Nghien Cuu Che Bien Va Bao Quan Banh Bao Khoai Lang Tim Sua

Cn Th, 2013

TRNG I HC CN TH

KHOA NNG NGHIP V SINH HC NG DNG

B MN CNG NGH THC PHM

NGHIN CU CH BIN V BO QUN

BNH BAO KHOAI LANG TM SA

NGUYN VIT KHOA

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LUN VN TT NGHIP K S

Chuyn ngnh: CNG NGH THC PHM

Cn Th, 2013

TRNG I HC CN TH

KHOA NNG NGHIP V SINH HC NG DNG

B MN CNG NGH THC PHM

NGHIN CU CH BIN V BO QUN

BNH BAO KHOAI LANG TM SA

Sinh vin thc hin:

Nguyn Vit Khoa

MSSV: 2091757

Lp: CNTP K35A

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LUN VN TT NGHIP K S

Chuyn ngnh: CNG NGH THC PHM

Gio vin hng dn:

Ths. Nguyn Th Thu Thy

Lun vn tt nghip kha 35 - 2013 Trng i hc Cn Th

Chuyn ngnh: Cng ngh thc phm i

Lun vn nh km sau y, vi ti: Nghin cu ch bin v bo qun bnh

bao khoai lang tm sa do Nguyn Vit Khoa thc hin v bo co, c hi

ng chm lun vn thng qua.

Gio vin hng dn Gio vin phn bin

Ths.Nguyn Th Thu Thy

Cn Th, ngy thng nm 2013

Ch tch hi ng


Chuyn ngnh: Cng ngh thc phm ii

LI CM T

Xin t lng bit n su sc n gio vin hng dn thc s Nguyn Th Thu Thy,

ngi tn tnh hng dn, gi v cho nhng li khuyn b ch trong vic

nghin cu v hon thnh lun vn ny.

Xin chn thnh cm n cc thy c v cn b B mn Cng ngh thc phm to

iu kin v h tr v mt phng tin v kin thc trong thi gian thc hin lun

vn ny.

Xin chn thnh cm n cc bn sinh vin ngnh Cng ngh thc phm kha 35 v

kha 37 Lin thng, bn b gip v chia s nhng kh khn ti c th hon

thnh lun vn ny.

Knh dng cha m, ngi ht lng nui con khn ln.

Ngi vit

Nguyn Vit Khoa


Chuyn ngnh: Cng ngh thc phm iii

LI CAM OAN

Ti xin cam oan y l cng trnh nghin cu ca bn thn. Cc s liu, kt qu

trnh by trong lun vn l trung thc v cha tng c ai cng b trong bt k

cng trnh lun vn no trc y.

Cn Th, ngy thng nm 2013

Sinh vin thc hin

Nguyn Vit Khoa


Chuyn ngnh: Cng ngh thc phm iv

MC LC

LI CM T ii

LI CAM OAN ..................................................................................................... iii

MC LC ................................................................................................................. iv

DANH SCH HNH ................................................................................................ vii

DANH SCH BNG ............................................................................................. viii

CHNG 1 T VN ...................................................................................... 1

1.1. GII THIU .............................................................................................. 1

1.2. MC TIU NGHIN CU ....................................................................... 2

CHNG 2 LC KHO TI LIU ..................................................................... 3

2.1 S LC V CH BIN LNG THC V BNH BAO ..................... 3

2.1.1 S lc v ch bin lng thc ..................................................... 3

2.1.2 Bnh bao ........................................................................................ 3

2.2 THNH PHN NGUYN LIU TRONG SN XUT BNH BAO ........ 4

2.2.1 Bt m ............................................................................................ 4

2.2.1.1 Thnh phn ca bt m ........................................................ 5

2.2.1.2 S hnh thnh khi bt nho................................................ 6

2.2.1.3 Cc phng php lm n bt .............................................. 6

2.2.1.4 Nhng bin i sinh ha xy ra trong bt nho .................. 6

2.2.2 Nm men ........................................................................................ 9

2.2.3 Khoai lang .................................................................................... 10

2.2.3.1 Cy khoai lang ................................................................... 10

2.2.3.2 c im sinh hc ............................................................. 11

2.2.3.3 Phn b v sn lng ........................................................ 11

2.2.3.4 Cu to v thnh phn ha hc .......................................... 11

2.2.3.5 Gi tr dinh dng v cng dng ca khoai lang .............. 13

2.2.4 Anthocyanin, ng dng v cc phng php trch ly .................. 14

2.2.4.1 S lc v anthocyanin ..................................................... 14

2.2.4.2 ng dng ca anthocyanin ................................................ 16


Chuyn ngnh: Cng ngh thc phm v

2.2.4.3 S thoi ha ca anthocyanin ............................................ 17

CHNG 3 PHNG TIN V PHNG PHP TH NGHIM ...................... 21

3.1. PHNG TIN NGHIN CU ................................................................ 21

3.1.1. Thi gian - a im nghin cu ................................................. 21

3.1.2. Nguyn liu v ha cht ............................................................. 21

3.1.3. Thit b v dng c ..................................................................... 21

3.2. PHNG PHP NGHIN CU ............................................................... 21

3.2.1. Phng php nghin cu ............................................................ 21

3.2.2. Phng php phn tch cc ch tiu l ha hc .......................... 23

3.3. B TR TH NGHIM ............................................................................... 24

3.3.1. Th nghim 1: Kho st nh hng ca t l nm men v khoai

lang so vi khi lng bt nho n cht lng cm quan sn phm .................. 24

3.3.2. Th nghim 2: Kho st t l ng v sa b sung vo bt nho

n gi tr cm quan ca sn phm ....................................................................... 26

3.3.3. Th nghim 3: Kho st kh nng bo qun sn phm cc iu

kin nhit khc nhau ........................................................................................ 27

CHNG 4 KT QU V THO LUN ............................................................. 28

4.1 KHO ST NH HNG CA T L KHOAI LANG V NM MEN

SO VI KHI LNG BT NHO N CHT LNG SN PHM ..... 28

4.1.1 n ........................................................................................... 28

4.1.2 Mu sc ........................................................................................ 29

4.1.3 Cu trc ........................................................................................ 29

4.1.4 Mi v ........................................................................................... 30

4.2 KHO ST T L NG V SA B SUNG VO BT NHO

N GI TR CM QUAN SN PHM ........................................................ 31

4.2.1 Mu sc ........................................................................................ 31

4.2.2 Cu trc ........................................................................................ 32

4.2.3 Mi v ........................................................................................................ 32

4.3 KHO ST KH NNG BO QUN SN PHM VI CC MC

NHIT KHC NHAU ................................................................................ 33

4.3.1 Kim tra vi sinh pht trin theo thi gian bo qun sn phm .... 33


Chuyn ngnh: Cng ngh thc phm vi

4.3.2 S thay i cu trc trong thi gian bo qun ............................. 34

CHNG 5 KT LUN V NGH ................................................................. 36

5.1 KT LUN .................................................................................................. 36

5.2. NGH ..................................................................................................... 36

TI LIU THAM KHO ......................................................................................... 37

PH LC


Chuyn ngnh: Cng ngh thc phm vii

DANH SCH HNH

Hnh 2.1 Bnh bao ....................................................................................................... 4

Hnh 2.2 T bo nm men Saccharomyces cerevisiae .............................................. 10

Hnh 2.3 Khoai lang tm Nht ................................................................................... 11

Hnh 2.4 Cu to chui tinh bt ................................................................................ 13

Hnh 2.5 Cu to khung anthocyanin ........................................................................ 14

Hnh 3.1. Quy trnh ch bin bnh bao khoai lang tm sa ....................................... 22

Hnh 3.2. S b tr th nghim 1 ........................................................................... 25

Hnh 3.3 S b tr th nghim 2 ............................................................................ 26

Hnh 3.4 S b tr th nghim 3 ............................................................................ 27

Hnh 4 S thay i cu trc ca sn phm trc v sau bo qun ........................... 35

Hnh 5 Sn phm bnh bao khoai lang tm sa ......................................................... 35


Chuyn ngnh: Cng ngh thc phm viii

DANH SCH BNG

Bng 2.1 Thnh phn ha hc ca mt s loi bt m ................................................ 5

Bng 2.2 Din tch, nng sut v sn lng ca cy khoai lang Vit Nam ........... 11

Bng 2.3 Thnh phn ha hc ca khoai lang tm Nht ........................................... 12

Bng 2.4 Cc nhm thay th trong phn t anthocyanidin ....................................... 14

Bng 2.5 Cc loi anthocyanin ph bin trong thc phm ....................................... 17

Bng 2.6 c im ca mt s anthocyanin ph bin .............................................. 19

Bng 3.1. Cc ch tiu l ha hc trong qu trnh th nghim .................................. 24

Bng 4.1 S thay i n ca bnh sau khi hp theo t l nm men v khoai lang

b sung ...................................................................................................................... 28

Bng 4.2 S nh hng ca t l nm men v khoai lang b sung n im nh gi

cm quan v mu sc ca bnh ................................................................................. 29

Bng 4.3 S nh hng ca t l nm men v khoai lang b sung n im cm

quan v cu trc ca bnh ......................................................................................... 30

Bng 4.4 S nh hng ca t l nm men v khoai lang n nh gi cm quan v

mi v ca bnh ......................................................................................................... 31

Bng 4.5 S nh hng ca t l ng v sa n im nh gi cm quan mu

sc ca bnh bao ........................................................................................................ 32

Bng 4.6 S nh hng ca t l ng v sa n im cm quan v cu trc ca

bnh bao .................................................................................................................... 32

Bng 4.7 S nh hng ca t l ng v sa n nh gi cm quan mi v ca

bnh bao .................................................................................................................... 33

Bng 4.8 Tng s vi sinh vt hiu kh trong thi gian bo qun cc nhit khc

nhau ........................................................................................................................... 34


Chuyn ngnh: Cng ngh thc phm ix

TM LC

ti Nghin cu ch binv bo qun bnh bao khoai lang tm sa c thc hin t thng 1/2013 n thng 4/2013 ti B mn Cng ngh thc phm thuc khoa Nng nghip v Sinh hc ng dng trng i hc Cn Th.

Kho st cc thnh phn nguyn liu phi trn vo bnh nh hng n gi tr cm quan ca sn phm bnh bao khoai lang tm Nht c ngun gc t huyn Bnh Tn, tnh Vnh Long. ti tin hnh ba th nghim nh sau:

- Kho st nh hng ca t l nm men v khoai lang so vi khi lng bt nho n cht lng cm quan sn cc t l nm men l 1%, 2%, 3% tng ng vi t l khoai lang b sung l 45%, 50% v 55%.

