bo, nh

bv du. Ngy nay, mc d chng c gi bng cc tn khc nhau trn ton thgii, mi

ngi ng mt iu khng c g nh bi biscuit!

Ngy nay, biscuit c sn xut tcc nguyn liu chyu l bt m, ng, cht

bo, trng

1.2. Phn loi

Biscuit c thc phn loi theo rt nhiu cch phn loi khc nhau:

- Da vo cu trc, cng, hnh dng-

Da vo thnh phn nguyn liu c nh hng chnh..- Da vo cu trc bt nho v phng php to hnh

Biscuit c nhiu hnh dng khc nhau v kch thc cng phong ph v kch cca khun

to hnh. C 2 loi biscuit chnh:

- Biscuit cng (bch quy dai).- Biscuit mm (bch quy xp).

Biscuit cng


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c im nguyn liu:hm lng ng v cht bo cao hn cracker.

c im bt nho:khung gluten pht trin (hard weet, semi weet dough): bt t dai,

n hi hn cracker. Cu trc cbn: mng protein lin tc bao bc quanh cc ht tinh bt

v cht bo.

To hnh:cn v ct.

Cu trc sn phm:gin, cng.

Biscuit mm

c im nguyn liu: hm lng ng v cht bo cao hn biscuit cng.

c im bt nho:sto khung gluten bhn chdo hm lng ng v cht bo

cao (short dough): bt rt t dai v n hi. Cu trc cbn gm hn hp tinh bt, protein v

ng, cht bo dng ht ln gng cc ht tinh bt vi nhau, xen vo l cc bt kh.

To hnh:c

Cu trc sn phm:gin, xp.

1.3. c tnh

Biscuit chim mt lng ln trong cc sn phm bnh nng c lm tbt m, l

loi bnh ngt khng ln men, bnh gin v kh v chng c hm lng nc thp, l loithc phm l tng dtr, c hnh dng nh, dy v bmt lng mt. N mang nhiu

ngha vn ha. M, biscuit l loi bnh nng mm, dy hoc l bnh cun nhtng t

nhl bnh nng xp. Anh, biscuit tng ng nhl bnh cookie v cracker M.

1.4. Gi trdinh dng

Vai tr v nh hng ca dinh dng thc phm n sc khe con ngi trthnh

mt chc quan tm cc k t nht l cc nc pht trin.

Ngy nay, nguyn liu dng sn xut bnh rt phong ph v bnh l mt mt hng c

gi tr cao vmt dinh dng v cung cp nhiu nng lng cho c thv trong bnh c

cha y cc thnh phn gluxit, protit, lipit v c thc bsung thm vitamin, cht

khong trong gluxit chim mt phn ln trng lng ca bnh. V d nh dng 100g

bnh quy c thcung cp cho cth387kcal.

1.5. Gi trsdng


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Bnh rt thun tin trong vic sdng. Bnh l mt loi thc phm n lin c gi tr

dinh dng cao v ngon ming. N rt thch hp vi cc bui lin hoan, picnic

Bnh ngy nay, c sdng nhmt loi thc n cbn trong cc ba n, bnh

c xem nhmt thc phm tng cng dinh dng v c bit bnh cn c dng lm

qu biu vo nhng dp L, Tt.

1.6. Sn phm trn thtrng

Nhng nm gn y, ngnh bnh Vit Nam pht trin

rc r, khng chnhiu vslng m cn phong ph v

mu m, gi thnh cng nhcht lng. Bnh quy sa Goodies ca cng ty cphn Bibica

Thnh phn:Thnh phn: Bt m, ng, cht bo

thc vt, mch nha, 6,5% sa bt, trng, mui, vani, cht

to xp (500ii, 503ii), hng (b, sa) tng hp, Beta-caroten.

Gi trdinh dng trn 100g:

Nng lng 450 kcal, Carbohydrate 72g, Cht bo 16g, Protein 6g

Mt ssn phm biscuit ca cng ty cphn Kinh

Mt ssn phm biscuit ca cng ty cphn bnh ko Hi H.


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2. Tng quan vnguyn liu

2.1. Bt m

Bt m c chto tht la m thuc hha tho bng phng php nghin. La

m c hai loi l la m en v la m trng. Do , ngi ta cng chia bt m thnh 2 loi:

Bt m en: Chbin tht la m en.

Bt m trng: Chbin tht la m trng.Ty theo cht lng bt ta chia ra lm cc

loi bt: thng hng, loi I, loi II, loi II, nghin ln.

Ty thuc vo ging la m sn xut bt m v bt m c thnh phn ha hc khc

nhau. Nhng nhn chung, bt m c cc thnh phn cbn nhsau :

Cht v c: chim t15-17%, chyu l nc v mui khong

Cht hu c: chim t83-87% gm glucid, lipid, protid, vitamin, sc t, enzyme..

C 2 phng php sn xut bt:

+ Phng php nghin th: Nghin khng phn loi, chthu c mt loi bt.

+ Phng php nghin tinh: Nghin phn loi, thu c nhiu loi bt.

Thnh phn ha hc ca bt m

Thnh phn ha hc trung bnh tnh bng % cht kh

Loi vhng bt Pentozan Tinh bt protit Cht bo

ng

chungXenluloza Tro

Bt mtrng

Thng 1,95 79,0 12,0 0,8 1,8 0,1 0,55


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hng

Hng I 2,5 77,5 14,0 1,5 2,0 0,3 0,75

Hng II 3,5 71,0 14,5 1,9 2,8 0,8 1,25

Bt men

Hng A 4,5 73,5 9,0 1,1 4,7 0,4 0,75

Hng B 6,0 67,0 10,5 1,7 5,5 1,3 1,45

Protid

Chim khong 8-25%, cu trc phn tprotid c nh hng ti cht lng gluten,

Cht lng gluten nh hng ti cht lng ca bnh. Nu t lmi lin kt disulfua tri

hn ngha l protid c cu trc bc ba v bc bn nhiu hn th gluten ca bt cht hn, sc

cng ln hn, cht lng bnh tt hn.

Protid ca bt m ch yu l dng n gin: protein. Protein ca bt m gm c 4

nhm: Albumin, Globulin, Glutelin, Prolamin.

Albumin, Globulinchim khong 20% protein ca bt m.

Glutelin v Prolamin l 2 protein quan

trng v chim khong 80% protein ca bt m.

Hai loi protein ny l tc nhn chnh to nn

mng phn bu trong khi bt nho khi kthp vi nc, mng li ny chnh l gluten.

