Cookie Bup Giam Thanh Tra

i

TM TT LUN VN

Mc ch ca bi nghin cu ny l ng dng ht bp gim vo sn phm bnh

cookie nhm nng cao gi tr s dng ht bp gim, l mt loi ht hin nay c thi

b nhng c gi tr dinh dng cao v cha thnh phn khng oxy ha cng nh c

kh nng lm gim cholesterol.

Lun vn bao gm cc ni dung sau:

Kho st qu trnh x l nguyn liu

Kho st mt s thng s ha l ca nguyn liu.

Kho st quy trnh ch bin bnh b sung ht bp gim

Kim tra sn phm

Kt qu:

Phng php sy nhit nhit 650C trong 5 pht loi c khong

37% lng v ban u, cho hiu sut thu hi ni nh ht cao (62.786%)

Hm lng protein v lipid c trong ht bp gim loi mt phn v ln

lt l 24.963 v 26.065 %.

Sn phm cui cng c nh gi cm quan bi ngi tiu dng cho kt

qu tt, mang tnh kh thi cao.

Sn phm bnh cookie b sung ht bp gim c hm lng protein cao so

vi bnh khng b sung ht bp gim (tng 14.22%)

ii

LI CM N

Li u tin, em xin chn thnh cm n c Trn Th Ngc Yn tn

tnh hng dn, gip vi kin thc chuyn ngnh em c th c c

nhiu kin thc hu ch to iu kin cho em hon thnh tt lun vn.

Em cng cm n c Nguyn Th Nguyn truyn dy kinh nghim,

cng nh h tr thit b dng c trong qu trnh nghin cu.

K n em xin by t lng bit n tp th qu thy c B mn Cng ngh

thc phm trng i hc Bch Khoa thnh ph HCM - nhng ngi dn

dt, ch dy v cung cp cho em kin thc. chnh l nn tng gip em hon

thnh tt lun vn ca mnh v l hnh trang cho em vng tin bc vo cuc

sng.

Con xin cm n ba m lun l ch da vng chc, ng h v gip

con.

Bn cnh , li cm n p p nht c gi n V Anh Kha l ngi

bn cnh em trong nhng lc vui bun, lun ng vin v nhit tnh h tr em

trong sut khong thi gian nghin cu.

Sau cng, em cng mun ni li cm n n bn Phan Th Thy v nhng

ngi bn phng th nghim, h l nhng ngi gip em trong lc thc

hin lun vn.

Do vn kin thc vn cn nhiu hn ch nn em khng trnh khi nhiu

thiu st. Em rt mong c s ch dn ca cc thy c. Em xin chc cc thy

c li chc tt p nht trong cng vic v trong cuc sng.

TP.HCM, ngy 23 thng 12 nm 2013

Sinh vin,

Nguyn Ngc Thanh Tr

iii

MC LC

TM TT LUN VN ...................................................................................................i

LI CM N ................................................................................................................. ii

MC LC ..................................................................................................................... iii

DANH MC CC HNH NH ...................................................................................... v

DANH MC BNG BIU ............................................................................................vi

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

CHNG 2: TNG QUAN ...................................................................................... 2

2.1 Mt s nt v bnh cookie ................................................................................. 2

2.1.1 nh ngha, phn loi v bnh cookie ......................................................... 2

2.1.2 Mt s yu t nh hng n cu trc sn phm ........................................ 2

2.2 Ht bp gim ...................................................................................................... 6

2.2.1 Thnh phn protein trong ht bp gim ...................................................... 8

2.2.2 Du ht bp gim ........................................................................................ 9

2.2.3 Gi tr dinh dng ht bp gim ............................................................... 11

2.2.4 Cc hot cht c trong ht bp gim ......................................................... 12

2.2.5 Tinh bt ..................................................................................................... 14

CHNG 3: PHNG PHP NGHIN CU ...................................................... 15

3.1 Nguyn liu ...................................................................................................... 15

3.2 Phng php nghin cu ................................................................................. 18

3.2.1 Mc ch nghin cu ................................................................................. 18

3.2.2 S nghin cu ....................................................................................... 18

3.3 Tin hnh th nghim ....................................................................................... 20

3.3.1 Ni dung 1: Kho st qu trnh x l loi v ht bp gim ...................... 20

iv

3.3.2 Ni dung 2: Kho st nguyn liu ht bp gim ....................................... 22

3.3.3 Ni dung 3: Kho st quy trnh ch bin bnh b sung ht bp gim ...... 24

CHNG 4: KT QU V BN LUN .............................................................. 32

4.1 Kho st quy trnh loi v ht bp gim .......................................................... 32

4.2 Kho st nguyn liu ht bp gim .................................................................. 34

4.2.1 Kho st kch thc v t l thnh phn ca ht bp gim ....................... 34

4.2.2 Xc nh cc thng s ha l ca nguyn liu .......................................... 35

4.3 Kho st quy trnh ch bin bnh ht bp gim ............................................... 36

4.3.1 La chn thi gian nng bnh chun ...................................................... 36

4.3.2 Kho st t l b sung bt ht bp gim .................................................... 37

4.3.3 Kho st t l b ........................................................................................ 50

4.3.4 Kim tra cht lng sn phm .................................................................. 53

CHNG 5: KT LUN V KIN NGH ............................................................ 58

5.1 Kt lun ............................................................................................................ 58

5.2 Kin ngh .......................................................................................................... 59

CHNG 6: TI LIU THAM KHO .................................................................. 60

CHNG 7: PH LC ........................................................................................... 64

v

DANH MC CC HNH NH

Hnh 3. 1 S nghin cu ........................................................................................... 19

Hnh 3. 2 Quy trnh loi v ht bp gim ...................................................................... 20

Hnh 3. 3 Quy trnh ch bin bnh chun ...................................................................... 24

Hnh 4. 1 Hiu sut thu hi theo cc phng php x l .............................................. 33

Hnh 4. 2 nh gi cm quan theo t l b sung ht bp gim...................................... 39

Hnh 4. 3 Biu th hin cng v m bt nho ................................................ 42

Hnh 4. 4 Kt qu kho st cu trc bt nho theo hm lng b sung ht bp gim .. 43

Hnh 4. 5 Biu m v cng ca bnh theo t l hm lng b sung ht bp

gim ............................................................................................................................... 45

Hnh 4. 6 Khi lng bnh theo t l b sung ht bp gim ......................................... 47

Hnh 4. 7 Kch thc bnh theo t l b sung ht bp gim .......................................... 47

Hnh 4. 8 Kt qu nh gi cm quan cho cc bnh b sung ht bp gim .................. 49

Hnh 4. 9 cng bnh theo t l b ............................................................................ 51

Hnh 4. 10 a thch ca bnh theo t l b ............................................................... 52

Hnh 4. 11 Hm lng protein tng ca bnh chun v bnh ht bp gim ................. 53

Hnh 4. 12 nh gi cm quan cho bnh ht bp gim ................................................. 55

Hnh 4. 13 Quy trnh ch bin bnh ht bp gim ........................................................ 57

Hnh 5. 1 Sn phm bnh cookie ht bp gim ............................................................. 58

vi

DANH MC BNG BIU

Bng 2.1 Thnh phn ha hc ca nguyn ht bp gim (% w/w) ................................. 7

Bng 2.2 Thnh phn acid amin trong ht bp gim ..................................................... 10

Bng 3.1 Ch tiu cht lng ca bt m (theo TCVN 4359:1996) .............................. 15

Bng 3.2 Ch tiu cht lng ca ng (6958:2001) .................................................. 16

Bng 3. 3 Yu cu k thut i vi trng g ti (TCVN 1858:1986) ........................ 16

Bng 3. 4 Yu cu k thut ca b (TCVN 7400:2004) ............................................... 16

Bng 3. 5 Yu cu k thut ca shortening (TCVN 6048:1995) .................................. 17

Bng 3. 6 Ch tiu ca mui n (TCN 3973:84) ........................................................... 17

Bng 3. 7 Lng ht bp gim thay i ........................................................................ 21

Bng 3. 8 X l loi v bng phng php rang .......................................................... 21

Bng 3. 8 X l loi v bng phng php phi .......................................................... 22

Bng 3. 9 Cc thi gian nng khc nhau ..................................................................... 26

Bng 3. 10 Lng ht bp gim thay i ...................................................................... 27

Bng 3. 11 Lng ht bp gim thay i ...................................................................... 28

Bng 3. 12 Lng b thay i ....................................................................................... 29

Bng 4. 1 nh hng ca cc phng php x l nguyn liu n hiu sut thu hi .. 32

Bng 4. 2 Kt qu kho st kch thc v thnh phn ca ht bp gim ...................... 34

Bng 4. 3 Kt qu kho st cc thng s ha l ca ht bp gim ............................... 35

Bng 4. 4 Kt qu kho st kch thc v thnh phn ca ht bp gim ...................... 37

Bng 4. 5 nh gi cm quan cho cc mu bnh M0, M1, M2, M3, M4 ..................... 38

Bng 4. 6 Kt qu nh gi cm quan cho cc bnh b sung ht bp gim ................. 38

Bng 4. 7 Kt qu kho st m bt nho .................................................................. 41

Bng 4. 8 Kt qu kho st cu trc bt nho theo hm lng b sung ht bp gim . 42

vii

Bng 4. 9 Kt qu kho st m v cng ca bnh theo t l b sung ht bp gim

....................................................................................................................................... 45

Bng 4. 10 Kt qu kho st khi lng, kch thc bnh theo t l b sung ht bp

gim ............................................................................................................................... 46

Bng 4. 11 Kt qu nh gi cm quan cho cc bnh b sung ht bp gim ............... 48

Bng 4. 12 Kt qu kho st s nh hng ca b n cng ca bnh ................... 50

Bng 4. 13 Kt qu kho st s nh hng ca b n a thch ca bnh .............. 51

Bng 4. 14 Kt qu kho st protein tng ca bnh ht bp gim ................................ 53

Bng 4. 15 Kt qu kim tra vi sinh ca bnh ht bp gim ......................................... 54

Bng 4. 16 Kt qu nh gi cm quan ca bnh ht bp gim .................................... 54

Bng 4. 17 Cng thc thnh phn nguyn liu ca bnh ht bp gim ........................ 56

1

CHNG 1: T VN

Bp gim hay cn gi l hng hoa, tn ting anh thng dng l roselle

(Hibiscus sabdariffa Linn) l loi cy tho dc mc thnh bi v sinh trng nhng

quc gia c kh hu nhit i v cn nhit i bao gm c Vit Nam. Loi cy ny

thng c trng ri ly i hoa lm tr tho mc, nc ung gii kht, mt hoc

jelly. Nam Nigeria, ht bp gim c ln men v xem nh l gia v trong ch bin

mt s mn n [1]. Trong nhng nm gn y c vi nghin cu trn ht bp gim

c tin hnh, kt qu cho thy ht bp gim tht s c nhiu li ch ng k. Da

vo cc kt qu phn tch thnh phn ht bp gim cho thy ht cha mt lng giu

nhng thnh phn dinh dng, c bit l protein, du v cht x [2]. V bn cnh ,

nhiu nghin cu trn ht c tin hnh v kt lun rng nhng chit xut t ht

bp gim c hot tnh chng oxy ha l kh cao nh -tocopherol v cc hp cht

phenolic [3] [4]. c nghin cu cho rng ht bp gim c kh nng gim hm

lng cholesterol mu [5]. Tuy nhin, Vit Nam thng th sau khi tch i, ht bp

gim c loi ra ngoi v thng thi b sau ma v.