- Kho st t l ng v sa b sung vo bt nho n gi tr cm quan ca sn phm cc t l ng l 18%, 20% v 22% tng ng vi t l sa b sung l 40%, 50% v 60%.

- Kho st kh nng bo qun sn phm vi cc mc nhit -20oC, -5oC v 4 oC.

T cc kt qu th nghim cho thy, ch bin sn phm bnh bao khoai lang tm c gi tr cm quan cao, mu sc thch hp, cc thng s cn thit cho quy trnh l:

- T l khoai lang tm b sung l 50% so vi khi bt ca lp bt th hai.

- T l nm men ti u cho sn phm l 1%

- T l ng b sung 20% so vi khi lng bt m v t l sa l 50% so vi lng nc b sung trong khi bt.


Chuyn ngnh: Cng ngh thc phm 1

CHNG 1 T VN

1.1. GII THIU

Carbohydrate l ngun thc phm khng th thiu trong thnh phn dinh dng ca

c th con ngi. Carbohydrate c mt trong hu ht cc loi thc phm c ngun

gc thc vt, ch yu t cc loi cy lng thc v rau c nh la m, la go, ng,

sn, khoai lang Trn 75% nng lng dng trong hot ng sng ca con ngi

v gia sc l do lng thc cung cp.

Sn phm t carbohydrate rt a dng, t cc sn phm ti cho n cc sn phm

c qua ch bin nh cc loi bnh, nc ung, hp Hu ht cc loi bnh

c lm t bt m, bt np hay bt go, to nn nhiu nn m thc khc nhau trn

th gii, c nhiu nt c trng ring gia phng ng v phng Ty.

L sn phm c ch bin t tinh bt la m, bnh bao l mt loi bnh quen

thuc i vi ngi Vit Nam. N c dng nh mn im tm sng thng dng,

khng ch d n nh hng v thm ngon, m nng m cn giu gi tr dinh dng,

gip cho ngi n no lu. Cc loi bnh bao trn th trng hin nay thng c

nhiu mu sc to v hp dn cho bnh nhng phn ln lm t cc cht mu

tng hp nn khng m bo sc khe cho ngi tiu dng. V vy, vic thay th

cc cht mu tng hp bng cc cht mu t nhin khng ch gip bnh c mu sc

hp dn m cn tng gi tr dinh dng cho bnh.

Khoai lang l loi rau c c v tr cao nht v dinh dng so vi cc loi rau c

khc, khoai lang hu nh cung cp y cc cht cn thit cho c th con ngi

hn c khoai ty (Bi c Hi, 2007). c bit, trong khoai lang tm c cha hm

lng ln anthocyanin, mt cht mu thc phm bn, c th iu chnh pH bin

i mu sc, do vy anthocyanin c kh nng hi phc li mu t nhin ban u,

to ra mu sc hp dn cho mi sn phm. Anthocyanin cn c ng dng rng

ri trong y hc: s dng chng lo ha, tr vim lot, chng c v hoi t gan,

khng khun, ngn s nhim m, x va ng mch

Bnh bao khoai lang tm l s kt hp gia tinh bt khoai lang vi tinh bt la m,

c ch bin bng phng php ln men, thay cho phng php s dng bt khai

truyn thng v c b sung thm sa trong thnh phn ca bnh nn gip cho bnh

c gi tr cao v mt cm quan ln gi tr dinh dng. Tuy nhin, c c sn

phm tt khi a ra th trng th cn phi theo di nhng bin i xy ra trong qu

trnh ch bin, t gip cho sn phm c gi tr kinh t cao hn, p ng c th

hiu ca ngi tiu dng.



1.2. MC TIU NGHIN CU

Mc tiu nghin cu l xy dng quy trnh ch bin sn phm bnh bao khoai lang

tm thng qua:

- Kho st t l nm men v khoai lang b sung thch hp vo bnh.

- Kho st nh hng ca t l ng v sa b sung n cm quan ca bnh.

- iu kin nhit tn tr n kh nng bo qun ca bnh.



CHNG 2 LC KHO TI LIU

2.1 S LC V CH BIN LNG THC V BNH BAO

2.1.1 S lc v ch bin lng thc

L thnh phn khng th thiu trong cc ba n chnh hu ht cc nc Chu ,

tinh bt nh go, np hay la m l cc loi lng thc truyn thng c ngun gc

kh lu i, c th xut hin t khi con ngi bit trng la. Rt nhiu loi bnh

c lm t bt go, bt np hay bt m, to nn nt p m thc c truyn ring

ca mt s nc, cho thy ngun gc lu i cng nh tnh ph bin ca chng.

C rt nhiu mn ngon trong m thc Vit Nam c lm t bt go, bt np hay

bt m c s dng ph bin t Bc ti Nam. Nh min Bc v min Trung dng

bt go lm bnh c, bnh bo, bnh xo, bnh cun, cao lu, bnh p Min

Nam ph bin c bnh b, bnh canh, bnh cng, bnh t, bnh u xanh hay bn

go Mi a phng u c c s lm bt khc nhau, xut pht t loi nguyn

liu, cht lng v mc ch s dng ca chng.

i cng vi qu trnh to ra cc loi bnh l qu trnh pht trin rt di ca cng

ngh ch bin, p ng cho nhu cu sn xut v s gia tng sn lng lng thc

khng ngng trn th gii. Cng ngh ch bin lng thc tri qua qu trnh sn

xut th cng cho ti sn xut cc x nghip ch bin nh ngy nay. Qu trnh ch

bin ngy cng c ci thin, t ci chy bng n cc my mc c ng c

in v dy chuyn sn xut hin i ha ton b. Cht lng sn phm sn xut t

nguyn liu tinh bt cng thay i rt nhiu, t mu sc, mi cho ti tinh sch

ca sn phm.

2.1.2 Bnh bao

Bnh bao c xut x t Trung Quc v gn ging bnh mn thu truyn thng ca

h v c th c hoc khng c nhn. Theo truyn thuyt th bnh bao do qun s

Gia Ct Lng to ra. Bnh bao l loi bnh c lm bng bt la m c nhn

c hp chn. Nhn bnh bao th c th c nhiu loi nh: hi sn, x xu, tht

Bnh bao tuy c xut t Trung Quc nhng khi du nhp vo Vit Nam th b bin

th rt nhiu. Bnh bao ca ngi Vit thng nh hn bnh bao Trung Quc (hnh

nh). Thnh phn nhn cng khc, thng thng th c tht heo xay, lp xng,

min, nm hng, mc nh, trng chim cc hoc trng g



Hnh 2.1 Bnh bao

Cc loi bnh bao Trung Quc thng dng v c bn trn th trng nc ta:

- Cha siu bau hay Charsiu bau (xoa thiu bao) l loi bnh bao nhn x xu.

- Goubuli baozi l bnh bao nhn tht. Sengjian mantou l mt loi bnh bao nh

chin nhn tht t Thng Hi.

- Zima bao (chi mau bao) l loi bnh bao nhn m en nh.

- Xiaolong bao (tiu long bao) l bnh bao nh nhn tht Thng Hi cha nc

tri cy.

- Naihuangbao (ni hong bao) l bnh bao nhn sa trng ngt mu vng.

- Doushabao (u sa bao) l mt loi bnh bao c nhn u nh.

- LianRong bao l mt loi bnh bao c nhn ht sen.

Ngoi sn xut th cng th ngy nay bnh bao cn c sn xut trn quy m cng

nghip. Bnh bao c sn xut trn quy m cng nghip dng nm men ca bt m

v lm ni bt, thay th cch lm th cng truyn thng l bng ph gia v

dng bt khai lm ni bnh. Bnh lm t th cng c mi khai khi n, trong khi

bnh cng nghip khng c mi ny.

2.2 THNH PHN NGUYN LIU TRONG SN XUT BNH BAO

2.2.1 Bt m

Bt m c sn xut t la m. C hai loi bt m: bt m trng v bt m en c

sn xut t la m trng (triticum) v la m en (secale) bng hai phng php

nghin ln v nghin phn loi. Nghin ln ch thu c mt loi bt, cn nghin

phn loi thu c hai hoc ba loi bt.



Bng 2.1 Thnh phn ha hc ca mt s loi bt m

Loi v hng bt

Thnh phn ha hc trung bnh (tnh bng % cht kh)

Pentosan Tinh

bt Protein Cht bo

ng chung

Cellulose Tro

Bt m trng

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

Hng I 2,5 77,5 14 1,5 2,0 0,3 0,76

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

Bt m en

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

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

(Ngun: Bi c Hi, 2007)

Ngun nguyn liu tinh bt ca nc ta ch yu l nhp t nc ngoi v nc ta

ch nhp loi bt m trng. La m trng c hai loi: loi cng v loi mm, loi la

m cng c cht lng tt hn.

Thnh phn ha hc ca la m ph thuc vo thnh phn ha hc ca ht v hng

bt.

2.2.1.1 Thnh phn ca bt m

Protein ca bt m

Hm lng protein trong cc loi bt m khc nhau th khng ging nhau. Hm

lng protein tng dn t hng bt cao n hng bt thp nhng v mt dinh dng

th protein trong hng bt cao c gi tr hn. Trong bt m c bn loi protein:

albumin v globulin chim 20%, prolamin v glutelin chim 80%. Khi nho bt vi

nc, prolamin v glotelin kt hp vi nhau to thnh khung gluten cho khi bt

nho. Gluten ca bt m c cht lng cao th n hi tt, chu ko va phi.

Nu gluten c chu ko ln th thi gian ln men di, nu gluten c ko nh

th bt nho thng b chy, bnh t n, b xp ca bnh km.

Glucid ca bt m

Trong bt m c cc loi glucid: tinh bt, dextrin, cellulose, hemicellulose, glucid

keo v cc loi ng. Tinh bt ca cc loi bt m khc nhau th khng ging nhau

v kch thc, hnh dng, kh nng trng n v nhit h ha cng khc nhau.

ln v nguyn ca ht tinh bt c nh hng n kh nng ht nc, tnh rn



chc v hm lng ng ca khi bt nho. Trong cc loi bt m thng hng

cha ti 80% tinh bt.

Trong bt c hm lng ng khng ln lm: tng hm lng glucose v fructose

0,10,25%, mantose 0,10,5%, saccarose 0,20,6%. Hm lng ng trong bt

ph thuc vo hng bt v cht lng ht bt m. Cht lng bnh ph thuc vo

kh nng sinh ng v to kh ca bt.

Dextrin l nhng cht keo kt hp vi nc to dung dch dnh. Khi lng phn t

v tnh cht ca dextrin ph thuc vo mc thy phn ca tinh bt.