Khi nho trn bt m vi nc, protein

ca bt m to thnh mng phn bu trong

khi bt nho, mng li ny va dai va n

hi, c tc dng gikh v lm khi bt nho


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n. Nu mang khi bt nho ra vi nc, tinh bt s tri i, phn cn li l protein cn

c gi l gluten.

Hm lng gluten t trong bt m chim khong 15 35 % ty thuc vo hm

lng protein ca bt m.

Gluten t cha ti 70% nc, 30% cht kh. Cht kh cn li ch yu l protein

(chim 90%), glucid, lipid, khong v enzyme (chim 10%).

Cht lng gluten c nh gi bng cc chsnh: mu sc, n hi, dn

di. Bt c gluten cht lng cao th n hi tt, dai cao v dn trung bnh, bnh sn

v ngon.

Trng hp gluten yu ngha l dn di ln, dai thp, t n hi th bt nho s

dnh, bnh t nv bb ra.

tng cht lng gluten khi nho bt c th b sung cc cht oxy ha: acid

ascorbic, kali bromat, peroxit,, ngc li nhng cht khslm gim cht lng gluten.

Glucid

Ch yu l cc loi glucid khng ha tan trong nc (tinh bt, celluloza,

hemicelluloza,) v mt st ng(saccharoza, glucoza, fructoza, maltoza).

Tinh bt:L glucid quan trng nht, cha trn 90% cht kh ca bt. Hm lng tinh

bt cng ln th hm lng protein cng nhv ngc li.

Celluloza v hemicelluloza: Ph thuc vo hng bt, hng bt cng thp th hm

lng 2 loi glucid ny cng cao.

ng trong bt chim khong 0,8-1,8%, bt hng cng thp th hm lng ng

cng cao.

Dextrin v pentozan: c nh hng xu ti cht lng bnh v dextrin khng ht nc

nn nhiu dextrin rut bnh t v t n hi, cn pentozan dkeo ha lm tng nht v

dnh ca bt nho.


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Cellulose v hemicellulose: c thngi khng tiu ha c nn trong bt cng t

cng tt, hm lng hai cht ny trong bt m ho hng v loi I t hn trong loi II v loi

th.

Lipid

Cha khong 0,8- 2,5% ty loi bt.

Trong bt m c khong 0,4- 0,7% photphatid, chyu l Leucithin.

Leucithin l cht bo c tnh ho nc v hot ng bmt cao nn nhha tt gip

cho gluten n hi tt hn lm tng cht lng bt nho v bnh nng.

Trong qu trnh bo qun, cht bo dbphn hy, gii phng acid bo tdo, nhhng ti acid v mi vbt.

Vitamin

Bt m cha nhiu vitamin nh: B1, B6, PP

Vitamin cha nhiu trong lp alron.

Hng bt cng cao th vitamin cng thp v ngc li.

Henzyme

Enzyme trong bt c y cc htrong ht m, tuy nhin trong sn xut cn c bit

lu protease v amylase.

Protease phn gii protein cu trc bc ba, do gluten b vn nt lm gim cht

lng bt nho. Protein bt m c hot ng mnh 45- 47oC v pH=4,5-5,6. Khi bsung

cht khth hot ca protease tng nhng vi cht oxy ha v mui n bkm hm.

Tc dng tch cc ny chi vi -amylase v n thy phn tinh bt thnh maltose,

cn -amylase thy phn tinh bt thnh dextrin m dextrin th lin kt vi nc km lmcho rut bnh bt, do lm gim cht lng bnh.

Chtiu nh gi bt mCht lng bt m c nh gi theo TCVN 1895776 hoc TCVN 1874:1995

Trong , bt m c nh gi vcc chtiu sau:

m:thng qua phng php sy.


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mn:thng qua vic sng trn ry in vn tc 180 - 200 vng/pht vi Kch thc ry:d = 125mm Mu sc, mi v:dng phng php cm quan. nhim cn trng:sng trn ry v quan st. Tp cht st:dng nam chm tch v nh gi. Khi lng, cht lng gluten t:cn, kim tra mu, cng, n hi. chua:sdng phng php trung ha. Hm lng tro:bng cch tin hnh v cho mu. c tnh ht nc, chc, c tnh lu bin ca bt mxc nh theo phng

php thfarinograph.

Cc chtiu cht lng bt m dng trong sn xut bnh biscuit

STT Tn chtiu Yu cu

1 Mu sc Trng ng hay trng c trng ca bt m tnhin

2 Mi Mi tnhin ca bt m, khng c mi l

3 V Khng c vchua, ng hay vl

4 Tp cht v c Khng c ct sn

5 Su mt Khng c

6 m 13%

7 mn

Cn li trn ry 420m Qua ry 118m

20%

80%

8 Gluten t

Hm lng Cm quan cng t

32 35%

Trng ng, mm mi, n hi tt

13 16 cm

9 Hm lng tro 0,4 0,75%


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10 chua 3,5ml NaOH/100g

11 Tp cht Fe 30mg/kg2.2. ng

Trong sn xut bnh, ng c dng chyu l ng saccaroza.

Ngun gc: ng saccharose rt phbin trong tnhin, c nhiu trong ma, cci

ng hay tri tht nt, tn ti di dng tinh thi khi cng c thtn ti di dng v

nh hnh nhng khng bn.

ng saccharose c:

Cng thc phn t: C12H22O11

Khi lng phn t: 324

Khi lng ring 1,5879g/cm3

Nhit nng chy 185oC

Tnh cht ca saccharose

Trong mi trng axit v nhit cao rt dbthy phn cho ra glucose v fructose

(tc xy ra hin tng nghch o ng).

Thng thng t ht m nhng khi un nng nhit cao (khong 130oC) th li c

khnng ht m mnh v n 160oC th bt u cho phn mg caramen ha.

Tan tt trong nc (ha tan 25oC l 2,04 kg/kg nc) v tan tng theo nhit .

ngt trong dung dch phthuc vo sc mt ca cc cht khc v iu kin mitrng nhpH, nht, v hm lng NaCl

Vai tr ca ng trong sn xut bnh:

Vai tr chnh ca ng l to vngt

Ngoi vic to v ngt, ng cn gp phn to cu trc, mu sc, hng v thm

ngon cho sn phm bnh nng.


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ng lm mm bt nho, gip bt m ht nc trng n

ng l ngun cung cp nguyn liu cho phn ng Maillard, phn ng Caramel.