Nhng nghin cu k trn cho thy ht bp gim l mt tim nng cha nhiu

thnh phn dinh dng cao v rt c ch trong ng dng vo ngnh cng ngh ch bin

thc phm. Trong bi nghin cu ny, mt gi thit c a ra l ng dng b sung

ht bp gim vo cng ngh ch bin bnh cookie nhm b sung protein gi tr dinh

dng cao v thnh phn khng oxy ha, giu vitamin E t du ht bp gim. Bnh

cookie l mt sn phm quen thuc v c a chung Vit Nam v trn th gii bi

tnh nng tin dng v gi c ph hp. Nhu cu s dng bnh trong nc hin nay rt

a dng v phong ph. Vic ng dng khng ch p ng c nhu cu ca ngi tiu

dng v gi tr dinh dng, m v kinh t nng nghip cn gp phn nng cao cht

lng s dng, x l c ngun ph thi v gp phn tng thu nhp cho ngi nng

dn. Bi nghin cu s kho st nhng yu t nh hng n gi tr dinh dng ca

ht v a ra iu kin, phng thc x l ht nguyn liu. Bn cnh , kho st

nhng yu t nh hng ca ht vo sn phm cng c tin hnh a ra hm

lng b sung thch hp.

2

CHNG 2: TNG QUAN

2.1 Mt s nt v bnh cookie

2.1.1 nh ngha, phn loi v bnh cookie

Bnh bch quy l dng sn phm nng c kch thc nh, m thp nn gin

v xp. Cc nguyn liu c bn sn xut bnh l bt m, mui, ng v nc.

tng gi tr cm quan, c th b sung thm trng, cc sn phm t sa, cht bo, cc

cht ph gia v nguyn liu khc [6].

Trong ngnh cng ngh sn xut bnh bch quy c chia thnh hai nhm chnh

l nhm bnh bch quy c lm t bt nho dai (hard dough hay developed dough) v

nhm bnh bch quy c lm t bt nho xp (short dough) [6].

Bnh cookie thuc nhm bnh xp (short dough). Sn phm thuc nhm ny

thng c phn bit vi cc nhm khc qua bt nho, bt nho ca loi bnh ny

thiu dai v n hi. Bt m hay cc loi bt khc l thnh phn nguyn liu ch yu,

hm lng cht bo v dung dch ng c mt trong bt nho to nn cu trc bt

nho mm, dnh v s hnh thnh mng gluten c gim ti thiu. Cu trc ca bnh

cookie loi ny gm mt hn hp protein, tinh bt v tinh th ng. Trong bt nho

khng c mt ma trn protein lin tc v cht bo th tn ti dng cc ht cu bo ln

hoc nhng khi (git) ln dnh lin vi nhau gia nhng khi protein v tinh bt. Cu

trc ca loi bnh ny kh th do c bt kh hnh thnh trong sut qu trnh nng [7].

Bnh cookie c th c phn loi theo phng php to hnh nh cookie dng

thanh, cookie to hnh bng cch p n, cookie to hnh bng cch nn, cookie to

hnh bng my p, cookie dng cun. Ngoi ra cookie cn th c phn loi theo tnh

cht c bit nh: cookie t calorie, cookie khng bo hay cookie giu x [8]

2.1.2 Mt s yu t nh hng n cu trc sn phm

Cc c tnh ch yu lin quan n cht lng ca bnh cookie l cu trc, mu

sc v mi v. C nhiu yu t nh hng ln cu trc ca bnh nh: thnh phn

3

nguyn liu, hm lng s dng, qu trnh nho trn, nhit v thi gian nng,

m v phng php bo qun.

2.1.2.1 nh hng ca cc thnh phn nguyn liu c bn n cu trc bnh

Bt m

Bt m l thnh phn ch yu ca bnh cookie. Bt m khng nh hng mi v

n sn phm nhng n gp phn to nn cu trc, cng v hnh dng ca bnh.

Nhng nh hng ny ca bt m mc nh th no ty thuc vo hm lng bo

v ng ca tng loi bnh khc nhau v cch thc trn bt nho. Tnh cht ch yu

ca bt m cn quan tm chnh l hm lng v cht lng protein trong bt m v

mng gluten hnh thnh khi trn bt m vi nc. Ty tng loi bnh v mc yu

cu pht trin mng gluten m s dng loi bt m c hm lng protein thch hp.

Bnh cookie, bt nho mm, hn ch hnh thnh mng gluten th nn s dng bt m

c protein < 9 % [7].

Cht bo

Cht bo l mt thnh phn cn thit trong sn xut bnh cookie v l thnh

phn quan trng nht sau bt m v ng. Cht bo th hin chc nng cu trc trong

bt nho. Trong qu trnh cookie nho trn bt nho, c s cnh tranh b mt bt m

gia pha nc v pha bo. Nc hay dung dch ng tng tc vi protein bt m

hnh thnh nn mt mng li dnh lin, dai gi l mng gluten. Khi cht bo ph ln

bt m, mng li ny b ph v tnh lin tc v tnh cht cm quan sau khi nng ca

bnh s t cng, mm hn v c khuynh hng tan ra trong ming. Nu hm lng

cht bo cao, chc nng bi trn trong bt nho th hin r rt, ch cn t nc hoc

thm ch khng cn nc, mng gluten hnh thnh km v s trng n, h ha ca

tinh bt cng gim to ra mt cu trc rt mm. Bt nho d dng t gy khi ko, ta

ch ko c on ngn. Do cht bo gip lm xp bnh cookie. Loi v lng cht

bo s dng c nh hng ln ln tc dng lm xp v v vy nh hng ln ln cht

lng bnh cookie. i vi bnh cookie, loi cht bo khng nh hng quan trng

nhng lng cht bo trong cng thc nh hng ln n ca bnh cookie v khi

tng hm lng cht bo th chc ca bt nho s gim [7].

4

Khi hm lng ng cao, trong qu trnh nng, cht bo s kt hp v ngn

cn ng tr thnh mt khi cng trong sut khi ngui. Nghin cu v s hnh thnh

cu trc l hng ca bnh trong qu trnh nng cho thy, cht bo c khuynh hng

km hm s lan truyn ca kh qua cc thnh t bo trong sut giai on ti hn ca

qu trnh nng giai on nhit khong 38 580C, khi bt nho tr nn mm hn

v trc khi cc ht tinh bt t mng gluten hp thu nc v trng n lm cho mng

gluten tr nn dai v chc hn. S n nh ny ca cc bt kh to nn mt cu trc tt

hn. Nhiu nghin cu gn y cho thy trong qu trnh lm bt nho, cc tinh th bo

dng bn rn s tch khi pha lng v b bao bc trong mng protein. Mng protein

ny cho php mt s lng ln cc tinh th ny gn kt vi cc bt kh. Trong qu

trnh nng, cc tinh th bo tan chy v mng protein gn cht trong b mt ca cc

bt kh nh th chng gin ra, v vy lm bn bt hn v nhng tinh th nh hn s c

nh hng ln hn n thuc tnh c hc trong qu trnh nng. iu ny gii thch l

do ti sao bt nho lm t cht bo dng bn rn to cu trc tt hn so vi cht bo

dng lng khi nng [7].

ng

ng gp phn to nn cu trc, hng, v ngt v mu sc cho bnh cookie.

Hm lng, kch thc ht v loi ng s dng c nh hng ln cht lng ca

bnh cookie. Hm lng ng tan vo dung dch ty thuc vo kch thc ht ng,

nh hng ln n ca bnh cookie v cc thuc tnh c hc ca bt nho. ng

c coi l mt tc nhn hn ch s hnh thnh mng gluten do n cnh tranh nc m

l ra s c hp thu bi gluten [7].

ng trong bt nho bnh cookie tan hon ton hoc tan mt phn cn ty

vo lng nc c trong bt nho v sau kt tinh li hoc to thnh dng tinh th

v nh hnh sau khi nng. Chnh v vy ng c nh hng mnh m ln cu trc

ca bnh cookie. Nu hm lng ng saccharose trong bnh cao th bnh cng.

Kch thc ca tinh th ng cng nh t l ha tan ca chng khi bt nho c lm

nng ln trong l nng nh hng n n ca bt nho xp (short dough) khi

nng v nh hng n hnh dng, gin ca bnh thnh phm. Khi ng tan n

ha vo pha lng ca bt nho n mt lc no dung dch ng s bo ha, lng

5

ng lm gim lng nc cn trong bt nho. ng lm thay i im h ha tinh

bt ln nhit cao hn, iu ny lm cho bt nho c nhiu thi gian n hn trong

l nng. ng c coi nh l mt cht chng oxy ha trong bnh cookie v n

gp phn tng thi gian bo qun ca bnh bng vic lm chm qu trnh i ha cht

bo [7].

2.1.2.2 nh hng ca cc qu trnh cng ngh n cu trc bnh

Nho trn

Trong qu trnh nho trn bt nho lm bnh cookie, cc lin kt ha hc

yu hnh thnh to nn mng li gluten. Cc gliadin, glutenin s lin kt vi nhau

bng lin kt hydro, bng lin kt tnh in gia cc phn t mang in tch tri du,

bng cu disulfide v bng tng tc a bo. Cc tng tc ny s to nn n hi

cho bt nho. Tnh lu bin ca khi bt nho s nh hng trc tip ln cc tnh cht

ca bnh. Cc tnh cht lu bin quan trng ca khi bt nho bao gm kh nng ht

nc, n hi, dnh nht, c qunh v xp. V vy, qu trnh nho trn s

kt thc khi t c s ng u v cc tnh cht lu bin thch hp ca khi bt

nho [6].