Lipid ca bt m

Trong bt m c cha phosphatid, triglycerin, sterin Trong bt cc loi lipid

dng kt hp vi protein v glucid. Nhng hp cht ny c nh hng n cht

lng ca gluten, chng gp phn lm cho gluten kt cht hn. Hm lng lipid

trong bt m khong 23%.

2.2.1.2 S hnh thnh khi bt nho

Trong bt nho c hai thnh phn chnh l glucid v protein. Protein ht nc mnh

c th gp 23 ln trong lng bn thn, sau trng ln. Glucid th ht nc t

hn 1/3 ln so vi trng lng nhng trong bt nho hm lng tinh bt rt nhiu

nn c protein v glucid gi nc tng ng. Khi ht nc protein trng ln,

cc cht khc bm vo protein to thnh mt khung lm cho khi bt do dai.

2.2.1.3 Cc phng php lm n bt

C nhiu phng php lm n bt nh phng php c hc, phng php ha hc

v phng php sinh hc (ln men). Trong phng php ln men c s dng

ph bin nht.

Phng php sinh hc lm n bnh c s dng rng ri khng nhng lm cho bt

nho n tt m cn lm bnh c mi thm, v ngon v d tiu ha. Trong qu trnh

ln men nhiu sn phm c to thnh: acid lactic, ru, aldehyd Nhng cht

ny gp phn lm cho bnh c mi v thm ngon. Tuy nhin phng php ny cng

c mt s hn ch l quy trnh sn xut di 46 gi, tn hao cht kh cho qu trnh

ln men 23%. Mc d vy phng php sinh hc vn c dng to n cho

khi bt nho (Nhan Minh Tr v V Trng Sn, 2000).

2.2.1.4 Nhng bin i sinh ha xy ra trong bt nho

C th chia qu trnh ln men trong khi bt nho t lc bt u cho n kt thc

lm hai giai on chnh:

Giai on 1: T lc bt u nho bt n trc khi bt. Giai on ny lm cho

khi gluten vng chc hn, lm cho nm men phn b u hn trong ton khi bt



to xp u hn cho bnh, ng thi lm cho nm men thch ng vi khi bt

trong lc nho. Giai on ny bnh cha n.

Giai on 2: Qu trnh ln men nhanh khi bt t lc bnh cho ti khi to hnh.

Mc ch l to hng v v to n cho bnh.

Trong ton b qu trnh ny lin quan n hot ng ca vi sinh vt, bin i ha

keo v ha sinh trong khi bt.

Qu trnh ln men ca vi sinh vt

Trong qu trnh ln men bt nho th ln men ru l ch yu v xy ra vi tc

dng ca h enzyme trong nm men. Cc enzyme chuyn ha cc loi ng thnh

CO2 v nc. Bt nho cng long th nm men sinh sn cng nhanh v d trao i

cht dinh dng vi mi trng v t bo nm men.

- Cc yu t nh hng n qu trnh ln men l nhit , hm lng ng, oxy,

nng H+, cc vitamin, khong cht

Nhit thch hp cho qu trnh ln men: 2535oC.

pH thch hp cho qu trnh ln men: pH 46.

- Cc sn phm ph v sn phm trung gian trong qu trnh ln men ru:

+ S to thnh acid

Trong qu trnh ln men lun to cc acid hu c: acid acetic, acid citric, acid

formic, acid lactic nhng nhiu hn c l acetic v lactic.

Acid acetic c th c to thnh t phn ng oxy ha kh gia hai aldehyde acetic

mt phn t b oxy ha, phn t th hai s b kh:

CH3CHO + CH3CHO + H2O CH3COOH + C2H5OH

Acid lactic c to t acid pyruvic do s tip nhn trc tip hydrogen t

dehydrase theo phng trnh sau:

CH3COCOOH + NADH2 CH3CHOHCOOH + NAD

Acid citric c to t aldehyde acetic, phn ng ny c biu din tng qut nh

sau:

9CH3CHO + 4H2O (CH2COOH)2C(OH)COOH + 6C2H5OH

+ S to thnh ester

Song song vi qu trnh to ra acid v alcol, di tc dng ca enzyme esterase ca

nm men, cc acid v alcol s tc dng ln nhau to ra nhng ester tng ng.

C th vit di dng tng qut sau:



R1CH2OH + R2COOH R2COOCH2R1 + H2O

Khi alcol ethylic kt hp vi acid acetic l nhn c ester ethylic hay acetate ethyl:

C2H5OH + CH3COOH CH3COOC2H5 + H2O

S to thnh ester s d dng hn khi cc cu t tham gia phn ng l cc aldehyde:

R1CHO + R2CHO R1COOCH2R2

Khi tt c cc bin i ca aldehyde s c thc hin m khng cn tiu tn

nng lng.

Cc aldehyde cng c th ngng t vi nhau to ra cht mi, va cha nhm

CHO va cha nhm OH.

CH3CHO + CH3CHO CH3CHOHCH2CHO

Khi tc dng vi alcol ethylic, aldehyde acetic s bin thnh dietyllacetate:

CH3CHO + 2C2H5OH CH3CH(OC2H5)2 + H2O

(Nguyn nh Thng v Nguyn Thanh Hng, 2007)

Qu trnh sinh kh CO2 tch t to thnh cc ti kh. Gluten c tc dng lm khung

gi cc ti kh, t to cho bnh n, xp v n hi.

Qu trnh vt l v keo ha

S bin i vt l ca khi bt nho trong thi gian ln men lin quan cht ch vi

s bin i ca protein. S thay i ny chu tc ng ca ba yu t: acid ca

khi bt nho tng, tc dng ca enzyme trong tinh bt, tc dng ca enzyme thy

phn protein trong nm men. Cc yu t ny nh hng n kh nng ht nc

trng n ca protein. Thy phn protein lm tng b mt t do ca protein gip

cho protein ht nc v trng n tt lm gim pha lng, t to tnh cht bt

nho tt. Ngc li, nu protein b peptid ha lm t mch polypeptide lm pha

lng tng ln lm cho bt c tnh cht vt l km.

Trong qu trnh keo ha ca bt nho cng ph thuc vo acid ca bt nho, nu

acid tng th peptid ha tng nhanh dn n protein trng n nhiu v lm thay

i tnh cht vt l ca khi bt nho (Nhan Minh Tr v V Trng Sn, 2000).

Qu trnh sinh ha

Qu trnh sinh ha trong khi bt nho c lin quan cht ch n enzyme vi sinh v

h enzyme trong bn thn nguyn liu. Nhng bin i ch yu c th xy ra nh

hng n cht lng bnh l h glucid-amylase v h protein-protease gy nn.

Hot h protein-protease ph thuc vo loi bt v cht lng nm men. Loi



bt xu cht lng nm men km, protein hot ng mnh th gluten b vn nt, do

kh nng gi kh km, bnh t n (Nhan Minh Tr v V Trng Sn, 2000).

2.2.2 Nm men

Nm men c pht hin nm 1973. Lc by gi c ngi pht hin trong cn b

ca dch ln men ru c nhiu t bo hnh trn v bu dc trong sut. Cc nh sinh

vt hc nghin cu v pht hin rng l loi sinh vt ch lc ca qu trnh ln

men, ngi ta gi l nm men. Nm men c cu to l n bo, sinh sn ch yu

bng cch ny chi v tc sinh sn nhanh.

C hai cch dinh dng i vi nm men, thng l dinh dng ngoi bo v dinh

dng ni bo. Cht dinh dng ngoi bo thm qua mng t bo t cc cht mi

trng nui cy bn ngoi. Khi mi trng bn ngoi ngho hoc cn cc cht dinh

dng th cc cht d tr ni bo trong t bo nm men nh glycogen, lipid, cc

hp cht cha N s c s dng dinh dng ni bo. Cc cht dinh dng khi

c s dng s i vo thnh t bo phc v cho sinh trng hay cung cp nng

lng cn thit cho i sng ca t bo (Lng c Phm, 2006).

Ngun dinh dng cho nm men: dinh dng carbon, dinh dng nit, dinh dng

cc cht sinh trng. Cc hp cht hu c khc nhau nh cc loi ng v dn

xut, cc ru, acid hu c, acid amine c th l ngun dinh dng carbon ca

nm men. Hu ht cc loi nm men u khng c enzyme polyhydrolase trong

c amylase v cellulose nn nm men khng s dng trc tip c tinh bt cng

nh cellulose v hemicellulose. Cc ngun carbon dinh dng trc ht phi k n

cc loi ng. Ngun nit v c c nm men s dng tt l cc mui amoni ca

acid v c cng nh hu c.

Nm men c s dng ging nh nm men dng trong sn xut bnh m l loi

nm men ru thuc h Saccharomyces cerevisiae. Nh hot ng ca nm men,

CO2 to thnh gip bnh n v to xp cho bnh. Thnh phn ca nm men ny

cha 6875% l nc, protein 1314%, glycogen 6,88% cellulose 1,8%, cht bo

0,92%, tro 1,772,5%. Ngoi ra cn c cc sinh t B1, B2, B5, B6, D, PP, acid folic

v biotic v cc nguyn t vi lng khc.



Hnh 2.2 T bo nm men Saccharomyces cerevisiae

(Ngun: http://eniw.ru/vinnye-drozhzhi.htm truy cp ngy 20/4/2013)

C th s dng ba loi nm men, nm men p, nm men kh v nm men lng.

Nm men p c mu vng nht, m W=6070%, c hot lc tng i cao

nhng kh bo qun, thng c bo qun nhit 04oC.

Nm men kh c sn xut t nm men p c cht lng cao. m ca nm men

kh khng qu W=1112%, lc n khng qu 110 pht. So vi nm men p th

nm men kh c bo qun lu hn, d dng hn tuy nhin hot tnh thp hn so

vi nm men p.

Nm men lng l dch nm men cha phn ly tch nm men, khi dng nm men

lng phi ch hm lng nc trong nm men lng trnh lm bt b nho. Nm

men ny hot ng thch hp nhit 2535oC, pH t 46.

2.2.3 Khoai lang

2.2.3.1 Cy khoai lang

Khoai lang c tn khoa hc l Ipomoea batatas (L.), thuc h Convolvulaceae, b

Solanales, l mt loi thc phm gn gi vi ngi dn Vit. Khoai lang l loi cy

sng nhiu nm, thn c nha m. L cy khoai lang l mt loi rau rt ngon, tnh

mt v nhiu dinh dng. C v rau khoai lang cn l v thuc phng cha bnh t

lu trong dn gian, c ni cn gi n l sm nam.