Cc chtiu cht lng ng dng trong sn xut bnh biscuit

STT Tn chtiu Yu cuRE RS1 Cm quan

Mu sc Mi V Trng thi

Trng sng, vng nhMi ng c trng, khng c mi l

Ngt thanh, khng ln vkhcTinh thri kh, tng i mm

2 Hm lng ng saccharose (%) 99,8 99,623 m (%) 0,05 0,074 Hm lng ng kh(%) 0,03 0,15 Hm lng tro (%) 0,03 0,07

Sau khi chn ng tinh tht cht lng nhtrn, ta em xay ng tinh ththnh

bt qu trnh ha tan nhanh hn.

2.3. Cht bo

Cc loi cht bo thng c sdng trong sn xut bnh l:

Shortening: l sn phm cht bo no, thu tqu trnh hydro ha du thc vt, nhit

nng chy cao, khng mi v, c mu trng ng v rn iu kin thng

B:thu nhn tvng sa, hm lng bo cao (trn 80%).

Vai tr ca cht bo:

Tng cht lng cm quan Lm mm bt Tng gi trdinh dng v nng lng

Chtiu bv shortening dng trong sn xut

Chtiu Shortening (TCVN6048:1995)

B(TCVN 7400:2004)

Cm quan Mu sc Mu trng sa Vng c trng


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Mi v Trng thi Tp cht

Khng c vl

Dng paste, mn

Khng c tp cht l

Mi vc trng

Mm, ng nht

Khng c tp cht

Ha hc m, % Hm lng lipid ChsAV ChsPV Hm lng cht

kh khng bo,

%

< 0,1

< 96


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Cc chtiu chn trng

STT Tn chtiu Yu cu

1

2

3

4

5

Mi

V

Bung kh

Lng

Lng trng

Khng mi l

Sch, khng mp mo, khng v


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2.5. Bt n

Sodium bicarbonat NaHCO3

Thuc nl hp cht ho hc bphn hutrong qu trnh nng v sinh ra cc sn

phm thkh, hnh thnh cc lhng kh bn trong bnh, to cu trc cho bnh v lm cho

bnh xp.

Sodium bircarbonat thng c gi l soda, dng tinh thhoc bt trng. Trong qutrnh nng soda phn huto ra kh CO2v lm tng thtch v xp ca bnh.

NaHCO3 Na2CO3 + CO2 + H2O

Khi c mt ca hi nc, NaHCO3 s phn ng vi mt s cht c tnh acid gii

phng ra kh CO2, phn li to thnh mui sodium v nc. Khi gia nhit, bicarbonat sgii

phng ra mt sphn tCO2v phn cn li l sodium carbonat. Lng kh thot ra lm

xp bnh l 50%. Kh CO2sinh ra khng mu, khng mi nn khng nh hng xu n

cht lng bnh v lm cho bnh c mu vng p v vngon c bit. y l loi thuc nic sdng rng ri.

Dng sodium bicarbonat qu mc slm cho bnh biscuit c tnh kim, c ming hi

vng vng bmt v c vkh chu. Gi trpH cao, nhvt qua gii hn pH = 8 th cng

c mi nhvy. Thng thng, mt vi loi bnh qui c bit, pH ca bnh l 7.0 0.5 v

iu ny t c bng cch dng mt lng sodium bicarbonat.

Yu cu kthut ca bt ntrong sn xut bnh biscuit cho theo bng

STT Cc chtiu Yu cu12

Cm quantinh khit

Ht mn, ng nht, mu trng, khng ln tp cht 90%

2.6. Mui

Mui dng trong sn xut bnh thng l NaCl

Hm lng sdng: khong 1 1.5 % khi lng bt nho


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Vai tr ca mui:

To v Tng dai ca gluten v gim dnh ca bt nho

2.7. Vani

Hng vani thin nhin c sn xut tqu trnh ln men tnhin ca tri vanilla.

Vanillin l thnh phn chnh ca hng vani thin nhin, chim n khong 85%, tip

theo l phydroxybenzal-dehyd khong 9% v p-hydroxy-benzyl methyl ether khong 1%;

phn cn li chia cho khong 200 cht to mi khc v tuy t, nhng chng to ra du n

ring cho cc thng hiu vani khc nhau, nhBourbon, Tahiti...

Vai tr ca hng vani trong sn xut bnh biscuit: To ra hng vring, c trng

cho sn phm.

3. Quy trnh sn xut

3.1. Squy trnh


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3.2. Thuyt minh quy trnh

3.2.1. Giai on chun bnguyn liu

Cc nguyn liu dng sn xut bnh biscuit bao gm: bt m, ng xay, bphe,

bt ni, trng, mui, vani. Tt ccc nguyn liu phi c cn ong chnh xc theo cng

thc v c xl nhsau:

Bt m:em ry loi btp cht, lm cho bt mn trnh ng cc trong qu trnh

nho trn.

ng:em xay nh thnh bt mn v cho qua ry loi b tp cht v trnh b

ng cc, dha tan

Trng:ra sch bi bn tp cht, vi sinh vt trn bmt. Sau bv, thu nhn lng

v lng trng trng.

Bphe:tan chy nhit thng do phi c bo qun lnh.

Mui n, bt nv vani:sau khi cn th cho trc tip vo khi bt trn kh.

3.2.2. nh kem

Trng cho vo my, nh vi vn tc cao nht, cho n khi trng ni bt hon ton,

bn trong nc khong 1-2 pht.

Sau cho ng vo nh vi trng cho ti khi c cng th dng, thi gian nh

khong 2-3 pht. Sau cng cho bvo tn u.

Sau khi nh xong sto thnh mt hn hp kem ng nht.

Cc yu tnh hng trong qu trnh nh kem:

Nhit mi trng:nu nhit mi trng qu cao s lm nh hng n khi

kem, khi kem btch lp, mt tnh ng nht.


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Tc v thi gian nh kem:tc qu cao, thi gian nh qu di sgy nn ma

st, sinh nhit lm cho khi kem btch lp

ng:nu qu nhiu slm cho khi kem bchy

3.2.3. Nho bt

Trc khi nho bt cn phi trn kh hn hp gm bt m, bt n, vani v mui,

nhm to sng u. Sau cho hn hp ny vo nh cng vi khi kem trong vng 1-2

pht, nh tht nhanh nhm trnh lm bin tnh protein ca trng.

Mc ch: to thnh khi bt nho c tnh cht thch hp, c tnh ng nht, mmdo, khng dnh tay.

c im bt nho:khung gluten pht trin, mng gluten lin tc bao bc quanh cc

ht tinh bt v cht bo.

Cc bin i xy ra trong qu trnh nho

Bin i vt l

Thn hp cc vt liu ri rc ban u to thnh mt khi bt nho ng nht, do

v n hi.