Nng

Vi mi loi bnh, ty vo cng thc bt nho, chiu dy v khi lng ming

bt m s c ch nng ph hp. Ch nng bnh c c trng vo ba thng

s: m tng i ca hn hp khng kh v hi trong bung nng, nhit cc

vng trong bung nng, thi gian nng. Trong qu trnh nng bnh c s to

thnh cu trc mao xp v s to thnh v. Protein v tinh bt ng vai tr ch yu

trong vic hnh thnh cu trc mao xp. nhit 50-700C, protein b mt nc v

ng t, cn tinh bt b h ha to thnh khung xp m trn b mt c hp th mt lp

cht bo mng. Lp v c hnh thnh khi cng bay hi m trn b mt xy ra

mnh m v tinh bt lp ngoi b h ha phn no, s chuyn m n b mt s

khng b p lng m mt i. Do vy, vic la chn ch nng thch hp th

cht lng v trng thi ca sn phm s tt hn [6].

6

2.2 Ht bp gim

Bp gim (Roselle/ Hibiscus sabdariffa Linn), thuc h Malvaceae, sinh trng

nhng quc gia c kh hu nhit i v cn nhit i bao gm c Vit Nam. T u

thp nin 1990, Cng ty dc liu trung ng 2 TP.HCM cho trng hng trm

hecta bp gim ti ng Nai, Mc Ha, Bnh Dng, Bnh Thun ,Tuy Ha ly i

hoa xut khu [9]. Ngun gc ca bp gim cha c xc nh r, c mt s cho rng

l n (Chen et al, 2005) [10] v s khc li tin rng bp gim c khi ngun

t Chu Phi (Maganha et al. , 2010) [11] v Rp Saudi (Abu-Tarboush et al., 1997)

[12]. Bp gim l loi cy tho dc mc thng ng thnh bi vi thn cy mu

hnh tr trn. Cy c th cao t 0.5- 3m vi cung cy c mu xanh hoc v i hoa

mu hoc mu vng ti. Cy bp gim thng sinh trng trong khong 3-4 thng

[13].

Ht bp gim l mt ngun cha protein, du v giu cc hp cht chng oxy

ha [2] [14] [15]. Ht c s dng nh thc phm cho ngi v cng c dng lm

thc n cho gia cm ti mt s nc. Ngi Sudan s dng ht nh mt loi nguyn

liu lm furundu (mn n truyn thng a phng), l mn ht bp gim

c ln men [16], tng t nhng nc chu Phi th c mn bikalga [17].

Nhng nghin cu trc cng ch ra c ht bp gim giu hm lng

protein, cht x v khong nh phospho, magie v calci. Kt qu thnh phn dinh

dng ca ht c hin th bng 2.1. C nhiu kt qu khc nhau cc tc gi,

nguyn nhn l do ging ht nghin cu cc ni l khc nhau, cng nh iu kin

kh hu, iu kin v thi im thu hoch. Thnh phn ha hc ca ht nh sau hm

lng protein dao ng 18.8 -33.5%, lipid 19.10-28.10%, carbohydrate 13.04-44.5%,

cht x 4.12-42.6 % , tinh bt 2.25-18.31% v khong 7.5%. Hm lng khong ch

yu c trong ht l kali (99-109 mg/100g), magie (26-28 mg/100g) v calci (24-31

mg/100g) [18].

Hu ht cc nghin cu u ch ra rng ht bp gim cha mt lng ln

protein v thnh phn du n c, mt t l gia x ha tan v khng ha tan l chp

nhn c so vi cc ngun x khc nh cm la m, cm go v x yn mch [5].

7

Bng 2.1 Thnh phn ha hc ca nguyn ht bp gim (% w/w)

Thnh phn Al-Wandawi et al.

(1984)

(Iraq)

El-Adawy &

Khalil (1994)

(Egypt)

Rao

(1996)

(India)

Abu-Tarboush et al.

(1997)

(Saudi Arabia)

Yagoub et al.

(2004)

(Sudan)

Anhwange et al.

(2006)

(Nigeria)

Hainida et al.

(2008a)

(Malaysia)

Yagoub et al.

(2008)

(Sudan)

Total protein 25.2 31.02E1.32 18.8 25.0E 0.31 28.59E 0.01 19.84E 0.21 35.35E 0.1 32.28E 0.01

Non-protein nitrogen - 2.5 E 0.11 - - 1.35E0.01 - - -

Total lipid 21.20 21.60E 0.57 19.1 20.3E 0.04 22.15E0.05 28.10E 0.44 27.22E 0.17 19.90E 0.19

Total carbohydrates 26.64 36.37E 1.86 - 44.5E0.22 28.96E 0.05 33.0E 0.14 2.27E0.30 12.56E 0.06

Total fiber 16.30 4.12E0.14 42.6 - 12.29E0.18 6.33E 0.07 25.48E 0.11 22.30E 0.31

Soluble fiber - - 12.1 - - - 5.89 E 0.01 -

Insoluble fiber - - 30.5 - - - 19.59 E 0.13 -

Sugar - 21.72 E 0.86 - - 11.07 E 0.40 - - 10.17E 0.06

Starch 2.25 14.65 E 0.94 - - 18.31 E 0.05 - - 2.39E 0.06

Total ash 5.19 6.89 E 0.23 5.4 4.8 E 0.00 5.13 E 0.12 5.55E 0.11 7.43 E 0.17 5.03 E 0.11

Moisture 5.57 9.25 E 0.98 8.6 5.3 E 0.19 4.05 5.98 E 0.11 6.81 E 0.19 -

8

Samy, (1980), El-Adawy & Khalil (1994), Rao (1996) v Hainida et al. (2008a) cho

kt qu tng t nhau v m, cht bo v hm lng tro khong. S khc bit gia

hm lng protein, x v carbohydrate ca cc kt qu tng i ln l do ngun gc

ban u ca ht khc nhau. Rao (1996) v Samy (1980) cho ra kt qu lng protein

thp (18.8%). D vy, hm lng protein ca ht vn cao hn so vi cc loi ht khc

nh ht ging en, ht hng dng, ht da, ht u nnh v u phng [19]. T

bng thnh phn, ta thy hm lng carbohydrate vn cha c con s c th. El-

Adawy & Khalil (1994) ch ra ht bp gim c hm lng carbohydrate cao t 36-

38%, bao gm hm lng x (1.23 -4.12%). Mc khc, Hainida et al. (2008a) th cho

kt qu v hm lng carbohydrate thp hn (13%). Trong khi , Rao (1996) th li

kt qu bo co v hm lng x rt cao (39-42%) c trong ht. Theo Hainida et al.,

(2008a), tng lng cht x trong ht thuc vng chp nhn c, t l x ha tan v

khng ha tan khong 1.2-3.3. T l ny tng ng vi kt qu ca Rao (1996).

2.2.1 Thnh phn protein trong ht bp gim

Theo nghin cu ca Abu-Tarboush & Ahmed (1996), hiu sut trch ly protein

ca ht bp gim ph thuc vo loi mui v nng mui cng nh pH trong qu

trnh chit tch. Hiu sut protein cao nht t ti pH 11 v nng mui CaCl2 0.4M.

im ng in ca protein ht nm trong khong pH 3-5 [20].

Fagbenro et al. (2004) ch ra vic s dng ht bp gim thay th cho ht

u nnh trong khu phn n ca c hi Nile. Khu phn n cung cp n gn 30%

tng lng protein [21]. Cng c nhiu nghin cu tin hnh nh gi ngun

protein v du c trong ht bp gim [18] [5] [12] [14] [2] [22]. Nghin cu cht dinh

dng v hm lng acid amin ca ht bp gim ch ra ht c th c s dng

nh mt ngun nguyn liu chc nng [18]. Ngoi ra, ht cn c xem nh ngun

du n c c hm lng gi tr cao tng ng vi du olive [23].

Bng kt qu thnh phn acid amin ca Rao (1996) ch ra ht bp gim c

hm lng lysine v tryptophan cao trong khi cc acid amin cha lu hunh th li

thp. Hm lng lysine ca ht cao hn nhng loi ng cc thng thng nh cao

lng, la m, bp v go nhng li thp hn nhng loi u nh u g, u sng.

9

[24]. Cc acid amin gii hn l valine, isoleusine v tryptophan, trong khi cc

acid amin cha lu hunh li khng phi l nhng acid amin gii hn [2].

Nhng nghin cu trc ch ra rng ht bp gim l ht giu lysine,

arginine, leucine, phenylalanine v acid glutamic [2] [18] [24]. Da theo bng 2.2,

methione v cysteine l nhng acid amin gii hn [12] [18] [24]. Nhng, Al-Wandawi

et al. (1984) v El-Adawy & Khalil (1994) cho rng nhng acid amin gii hn l

tryptophan, valine, isoleucine, threonine. Mc d c s thiu ht v threonine v

trytophan nhng ht bp gim l mt ngun cung cp protein tt cho nhng ngun

protein thiu acid amin cha lu hunh nh h u [25] [24]. Hainida et al. (2008a)

cho rng hm lng cysteine v methionne c trong ht bp gim l cn thit cho nhu

cu ca con ngi.

2.2.2 Du ht bp gim

Ht bp gim cha 19-28% lng du vi hm lng cao acid bo khng bo

ha [26] [23] [24] [2] [27]. Bamboye & Adejumo (2009) nhc n du ht bp

gim c xem nh mt ngun du n c c gi tr dinh dng cao, vi thnh phn

tng t nh du olive th [28], mc khc; Ahmed & Hudson (1982) li kt lun rng

du ht bp gim ging nh du ht cotton [29]. Thnh phn l ha v thnh phn acid

bo ca du ht bp gim th c c tnh tng t nh du bp, v th c th cho rng

du ht bp gim l du n c [23].

Du t ht bp gim c em i trch ly, phn tch v thng s ha l ca ht

c tng kt nh sau: acid 2.24%; ch s peroxide 8.63 meq/kg; h s hp th ti

bc sng 232 nm v 270 nm ln lt l 3.19 v 1.46; bn oxy ha 15.53h; t trng

0.92 kg/L; v nht 15.9 cP. Du ht bp gim cha hn 70% lng acid bo cha

bo ha, c thnh phn acid bo chnh trong du l linoleic (40.1%), oleic (28%), k

l cc acid bo khc nh palmitic (20%), stearic (5.3%), v nonadecenoic (1.7%)

[4]. Myristic (C14:0), myristoleic (C14:1), palmitoleic (C16:1), arachidic (C20:0), v

eicosatrienoic (C20:3n-6) c tm thy trong ht bp gim di dng vt (

10

Bng 2.2 Thnh phn acid amin trong ht bp gim

Acid amin

El-Adawy &

Khalil (1994)

(g/16g N)

Rao (1996)

(g/16g N)

Al-Numair &

Ahmed (2008)

(g/100g protein)

Hainida et al.