Khoai lang c ngun gc t khu vc nhit i Chu M, c con ngi trng cch

y trn 5000 nm v ph bin rt sm trong khu vc ny bao gm c khu vc

Caribe. N c bit n trc khi c s thm him ca ngi phng Ty ti

Polynesia. Cy khoai lang c a vo Trung Quc nm 1954 v Papuaniu Ghine

khong 300400 nm trc. Mt s loi khoai lang c trng ph bin nc ta:

- Khoai lang Hong Long.

- Khoai lang Hng Lc 4.

- Khoai lang Hng Lc 14 (Nht vng).

- Khoai lang Hng Lc 284 (Nht trng).



- Khoai lang Hng Lc 491 (Nht tm).

- Khoai lang Hng Lc 518 (Nht ).

Hnh 2.3 Khoai lang tm Nht

2.2.3.2 c im sinh hc

L loi cy thn tho, c m thn v c, thng b hay leo. Khoai lang c th

sng a nin nhng thng c trng t 38 thng.

Khoai lang l cy mu a m nn c trng ph bin cc nc nhit i. nc

ta, khoai lang gi v tr quan trng ch sau la v ng. T ng bng n trung du

u trng khoai lang, c bit l cc vng c nhiu t ct v ph sa. Khoai lang rt

d trng, c th trng c nhiu v trong nm, trong v ng xun v thu ng

l hai v chnh.

2.2.3.3 Phn b v sn lng

Khoai lang l cy trng quan trng c trng nhiu ni trn th gii: Chu M

latinh, Chu , Chu Phi. nc ta khoai lang c trng ch yu cc tnh min

Nam: Vnh Long, An Giang, Kin Giang cho sn lng kh v mang li thu nhp

n nh cho cc khu vc ny.

Din tch, nng sut v sn lng ca cy khoai lang Vit Nam c trnh by bng

2.1.

Bng 2.2 Din tch, nng sut v sn lng ca cy khoai lang Vit Nam

Nm 2000 2005 2006 2007 2008 2009

Din tch (1000 ha) 28 35 37,6 38,4 41,2 37,5

Nng sut (t/ha) 112,7 105,7 111,4 113,6 118,2 117,9

Sn lng (1000 tn) 316 370 419,2 436,7 486,2 442,8

(Ngun: http://faostat.fao.org)

2.2.3.4 Cu to v thnh phn ha hc

Cu to ca khoai lang gm ba phn: lp v la, v ci v tht c. Lp v ci khng

r rt v khi luc kh bc. V la chim khong 1% cn v ci chim t 510%



khi lng ton c. Cu to thnh t bo ch yu l cellulose bo v khoai khi tc

ng t bn ngoi v chm mt nc.

Lp v ci gm nhng t bo thnh mng cha tinh bt, cht nguyn sinh v dch

th. Trong dch th cha nhiu cht khc nhau bao gm tannin, sc t, enzyme

Hm lng tinh bt trong t bo ny t hn t bo trong tht c.

Tht c bao gm nhng t bo nhu m cha tinh bt, cc cht nitron v mt s cht

vi lng khc. Tinh bt khoai lang ch yu phn tht c. M khoai lang khng

nhng nhiu lp v ci m cn c nhiu trong lp tht c.

Khoai lang l ngun cung cp tinh bt, ng, protein v cc vitamin cho con ngi

nh vitamin A, C, v B6. Tinh bt khoai lang cng cha nhiu cht x.

Thnh phn ha hc ca khoai lang tm Nht c trnh by bng 2.2.

Bng 2.3 Thnh phn ha hc ca khoai lang tm Nht

Thnh phn Hm lng (%)

Nc 68,1

Glucid 17,9

Protein 1,6

Cht bo 0,5

Cellulose 0,9

Tro 1,0

(Ngun: Bi c Hi, 2007)

- Tinh bt khoai lang: gm hai thnh phn chnh l amylase v amylopectin. Ngoi

ra n cn cha cht mu anthocyanin. H thng tinh bt khoai lang thuc h thng

tinh bt trong cc loi c. Nhit ph v ht chuyn tinh bt t trng thi u

c mc hydrat ha khc nhau thnh dung dch keo gi l nhit h ha. Hu

ht tinh bt b h ha khi nu v trng thi trng n c s dng nhiu hn

trng thi t nhin. Cc bin i ha l khi h ha nh sau: ht bt trng ln, tng

trong sut v nht, cc phn t mch thng v nh th ha tan v sau t

lin hp vi nhau to thnh gel. Nhit h ha khng phi l mt im m l

mt khong nhit nht nh. Ty iu kin h ha nh nhit , ngun gc tinh

bt, kch thc ht v pH m nhit ph v v trng n ca tinh bt bin i mt

cch rng ln. Cc cht khng in ly nh ng v cn cng nh hng n nhit



h ha tinh bt, lm cho nhit h ha ca tinh bt tng ln. Nhit h ha

ca tinh bt khoai lang l 5565oC.

Hnh 2.4 Cu to chui tinh bt

- Cht mu: trong khoai lang tm c cha anthocyanin, y l mt hp cht thuc

nhm flavonoid. Anthocyanin l cht mu t nhin c nhiu tnh cht v tc dng

qu bu, bi vy n c s dng ngy cng rng ri trong cng nghip thc phm

cng nh trong y hc.

2.2.3.5 Gi tr dinh dng v cng dng ca khoai lang

Nm 1992 ngi ta so snh gi tr dinh dng ca khoai lang vi cc loi rau

khc. Lu vi hm lng x, carbohydrate, cc protein, cc vitamin A v C, st

v calxium th khoai lang ng v tr cao nht v gi tr dinh dng hn c khoai

ty. Trong mt s quc gia khu vc nhit i th khoai lang c s dng lm

lng thc ch yu.

Khoai lang thng c luc, nng hay rn. Chng c th c ch bin thnh

tinh bt v thay th mt phn bt m. Trong cng nghip ngi ta dng khoai lang

sn xut tinh bt v cn cng nghip.

C khoai lang c tnh bnh, v ngt, c tc dng bi b c th, ch kh, cng thn,

kin v, tiu vim, thanh can, li mt v sng mt. Rau lang cng c tnh bnh, v

ngt dng cha t h, km n, thn m bt tc. Rau lang c nhiu vitamin v

khong cht, giu cht x Cht x c tc dng hp thu, lm hn ch hm lng

cholestorol trong mu, hn ch mc bnh ung th i trng.

Khoai lang tng i y cc cht dinh dng. Thnh phn tinh bt d c c th tiu ha, hp thu v tn dng. Khoai lang c cha nhiu nucoprotein, c kh nng cn tr s lng ng ca cholesterol trn thnh mch, trnh x cng ng mch, ng thi gi c tnh n hi ca mch mu, li cn c th trnh teo m lin kt m v thn. Trong khoai lang c cha mt s cht c th phng bnh ung th, thc y nhu ng rut, trnh to bn.



2.2.4 Anthocyanin, ng dng v cc phng php trch ly

2.2.4.1 S lc v anthocyanin

Anthocyanin l dn xut ca polyhydroxy v methoxy ca flavylium. C 6

anthocyanin ph bin trong thc phm, n khc nhau do hydroxyl v methoxy

ha vng B.

Hnh 2.5 Cu to khung anthocyanin

Cc anthocyanin khc nhau do s khc nhau ca nhm th vng B ca

anthocyanidin. Cc anthocyanin ph bin trong thc phm c lit k bng sau.

Bng 2.4 Cc nhm thay th trong phn t anthocyanidin

Anthocyanidins

Nhm th

R1 R2

Pelargonidin H H

Cyanidin OH H

Delphinidin OH OH

Peonidin OCH3 H

Petunidin OCH3 OH

Malvidin OCH3 OCH3

(Ngun: Nguyn Th Thu Thy, 2010)

Trong cc thc phm c ngun gc t nhin th anthocyanin l h mu ph bin

nht tn ti trong hu ht cc thc vt bc cao. Anthocyanin c tm thy trong

mt s loi rau, qu, hoa v cc b phn khc ca thc vt, hu ht chng c mu

, xanh dng v mu tm. Chng c tm thy trong t bo thc vt nh l

glucoside, l ester ca anthocyanidin vi mt s monosaccharide i khi l hai. Cc



carbohydrate ph bin trong lin kt vi anthocyanidin l glucose, galactose,

rhamnose v i khi l pentose v tr 3, di v tri saccharide v tr 3 v 5, 3 v 7.

Hu ht anthocyanin u tan trong nc, to kt ta khi un si v c s hin din

ca ion kim loi. Anthocyanin b thy phn to anthocyanidin v carborhydrate,

anthocyanidin t tan trong nc hn anthocyanin v khng tm thy dng t do

trong t nhin.

Trong m thc vt, c mt nhm sc t ging anthocyanin nhng khc nhau

carbohydrate, l hp cht c to thnh t s thy phn anthocyanin vi acid

hydrochloride nh pelagonidin cloride, cyanidin cloride v delphinidin cloride.

Cc dn xut methyl ca vng benzen bao gm cc cht peonidin, syringnidin,

petunidin, malvidin v hirsutidin. Mt vi loi sc t althocyanin t nhin c tm

thy l ester ca organic acid, p-hydroxy benzoic acid, maloic acid, p-hydroxy

cinnamic acid v p-cumaric c tm thy. S ester ha khng ch nhm hydroxyl

ca phn t anthocyanidin m cn trn c phn t carbohydrate.

S a dng v mu sc v trng thi ca anthocyanin trong t nhin bao gm cc

nhn t sau:

- Thay i theo pH: khi pH thp th hin mu , ty theo mi nguyn liu s c s

th hin khc nhau nhng hu ht u c mu hi . pH thp, pelagonidin hoc

dn xut ca n th c mu cam , trong khi delphinidin c mu hi xanh. Khi

pH dn tng cao, anthocyanin chuyn sang mu tm, sau l mu xanh dng.

Mt s chng chuyn sang mu xanh l cy v mu vng pH rt cao, nhng t

thy trong thc vt t nhin. Cht mu trong hoa hng c tm thy l mui ca

cyanin vi mt acid trong khi cng l sc t ny trong hoa c bp li c tm thy

l mui ca mt kim loi. Khi thm KOH vo trong dung dch anthocyanin th s

thay i mu c th hin nh sau:

Anthocyanin Anthocyanidin + Monose



Hnh 2.5 S thay i mu theo pH ca Cyanin

(Ngun: Meyer, 1960)

C s bin i mu sc khi em pha long dch mu. Khi pha long delphinidin th

dung dch th hin mu xanh dng, trong khi c c th cho mu . Mu trung

gian c th hin l mu tm.