Trong khi bt nho, ng thi vi pha lng cu to t nc tdo, protit ha tan,

ng v cc cht khc, cn c pha kh c to nn ts tch ly cc bt kh trong qu

trnh nho.

Lc u, khi nho, khi bt cn dnh do lng nc tdo cn nhiu. Sau khi nho

mt thi gian nht nh, cc nguyn liu lin kt cht chvi nhau th dnh gim, ngthi thtch v khi lng ring cng gim. Nhng sau , do c sxm nhp v tch ly

kh trong khi bt nho nn thtch khi bt li tng ln.

Trong qu trnh nho, nhit ca khi bt tng ln do nng lng ca qu trnh c

hc chuyn thnh nhit, nhng khng ng k.


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Ngoi ra, cn c sthm thu ca cc hp cht mu, mi, v, tcc nguyn liu ph

v phgia vo trong khi bt nho.

Bin i ha l

Ht tinh bt trng ndo ht nc, protein ht nc to trng thi do

Cc thnh phn ri rc lin kt vi nhau to khi ng nht, khi lng ring v

nht ca hn hp thay i. nht tng.

Xy ra sha tan ca cc nguyn liu.

Thnh phn chnh trong vic hnh thnh nn khung gluten l gliadin v glutenin. Khinho bt, hai thnh phn ny sht nc v tng tc vi nhau, vi cc thnh phn khc

trong khi bt nho, to thnh nhng si chmng v mng mng dnh cc ht tinh bt thm

nc vi nhau to thnh hkeo.

C shp thu cht bo ln bmt cc misen lm cho lin kt gia cc misen gim,

lm gim n hi ca khi bt nho nhng tng xp.

Mui n phn ly thnh cc ion. Cc ion ny slm tng hng sin mi ca nc,gim dy v in tch ca cc ion bao quanh cc phn tprotein, lm cho cc phn t

protein tin li gn nhau hn gip hnh thnh lin kt a nc v knc, to nn phn t

protein c khi lng ln v tng cht ca mng gluten

Bin i ha hc

Xy ra cc phn ng ha hc to xp cho sn phm do c sdng bt n. Soxi

ha cht bo di tc dng ca oxi.

To nn nhng lin kt ha hc mi do trong qu trnh hnh thnh mng gluten nh

lin kt hidro, lin kt cu disunfua, tng tc a bo.

Bin i ha sinh

Di tc dng ca enzym protease, amylase v lipase th protein, tinh bt v lipit thy

phn to thnh nhng phn tn gin.


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Bin i cm quan

Chyu l sthay i vtrng thi nguyn liu, ngoi ra cn c sthay i vmusc v mi v.

3.2.3.1.Cc yu tnh hng trong qu trnh nho bt

nh hng ca nguyn liu

Bt mProtein: hm lng protein cng nhiu th kh nng ht nc cng tt, cht lng

gluten cng cao. Protein trong bt m (gliadin v glutenin) sht nc to khung gluten chobt nho.

Dextrin: dextrin t lin kt vi nc, nu dng bt c hm lng dextrin cao th bt

nho sbt v km n hi.

Pentozan: dkeo ha lm tng nht v dnh ca bt nho, nh hng n kh

nng to hnh

m: m bt m cng cao th khnng ht nc cng gim

Cht: bt cng mn, tit din bmt cng ln nn tc ht nc cng nhanh. Do

yu cu phi sdng bt mn

ngng lm cho bt nho trnn mm, nht, nu qu nhiu ng th bt nho sb

nho, dnh tay.

ng cha nhiu nhm OH, khi cho ng vo bt th khnng ht nc ca bt

v gluten gim. Do lng nc lin kt vi bt nho gim, lng nc t do dng

ng tng. V vy nu cho qu nhiu ng th bt nho sbnho, dnh tay, cng nhiu

ng th bt nho cng chy. Ngoi ra, ht m ca ng cng ln th bt nho cng

nho.


22/42



Lng ng nh hng n khnng ht nc ca bt. Khnng ht nc ca bt

gim 0,6% khi tng lng ng ln 1%.

Kch thc tinh thng cng nh hng n cht lng sn phm: nn sdng

ng ht mn dha tan, trnh trng hp ng cn ng li trn bmt bnh

Cht boCht bo to thnh mt mng mng bao bc cc ht tinh bt nn bt khng ht nc,

trng nlm cho mng gluten khng cht, khi bt nho mm. V n c tc dng nhmt

cht bi trn, nn vi slng ln cht bo sto nn cu trc bt nho c, mm.

Lm gim tnh n hi ca khung gluten: v n to ra mt mng mng trn bmt cc

misen t lm yu lin kt gia cc misen vi nhau. Do co gin ca khung gluten b

gim. Hm lng cht bo cng ln, bnh biscuit sau khi nng cng b.

Cht bo to xp cho sn phm: khi cho vo khi bt nho, cht bo to nn mt

mng mng c tc dng bao trm v bi trn cc ht bt, nh gic lng kh trong

bt nho. Do khi nng, lng kh sthot ra to xp cho bnh.

TrngTo cu trc ti, xp cho bt nho, lng trng trng cha albumin c tc dng to bt

cho khi bt nho.

Cht lexitin trong lng trng l mt cht nhha rt tt, lm tng khnng phn

tn ca cht bo, c tc dng lm gim nht v tng tnh do cho khi bt nho

Ngoi ra cc protit v lipit tn ti dng lipoprotein c tc dng lm bn h nh

tng.

MuiMui khi cho vo khi bt nho sbphn ly to thnh cc ion, hnh thnh cc tng

tc knc v a nc, to thnh phn tprotein c khi lng ln hn, lm tng cht

ca mng gluten.


23/42



Mui lm gim hm lng gluten nhng li lm tng cht lng gluten

Mui c khnng ht nc rt cao, do khi c mt ca mui, n shn chkh

nng ht nc ca bt, lm gim hm lng gluten.

Trong mui c ion Na+ nn to ra lin kt ion gia cc chui protein, lm khung

gluten cht li, do lm tng cht lng khung gluten.

Mui c chhot ng ca enzym protease, l enzym thy phn protein, nn mui

gip khung gluten pht trin tt hn.

Tinh btLm cho bt nho do, sn phm t, ti xp. Do tinh bt cng c kh nng ht

nc, nn n shn chsht nc ca protein, lm khung gluten khng chc.