(2008a)

(g/100g protein)

Essential

Lysine 5.37 4.3 5.1 E 0.41 13.77

Threonine 4.86 4.2 2.91 E 0.28 8.550

Valine 3.26 5.0 4.55 E 0.02 9.85

Methionine 1.13 1.2 1.48 E 0.01 2.50

Cysteine 2.64 1.0 2.41 E 0.09 4.04

Methionine +Cysteine 3.77 2.2 3.89 6.55

Isoleucine 3.24 5.0 3.01 E 0.17 7.17

Leucine 7.32 6.5 5.92 E 0.50 15.44

Phenylalanine 5.09 4.8 5.99 E 0.29 11.11

Tyrosine 3.46 2.7 2.72 E 0.26 6.09

Phenylalanine +Tyrosine 8.55 7.5 8.71 17.20

Histidine 2.97 2.5 1.8 E 0.18 7.04

Tryptophan 0.37 1.2 0.76 E 0.18 Nd

Non-essential

Arginine 10.58 9.9 9.58 E 0.26 -

Aspatic acid 10.91 9.1 10.28 E 0.29 -

Glutamic acid 21.30 21.6 24.00 E 0.59 -

Proline 4.14 5.2 4.30 E 0.20 -

Glycine 4.27 6.4 5.09 E 0.21 -

Alanine 4.69 6.1 5.56 E 0.06 -

Serine 4.40 5.2 4.70 E 0.21 -

11

C vi nghin cu cho rng c s hin din ca cyclopropenoid trong du ht

bp gim [30] [14] [27]. Ahmad et al. (1979) tm thy ba acid bo khng bnh

thng phn ng vi HBr l cis-12,13-epoxy-cis-9octadecenoi (12,13-epoxyoleic)

(4.5%), sterculic (2.9%) v malvalic (1.3%) v cho rng hp cht khng bo ha l

acid 12,13-dihydroxyoleic c ngun gc t acid 12,13-epoxyoleic. Acid dihydroxy l

ng phn threo v v th nhm chc epoxide c cu hnh dng cis [30]. Nhng thnh

phn gy ung th ca mt lng nh acid phn ng HBr c mt trong ht c th gy

nh hng xu n n nh v cc thnh phn dinh dng. Ht bp gim t Vit

Nam cng c cha cc acid cyclopropenoic (0.5 g/100 g (acid sterculic) v 1.2 g/100 g

(acid malvalic)). Tuy nhin, cc acid cyclopropenoic c th b ph hy ti nhit cao

[31]. Mc khc, theo nghin cu ca Rukmini et al. (1982) li cho rng mc d ht

bp gim c cha acid bo cyclopropernoid (2.9%) v acid bo epoxy (2.6%) nhng

du ca ht vn c th dng c cho ngi [32].

Cc acid bo t do v cc cht khng c tnh x phng ha s gim ng k khi

lc du. Thnh phn acid bo ca du lc ht bp gim gn ging nh thnh phn acid

bo ca cc du n c vi t l cao acid khng bo ha: acid bo ha. Du th khng

qua lc th khng s dng c v mu du ti, hm lng acid bo t do cao v

nht cao. Qu trnh lc du iu chnh cm quan v tnh ha l ca du [27].

2.2.3 Gi tr dinh dng ht bp gim

Abu-Tarboush et al. (1997) bo co m hnh th nghim in vitro v ch s

tiu ha protein ca ht bp gim tch bo (defatted roselle seed -DRS), protein

concentrate ht bp gim (Roselle protein concentrate -RPC), protein isolate ht bp

gim (Roselle protein isolate -RPI) v casein l 82.14, 85.12, 87.09 v 88.95%. Trong

khi , trn m hnh i vi sn phm u nnh (ht tch bo, protein concentrate v

protein isolate) l 76.32, 8727 v 88.45%. Ch s tiu ha protein trn m hnh in vitro

cao ch hm lng phn trm protein tiu ha cao [12]. Abu-Tarboush (1996) cn ch

ra rng vic x l nhit ht bp gim c th lm v hot cc thnh phn xu hay cc

cht c ch enzyme. iu ny gii thch v sao lng protein cao hn trong ht bp

gim c luc [20].

12

Theo Hainida et al. (2008b), t l gia thnh phn x ha tan v x khng ha

tan l khong 1.0 -2.3 c th gy ra nh hng sinh l. Kt qu cho thy DRS c

tim nng lm gim cholesterol trong mu nu c b sung vi liu lng l 5% v

15% DRS cho khu phn n ca chut th nghim, s gip gim tng lng cholesterol

huyt tng v lng cholesterol lipoprotein t trng thp [5]. Cholesterol gim c th

l do hm lng cht x, protein, methionine v t l lysine i vi arginine trong

DRS. Cholesterol huyt thanh gim l do s kt hp gia cht x trong ht bp gim

vi cc acid mt. Hn na, hm lng protein cao trong ht cng l nguyn nhn gip

gim cholesterol. Methionine ng vai tr chnh trong vic lm gim cholesterol.

Nhiu kt qu cng cho thy ht c hm lng methionine cao hn so vi nhng thc

phm c chc nng lm gim cholesterol khc. V th, ta c c s cho rng lng

methionine trong DRS ng mt vai tr quan trng trong vic gim cholesterol mu

[5]. Bn cnh , Rao (1996), Abu-Tarboush et al. (1997) v Hainida et al. (2008a)

cho bit t l lysine vi arginine l thp trong ht bp gim (0.4-0.5). T l ny c th

l mt trong nhng yu t lm gim cholesterol [24] [12] [18].

2.2.4 Cc hot cht c trong ht bp gim

Trc , ta bit c i hoa bp gim c kh nng khng oxy ha cao. V

bn cnh , nhiu nghin cu trn ht c tin hnh v kt lun rng nhng chit

xut t ht bp gim c hot tnh chng oxy ha l kh cao.

Cc phn tch v hot chng oxy ha, hot kha gc t do v hm lng

tng polyphenol c trong tng phn ca cy bp gim c tin hnh bi Mohd-Esa et

al. (2010) [33]. Kt qu cho thy ht, hot chng oxy ha l cao nht, cng nh

hot kha gc t do l mnh nht. Th nghim chng oxy ha c tin hnh bng

cc th nghim s dng -carotene kh mu, DPPH (2,2-diphenyl-1-picrylhydrazyl) v

kho st hiu sut chng oxy ha bng thiobarbituric (TBA) trong ton h thng thc

phm, kim tra s nh hng n s oxy ha cht bo trong bnh tht b bo qun ti

40C trong 14 ngy. Kt qu cho thy bnh tht b c cha ht bp gim th c s oxy

ha cht bo thp hn so snh vi s dng BHT. Tc gi nhn nh rng ht bp gim

c tim nng ng dng trong vic chng oxy ha trong thc phm. Hp cht phenolic

ca cy bp gim khi c trch ly bng methanol th cho hiu sut cao hn so vi

13

trch ly bng nc. Tuy nhin, hot tnh chng oxy ha ca dch trch bng nc cao

hn so vi dch trch bng methanol [33].

Amin & Chew (2006) nh gi hiu qu chng oxy ha ca ht bp gim

trn cm bin ca tht b ch bin n s oxy ha cht bo. H gim st s hnh

thnh ca nhng cht phn ng li TBA trong mu tht b ch bin b sung chit xut

ht bp gim bo qun 40C trong hai tun. Nghin cu cho thy chit xut ht c kh

nng lm gim s oxy ha cht bo trong mu tht b ng lnh. Da vo ch s TBA,

hot chng oxy ha ca chit xut ht bp gim c cho rng l hiu qu hn so

vi BHT v -tocopherol [34].

Arvind Mungole v Alka Chaturvedi (2011) tin hnh phn tch nh tnh

nhng hp cht c mt trong cc b phn ca cy bp gim nh i, l, r, ht. [15]

V kt qu nh tnh cc cht c mt trong ht gm c nhng hp cht sau: flavonoids,

carotenoid, steroids, F.acids, phenolic, flavonoids, tannins, alkaloids, saponins, gum v

mucilage. H tin hnh trch ly cc hot cht bng nc v cn. Phenolic c tc dng

cha tr bnh thn v d dy cng nh c ch trong vic chng vim nhim.

Triterpenoid khng c mt trong ht. Steroid c cho rng c thnh phn chng vim

[15].

Trn Th Ngc Yn et al. (2012) tin hnh trch ly ht bp gim kh bo

(defatted roselle seed) vi nc di im ti hn (subcritical water, 1600C) v kt

qu cng cho thy rng trong ht bp gim tch bo c cha nhng hp cht

phenolic c gi tr vi kh nng chng oxy ha cao [3].

Cc hot cht c tm thy trong du ht bp gim bao gm sterol, phytosterol

v acid phenolic. Kosakowska et al. (2005) nghin cu thnh phn acid bo v

sterol trong du ht bp gim t cc cc loi ht khc nhau Ai Cp [35]. Theo kt

qu phn tch HPLC ch ra s c mt ca bn sterol t do c trong du ht l viz.

brassicasterol, campesterol, stigmasterol v sitosterol. Sitosterol l sterol chnh trong

ht v hm lng ca n ph thuc vo loi ht. Cc sterol l mt trong thnh phn

quan trng trong cc hot cht sinh hc trong ht. Trc , Atta & Imaizumi (2002)

14

cng tm ra ba trong s bn sterol; v kt qu ch ra ht bp gim l ngun giu cc

acid bo khng bo ha v sterol [23].

Nyam et al. (2009) cho bit cc hot cht hin din trong ht bp gim l cc

acid phenolic, sterol, squalene v tocopherol. Cc acid gallic, protocatechuic, p-

hydroxybenzoic, vanillic, caffeic, syringic, pcoumaric v ferulic c tm thy trong

du ht. Trong s , acid vanillic l thnh phn chnh trong du. Du ht cn cha

nhiu tocopherol vi -tocopherol l thnh phn chnh. Trong s cc phytosterol,

sitosterol l thnh phn chnh trong s [26] .

Mohamed et al. (2007) nghin cu v kh nng chng oxy ha ca chit xut

cy bp gim; kt qu cho thy ht bp gim l ngun nhiu cht bo ha tan chng

oxy ha, c bit l -tocopherol. Du t ht bp gim c em i trch ly, phn tch

v thng s ha l ca ht c tng kt nh sau: acid 2.24%; ch s peroxide 8.63

meq/kg; h s hp th ti bc sng 232 nm v 270 nm ln lt l 3.19 v 1.46;

bn oxy ha 15.53h; t trng 0.92 kg/L; v nht 15.9 cP. Du ht bp gim c thnh

phn acid bo chnh trong du l linoleic (40.1%), oleic (28%), k l cc acid bo

khc nh palmitic (20%), stearic (5.3%), v nonadecenoic (1.7%). Cc sterol ch yu

bao gm -sitosterol (71.9%), campesterol (13.6%), -5-avenasterol (5.9%),

cholesterol (1.35%), v clerosterol (0.6%). Tng lng tocopherol xp x 2000 mg/kg,

bao gm -tocopherol (25%), -tocopherol (74.5%), v -tocopherol (0.5%) [4].