- Anthocyanin thng lin kt vi cht keo bn trong nha cy v cc

polysaccharide. ti mt pH nht nh s kt hp ca anthocyanin vi nhau th

hin mu sc c trng ring ca thc vt .

- Trong thc vt khng ch c duy nht anthocyanin th hin sc t m cn c sc t

vng ca anthocyanin hoc mu vng ca carotennoid.

- S kt hp ca anthocyanin v tannin cng dn n s bin i mu sc (Meyer,

1960).

2.2.4.2 ng dng ca anthocyanin

Khoai lang tm l mt loi khoai lang c nghin cu a vo sn xut bi Vin

nghin cu nng nghip quc gia Nht Bn c tn Okinawa. y l mt ngun cht

mu tm tt v n nh v hm lng anthocyanin cao.

Trong sn xut thc phm, cng vi cht mu t nhin khc nh carotenoid,

chlorophyll, anthocyanin gip sn phm hi phc li mu t nhin ban u, to ra

mu sc hp dn cho mi sn phm. ng thi do c kh nng khng oxy ha nn

chng cn dng lm bn cht bo.

Trong y hc tc dng ca anthocyanin rt a dng nn c ng dng rng ri: so

kh nng lm gim tnh thm thnh mch v thnh t bo nn c s dng trong

trng hp chy mu hoc c nguy c chy mu, do c kh nng chng oxy ha

nn c s dng chng lo ha, hn ch s gim sc khng do s suy gim

KOH

KOH



ca h thng min dch, nh c tc dng chng tia phng x nn c th h tr cho

c th sng trong mi trng c bc x in t.

Vi nhiu c th qu bu, anthocyanin cn c dng chng d ng, vim lot

do nguyn nhn ni sinh hay ngoi sinh, khng nhiu loi vi khun kh dit, tng

chc nng chng c ca gan, ngn nga s nhim m gan v hoi t m gan, iu

ha lng cholesterol trong mu, trnh tc nghn x va ng mch, phc hi

trng lc tim, iu ha nhp tim v huyt p, iu ha chuyn ha canxium, lm

gim au do tc dng co tht c trn, lm gim cc m xut huyt nh trong bnh

tiu ng. Ngoi ra anthocyanin cn c nhiu ng dng khc do cc phn ng a

dng ca chng trong cc enzyme v cc qu trnh trao i cht khc nhau, chnh v

vy vic quan tm n thc phm giu anthocyanin ngy cng c tng cng v

n c li cho sc khe con ngi.

Khoai lang tm Nht rt giu anthocyanin m chng l dn xut ca peonidin v

cyanidin (Teow, 2005).

Mt s loi anthocyanidin ph bin trong thc phm c trnh by bng 2.4.

Bng 2.5 Cc loi anthocyanin ph bin trong thc phm

Loi nng sn Anthocyanidin

u , u en Pelargonidin, cyanidin, delphinidin

Bp ci Cyanindin

C tm Delphinidin

C hnh Cyanidin, peonidin

Khoai Pelargonidin, cyanidin, delphinidin

To Cyanidin

Nho Cyanidin, delphinidin, peonidin, malvidin, petunidin

Xoi Peonidin

Cam Cyanidin, delphinidin

(Ngun: Nguyn Th Thu Thy, 2010)

2.2.4.3 S thoi ha ca anthocyanin

Cc loi rau qu cha anthocyanin thng c mu v tm. Cn quan tm bo v

anthocyanin trong qu trnh ch bin v nu nng v chng thng tan trong nc

gy tnh trng tht thot. Nhng nu mng t bo khng b v th lng anthocyanin

c gi li rt cao. Mu ca tri mm xi vn gi c tt khi ng lnh trong



khi mu ca tri du b tan ra ngoi dch ngm cho n khi khng cn mu. Khi

c ci ng c gt v hay ct khi b mt mu nhiu hn khi khng gt v v

nguyn c. Trc khi trch dch qu nho th ngi ta nghin nh v cho ln men

nh anthocyanin trong v di chuyn vo dch qu, sau trch ly s thu c

hon ton anthocyanin.

S thoi ha ca anthocyanin ph thuc vo nhit , s hin din ca oxy, acid

ascorbic, ion kim loi v s hin din ca cc hp cht khc (Davidek al, 1990).

- Cc enzyme thy phn hay oxy ha lm phai mu anthocyanin. Glucosidase thy

phn lin kt 3-glycoside to thnh anthocyanidin t n nh, mt mu nhanh.

Phenol oxydase lm thoi ha d dng loi o-dihydroxyphenyl nh catechin v

chlorogenic. Cc enzyme ny thng c gi l cc anthocyanidase. Enzyme ny

c th b v hot nhit 90100oC trong 4560 giy (Bi Hu Thun, 2000).

- Nhit cng rt quan trng, anthocyanin b thy phn chm nhit thng v

nhanh nhit cao. Cc nghin cu mu ca anthocyanin trong du ty cho thy

khi tn tr 1,1oC lng anthocyanin gim rt t so vi khi tn tr nhit

18,3oC, 21,1

oC v 37,8

oC. Nhiu nghin cu trn qu nho Hy Lp, qu mm xi v

du cng cho kt qu ging nhau. S h hng mu sc trong bo qun ca dch

nc l, mn, o v nho ph thuc vo nhit v oxy hin din hn l nh sng.

Acid ascorbic bo v v lm gim s thoi ha mu sc ca anthocyanin trong du

ty, mn, o nhng trong nc nho th khng (Meyer, 1960).

- S hin din ca oxy v nhit cao lm thoi ha anthocyanin.

- H2O2 oxy ha anthocyanin.

- SO2 lm nht mu anthocyanin trong bo qun tri cy, thng c dng nng

5002000 ppm. Nng 11,5% lm bin mu thun nghch. Nng thp 30

ppm ngn c s h hng anthocyanin do phenolase.

- Cc sn phm anthocyanin khng n nh trc nh sng. Sn phm c hai ni

diglycoside c acyl ha, methyl ha l cc anthocyanin ca ru vang n nh

nht i vi nh sng.

- Anthocyanin ngng t vi chnh n v cc cht hu c khc to thnh phc

protein, tannin, flavonoid, polysaccharide. Phn ng ny lm tng mu anthocyanin,

bn trong ch bin v tn tr. Mu n nh ca ru vang c cho l s kt hp

ca anthocyanin. Cc cht ny t nhy cm vi pH, s lin kt v tr C4 chng li

s mt mu bi SO2. Nhng phn ng ngng t khc c th dn n s mt mu:

mt s cht thn hch nh amoni acid, catechinc th ngng t vi flavonoid cho

cht khng mu.



- Anthocyanin cha glycoside o-hydroxy nh cyanidin, delphinidin to mu vi kim

loi. Cc hp cht ny n nh vi nh sng v pH. Mu sc mui kim loi ca

anthocyanin khng ch ph thuc vo anthocyanin m cn ph thuc vo ion loi

v hu ht c mu tm. Cc ion kim loi ny c trong cc dng c cha ng

trong qu trnh ch bin. Cc hp thic dng cha rau qu c cha anthocyanin

c th b try xt do qu trnh vn chuyn, gia cng lm cho thic di chuyn vo

trong hp lm cho ci qu vit quc chuyn sang xanh xm, anthocyanin to phc

vi thic cho mu xanh da tri trong mt s nc berry. Khi lp thic b bong trc

ra th lm cho st bn trong b phn hy bi acid trong thc phm (rau qu), ion st

c th nh hng ln anthocyanin, vi mui F2+, Fe3+ to phc mu xanh da tri vi

anthocyanin vi pH>5,5. Nu tri du b ct bi dao thp th vt ct s tr nn sm

mu. Mui nhm c to thnh vi anthocyanin cng lm thay i mu sc ban

u ca n, cyanidin 3-glycoside to phc vi nhm pH trn 5,5. c im ca

mt s anthocyanidin c trnh by bng 2.5.

Bng 2.6 c im ca mt s anthocyanin ph bin

Pelargoni

din

Cyanidin Delphinidin Peonidin Malvidin

hoc Syringidin

Hirsutidin

Mu khi

tan trong

nc

Tm hi xanh Tm Tm Tm

Tnh tan

trong dung

dch Cloride

D dng Khng ng k

Tan D dng Khng ng k

Khng ng k

nh hng ca mui st clorua

Khng

xc nh Xanh

dng m

Xanh dng m

Khng

xc nh Khng thay

i Khng thay

i

S i mu trong dung

dch soda

Tm sau

xanh dng

Tm sau

xanh dng

Tm sau xanh dng

Tm sau

xanh dng hi xanh l

Tm sau xanh dng

Tm sau xanh dng hi xanh l

S i mu bi nhit

Nht mu iu kin thng

Mt mu khi gia

nhit

Nht mu chm nhit thp, mt mu nhanh

khi gia nhit

Mt mu khi gia

nhit

Mu rt nht v mt mu khi gia

nhit

Mu rt nht v mt mu khi gia

nhit

(Ngun: Meyer, 1960)



Tt c cc anthocyanin u tan trong nc, khng tan trong eter, benzen, aceton v

chloroform. Cc cht anthocyanin to thnh kt ta trong dung dch nc v ru

cc dng mui ch xanh, mui ny tan trong dung dch acid acetic bng v to thnh

dung dch mu ti. Mun tch cht anthocyanin ra khi nguyn liu ti ngi ta

thng dng cht kt ta trn. Thng thng cc cht anthocyanin c tch ra

khi nguyn liu kh bng dung dch HCl 12% trong methanol v sau kt ta

li mt vi ln v cui cng lm sch sn phm bng cch kt tinh dng picrat

hoc clohydrat.

Nguyn tc chung v tch chit v lm sch cc cht anthocyanin l c c dch

chit trong chn khng v lm sch qua cch kt tinh picrat hoc thng qua mui

ch v picrat. Bng phng php sc k cng tch c v xc nh nhanh cc cht

mu ca anthocyanin (Nguyn Kim Anh, 2003).

2.3 CC NGHIN CU LIN QUAN N TH NGHIM TRCH LY

ANTHOCYANIN

C.C.Teow, antioxidant activity and bioactive compounds, xc nh hm lng

anthocyanin trn cc ging khoai lang tm Puerto Rico, Peru, Japan, Philipine v

Hn Quc t xc nh hot tnh chng oxy ha ca n. Kt qu cho thy hm

lng anthocyanin trong mi ging khc nhau thay i trong khong t 12,3162

mg/100g cht kh. Trong hm lng anthocyanin trong khoai lang tm ging

Nht th dao ng t 5,353,6 mg/100g cht kh. Bn cnh hm lng

anthocyanin trong dch trch cn b nh hng bi nhit .