Lm bmt sn phm lng bng: khi gia nhit, nhit cao tinh bt bphn gii to

thnh dextrin trn bmt bnh. iu kin thiu nc, dextrin lm cho bmt bnh lng

bng.

nh hng ca chnho

Thi gian nhoNho cng lu th khnng ginc ca gluten gim, lng nc lin kt gim v

lng nc tdo ca khi bt nho tng ln, v protit bbin tnh di tc dng chc.

Trong khi nho th bt strn ln hon ton vi nc, bt nho sbdnh. Nho n

mt thi gian nht nh th dnh ca bt nho sgim, do trong thi gian nho protit v

cc cht khc trong bt lin kt vi nc, hm lng nc tdo trong bt nho gimxung.

Tng thi gian nho trn slm mm khi bt nho, lm gim nht v tnh n hi

ca khung gluten.

Thi gian nho phthuc vo cc yu tsau:


24/42



Loi bt nho:i vi bt nho dai th thi gian nho lu hn bt nho xp to

iu kin cho gluten trng nhon ton

Hm lng gluten trong bt:khi hm lng gluten tng th gim thi gian nho bt

Nhit ca hn hp nguyn liu:do nhit nh hng n strng nca protit

nn khi nhit ban u cao th thi gian nho bt gim.

m bt nho:m ln th gluten trng nnhanh, do nu tng m bt

nho m cc iu kin khc khng thay i th phi rt ngn thi gian nho bt li.

Cng nhoCng nho phthuc vo cht lng bt v loi bnh

Nu nho vi cng nhanh th cc thnh phn ca khi bt nho snhanh chng

c trn u, nhng nht v n hi ca bt nho li gim xung, lm khung gluten

d b gy. Do mun hnh thnh khung gluten vng chc (i vi bnh cracker, khung

gluten pht trin ti a), th nn nho chm, cn i vi bnh cookies, yu cu khung gluten

hn chti a, nn cn nho nhanh chng ct t mch ca khi bt. Bt nho ca bnhbiscuit c khung gluten pht trin nn nho vi cng va phi.

Nhit nhoNhit nh hng n s trng n v tnh cht vt l ca bt nho, bt nho

trng ntt nht 40oC .

Nhit nh hng ti nht v n hi ca khi bt: tnh cht lu bin ca bt

nho chu nh hng bi thnh phn protein. Bnh thng cc chui polyme lin kt vinhau bng lin kt hydro v tng tc knc. Vic tng nhit nho slm tng lin kt

ngang ca chui polyme v tng thi gian tn ti ca chng, do tng n hi ca khi

bt nho.

Stng nhit cng nh hng n ttrng: do c schy ca cht bo. Cc tinh

thbo trong bt nho c tc dng n nh cc bong bng kh, khi nho bt, cc bong bng


25/42



kh c hnh thnh lm tng ttrng ca khi bt nho. Nhng khi tng nhit qu cao

th hu ht cc tinh thbo b tan chy, cc bong bng kh bvs lm gim t trng

khi bt nho.

m bt nhoNc l thnh phn quan trng trong vic hnh thnh khi bt nho, n rt cn thit

trong vic ha tan cc thnh phn khc, hydrat ha protein to khung gluten.

Nc cng l mt yu tquan trng nh hng n tnh cht lu bin ca khi bt

nho.

Nu m qu cao sgy kh khn cho cc giai on tip theo:

Bt nho dnh, gy kh khn trong qu trnh to hnh Trong qu trnh nng, thi gian nng ko di, lng hi v kh to ra

nhiu gy nh hng n cht lng ca bnh. m cao th cng trao i nhit cao,

dto nn cc phn ng khng mong mun, nh hng n cht lng bnh.

Hm lng nc cng nhiu cng lm cho bt nho dbchy, tng tnh dnh v lmgim n hi ca khi bt.

3.2.4. To hnh

Mc ch:to ra nhng ming bt sng c kch thc, hnh dng, hoa vn theo yu

cu

Cch tin hnh:

Bt sau khi nho xong phi em to hnh lin trnh nh hng xu n cht lng

bnh

Cho bt nho vo thit bto hnh biscuit press, ty theo yu cu vkch thc bnh

m tin hnh to hnh nhng mc ln nhkhc nhau.

Bnh c to hnh trn khay nng bnh c chun b sn, qut ln khay mt t

du bnh thnh phm khng bdnh khay khi nng.


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To hnh xong phi em i nng ngay, khng c lu. V lu bnh sxut

hin cc lkh, bt bchy ra, cht lng bnh bgim. Ngoi ra, nu bt qu lu trn

khay slm dnh khay, sau khi nng xong kh ly ra.

Yu cu: to hnh phi nhanh chng nu khng s lm thay i cu trc bt nho.

Bnh to hnh xong phi c kch thc v khi lng ng u nhau.

3.2.5. Nng

Mc ch

- Lm chn bnh- Gim m ca bnh- Tiu dit vi sinh vt- To cu trc cho bnh- Cnh khung gluten- To mu, mi cho bnh

Cch tin hnh

Cho khay bnh sng vo l nng bng in.

Do bnh biscuit vani c hm lng ng v cht bo cao nn chn chnng l

nhit thp, thi gian di

Bnh nng nhit 160oC v thi gian l 15-20 pht.

Cc bin i ca nguyn liu trong qu trnh nngBin i vt l

Bin i vnhit v m

Nhit bnh thay i khng ngng trong qu trnh nng do sthay i nhit ca

bnh sng vi bmt t nng ca l v khng kh trong l nng. Nhit di chuyn tv

vo tm bnh.

Chia thnh 3 giai on thay i nhit :


27/42



Giai on u ca qu trnh nng: nhit tng dn. Khi bnh mi cho vo l

nng, nhit bnh bng nhit mi trng, cn nhit l nng cao (160-200oC),

nn c struyn nhit tbmt vo trong bnh. Trong nhng pht u tin ca qu trnh

nng, m cng bt u di chuyn vo trong lm kh bmt bnh. trnh trng hp b

mt bkh, ta tng m bng cch hnhit trong l nng.

Giai on ny kt thc khi rut bnh t nhit khong 75-80oC, vbnh t nhit

khong 100oC. y l giai on truyn nhit cho bnh, trnh to vbnh qu cng.

Giai on trung gian ca qu trnh nng: nhit vn nh, nhit tm bnh tng

ln. Nc m tdo bt u thot ra ngoi.

Giai on cui ca qu trnh nng: nhit ti vtng dn ttn khong 180oC

th dng li v nhit ca lp st vkhng c qu 100oC. m tdo gim, to v

ngn cn s thu nhit t ngoi vo v thot m ra. Lng nc trong v bnh mt phn

chuyn vo mi trng bung nng, mt phn chuyn vo pha trong rut bnh. m

chuyn dch tkhu vc nng hn n khu vc ngui hn v tkhu vc m hn n khu vc

kh hn. Tc bc hi m gim dn v bng khng.