2.2.5 Tinh bt

Hm lng tinh bt trong ht bp gim c xc nh t khong 2.25-18.31%

[2] [14] [16]. Thnh phn tinh bt ph thuc vo c tnh vt l v ha hc nh kch

thc ht tinh bt v s phn b kch thc, t l amylose/amylopectin v hm lng

khong. Hm lng amylose ca ht tinh bt khc nhau vi ngun tinh bt, nh hng

bi kh hu v t ai trng trt [3].

15

CHNG 3: PHNG PHP NGHIN CU

3.1 Nguyn liu

3.1.1 Ht bp gim

Ht bp gim c thu mua t cc h dn trng cy bp gim Bnh Thun. Ht

c ng u cao v hnh dng, kch thc v khi lng. Ht khng c du hiu b

mt. Ht c cn v bao gi, vi khi lng mi bao l 500g. Ht c bo qun t

ng.

Nguyn liu ht bp gim s dng cho bnh l dng bt t nguyn ht sau khi x

l loi v v qua qu trnh nghin ry cho ra.

3.1.2 Bt m

Nghin cu ny s dng bt m s 8 ca hng Interflour.

3.1.3 ng

Nghin cu ny s dng ng tinh luyn RE do cng ty ng Bin Ha

sn xut, c bn ph bin cc ch, ca hng. ng c s dng di dng

ht nhuyn. ng tinh luyn RE s dng c cc ch tiu c trnh by trong

bng 3.2.

Bng 3.1 Ch tiu cht lng ca bt m (theo TCVN 4359:1996)

Ch tiu Bt m

m 15.5%

Protein (Nx 5.7) 7.0%

acid 50 mg KOH/ 100 g bt m

Hm lng tro -ha tan HCl 0.22%

Mi v Khng c mi l

Potassium Bromate Khng c

16

3.1.4 Trng

3.1.5 B

Nghin cu s dng b lt ca c, mua ti cng ty Hn Phong.

Bng 3. 4 Yu cu k thut ca b (TCVN 7400:2004)

Ch tiu B lt

Cm quan -Mu sc -Mi v -Trng thi

Vng c trng ca b Thm ngon c trng, khng c mi l Mm, ng nht

m (%) 16

Cht bo (%) >80

Hm lng cht kh khng bo (%) 2

Nm v vi khun ng rut Khng c

Bng 3. 3 Yu cu k thut i vi trng g ti (TCVN 1858:1986)

Ch tiu Trng g

Mi Khng c mi l

V Khng mo m, sch, khng v

Bung kh 8 mm

Lng Khi xoay cho php lch khi tm qu trng mt t

Lng trng Trong, khng c long qu

Bng 3.2 Ch tiu cht lng ca ng (6958:2001)

Ch tiu ng tinh luyn RE

Pol (0Z) 99.80

m (%) 0.05

ng kh (%) 0.03

Hm lng tro (%) 0.03

Tp cht (ppm) 0.03

mu 300 Icumsa

17

3.1.6 Shortening

Bi nghin cu s dng shortening ca cng ty du thc vt Tng An

3.1.7 Mui

3.1.8 Bt ni

Bi nghin cu s dng bt ni mua ti cng ty Hn Phong.

Bng 3. 6 Ch tiu ca mui n (TCN 3973:84)

Ch tiu Mui

NaCl (% cht kh) 97.0

m (%) 9.5

Cc cht kh khng tan trong nc (%)

0.25

Cc tp cht hn hp khc (%)

Ca2+

0.3

Mg2+

0.4

SO4 2-

1.4

Bng 3. 5 Yu cu k thut ca shortening (TCVN 6048:1995)

Ch tiu Shortening

Cm quan -Mu sc -Mi v -Trng thi

Mu trng hoc trng ng Khng c mi l rn bnh thng

m (%) 96

Ch s x phng ha (ml KOH 1N/kg mu) 190-209

Ch s Peroxide

18

3.2 Phng php nghin cu

3.2.1 Mc ch nghin cu

Mc ch ca bi nghin cu ny l ng dng ht bp gim vo sn phm bnh

cookie nhm nng cao gi tr s dng ht bp gim, l mt loi ht hin nay c thi

b nhng c gi tr dinh dng cao v cha thnh phn khng oxy ha cng nh c

kh nng lm gim cholesterol. Bn cnh , bi nghin cu cn l bc u xy dng

mt quy trnh cng ngh sn xut sn phm bnh cookie ht bp gim thng qua xc

nh cc thng s cng ngh cho qu trnh sn xut.

3.2.2 S nghin cu

19

Hnh 3. 1 S nghin cu

TN1: Kho st quy trnh ch bin bnh

chun

TN2: Kho st hm lng b sung ht bp gim

TN3: Kho st t l b TN4: Kim tra cht lng

sn phm

Kho st s nh hng ca ht bp gim ln bt nho v bnh.

nh gi cm quan

sn phm

Xc nh cc thng s

ha l.

Kim tra vi sinh.

nh gi cm quan sn

phm cui.

Kho st s nh

hng ca b ln

sn phm

nh gi cm quan

bnh

La chn thi gian

nng bnh chun

ND1: Kho st qu trnh

x l loi v ht bp gim

ND2: Kho st nguyn liu

ht bp gim

ND3: Kho st quy trnh ch bin bnh b sung ht bp gim

Tnh hiu sut thu hi ca 3 phng php x l ht loi v: - Phi - Sy - Rang

o kch thc, khi lng v t l thnh phn ca ht bp gim

Kho st mt s thng s ha l ca ht bp gim v ht bp loi v nh: m, ng tng, ng

kh, protein tng, lipid tng

20

3.3 Tin hnh th nghim

3.3.1 Ni dung 1: Kho st qu trnh x l loi v ht bp gim

Quy trnh kho st loi v ht bp gim

th nghim ny, ht bp gim c tin hnh x l loi v theo quy trnh 3.2

Thuyt minh quy trnh loi v ht bp gim

La chn

Qu trnh la chn thu nhn nhng ht c yu cu ph hp cho qu trnh ch

bin v loi b nhng ht khng t yu cu nh ht rng, bn cnh cn to s

Hnh 3. 2 Quy trnh loi v ht bp gim

Rang

Bt ht bp

gim loi v

Ry

Nghin

V

Phi Sy

Ht h

Tp cht

Ht bp gim

La chn

Ra sch

21

ng nht cht lng nguyn liu s dng. Cn 10 g ht v ngm ht trong nc,

nhng ht rng v tp cht ni ln b mt nc s c vt b.

Ra sch

Qu trnh ny gip loi b cc tp cht nh: t, ct, bi v mt s vi sinh vt

bm trn ht. Ht c ra qua bn ln nc sch lp bi bm trn ht.

Sau khi ra ht, ta tin hnh 3 phng php x l nguyn liu khc nhau nhm

h tr cho qu trnh nghin v ry.

Phng php 1: Sy

Ht bp gim c em i sy nhit 650C trong cc khong thi gian

ln lt l 5 pht, 7 pht, 9 pht.

Phng php 2: Rang

Ht bp gim c em i rang nhit 1600C trong cc khong thi

gian ln lt l 1 pht, 2 pht, 3 pht.

Phng php 3: phi

Ht bp gim c em i phi nhit phng trong cc khong thi

gian ln lt l 4 gi, 5 gi, 6 gi.

Bng 3. 8 X l loi v bng phng php rang

Mu R1 R2 R3

Thi gian (pht) 1 2 3

Bng 3. 7 X l loi v bng phng php sy

Mu S1 S2 S3

Thi gian (pht) 5 7 9

22

Nghin

Nghin lm gim kch thc ca ht nguyn liu, gip cho vic b sung nguyn

liu d dng hn v nguyn liu phn b ng u hn trong khu nho trn. Tng

thi gian nghin l 3 pht. Ht c xay bng my xay sinh t gia nh.

Ry

Bt ht bp gim sau khi nghin c ry loi v, v v c kch ln hn ni

nh bn trong nn phn ln s c gi li trn ry. Kch thc l ry l 350 m.

Bao gi

Bt ht bp gim sau khi c x l tch v s c bao gi trong bao

ca hng Ziploc c rnh kha ming.

Phng php nh gi

Kt qu thu nhn l quy trnh loi v ht bp gim x l nguyn liu cho qu trnh

lm bnh cookie thng qua tnh ton hiu sut thu hi ni nh ht l hiu qu nht.

3.3.2 Ni dung 2: Kho st nguyn liu ht bp gim

3.3.2.1 Kho st kch thc v t l thnh phn ca ht bp gim

Mc ch

Xc nh thng s vt l ca nguyn ht bp gim.

Xc nh t l thnh phn v v ni nh ca ht bp gim.

Bng 3. 9 X l loi v bng phng php phi

Mu P1 P2 P3

Thi gian (gi) 4 5 6

23

Tin hnh

Xc nh cc thng s:

S lng ht trn 1 gam ht.

Kch thc trung bnh ca ht: chiu di, chiu rng, chiu dy[7.1.1]

% khi lng v, % khi lng ni nh [7.1.2]

3.3.2.2 Xc nh cc thng s ha l ca nguyn liu

Mc ch

Kho st mt s thnh phn ha l ca nguyn ht bp gim v ht bp gim loi

v.

Tin hnh

Xc nh cc thng s ha l ca ht bp gim v ht bp gim loi v:

m: Mu em sy di dng bt v c sy trong t sy (nhit 1050C)

n khi lng khng i. [7.1.3]

Hm lng ng kh: Xc nh bng phng php quang ph so mu(DNS).

[7.1.4]

Hm lng ng tng: Xc nh lng ng tng bng phn ng mu vi

phenol v acid H2SO4 m c.[7.1.5]

Hm lng protein tng: Xc nh hm lng protein theo phng php

Kjeldahl [7.1.6]

Hm lng lipid tng : Xc nh hm lng lipid th bng my Soxhlet [7.1.7]

24

3.3.3 Ni dung 3: Kho st quy trnh ch bin bnh b sung ht bp gim

Quy trnh cng ngh ch bin bnh chun d kin

Thuyt minh quy trnh cng ngh ch bin bnh ht bp gim

Trn bt

Bt m c trn u vi bt ni, vani v mui.

Hnh 3. 3 Quy trnh ch bin bnh chun

Bt m, mui,

bt ni, vani

Trng g, ng,

b, shortening

Nho trn

Trn u

nh u

t = 3 pht

To hnh

Ph du

Nng

ngui

Bnh cookie

t =20 pht

pht

25

Nho trn

Dng my nh trng nh ni trng g, sau cho ng xay vo trng v

tip tc nh ti. Tip , thm b thm v shortening vo hn hp ri nh tip

thnh mt h ng nht c hn hp dch nh tng. Dch nh tng c

trn vi bt m bng my nho trn trong vng 3 pht.