Hunh Th Kim Cc v cng s, xc nh hm lng anthocyanin trong mt s

nguyn liu rau qu bng phng php pH vi sai, kt qu cho thy ph hp th ca

dch chit t cc mu nghin cu nm trong vng ph hp th ca cc anthocyanin

( bc sng t 510540 nm). Dch chit bp ci tm, l ta t, tr , v qu nho,

v c tm c bc sng hp th nm trong khong 520525 nm, trong khi hp

th cc i ca anthocyanin tinh khit trong l ta t l 525 nm, chng t tin cy

ca phng php pH vi sai l kh cao.



CHNG 3 PHNG TIN V PHNG PHP TH NGHIM

3.1. PHNG TIN NGHIN CU

3.1.1. Thi gian - a im nghin cu

Th nghim c thc hnh ti cc phng th nghim ca B mn Cng ngh Thc

phm, Khoa Nng nghip v Sinh hc ng dng, Trng i hc Cn Th.

Thi gian thc hin ti t ngy 7-1-2013 n ngy 28-4-2013.

3.1.2. Nguyn liu v ha cht

Khoai lang tm Nht c mua huyn Bnh Tn, tnh Vnh Long.

Bt m: s dung loi bt m thng hng Cha Kha Xanh Bnh Bao l nhn hiu

bt m ca Cng ty TNHH Xay La M Vit Nam (VFM).

ng tinh luyn Bin Ha, sa ti khng ng Vinamilk.

Cc ha cht dng phn tch: NaOH, Na2SO4, HCl, Pb(CH2COO)2,

phenolphthalein, methyl xanh

3.1.3. Thit b v dng c

Cn phn tch.

My nho bt.

T cy v trng DALTON Japan, 1996.

My lc SH 600, Korea.

Ni tit trng.

My o cu trc Pheotex.

T lnh.

T ht.

Microware oven.

3.2. PHNG PHP NGHIN CU

3.2.1. Phng php nghin cu

Quy trnh th nghim ch bin bnh bao khoai lang tm c trnh by trong hnh

3.1.



Nghin mn thnh bt

Hnh 3.1. Quy trnh ch bin bnh bao khoai lang tm sa

Chn khoai lang cht lng tt ra sch ri i lm chn bng Microwave oven. Sau

khi chn ta loi b phn v v x, em nghin nh khoai lang n khi mn thnh

bt.

Sa, nc Bt m Nm men

Ra s b

Khoai lang

Lm chn bng microware oven

Cn nh lng

Phi trn

p phng

Chng lp

Cun to hnh

Hp

Thnh phm

Bao gi

Bo qun

Sn phm



Mt mu bnh c gi c nh l 1kg (tng trng lng cc cht kh). T l cc

thnh phn ca bnh trong 1kg: ng 20%, nm men 1%, bt n (NaHCO3) 1,2%,

cn li l bt m (i vi mu i chng cha b sung khoai lang).

Khi lng nc l 200g v sa l 200g c gi c nh cho mt mu bnh.

bnh trong iu kin ym kh c gi c nh l 1,5 gi cho mt mu bnh

trong ton b cc th nghim.

Cch tin hnh lm bnh: Cn nh lng cc cht, ha tan nm men vo lng

nc v sa c trn chung, phi trn cc thnh phn trn vi nhau (sao cho

khng cn tinh bt ri rc, bt v cc cht hp thnh mt khi) ri em i nho cho

ti khi khi bt mn, khng cn dnh tay l c, sau em i . Tng khi lng

ca khi bt l 1400g (b qua s thay i khi lng ca khi bt trong qua trnh

).

Bnh bao gm 2 lp xen k nhau vi t l 1:1.

Lp 1: L lp bnh trng, khi lng: 933g (c ly t khi bt sau khi ).

Lp 2: Phi trn hm lng bt khoai lang vi cc t l 45%, 50%, 55% so vi bt

m sau khi , sao cho tng khi lng ca lp 2 bng vi lp 1.

Tin hnh nhi khi bt nho ca lp 2 cho n khi bt khoai lang v khi bt sau

khi ng nht. To hnh cho bnh bng cch cn mng hai khi bt bng nhau

gia hai loi c v khng c b sung khoai lang thnh hnh ch nht bng nhau, sau

xp chng hai lp ln nhau ri cun li to hnh cho bnh. Cc mu c ct

khc v tin hnh hp chn vi thi gian 6 7 pht. Sn phm bnh bao khoai lang

c nh gi cm quan, bo qun vi cc mc nhit theo b tr th nghim.

Tin hnh kim tra vi sinh theo thi gian bo qun.

Cc kt qu ti u ca th nghim trc l tin kho st cc th nghim sau.

Thu thp v x l s liu bng chng trnh phn tch thng k Statgraphics v

Microsoft Exel.

Thang im nh gi cm quan c th hin bng 3.1.

3.2.2. Phng php phn tch cc ch tiu l ha hc

Phn tch cc ch tiu l ha hc cho qu trnh th nghim c th hin bng 3.2.



Bng 3.1. Cc ch tiu l ha hc trong qu trnh th nghim

Ch tiu phn tch Thit b, phng php phn tch

o bng my Rheotex

Tnh n hi E

E )/( 2mmgSuccang

Ungsuat

)/( 2mmg

A

F

L

L

Cu trc (g/mm2)

Vi F: l lc ct (g lc)

A: din tch mu (mm2)

l: khong ng i dc ng trn my

L: chiu dy mu o (mm)

Vi sinh vt tng s (cfu/g) Mi trng nui cy: Nutrient agar

im s khun lc trn mi trng thch dinh dng t mt lng mu xc nh trn c s xem khun lc mc t mt t bo vi sinh duy nht (Bi Th Qunh Hoa, Nguyn Hu Lc, 2007).

3.3. B TR TH NGHIM

3.3.1. Th nghim 1: Kho st nh hng ca t l nm men v khoai lang so

vi khi lng bt nho n cht lng cm quan sn phm

Mc ch: Xc nh t l nm men v khoai lang b sung trong khi bt nho t

sn phm tt nht.

Th nghim gm 2 nhn t vi 3 mc v 2 ln lp li.

Cch tin hnh th nghim: Mt mu bnh c gi c nh l 1kg (tng trng

lng cc cht kh). T l cc thnh phn ca bnh trong 1kg: ng 20%, nm

men 1%, bt n (NaHCO3) 1,2% cn li l bt m. Khi lng nc l 200g v sa

l 200g c gi c nh cho mt mu bnh (tng t l nc v sa l 40% tng

trng lng cc cht kh). Tin hnh kho st t l nm men v khoai lang nh

trong phng php nghin cu.

Nhn t A: T l khoai lang b sung so vi khi bt nho (%):

A1:45

A2:50

A3:55



Nhn t B: T l nm men b sung so vi khi bt nho (%):

B1: 0,5

B2:1

B3:1,5

Tng s th nghim l 3x3x2=18

Ch tiu quan st: nh gi cm quan v cu trc, mu sc v mi v ca sn phm.

B tr th nghim: S b tr th nghim c th hin hnh 3.2.

.......

Hnh 3.2. S b tr th nghim 1

B sung khoai lang

.

Cn nh lng

Phi trn

A1 A2 A3

B1 B2 B3 B1 B2 B3 B1 B2 B3

Sn phm



3.3.2. Th nghim 2: Kho st t l ng v sa b sung vo bt nho n gi

tr cm quan ca sn phm

Mc ch: Xc nh t l ng b sung vo bt nho v lng sa thm vo nc

phi trn nh hng n gi tr cm quan ca sn phm.

Th nghim 2 nhn t, mi nhn t 3 mc v 2 ln lp li.

Nhn t C: t l ng b sung (%)

C1: 18

C2: 20

C3: 22

Nhn t D: t l sa b sung (%)

D1: 40

D2: 50

D3: 60

Tng s th nghim l 3x3x2=18

Ch tiu quan st: nh gi cm quan v cu trc, mu sc v mi v ca sn phm.

Cch tin hnh th nghim: Tin hnh b sung khoai lang nh kt qu th nghim 1.

Kho st t l ng v sa b sung nh nu trong phng php nghin cu.


Hnh 3.3 S b tr th nghim 2

Sn phm

Phi trn

.

C1 C2 C3

D1 D2 D3 D1 D2 D3 D1 D2 D3



3.3.3. Th nghim 3: Kho st kh nng bo qun sn phm cc iu kin

nhit khc nhau

Mc ch: Th nghim tin hnh kho st nhit bo qun thch hp nht n cht

lng sn phm.

Th nghim 1 nhn t, 3 mc v 2 ln lp li.

Nhn t E: Nhit bo qun (oC)

E1: -20oC

E2: -5oC

E3: 4oC

Cch tin hnh th nghim: Sau khi chn c kt qu ti u th nghim 1 v 2.

Tin hnh kho st kh nng bo qun bnh bao vi cc mc nhit theo b tr th

nghim. Cc mu c kim tra tng s vi sinh vt hiu kh v hm lng

anthocyanin theo thi gian bo qun l 5, 10, 15 v 20 ngy.

Ch tiu nh gi: nh gi cm quan v cu trc, mu sc v mi v ca sn phm.


Hnh 3.4 S b tr th nghim 3

Nhit bo qun

E3 E1 E2

Kim tra vi sinh theo thi gian bo qun

Sn phm



CHNG 4 KT QU V THO LUN

4.1 KHO ST NH HNG CA T L KHOAI LANG V NM MEN

SO VI KHI LNG BT NHO N CHT LNG SN PHM

4.1.1 n

n l yu t quan trng nh hng n cht lng ca bnh. n ca bnh

ph thuc vo nhiu yu t: cht lng bt m, nng nm men, thi gian v nhit

ln men

S thay i n ca bnh sau khi v sau khi hp theo nng nm men v t l

khoai lang c th hin bng 4.1.

Bng 4.1 S thay i n ca bnh sau khi hp theo t l nm men v khoai lang b sung

T l khoai lang

(%)

Nng nm men (%)

TBNT

0,5 1,0 1,5

0 2,14 2,21 2,18 2,18c

45 2,12 2,18 2,18 2,16c

50 2,00 2,07 1,97 2,01b

55 1,43 1,51 1,48 1,47a

TBNT 1,92a 1,99

c 1,95

b

Ghi ch: Nhng ch ci khc nhau (a, b, c) trong cng mt ct hoc hng th hin s khc bit c

ngha 5% gia cc mu kho st.