Bin i vkch thc

C s thay i do tc dng ca cc kh sinh ra khi phn hy thuc n nhit

nng. Khi nhit bnh tng th p sut v th tch ca cc kh tng ln, dn n kch

thc cc lhng trong bnh tng v lm cho thtch bnh tng.

Nhit phn hy ca NH4HCO3l 60oC.

Phng trnh: NH4HCO3

NH3+ CO2+ H2O Nhit phn hy ca NaHCO3l 80-90oC. Phng trnh: 2NaHCO3Na2CO3+CO2+H2O

Sgin nthtch trong qu trnh nng phthuc vo cc thng ssau:

Phng php lm n Lng v loi bt n


28/42



Nhit v m l nng m v thnh phn bt nho Kch thc v hnh dng ming bnh

Khi lng v khi lng ring gim i ng kdo bmt nc

Bin i ha l

Hkeo:thay i

Protein: 30oC bt u trng n, 40oC trng ntrit , 50 - 70oC bbin tnh.

Tinh bt:trng ntt nht nhit 40 - 60oC, ng thi vi strng nl sh

ha. Shha xy ra trong sut qu trnh nng, thu ht mt lng nc ng klm bnh

t c kh thch hp

Trng thi: di tc dng ca nhit cao, trng thi ca sn phm bin i to

thnh cu trc xp v sto thnh v. Schuyn trng thi sng sang chn.

Sto thnh khung xp do

Protit ng t, tch nc xy ra 50-70oCTinh bt ht nc trng nv bhha lm bnh kh hnTinh bt thy phn mt phn to dextrin

Sto v

Khi cng bay hi m trn bmt xy ra mnh mv tinh bt lp ngoi bh

ha phn no, schuyn m n bmt skhng b p lng m mt i, bmt skh

dn v to thnh lp vcng.

Bin i ha sinh

Vi sinh vt

Khi nhit ca nguyn liu tng ln qu 60oC, vi sinh vt btiu dit dn cho n

tiu dit gn nhhon ton sau khi nng.

Enzym


29/42



Ti nhng im m tc nhit tng nhanh (phn v) cc loi enzyme hu nhbv

hot ngay. Cn li nhng phn bn trong ca bnh nhit tng chm hn, thi gian

enzyme c duy tr nhit ti thch cho hot ng ca chng ko di hn, do vy chng

hot ng mnh hn.

Bin i ha hc

Tinh bt:hm lng tinh bt gim v mt phn bphn hu trong qu trnh nng

bnh to ra cc dextrin v ng.

ng:hm lng gim do tham gia phn ng Caramel v Maillard, tuy vy lng

ng ny gim khng ng k.

Protit:hm lng protit tng nhn chung khng thay i nhng tng loi protit ring

bit th c sthay i ln.

Cht bo:hm lng cht bo gim do hp thkhng bn ln khung bnh, tuy nhin

lng cht bo gim khng ng k.

Chsit ca cht bo:sau khi nng chsit ca cht bo gim i rt nhiu. Ch

saxit ca cht bo c thay i nhng khng theo quy lut nht nh.

kim:gim nhiu do tc dng ca bt nkim vi cc cht c tnh axit trong bt

nho.

Cht khong:hu nhkhng thay i trong qu trnh nng

Bin i cm quan:

Mu

Trong qu trnh nng, trn bmt xut hin mt lp v vng mu nu v to ra

hng vthm ngon

Bnh chuyn dn sang mu vng nu do:

Phn ng Maillard Phn ng to dextrin ca tinh bt


30/42



Phn ng Caramel.Mi

Sphn hy ng khto ra fucfurol v cc andehyt khc lm cho bnh c hng

thm v mi vdchu c bit.

Phn ng oxy ha cht bo tdo to aldehyt, lactone, ceton, nhng cht to hng

thm c bit.

3.2.6. Lm ngui

Mc ch: lm ngui gip cho qu trnh bao gi c thun li v trnh ngng tmsau khi bao gi gip bo qun bnh c tt hn.

Cch tin hnh: sau khi ra khi l nng, nhit ca bnh cn cao, bnh ang

mm phi lm ngui sbn nhit 65-70oC, tch bnh ra khi khay v lm ngui n

nhit thng.

Tc nhn lm ngui l khng kh. Bnh dbht m khng kh nn phi chuyn vo

gi ngay.

3.2.7. Bao gi

Mc ch:

- Bo qun: do bnh biscuilt l sn phm dht m nn thit kbao b kn, chng m.- Thun tin trong qu trnh vn chuyn v phn phi

4. Btr th nghim

4.1.

Th nghim 1:

Tin hnh lm bnh theo quy trnh v thao tc nu. Nhn xt cm quan vsn phm

(1).

Tin hnh lm bnh theo quy trnh nhtrn, vi cc thnh phn v khi lng nhsau:

Nguyn liu Khi lngBt m s8 160g


31/42



B 50gng 90g

Trng 1 quBt ni 5gVani 1 ngMui 1 cht

Cc thng strong th nghim 1:

Thi gian nh trng: 7 pht, nh mc ln nht (mc 3) Thi gian nh ng: 2 pht Thi gian nho bt: 1 pht, nho mc ln nht. Phng php to hnh: to hnh bng thit bbiscuit press. To hnh: mc 1v mc 2. Thi gian nng: 20 pht. Nhit nng: 160oC.

Nhn xt cm quan vsn phm:

Mi thm ca vani v b, mu sc: hi sm mu, ngt: va phi, bnh cng gin.

Bmt khng lng mt, c cc lnhtrn mt bnh.

Kch thc bnh c to hnh mc 1 va phi p hn bnh c to hnh mc

2, do bnh c to hnh mc 2 sau khi nng c kch thc qu ln.

Gii thch:

Mu ca bnh bsm nn trong cc th nghim sau mun mu ca bnh sng hn th

phi to hnh mc 1, nng nhit cao, thi gian ngn.

Bmt bnh c nhiu lnh, khng lng mt l do khi to hnh khng nn cht khi

bt nho trong thit bbiscuit press nn c nhiu khng kh ln vo, khi nng kh thot ra

to nn cc lnhtrn bmt bnh, lm gim cht lng cm quan. V vy khi to hnh

phi nn cht khi bt nho, thao tc dt khot v to hnh tht nhanh.