Sau khi nho trn, bt c trong vng 20 pht n nh cu trc bt nho.

To hnh

Bt nho c to hnh bng khun ct c ng knh 4.5 cm, dy 4 mm. Khi

to hnh cho bnh phi ch to cho bnh c hnh dng v kch thc ng nht,

khng c s chnh lch qu ln.

Ph du

Khi cho bnh vo khay nng, pht mt lp mng du ln trn b mt s gip

d dng ly bnh ra khi khay sau khi nng xong. Tuy nhin, khng nn pht

lng du ln v khi , du dng t do v s li lp du trn b mt sn phm

sau khi nng s gy mt cm quan v d b h hng hn trong qu trnh bo qun.

Nng

Bnh sau to hnh c xp ln khay v cho vo l nng ch 150oC, v

thi gian nng s c kho st vo phn 3.3.3.1.

ngui

Bnh khi mi nng xong, khng nn ly ra khi khay ngay v bnh khi cn

nng rt d gy vn. Bnh sau khi nng c ly ra khi l v ngui t nhin.

Bao gi

Sn phm bnh c trong bao ca hng Ziploc c rnh kha ming.

26

3.3.3.1 La chn thi gian nng bnh chun

Mc ch

Xc nh thi gian nng ph hp to nn bnh chun dng so snh vi mu sn

phm bnh b sung ht bp gim lc sau.

Tin hnh

Tin hnh kho st thi gian nng cho bnh khng b sung ht bp gim. Ta c nh

nhit nng trong l l 1500C. Cng thc thnh phn nguyn liu nh sau:

Nguyn liu Hm lng ngh, % w/w Bt m 100 ng 50 Trng g 30 B thm 35 Shortening 25

Bt ni 1.75 Vani 0.1

Mui 0.5

Thng s thay i:

Thi gian nng thay i c th hin bng:

Phng php nh gi

Kt qu thu c trong th nghim ny da trn nh gi cm quan v hnh thi,

mu sc, mi, v ca bnh thnh phm. Tin hnh th nghim cm quan vi php th

m t .

Hun luyn mt hi ng cm quan gm 9 ngi. Nhng cm quan vin c

hiu bit v mu bnh cookie truyn thng. Mi ngi th s nhn c 5 mu bnh

khc nhau v c yu cu a ra nhn xt v tng mu bnh.

Bng 3. 10 Cc thi gian nng khc nhau

Mu M9 M11 M13 M15 M17

Thi gian (pht) 9 11 13 15 17

27

3.3.3.2 : Kho st hm lng b sung ht bp gim

Mc ch

Sn phm bnh phi cha mt t l ht bp gim ph hp m bo c yu cu:

- Ngi tiu dng cm nhn c hng v bp gim c trng.

- Bnh cookie c hng v hi ha.

Tin hnh

Xc nh khong hm lng b sung

Ta tin hnh kho st t l b sung ht bp gim vo bnh. Ta c nh nhit

nng trong l l 1500C vi thi gian nng c nh l 13 pht. i vi cng thc

nguyn liu, ta s thay th thnh phn bt m bng bt ht bp gim vi t l ln lt l

5%, 10%, 15%, 20%, ngha l:

Phng php nh gi



so hng th hiu v mc a thch ca ngi th cho cc mu bnh.

Mi ngi th s nhn c 5 mu bnh khc nhau c m ha. S lng

ngi th cho th nghim ny l 9 ngi th. Trt t trnh by mu theo hnh vung

Latin William.

Xc nh hm lng b sung ph hp

Ta tin hnh kho st t l b sung ht bp gim vo bnh. Ta c nh nhit

nng trong l l 1500C vi thi gian nng c nh l 13 pht. i vi cng thc

Bng 3. 11 Lng ht bp gim thay i

Nguyn liu M0 M1 M2 M3 M4 Bt m 100 95 90 85 80 Bt ht bp gim 0 5 10 15 20

28

nguyn liu, ta s thay th thnh phn bt m bng bt ht bp gim vi t l ln

lt l 5%, 7.5%, 10%, 12.5%, ngha l:

Phng php nh gi

Kho st s nh hng ca nguyn liu ht bp gim ln bt nho:

- m bt nho: xc nh m bng phng php sy n khi lng khng

i.

- Cu trc bt nho: xc nh cu trc bng thit b o cu trc theo phng php

o TPA, cc ch tiu cn o l: cng, c kt, bm dnh v n hi.

Php o cu trc s dng l php o TPA:

Trigger: 4.5 g

Speeds: 0.5 mm/s

Distance: 4 mm

u o: TA10

Kho st s nh hng ca nguyn liu ht bp gim ln sn phm:

- m bnh: xc nh m bng phng php sy n khi lng khng i.

- Khi lng : Tin hnh cn khi lng ca cc mu bnh

- Kch thc: Tin hnh o chiu di, chiu rng, chiu dy v t l m rng ca

bnh

- Cu trc bnh: xc nh cu trc sn phm bng thit b o cu trc theo

phng php o nn p, ch tiu cn o l: cng.

Bng 3. 12 Lng ht bp gim thay i

Nguyn liu M0 M5 M6 M7 M8

Bt m 100 95 92.5 90 87.5

Bt ht bp gim 0 5 7.5 10 12.5

29

Php o cu trc s dng l php o nn p

Trigger: 4.5 g

Speeds: 0.5 mm/s

Distance: 3mm

u o: TA39 - 2 mm D, 20 mm L



th hiu so hng v mc a thch ca ngi th cho cc mu bnh. Mi ngi th

s nhn c 5 mu bnh khc nhau c m ha. S lng ngi th cho th

nghim ny l 30 ngi. Trt t trnh by mu theo hnh vung Latin William.

3.3.3.3 Kho st t l b

Mc ch

Sn phm bnh phi cha mt lng b ph hp cho ra sn phm bnh c

cu trc mm hn so vi bnh b sung ht bp gim. Ngoi ra, bnh phi c mi v

thm ngon hi ha kt hp vi hng v c trng ca nguyn liu ht bp gim b

sung.

Tin hnh

Tin hnh kho st t l b cho bnh, c nh nhit nng trong l l 1500C

vi thi gian nng c nh l 13 pht. i vi cng thc nguyn liu s c thay

i thnh phn b theo t l ln lt l 35%, 40%, 45%, 50%, ngha l:

Bng 3. 13 Lng b thay i

Mu B35 B40 B45 B50

B (%) 35 40 45 50

30

Phng php nh gi

Hm mc tiu ca th nghim l cng ca sn phm. Mu s c xc

nh cu trc sn phm bng thit b o cu trc theo phng php o nn p, ch tiu

cn o l: cng

Php o cu trc s dng l php o nn p:

Trigger: 4.5 g

Speeds: 0.5 mm/s

Distance: 3mm

u o: TA39 - 2 mm D, 20 mm L



th hiu so hng v mc a thch ca ngi th cho cc mu bnh.


ngi th cho th nghim ny l 9 ngi. Trt t trnh by mu theo hnh vung Latin

William.

3.3.3.4 Kim tra cht lng sn phm

Kim tra cc thng s ha l ca sn phm

Hm lng protein tng : Xc nh hm lng protein theo phng php Kjeldahl

Ch tiu vi sinh

Mu bnh thnh phm c gi kim vi sinh Trung tm Dch v Phn tch Th nghim

( 02 Nguyn Vn Th, akao, qun 1, TP H Ch Minh).

Tn cc ch tiu:

Tng s vi khun hiu kh (TPC)

Coliform

Escherichia coli

Tng s nm men

Tng s nm mc

31

Ch tiu cm quan

nh gi cm quan v mc yu thch cc ch tiu cm quan ca bnh b

sung ht bp gim so vi bnh chun. Tin hnh th nghim cm quan vi php th so

hng th hiu trn thang im 9 v mc a thch ca ngi th v thi, mu sc,

mi, v ca bnh ht bp gim vi bnh chun.


ngi th cho th nghim ny l 60 ngi. Trt t trnh by mu theo hnh vung Latin

William.

32

CHNG 4: KT QU V BN LUN

4.1 Kho st quy trnh loi v ht bp gim

V ht bp gim lm nh hng n cm quan ca bnh, khin bnh ti mu v

gy sn trong khi n; v th vic kho st cch x l nguyn liu c tin hnh sao

cho nhn c lng ni nh ht nhiu nht v ng thi cng loi c v ht ci

thin cm quan ca bnh v gi c dinh dng, cng nh hng v ca ht bp

gim.

th nghim ny, ht bp gim c tin hnh x l loi v theo quy trnh 3.2.3 bng

3 phng php tin x l khc nhau l: sy, rang, phi.

Ch thch a, b, c k t khc nhau trn cng mt hng biu th cho s khc

nhau c ngha (p

33

phng php rang, vi thi gian rang l 1 pht th cha lm kh ht

hon ton nn cho kt qu hiu sut thu hi thp (55.266%). Vi thi gian 2 pht, mu

R2 cho hiu sut thu hi cao (60.259%) nhng vic x l nhit cao s lm tn

tht nhng thnh phn chng oxy ha vn c trong ht nh cc hp cht polyphenol v

-tocopherol. Bn cnh , qu trnh rang gy mi kh chu, iu ny s lm nh

hng n cm quan ca bnh lc sau. Ngoi ra, qu trnh rang kh kim sot nn d

gy ra hin tng chy ht. Ti thi gian rang l 3 pht, hiu sut thu hi ni nh c

gi tr cao (63.469%) nhng mu R3 c mi chy kht.

phng php phi, vi khong thi gian l 5 gi v 6 gi, cc mu P2, P3

cho kt qu hiu sut thu hi cao (64.337 v 64.687%) so vi P1 c kt qu thp hn

(59.845%). Vi kt qu tng ng, nhng P3 tn nhiu thi gian hn so vi P2 (6

gi v 5 gi).

Hiu sut thu hi ca phng php sy cho kt qu ca cc khong thi gian

kho st (5 pht, 7 pht, 9 pht) l tng ng nhau, theo kt qu x l s liu bng

ANOVA cho thy vi mc ngha 5%, sai khc y l sai khc khng c ngha.

T bng kt qu trn, so snh cc mu S1, P2, tuy phng php sy c hiu sut thu

hi thp hn vi phng php phi nhng theo kt qu x l s liu bng ANOVA

Hnh 4. 1 Hiu sut thu hi theo cc phng php x l

S1

R1

P1 S2

R2

P2

S3

R3

P3

50

52

54

56

58

60

62

64

66

Sy Rang Phi

Hi

u s

u

t th

u h

i

(%)

Sy

Rang

Phi

34

cho thy vi mc ngha 5%, sai khc y l sai khc khng c ngha. Mt khc,

vic phi ht tn thi gian nhiu hn ng k so vi x l sy ht (5 gi v 5 pht).