Kt qu cho thy hm lng khoai lang b sung nh hng n n ca bnh. Khi

hm lng khoai lang tng th n ca bnh gim l do lin kt trong mng

gluten ca khi bt m gim v b cc tinh bt khoai lang chen vo, lm t mt

phn khi gluten.

Kt qu kho st cho thy khi thay i t l nm men th n ca bnh thay i.

iu ny chnh l do trong qu trnh ln men t bo nm men sinh sn v pht trin

h enzyme trong nm men chuyn ha cc loi ng thnh CO2 v nc. Chnh

lng CO2 ny tch t to thnh cc ti kh v gluten c tc dng lm khung gi cc

ti kh t to cho bnh n, xp (Nhan Minh Tr, V Trng Sn, 2000).

n ca bnh cao nht th hin nng nm men s dng l 1% v khc bit

c ngha v mt thng k vi cc mu cn li. Khi b sung 0,5% nm men, bnh

n t so vi 2 t l b sung cn li. Tuy nhin nng nm men qu cao lm n



ca bnh gim. Nng nm men qu ln, lng kh CO2 sinh ra qu nhiu lm

cho khung gluten khng gi cht cc ti kh lm ph v mng gluten nn lm

bnh b xp sau khi hp.

T l khoai lang b sung vo trong bnh c nh hng ln n n ca bnh. Kt

qu bng 4.1 cho thy vi mu b sung 45% khoai lang, n ca bnh cao nht,

khng khc bit c ngha so vi mu i chng. Khi tng lng khoai lang b

sung th n ca bnh gim.

4.1.2 Mu sc

Mu l mt trong nhng yu t quan trng nh hng n cm quan ca bnh bao

khoai lang tm. nh hng ca t l khoai lang b sung n im nh gi cm

quan v mu sc ca bnh c th hin bng 4.2.

Bng 4.2 S nh hng ca t l nm men v khoai lang b sung n im nh gi cm

quan v mu sc ca bnh

T l khoai lang

(%)

T l nm men (%)

TBNT

0,5 1,0 1,5

45 3,51 3,51 3,41 3,48a

50 4,40 4,51 4,57 4,49c

55 3,98 4,20 4,02 4,07b

TBNT 3,96a 4,08

a 4,00

a



T bng 4.2 cho thy mu sc ca bnh c nh gi cm quan cao nht t l

khoai lang b sung l 50% v khc bit c ngha v mt thng k vi cc mu cn

li, tuy nhin t l nm men b sung khng nh hng n gi tr cm quan v mu

sc ca bnh.

4.1.3 Cu trc

Cu trc ca bnh ph thuc ln vo t l nm men v khoai lang b sung, kt qu

nh gi cm quan c th hin bng sau:



Bng 4.3 S nh hng ca t l nm men v khoai lang b sung n im cm quan v cu

trc ca bnh

T l khoai lang (%)

Nng nm men (%) TBNT

0,5 1,0 1,5

45 4,09 4,35 4,10 4,18c

50 3,87 4,18 3,97 4,01b

55 3,22 3,41 3,31 3,31a

TBNT 3,73a 3,98

c 3,79

b



cc t l nm men khc nhau c s khc bit v cm quan cu trc ca sn phm.

Cu trc ca bnh cao nht t l nm men 1% (3,98), c s khc bit ngha v

mt thng k so vi cc mu b sung 0,5% v 1,5% nm men.

Kt qu kho st cho thy t l khoai lang b sung cng cao th n ca bnh

cng gim. Vi t l b sung 45% khoai lang th bnh c nh gi cm quan tt

nht vi im cm quan cao nht (4,18) so vi cc mu t l khoai lang b sung

50% v 55%.

4.1.4 Mi v

Vic b sung nm men vo khi bt trong qu trnh ch bin bnh chng nhng nh

hng n xp ca bnh, m cn nh hng n mi thm ca bnh do c s

sinh ra cc cht to mi trong qu trnh ln men. Ngoi ra, khi b sung lng khoai

lang thch hp, to mu sc hp dn cho bnh, ng thi to mi thm ca khoai

lang nhng khng lm mt mi thm c trng ca bnh bao. nh hng ca t l

nm men v khoai lang b sung n gi tr cm quan v mi v ca bnh c trnh

by bng 4.4.



Bng 4.4 S nh hng ca t l nm men v khoai lang n nh gi cm quan v mi v

ca bnh

T l khoai lang (%)

Nng nm men (%) TBNT

0,5 1,0 1,5

45 3,32 3,45 3,51 3,42a

50 3,67 4,00 3,80 3,82c

55 3,49 3,73 3,58 3,60b

TBNT 3,49a 3,72

b 3,63

b



Mi v ca bnh cao nht th hin t l nm men s dng l 1% (3,72) v khc

bit c ngha v mt thng k vi cc mu cn li. Vi t l nm men b sung l

0,5% th im cm quan v mi v ca bnh l thp nht, nguyn nhn l do t sinh

ra cc hp sn phm ph nh: acid lactic, ru, aldehyd to mi thm cho bnh.

Vi t l nm men l 1,5% th mi v ca bnh hi b chua do qu trnh ln men

sinh qu nhiu acid, ngoi ra bnh c mi men. t l nm men l 1% th mi v

ca bnh hi ha nht.

T l khoai lang b sung cng nh hng ln n gi tr cm quan ca sn phm.

Mi v ca bnh cao nht th hin t l khoai lang b sung l 50% (3,82) v khc

bit c ngha v mt thng k vi cc mu cn li. Vi t l khoai lang b sung

45% th bnh c mi nht, kh cm nhn mi v ca khoai lang. Vi t l 55%

khoai lang b sung th mi v ca khoai lang qu nhiu lm nh hng n mi v

c trng ca bnh bao.

Kt lun: tng hp cc kt qu nh gi cm quan v cu trc, mu sc, mi v ca

bnh th t l nm men l 1% v t l khoai lang b sung l 50% cho kt qu ti

u nht. Gi tr ti u ny c chn tin hnh thc hin cc th nghim tip

theo.

4.2 KHO ST T L NG V SA B SUNG VO BT NHO N

GI TR CM QUAN SN PHM

4.2.1 Mu sc

Vic b sung ng v sa vo bnh gip lm tng gi tr cm quan v v v gi tr

dinh dng cho bnh, tuy nhin n c th lm nh hng n gi tr cm quan v

mu sc ca bnh. Kt qu nh gi nh hng c m t bng 4.5.



Bng 4.5 S nh hng ca t l ng v sa n im nh gi cm quan mu sc ca

bnh bao

T l ng (%) T l sa (%)

TBNT 40 50 60

18 4,01 4,01 3,91 3,98a

20 3,97 4,08 4,14 4,06a

22 3,91 4,13 3,95 4,00a

TBNT 3,96a 4,08

a 4,00

a



T bng 4.5 c th nhn thy rng mu sc ca bnh khng c s thay i khi thay

i t l ng v t l sa. iu ny c th kt lun rng vic b sung ng v

sa khng lm nh hng n mu sc ca sn phm.

4.2.2 Cu trc

Bng 4.6 S nh hng ca t l ng v sa n im cm quan v cu trc ca bnh bao

T l ng (%) T l sa (%)

TBNT 40 50 60

18 4,42 4,35 4,47 4,41a

20 4,37 4,40 4,41 4,39a

22 4,39 4,41 4,41 4,40a

TBNT 4,39ab

4,38a 4,43

b



T bng 4.6 c th nhn thy rng cu trc ca bnh khng c s thay i khi thay

i t l ng v t l sa. iu ny cho thy rng nng ng v sa khng

c nh hng n cu trc ca sn phm.

4.2.3 Mi v

Khi b sung ng v sa vo khi bt, gip gia tng gi tr cm quan v mi v

cho bnh, tuy nhin, nu b sung nhiu qu, s to cm gic khng ngon ming do

v bnh qu ngt hoc qu bo. Kt qu kho st nh hng ca vic b sung

ng v sa n mi v bnh c th hin bng sau.



Bng 4.7 S nh hng ca t l ng v sa n nh gi cm quan mi v ca bnh bao

T l ng (%) T l sa (%)

TBNT 40 50 60

18 3,82 3,95 4,01 3,92a

20 4,10 4,43 4,23 4,25c

22 3,96 4,20 4,05 4,07b

TBNT 3,96a 4,19

b 4,10

b



Kt qu t bng 4.7 cho thy c s khc bit v nh gi cm quan ca cc mu

khc nhau vi cc t l ng v sa khc nhau. t l sa b sung l 50% v 60%

th gi tr cm quan ca bnh l cao nht, khng khc bit thng k so vi nhau, tuy

nhin mu b sung 50% sa cho gi tr im cm quan cao nht. t l b sung

40% sa th mi v ca sa trong bnh qu nht, khng to c s c trng ca

sa trong bnh. t l b sung 60% sa th mi v ca sa qu nhiu, ln t mi v

ca khoai lang trong bnh nn khng to c v hi ha gia sa v khoai lang

trong bnh. t l b sung 50% sa trong bnh th mi v ca bnh hi ha nht,

mang li gi tr cm quan cao nht v c s khc bit ngha v mt thng k so

vi hai mu cn li.

T l ng b sung cng nh hng ln n gi tr cm quan ca bnh. t l

ng b sung l 20% th gi tr cm quan ca bnh l cao nht (4,25) v c s

khc bit c ngha v mt thng k so vi cc mu cn li. cc mu b sung

18% v 22% th gi tr cm quan ca sn phm thp hn, sn phm qu lt hoc qu

ngt.

Da trn cc kt qu nh gi cm quan ca bnh bao, chn t l sa l 50% v t

l ng l 20% b sung vo khi bt, cho bnh c gi tr cm quan l cao nht.