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4.2. Th nghim 2

4.2.1. Xc

nh

m b

t m

Phng php tin hnh:Xc nh m ca bt m bng phng php sy kh

Ly chn sy m em sy 100-105oC cho n trng lng khng i (ngha l sau

khi ngui v cn li, kt qugia 2 ln lin tip khng cch nhau qu 0,5mg). ngui

trong bnh ht m v em cn bng cn phn tch chnh xc n 0,0001g (G)

Cho vo cc cn khong 2g bt chun bsn, nghin nh. Cn tt ccn phn

tch vi chnh xc nhtrn. (G1)

Cho tt cvo tsy 105oC, sy kh cho n khi lng khng i, thi gian sy t

nht 2 gi.

Sy xong em lm ngui bnh ht m v em cn cn phn tch vi chnh xc

nhtrn. (G2)

Kt qu:

Khi lng ca chn sau khi sy n khi lng khng i (g): G = 224,6g

Khi lng ca chn v mu trc khi sy (g): G1 = 226,6g

Khi lng ca chn v mu sau khi sy ti khi lng khng i (g): G2 = 226,4g

Tnh kt qu

m theo phn trm (X) c tnh bng cng thc:

X =

Trong :

G: khi lng ca chn sau khi sy n khi lng khng i (g)

G1: khi lng ca chn v mu trc khi sy (g)

G2: khi lng ca chn v mu sau khi sy ti khi lng khng i (g)


33/42



Vy m ca bt m l: 10%

4.2.2. Xc nh hm lng v cht lng gluten bt m

4.2.2.1. Xc nh hm lng gluten t

Phng php tin hnh:

Cn khong 25g bt m trn cn kthut vi chnh xc 0,01g cho vo chn x

Cho vo 15ml nc nhit 16-20oC, dng a thy tinh trn u cho n khi

thnh khi ng nht

Dng dao vt cc mnh bt cn dnh a v chn, v khi bt thnh hnh cu,

cho vo chn v y chn bng tm knh. yn 20 pht nhit phng.

Sau ra gluten bng mt trong hai cch sau:

Ra trong chu: 1-2 lt nc vo trong chu, va ngm va tch tinh bt. Tin

hnh ra lin tc, trnh gluten mt i cng tinh bt. Thay nc ra 3-4 ln ty theo mc

tinh bt trong nc ra. Mi ln nc phi qua ry gili vn gluten.

Ra di tia nc nhtrn ry mau: cho bt v nhtrn vo lng bn tay tri, nm

cc ngn tay li v a vo vi nc my. ng thi dng tay phi iu chnh dng nc

chy nhvi tc 1 lt nc trong 5 pht. trnh mt gluten phi t pha di tay tri

mt ci ry. Tip tc ra di dng nc nhcho n khi gluten trthnh mt khi dnh n

hi th tng tc dng nc ln. Gitc ny cho n khi gluten sch ht tinh bt.

xc nh vic ra xong, sdng cc phng php sau:

Cho vo nc vt tgluten mt git dung dch I2nu dung dch khng c muxanh chng t ra ht tinh bt.

Hoc nh2-3 git nc vt tgluten vo mt cc nc trong thy nc khngc l xong.


34/42



Khi ra xong dng tay vt kit nc trong gluten, p gluten gia 2 lng bn tay, thnh

thong thm bng khn kh. Cn gluten p kh vi chnh xc 0,01g.

Kt qu

Khi lng mu cn : G = 25g

Khi lng gluten t cn c : G1= 7,6g

Tnh kt qu

Hm lng gluten t c tnh theo cng thc:

X =[G1/G].100 = [ 7,6/25].100 = 30,4%

Vy hm lng gluten t l: 30,4%

4.2.2.2. Xc nh cht lng gluten t

Cht lng gluten t c t trng bi: mu sc, cng t v n hi.

Mu sc gluten: mu trng ng, hi vng.

Xc nh cng t:

Tin hnh:Cn 4g gluten, v thnh hnh cu ri ngm trong chu nc c nhit 16-

20oC trong 15 pht. Sau dng hai tay ko di khi gluten trn thc chia milimet cho ti

khi t, tnh chiu di tlc t. Thi gian ko di l 10 giy. Khi ko khng c xon si

gluten.

cng t biu thnhsau:

cng ngn: 10cm cng trung bnh: 10-20cm cng di: >20cm.

Kt quth nghim: cng t 13 cm.

Vy cng t trung bnh.


35/42



Xc nh n hi

nh gi n hi, dng khi lng cn li khi xc nh cng t. Dng haitay ko di ming gluten trn thc khong 2cm ri bung tay ra hoc dng ngn tay tr

hoc ngn tay ci bp ming gluten.

Theo mc v vn tc phc hi chiu di v hnh dng ban u ca ming gluten,

nhn nh n hi ca n theo ba mc :

Gluten n hi tt:gluten c khnng phc hi hon ton chiu di v hnh dng ban

u sau khi ko hay nn

Gluten n hi km:hon ton khng trli trng thi ban u v bt sau khi ko

Gluten n hi trung bnh:gluten c nhng c tnh gia hai loi tt v km

Kt quth nghim: khi ko hay nn th gluten u trli trang thi ban u.

Vy gluten c n hi tt.

Cht lng gluten

Ty theo n hi v cng t, cht lng gluten c chia thnh ba nhm:

Tt:gluten c n hi tt, cng t trung bnh

Trung bnh:gluten c n hi tt, cng ngn hoc c n hi trung bnh,

cng t trung bnh

Km:c n hi km, bvng, bt khi cng.

Vy bt m s8 trong th nghim ny l loi bt m c cht lng gluten tt.

4.2.2.3. Xc nh hm lng gluten kh


36/42



Tin hnh: saukhi xc nh gluten t, cn khi gluten v em sy n khi lng

khng i, ta c gluten kh. Sau em cn lng gluten kh thu c (G)

Hm lng gluten kh c tnh theo cng thc:

X = (G/G).100 = (4,6/25).100 = 18,4%

Trong :

G = 4,6g: khi lng gluten t sau khi em sy (g)

G = 25g: khi lng mu cn (g)

Vy hm lng gluten kh l: 18,4%

4.2.2.4. Khnng ht nc ca gluten (tnh theo phn trm):

W =

4.3. Th nghim 3

Phn tch m bt nho. Lin hvi qu trnh to hnh, nhn xt sph hp ca

m bt nho vi phng php to hnh sdng. Ththay i phng php to hay kch

thc bnh sng vi quy trnh v cng thc trn. Nhn xt cm quan sn phm tm kch

thc bnh sng v phng php to hnh ph hp.