Hai mu ht c x l bng phng php sy v phi l S1 v P2 c em i o

m. Kt qu cho thy hai mu c hm lng m tng ng nhau ( 9.90%). V th,

phng php sy c chn l cch x l nguyn liu ht bp gim ban u.

cch x l sy, ta nhn thy hiu sut tch v tng ng vi hm lng v

c trong ht (=37 37.905% [4.2.1]). Tuy l mt phn v c kch thc nh hn l

ry lt qua ry, ng thi thnh phn nhn c kch thc ln cng b gi li ry

nhng phn khng nhiu. V th, v vic chn cch tin x l nguyn liu, chn

cch x l l sy nhit 600C trong vng 5 pht. Kt qu cho ra nguyn liu s

dng lm bnh l bt ht bp gim loi mt phn v (ht bp gim loi v).

4.2 Kho st nguyn liu ht bp gim

4.2.1 Kho st kch thc v t l thnh phn ca ht bp gim

Nh cp trong phn phng php nghin cu, tin hnh o kch thc

ca ht: chiu di (a), chiu rng (b) v chiu dy (c) (mm). Bn cnh , trung bnh

s ht trn 1 gam ht cng c tnh.

Cu trc ca ht bp gim gm lp v ht, v la, ni nh v phi mm. Qua

kho st, ta c kt qu t l thnh phn v v ni nh ca ht.

Kt qu kho st kch thc nguyn liu cho thy: chiu di, chiu rng v

chiu dy ca ht bp gim c dao ng ln ( bin ng ln hn 5%)[bng 7.3].

iu ny cho thy kch thc ca ht l khng ng nht.

Qua quan st hnh thc ban u ca ht v kt qu o c, ht tng i nh

hn so vi ht trong bi bo co ca Omobubajo (2000), c kch thc l 5.58 x 5.21

Bng 4. 2 Kt qu kho st kch thc v thnh phn ca ht bp gim

a x b x c

(mm x mm x mm)

S ht /g (ht/g)

V (% w/w)

Ni nh (% w/w)

5.21 x 4.37 x 2.27 30 E1 37.905E2.251 50.57E2.402

35

x 2.81(mm). Do th nhng, iu kin thi tit v ging trng ban u khc nhau nn

c nhiu cy bp gim khc nhau, thnh ra cc ht mi vng l khc nhau v kch

thc. Trong mi gam ht th c trung bnh khong 30 ht.

T kt qu kho st thnh phn ht, cho thy t l ca v chim tng i ln

(37.905% w/w), cao hn so vi ht la m (14% w/w). V c cha thnh phn khng

dinh dng nh phytate, saponin, gossypol v c v hi nhn. Vic loi v gip loi

nhng thnh phn khng dinh dng nng cao gi tr dinh dng v gi tr cm

quan ca bnh. V th, bi nghin cu tin hnh th nghim kho st cch x l loi

v trong phn 3.3.1.

4.2.2 Xc nh cc thng s ha l ca nguyn liu

Kt qu kho st cc thng s ha l ca ht bp gim v ht bp gim loi v

c trnh by bng 4.3.

T kt qu kho st hm m ca ht cho thy nguyn liu ht bp gim c hm

m cao hn so vi kt qu ca Hainida (2008) (10.396 > 9.9).

Ch thch a, b k t khc nhau trn cng mt hng biu th cho s khc nhau

c ngha (p

36

Hm lng carbohyrate o c thp hn so vi hm lng carbohydrate ca

Hainida (2008) l 13% v ca El-Adawy (1994) l 36%. Do c nhiu loi ging trng

cy bp gim khc nhau, nn hm lng carbohyrate trong cc ht mi nc cng

khc nhau. T kt qu thc nghim, ht bp gim c loi v cho hm lng

carbohydrate cao hn so vi ht khng c loi v.

Hm lng ng kh o c thp hn so vi kt qu ng kh ca El-

Adawy (1994) l 3.5 %. Do c nhiu loi ging trng khc nhau nn hm lng ng

kh ca cc ht cng khc nhau. Bn cnh , ht bp gim c s dng cn l ht

non nn lng ng a cha chuyn ha ht thnh ng n, thnh ra hm lng

ng kh thp hn.

Kt qu cng cho thy, hm lng ng kh ca ht bp gim khng loi v

cao hn ht bp gim c loi v (1.359 > 0.803) do vic ra ht trong qu trnh x

l nguyn liu lm tn tht mt lng ng kh.

Hm lng protein tng ca ht bp gim loi v cao hn so vi ht bp gim

c v (24.963 > 22%). Kt qu tng t cho hm lng lipid tng ca ht bp gim

loi v cng cao hn so vi ht bp gim c v ( 26.065 > 28.68%). V protein v cht

bo hu ht nm trong ni nh ht, nn khi loi v th mu c gi tr protein v lipid

cao hn.

4.3 Kho st quy trnh ch bin bnh ht bp gim

4.3.1 La chn thi gian nng bnh chun

Da vo bng cng thc thnh phn cp trong phn 3.3.3.1 v quy trnh

ch bin bnh cookie chun d kin (hnh 3.3), tin hnh kho st thi gian nng cho

bnh khng b sung ht bp gim v c nh nhit nng trong l l 1500C vi thi

gian s pht ln lt l 9, 11, 13, 15 v 17. Bng 4.2 ch ra nhn xt chung v cc mu

bnh .

Vi thi gian l 9 pht th bnh cn sng v mm. Bnh c mu vng nht v

khng c mi thm l do cha thi gian xy ra phn ng maillard ca phn t

ng v cc amino acid.

37

pht th 11, bn ngoi bnh chn nhng bn trong vn cn mm v bnh n t. Bnh

c mi thm do c phn ng Maiilard din ra. Tuy c v hi ha nhng v hnh thi

mu sc th c mu vng khng ng u.

Khi bnh c nng trong 17 pht th bnh chy xn v c mu vng m.

Hn na, bnh cn c mi kht v v ng.

Bnh c nng t thi gian 13 n 15 pht c kt qu ging nhau l cho

bnh chn u, thm v c v va n, khng ngt gt. Nhng ta s chn nhit nng

l 13' v lc bnh c mu vng sng p. Kho st quy trnh ch bin bnh ht bp

gim.

4.3.2 Kho st t l b sung bt ht bp gim

4.3.2.1 Xc nh khong hm lng bt ht bp gim b sung

V y l mt nguyn liu kh mi nn khng xc nh c khong hm lng

b sung ph hp vi khu v ca ngi tiu dng cng nh cu trc ca sn phm. V

th, ta tin hnh kho st khong t l thch hp b sung ht bp gim vo bnh sau

a ra mt thng s chi tit hn. Nhit nng trong l l 1500C vi thi gian

nng c nh l 13 pht. i vi cng thc nguyn liu, ta s thay th thnh phn bt

m bng bt ht bp gim vi t l ln lt l 5%, 10%, 15%, 20%. Ta c bng nh

gi cm quan nh sau:

Bng 4. 4 Kt qu kho st kch thc v thnh phn ca ht bp gim

M9 M11 M13 M15 M17

Trng thi Bnh sng, mm

Bnh chn, n t, cn mm bn trong

Bnh chn u, gin, xp

Bnh chn u, gin, xp

Bnh hi chy xn

Mu Mu vng nht

Mu vng m nht khng u

Mu vng p u

Mu vng hi m

Mu vng rt m

Mi Khng c mi thm

C mi thm

Rt thm Rt thm C mi kht

V - V hi ha V hi ha V hi ha C v ng

38

Hi ng phn tch cm quan gm 9 thnh vin, thng qua php th cm quan l php

th so hng v cho im, ta c kt qu nh gi cm quan cho cc mu M0, M1, M2,

M3, M4.

Bng 4. 6 Kt qu nh gi cm quan cho cc bnh b sung ht bp gim

Hm lng b sung

Hnh thi Mu Mi V

M0 7.333E0.707a 7.333E1.118a 7.333E1.118a 7.333E1.225a

M1 6.889E1.616a 6.556E1.13a,b 6.556E1.13a,b 6.778E0.667a,b

M2 6.333E1.658a,b 6.222E1.481a,b 6.222E1.481a,b 6.667E1.225a,b

M3 6.111E 1.9a,b 5.556E 1.424b,c 5.556E 1.424b,c 6.222E 1.202a,b

M4 5.111E 1.9b 4.778E 1.716c 4.778E 1.716c 6E 1.658b

Bng 4. 5 nh gi cm quan cho cc mu bnh M0, M1, M2, M3, M4

M0 M1 M2 M3 M4

Trng thi Bnh chn u, gin, xp.

Bnh chn, gin xp.

Bnh chn, gin cng bn ngoi, bn trong cn mm.

Bnh chn gin cng bn ngoi, bn trong cn mm.

Bnh chn gin cng, kh.

Mu Mu vng p u.

Mu vng c m en ca v ht

Mu vng c m en ca v ht

Mu vng m c nhiu m en ca v ht

Mu vng m c nhiu m en ca v ht

Mi Rt thm Thm Thm Thm Thm, c mi l

V V hi ha V hi ha, cha nhn ra v l

C v l, ngt bi

C v l, ngt bi, c hu v hi nhn

C v l, ngt bi, c hu v nhn v hi chua

39

Ch thch a, b, c k t khc nhau trn cng mt hng biu th cho s khc nhau c

ngha (p

40

5%. Nhng khi cho vo nhiu hn vi t l 15% v 20% th kt qu nh gi li gim

xung.

V: Bnh c b sung ht bp gim c im thp hn so bnh khng b sung ht,

nhng im sai khc khng ngha theo kt qu phn tch ANOVA vi mc ngha

5%, ngha l nh hng khng nhiu nu bnh c b sung vi hm lng 5, 10%.

So vi cc ch tiu cm quan hnh thi, mu sc, mi th v c nh gi cao hn cc

ch tiu cn li, k c bnh c b sung ht bp gim.

Theo kt qu x l s liu bng ANOVA cho thy vi mc ngha 5%, t l ht

bp gim cho vo nh hng c ngha n cht lng cm quan ca sn phm, v

hnh thi, mu sc v mi v.

T kt qu trn v da vo im s kho st v yu thch ca ngi cm

quan, kt qu x l LSD cho thy t l 5% v 10% c s khc nhau khng ngha.

Bn cnh , ta kho st th nghim ny a ra khong hm lng b sung thch

hp. V th, ta chn t l kho st cho cc th nghim sau khong 5%10%

4.3.2.2 Xc nh hm lng bt ht bp gim b sung thch hp

Sau khi xc nh c khong hm lng b sung thch hp, ta tin hnh kho

st t l b sung ht bp gim vo bnh. i vi cng thc nguyn liu, ta s thay th

thnh phn bt m bng bt ht bp gim vi t l ln lt l 5%, 7.5%, 10% v 12.5%.