4.3 KHO ST KH NNG BO QUN SN PHM VI CC MC

NHIT KHC NHAU

4.3.1 Kim tra vi sinh pht trin theo thi gian bo qun sn phm

Tng s vi sinh vt hiu kh ca cc mu theo thi gian bo qun, a x 105 cfu/g

(trung bnh ca 3 ln lp li) c th hin bng sau:



Bng 4.8 Tng s vi sinh vt hiu kh trong thi gian bo qun cc nhit khc nhau

Thi gian bo qun (ngy)

Nhit bo qun (oC)

-20 -5 4 Nhit phng

(28-30oC)

5 0,77 0,92 0,83 8,48

10 0,73 2,18 2,27 25,73

15 2,74 4,21 8,31 65,74

20 4,27 5,73 15,73 116,91

25 7,56 9,63 42,48 237,91

30 9,35 23,61 107,42 426,76

T bng kt qu phn tch vi sinh ca sn phm bnh bao khoai lang tm sa qua 30

ngy bo qun cho thy qua thi gian bo qun cc mc nhit khc nhau th c

s khc bit gia cc mu bo qun. Mt s vi sinh vt cho php l 106 cfu/g

(Lng c Phm, 2005). nhit phng (28-30oC) th sn phm h hng rt

nhanh, thi gian bo qun bnh ch c 5 ngy, mt s vi sinh vt hiu kh l 8,48 x

105cfu/g. nhit 4oC th bnh bo qun c 15 ngy, tng s vi sinh vt hiu kh l

8,31 x 105cfu/g, thi gian bo qun tng thm th sn phm bnh b h hng. nhit

bo qun l -5oC th bo qun bnh c 25 ngy (tng s vi sinh vt hiu kh l 23,61 x

105cfu/g). nhit -20oC th bo qun bnh c lu nht, sau 30 ngy bo qun bnh

vn cha h hng (tng s vi sinh vt hiu kh l 9,35 x 105cfu/g).

Sn phm b h hng ch yu do tc ng ca nm mc v cc vi sinh vt hiu kh.

Kt lun: Nhit bo qun -20oC t hiu qu bo qun cao nht, c chn bo

qun bnh.

4.3.2 S thay i cu trc trong thi gian bo qun

Cu trc ca sn phm cng b bin i trong thi gian bo qun. S thay i c th

hin trong hnh 4.



3.813.89 3.91

3.974.01 4.05

4.09

3

3.2

3.4

3.6

3.8

4

4.2

0 5 10 15 20 25 30

Thi gian bo qun (ngy)

L

c c

t

(gam

/mm

)

Hnh 4 S thay i cu trc ca sn phm trc v sau bo qun

T kt qu trong hnh 4, cu trc ca sn phm c b bin i nhng khng qu ln,

sn phm vn gi c cu trc, mu sc v mi v c trng.



CHNG 5 KT LUN V NGH

5.1 KT LUN

T cc kt qu th nghim cho thy, ch bin sn phm bnh bao khoai lang tm

c gi tr cm quan cao, mu sc thch hp, cc thng s cn thit cho quy trnh l:

- T l khoai lang tm b sung l 50% so vi khi bt ca lp bt th hai.

- T l nm men ti u cho sn phm l 1%

- T l ng b sung 20% so vi khi lng bt m v t l sa l 50% so

vi lng nc b sung trong khi bt.

5.2. NGH

Do thi gian c hn, nn ti khng th kho st tt c cc ni dung lin quan nn

c mt s ngh nh sau:

- nh gi s hao ht hm lng anthocyanin trong sn phm sau khi ch bin

v bo qun bnh bao.

- Nghin cu ch bin sn phm bnh bao khoai lang t cc loi khoai lang

khc nh khoai lang vng, khoai b v khoai mt.

Hnh 5 Sn phm bnh bao khoai lang tm sa



TI LIU THAM KHO

Bi i (2003). Cng ngh ln men ng dng trong cng ngh thc phm. Nh xut bn i hc

Quc Gia Thnh ph H Ch Minh.

Bi c Hi (2007). K thut ch bin lng thc. Trng i hc Bch Khoa H Ni.

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Chuyn ngnh: Cng ngh thc phm

PH LC

A. NH GI CM QUAN

Bng A1. Thang im nh gi cm quan sn phm theo t l nm men v khoai lang b

sung (th nghim 1)

im Mu sc im Cu trc im Mi v

5 Mu tm sng c

trng ca khoai lang

5 Mm, xp 5 Rt thm c trng ca bnh

bao khoai lang tm sa

4 Mu tm va, hi

sng ca khoai lang

4 Mm, xp,

hi dai

4 Thm c trng bnh bao

khoai lang tm sa

3 Mu tm va, khng

sng

3 Mm, t xp,

hi dai

3 t thm, t mi khoai lang v

sa b sung

2 Mu tm nht, khng

sng

2 Hi cng, t

xp, dai

2 Hi thm, t mi khoai lang

v sa b sung

1 Mu tm nht hoc

qu m khng sng

1 Cng, dai 1 Khng thm, mt mi khoai

lang v sa b sung

0 Mu l 0 Cng, khng

xp, dai

0 C mi l kh chu

Bng A2. Thang im nh gi cm quan sn phm theo t l ng v sa b sung (th

nghim 2)

im Mu sc im Cu trc im Mi v

5

Mu tm sng c

trng ca khoai lang 5

Mm, xp

5

Rt thm c trng ca bnh

bao khoai lang tm sa, ngt

va n

4

Mu tm va, hi

sng ca khoai lang 4

Mm, xp,

hi dai 4

Thm c trng bnh bao

khoai lang tm sa, ngt va

hoc lt va

3

Mu tm va, khng

sng 3

Mm, t xp,

hi dai 3

t thm, t mi khoai lang v

sa b sung, hi ngt hoc

hi lt

2

Mu tm nht, khng

sng 2

Hi cng, t

xp, dai 2

Hi thm, t mi khoai lang

v sa b sung, qu ngt

hoc qu lt

1

Mu tm nht hoc

qu m khng sng 1

Cng, dai

1

Khng thm, mt mi khoai

lang v sa b sung, qu

ngt hoc qu lt

0 Mu l

0 Cng, khng

xp, dai 0

C mi l kh chu, qu

ngt hoc qu lt



B. KT QU THNG K

1. Kho st nh hng ca t l khoai lang v nm men so vi khi lng bt

nho n cht lng sn phm

1.1 n

Analysis of Variance for Do no - Type III Sums of Squares

Source Sum of Squares Df Mean Square F-Ratio P-Value

MAIN EFFECTS

A:Ty le khoai 2.95143 3 0.983811 1662.78 0.0000

B:Ty le nam men 0.02985 2 0.014925 25.23 0.0000

Multiple Range Tests for Do no by Ty le khoai

Method: 95.0 percent LSD

Ty le khoai Count LS Mean LS Sigma Homogeneous Groups

55 9 1.47111 0.00810807 X

50 9 2.01444 0.00810807 X

45 9 2.15778 0.00810807 X

0 9 2.17667 0.00810807 X

Multiple Range Tests for Do no by Ty le nam men


Ty le nam men Count LS Mean LS Sigma Homogeneous Groups

0.5 12 1.9225 0.00702179 X

1.5 12 1.95 0.00702179 X

1 12 1.9925 0.00702179 X

1.2 Mu sc

Analysis of Variance for Mau sac - Type III Sums of Squares


MAIN EFFECTS

A:Ty le khoai lang 4.67316 2 2.33658 98.59 0.0000

B:Ty le nam men 0.0596963 2 0.0298481 1.26 0.3077

Multiple Range Tests for Mau sac by Ty le khoai lang


Ty le khoai lang Count LS Mean LS Sigma Homogeneous Groups

45 9 3.47778 0.051316 X

55 9 4.06889 0.051316 X

50 9 4.49222 0.051316 X

Multiple Range Tests for Mau sac by Ty le nam men



0.5 9 3.96222 0.051316 X

1.5 9 4.00111 0.051316 X

1 9 4.07556 0.051316 X



1.3 Cu trc

Analysis of Variance for Cau truc - Type III Sums of Squares


MAIN EFFECTS

A:Ty le khoai lang 3.80992 2 1.90496 1000.66 0.0000

B:Ty le nam men 0.298785 2 0.149393 78.47 0.0000

Multiple Range Tests for Cau truc by Ty le nam men



0.5 9 3.72778 0.0145438 X

1.5 9 3.79444 0.0145438 X

1 9 3.97667 0.0145438 X

Multiple Range Tests for Cau truc by Ty le khoai lang



55 9 3.31111 0.0145438 X

50 9 4.00778 0.0145438 X

45 9 4.18 0.0145438 X

1.4 Mi v

Analysis of Variance for Mui vi - Type III Sums of Squares


MAIN EFFECTS

A:Ty le khoai lang 0.710585 2 0.355293 24.26 0.0000

B:Ty le nam men 0.245785 2 0.122893 8.39 0.0027

INTERACTIONS

Multiple Range Tests for Mui vi by Ty le nam men



0.5 9 3.49222 0.0403381 X

1.5 9 3.63111 0.0403381 X

1 9 3.72444 0.0403381 X

Multiple Range Tests for Mui vi by Ty le khoai lang



45 9 3.42444 0.0403381 X

55 9 3.60222 0.0403381 X

50 9 3.82111 0.0403381 X

2. Kho st nh hng ca t l ng v sa b sung vo bt nho n gi tr

cm quan sn phm

2.1 Mi v

Analysis of Variance for Mui vi - Type III Sums of Squares


MAIN EFFECTS

A:Ty le duong 0.481652 2 0.240826 16.44 0.0001

B:Ty le sua 0.245785 2 0.122893 8.39 0.0027

Multiple Range Tests for Mui vi by Ty le sua




Ty le sua Count LS Mean LS Sigma Homogeneous Groups

40 9 3.95889 0.0403381 X

60 9 4.09778 0.0403381 X

50 9 4.19111 0.0403381 X

Multiple Range Tests for Mui vi by Ty le duong


Ty le duong Count LS Mean LS Sigma Homogeneous Groups

18 9 3.92444 0.0403381 X

22 9 4.07222 0.0403381 X

20 9 4.25111 0.0403381 X

2.2 Mu sc

Analysis of Variance for Mau sac - Type III Sums of Squares


MAIN EFFECTS

A:Ty le duong 0.034763 2 0.0173815 0.73 0.4941

B:Ty le sua 0.0596963 2 0.0298481 1.26 0.3077

Multiple Range Tests for Mau sac by Ty le duong



18 9 3.97778 0.051316 X

22 9 3.99889 0.051316 X

20 9 4.06222 0.051316 X

Multiple Range Tests for Mau sac by Ty le sua



40 9 3.96222 0.051316 X

60 9 4.00111 0.051316 X

50 9 4.07556 0.051316 X

2.3 Cu trc

Analysis of Variance for Cau truc - Type III Sums of Squares


MAIN EFFECTS

A:Ty le duong 0.00202222 2 0.00101111 0.54 0.5934

B:Ty le sua 0.0101556 2 0.00507778 2.70 0.0944

Multiple Range Tests for Cau truc by Ty le duong



20 9 4.39222 0.0144587 X

22 9 4.40111 0.0144587 X

18 9 4.41333 0.0144587 X

Multiple Range Tests for Cau truc by Ty le sua



50 9 4.38333 0.0144587 X

40 9 4.39444 0.0144587 XX

60 9 4.42889 0.0144587 X

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