Tin hnh lm bnh theo 2 cng thc:

Cng thc 1: sdng cng thc nhth nghim 1 (3.1)

Nguyn liu Khi lngBt m s8 160gB 50gng 90gTrng 1 quBt ni 5gVani 1 ngMui 1 cht


37/42



Cng thc 2: gim lng bt m t160g xung cn 150g, cc thnh phn cn li gi

nguyn khi lng (3.2)

Nguyn liu Khi lngBt m s8 150gB 50gng 90gTrng 1 quBt ni 5gVani 1 ngMui 1 cht

So snh 2 loi bnh chn cng thc v phng php to hnh ph hp.

- Bnh (3.1) c m bt nho thp hn (3.2) do bnh (3.2) gim lng bt m do m cao hn. Bnh (3.1) khi to hnh bng thit bbiscuit press khng bdnh, b

mt bnh sng lng mt, trong khi bnh (3.2) bdnh v chy sau khi to hnh do

bt nho t hn.

- Sau khi nng cht lng cm quan ca 2 loi bnh cng c skhc nhau:Sn phm (3.1) (3.2)

Mu sc Mu vng sm Vng nht

Mi Vani v b Vani v b

V Ngt va phi Ngt va phi

Bmt Lng bng Khng p do bnh bchy khi tohnh

Cu trc Bnh cng gin Bn ngoi cng nhng bn trongmm

Sau khi so snh 2 sn phm bnh ta thy c skhc nhau vm bt nho cng nh

cht lng cm quan ca 2 sn phm bnh. Bnh (3.1) ph hp vi phng php to hnh


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bng biscuit press, cn bnh (3.2) khng ph hp do m cao hn. Cht lng cm quan

ca bnh (3.1) cng tt hn bnh (3.2)

Vy cng thc ph hp l cng thc 1 (3.1).

4.4...............................................................................................................................T

h nghim 4

Thay i bt m s8 bng bt m s11. Tin hnh lm bnh theo cc thng s

chn th nghim 3.

Nhn xt cm quan sn phm (4) v so snh vi sn phm (1).

Sn phm (1) (4)

Mu sc Mu vng Vng nht

Mi Vani v b Vani v b

Bmt Lng bng Khng lng mt do bnh bchy

khi to hnh, c nhiu lkhCu trc Bnh cng gin Bn ngoi cng nhng bn trong

mm xp

Hnh dng ng u Khng ng u do bt nho bnho, bnh bbin dng sau khi to

hnh

Nhn xt:bnh sdng bt m 11 c mu vng nht v bn trong bnh mm hn

bnh sdng bt m s8.

Gii thch:bnh khi sdng bt m s11 bn trong bmm do bt m s11 c hm

lng gluten cao hn bt m s8 nn khung gluten ca bt m s11 tt hn, khnng gi

kh tt hn. Do khi nng kh cn gili trong bnh, lm cho bnh bmm, c mu vng

nht trong khi bnh sdng bt m s8 do lng kh thot ra gn ht nn c cu trc

cng gin, bmt c mu vng c trng.


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Sau khi so snh cht lng bt nho v cht lng cm quan ca sn phm (1) s

dng bt m s8 v sn phm (4) sdng bt m s11, th ta thy sn phm (1) c cht

lng bt nho v cht lng cm quan tt hn sn phm (4).

Vy loi bt m thch hp l bt m s8.

4.5. Th nghim 5

Thay i hm lng bt ntheo bng sau:

Lng sdng so vi bt

% 3,12 1,5 3,5Khi lng (g) 5 2,4 5,6Sn phm Mu i chng (5.1) (5.2)

Nhn xt cmquan

Mu vngNto, khng pC mi nng, kh

chuC vi chbrnnt, bmt khng

lng mn

Cu trc cng gin

Mu vng c trngBnh nva phi

Mi thm ca bvvani

Bmt lng mn,khng brn nt

Cu trc cng gin

Mu vng nhtBnh nqu to

C mi rt nng,bnh khng thmBmt c nhiuvt rnt, khng

lng mn

Cu trc mmNhn xt:bnh (5.1) c cht lng cm quan tt hn mu i chng v bnh (5.2), do

2 bnh ny sdng hm lng bt nln, lm cho bnh nqu to v c mi nng kh chu

hn bnh (5.1).

Vy hm lng bt nthch hp l 1,5% so vi bt m.

4.6. Th nghim 6

Thay i loi bt nsdng (3 loi):

Loi 1 Loi 2 Loi 3Tn loi bt n Alsa Mauri NaHCO3 Kim Nga

% 1,5 2 1,5 0,75Khi lng (g) 2,4 3,2 2,4 1,2

Sn phm Mu i chng (6.1) (6.2) (6.3)Nhn xt cm Mu vng c Mu vng nht Mu vng c C ni nng ca


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quan trngBnh nva to

Mi thm cabv vaniBmt khng

lng mn, brnnt

Bnh mm,khng xp gin

trngBnh nva

phiMi thm cabv vaniBmt lng

mn, khng brn nt

Cu trc cnggin

viMu vng sm

Bnh qu cngnt

Nhn xt: saukhi nhn xt cm quan v so snh cc loi bnh sdng cc loi bt n

khc nhau ta thy loi bt nchc thnh phn l NaHCO3cho bnh c cht lng cm

quan tt nht.

Vy loi bt nthch hp l NaHCO3

4.7. Th nghim 7

Thay bbng shortening:

Lng sdng theo % tng cht boB 100 (50g) 50 (25g) 0Shortening 0 50 (25g) 100 (50g)Sn phm Mu i chng (7.1) (7.2)

Nhn xt cmquan

Mu vng c trngBnh nva phi

Mi thm ca bvvani

Bmt lng mn,khng brn nt

Cu trc cng gin

Mu vng nhtBnh xp, cngBmt bntKhng c mi thm

Mu trngBnh xp, cngBmt bntKhng c mi thm

Nhn xt:

4.8. Th nghim 8

Nhit nngoC 160 145 175

Thi gian nng


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(pht)Sn phm Mu i chng (8.1) (8.2)

Nhn xt

Nhn xt:

TI LIU THAM KHO

http://www.answers.com/topic/biscuit

http://en.wikipedia.org/wiki/Biscuithttp://wordsofbabel.blogspot.com/2007/07/history-of-biscuits-britannia.html

http://www.ebook.edu.vn/?page=1.18&view=2992

Phgia trong CNSX bnh TS. ng ThAnh o Ngun: www.ebook.edu.vn


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