Ta s kho st s nh hng ca ht n m v cu trc bt nho, m v cu trc

bnh, sau l nh gi cm quan ca cc mu bnh M5, M6, M7, M8. Kt qu nh

gi cm quan, cng nh bng x l s liu ANOVA c trnh by phn mc lc.

Kt qu kho st s nh hng ca hm lng b sung ht bp gim n

m bt nho

m ca bt nho tng theo t l b sung ht bp gim. Khi b sung ht t l

5% v 7.5% th s khc bit khng ngha so vi bt nho khng b sung ht. Nhng

khi b sung vi mt hm lng cao hn l 10% v 12.5% v theo kt qu x l s liu

ANOVA mt chiu, th ta nhn thy hm lng b sung nh hng c ngha n vi

41

m bt nho (15.549

42

Ch thch a, b k t khc nhau trn cng mt hng biu th cho s khc nhau c

ngha (p

43

Theo kt qu x l s liu cu trc bng phng php ANOVA mc ngha

5%, t l ht bp gim b sung nh hng n cng, bm dnh, c kt v

n hi ca khi bt nho. Kt qu x l ANOVA c trnh by phn ph lc.

Khi thay th mt lng bt m bng bt ht bp gim th lm nh hng n

cu trc ca khi bt nho. Khi hm lng b sung tng t 0% n 12.5%, cng

tng t 117.8 ln 133.3 (g). Da theo kt qu, ta thy cc mu khng c s khc nhau

c ngha gia cng khi hm lng b sung l 5%,7.5%, 10% , s khc nhau ch

c ngha khi hm lng ht b sung l 12.5%. iu ny cho thy, cng ca khi

bt nho ph thuc vo thnh phn nguyn liu ban u. Tuy ht bp gim c b

sung vo di dng bt nhng mn ca bt ht bp gim vn cha bng bt m, hn

na, nh cp trc l vn cn st mt phn v trong bt ht bp gim; v v vy

c th l yu t nh hng n vic o cu trc ca bt nho.

c kt ca bt nho l c trng cho kh nng lin kt trong khi bt nho.

Da vo th, c kt c khuynh hng gim u khi hm lng b sung tng t

0% n 12.5%. Ta thy cc mu khng c s khc nhau c ngha gia c kt khi

Hnh 4. 4 Kt qu kho st cu trc bt nho theo hm lng b sung ht bp gim

117.8 108.467 116.9 123.133

133.3

-216.98

-40.947 -47.777 -46.937 -46.513

0.333 0.29 0.267 0.257 0.25

3.533

1.663 1.683 1.68 1.65

0

0.5

1

1.5

2

2.5

3

3.5

4

-250

-200

-150

-100

-50

0

50

100

150

200

M0 M5 M6 M7 M8

cng- bm dnh- c kt- n hi

cng (g) bm dnh(gs) c kt n hi (mm)

44

hm lng b sung l 5%,7.5% , s khc nhau ch c ngha khi hm lng ht b

sung l 10%, 12.5%. S gim ca c kt cho thy thnh phn ht bp gim lm

gim kh nng lin kt trong khi bt nho.

bm dnh biu th cng di chuyn u o ra khi b mt khi bt nho.

Da vo th, kt qu x l ANOVA mt chiu , ta thy bm dnh tng cao khi

b sung ht bp gim (-216.98

45

cha bng bt m, hn na, nh cp trc l vn cn st mt phn v trong bt

ht bp gim; v v vy c th l yu t nh hng n vic o cu trc ca bnh.

Ch thch a,b,c k t khc nhau trn cng mt hng biu th cho s khc nhau c

ngha (p

46

Kt qu kho st nh hng ca ht bp gim khi lng, kch thc ca

bnh

Theo kt qu x l s liu ANOVA mc ngha 5%, t l b sung ht bp

gim nh hng c ngha n khi lng ca sn phm. Khi lng ca bnh tng

theo hm lng b sung ht bp gim. S tng khi lng ny b nh hng bi nhiu

yu t. Do hm lng gluten trong bt m cao hn so vi bt bp gim nn kh nng

lin kt v trng n cng cao hn trong khi bt nho, dn n th tch ca khi bt

khng b sung ln hn so vi khi bt b sung ht. Bn cnh , bt c b sung ht

li c chiu hng cng hn v to khi cht li vi nhau. n khu to hnh, do

phng php to hnh l khun p ct, vi cng mt th tch khun th khi bt khng

b sung xp hn v cn mt lng bt t hn so vi khi bt c b sung ht. V th,

khi lng bnh ht bp gim ln hn so vi bnh chun, nhng lch khng ng

k (5.27 < 5.826).

Ch thch a,b,c,d k t khc nhau trn cng mt hng biu th cho s khc nhau c

ngha (p

47

Da vo th 4.7 , ta thy bnh khng c s thay i nhiu v ng knh,

nhng dy th c xu hng tng (4.7

48

Kt qu nh gi cm quan cc mu bnh M5, M6, M7, M8

Theo kt qu x l s liu cm quan bng phng php ANOVA mc ngha

5%, t l ht bp gim b sung nh hng n hnh thi, mu sc, mi v ca sn

phm. Bng im, kt qu x l ANOVA v LSD c trnh by phn ph lc.

Theo kt qu cho im cc ch tiu, ta nhn thy:

Hnh thi: t l ht bp gim cho vo cng nhiu th hnh thi ca sn phm

khng c nh gi cao nn s im gim. Nhng so snh vi 4 t l b sung th sai

khc y khng c ngha. Nhn chung l ngi n vn khng thch nhng m en

c mt trn bnh v khi n phi v th cm gic c sn.

Ch thch a,b,c k t khc nhau trn cng mt hng biu th cho s khc nhau c

ngha (p

49

Mi: t l 10%, kt qu nh gi cm quan tt hn so vi t l b sung 5% v

7.5%. Nhng khi cho vo nhiu hn vi t l 12.5% th kt qu nh gi li gim

xung. V vy, hm lng b sung nh hng c ngha n mi ca sn phm. Da

vo kt qu x l, ta nhn thy kt qu cho t l b sung 10% c s tng ng vi

im s v mi ca bnh chun.

V: Bnh c b sung ht bp gim c im thp hn so bnh khng b sung ht,

nhng im sai khc khng ngha theo kt qu phn tch ANOVA vi mc ngha

5%, ngha l nh hng khng nhiu nu bnh c b sung vi hm lng 10%. Khi

b sung hm lng ln ht khong 12.5% th ngi cm quan nhn thy c v nhn

ca bnh, v s ng ngi khng thch v l ny. Nhng khi b sung mt khong va

phi l 10%, th li c nhiu ngi nh gi cao hn so vi bnh khng b sung

hoc b sung t hn.

Theo kt qu x l s liu bng ANOVA cho thy vi mc ngha 5%, t l ht

bp gim cho vo nh hng c ngha n cht lng cm quan ca sn phm, v

hnh thi, mu sc v mi v. T kt qu trn v da vo im s kho st v yu

thch ca ngi cm quan, kt qu x l LSD cho thy, vi t l b sung 10% ta c

kt qu tng ng vi bnh chun v c tng s im ca 4 ch tiu cao hn so

Hnh 4. 8 Kt qu nh gi cm quan cho cc bnh b sung ht bp gim

7.9

5.967 5.733 5.733 5.633

8.033

6.367 6.2 6.333 5.967

7.733

6.533 6.9

7.1

6.267

7.9

6.233

6.867 7.133

5.733

0

1

2

3

4

5

6

7

8

9

M0 M5 M6 M7 M8

i

m HNH THI

MU

MI

V

50

vi cc t l b sung cn li. V th, ta chn t l kho st cho cc th nghim sau l

10%.

4.3.3 Kho st t l b

Kho st s nh hng ca b b sung n cng ca bnh, bng kt qu v

biu o cu trc c trnh by phn ph lc [7.4].

Theo kt qu x l s liu ANOVA mc ngha 5%, t l thnh phn b nh

hng c ngha n cng ca sn phm. Khi thay i hm lng b th lm

thay i cu trc ca bnh, cng gim t 944.867g xung 703.067g khi tng hm

lng b t 35% ln 50%. iu ny cho thy b nh hng n cu trc bt nho. S

gim ny c th c gii thch nh sau. Trong qu trnh trn bt, c s cnh tranh

phn ng vi b mt bt m gia pha nc v pha bo. Nc hoc ng tng tc vi

protein bt m to mng gluten. Khi cht bo bao ph bt m th s hnh thnh

mng gluten ngng, iu ny gip bnh sau khi nng s t cng hn, d tan chy

trong ming hn. Nu hm lng cht bo cao to s trn mt trong khi bt

nho th khi ta khng cn b sung thm nc t chc bt nho, mng gluten

yu c hnh thnh v ng thi s trng n tinh bt v s gelatin ha gim lm

cho cu trc mm bnh hn.

Ch thch a,b k t khc nhau trn cng mt hng biu th cho s khc nhau c

ngha (p

51

Kho st kt qu nh gi cm quan

Hi ng phn tch cm quan gm 9 thnh vin, thng qua php th cm quan

l php th th hiu so hng v cho im, ta c kt qu nh gi cm quan cho cc

bnh c t l b ln lt l 35%, 40%,45%, 50%.


ngha (p

52


5%, t l b nh hng n tnh cht cm quan ca sn phm. Bng im, kt qu x

l ANOVA v LSD c trnh by phn ph lc.

Theo kt qu cho im v yu thch sn phm, ta nhn thy t l b 40% v

45% c a thch hn so vi 35% v 50%, theo kt qu x l ANOVA th y l sai

khc c ngha. Mu 35% khng c nh gi cao l do bnh cng, khng thm

nhiu, ngc li bnh c t l b 50% th c v bo cao nhng vn khng c a

thch nhiu v do qu bo, v li theo ng ngi Vit Nam th khng thch nhng

mn qu bo. Song, bnh c t l 40% v 45% th li c a chung hn do v bo

va phi, bnh mm v thm mi b. Ta nhn thy, vic thay i hm lng b lm

ci thin mi v cho bnh, gip bnh to mi c trng ca bnh cookie truyn thng

bn cnh mi c trng ca nguyn liu ht bp gim b sung vo.

Hai kt qu v a thch cho hai t l 40% v 45% l tng ng nhau,

nhng xt v tnh kinh t ta s chn t l b thch hp l 40%.

Hnh 4. 10 a thch ca bnh theo t l b

6.667

7.778 7.556

6.667

1

2

3

4

5

6

7

8

9

35 40 45 50

i

m

T l b (%)

a thch (im)

53

4.3.4 Kim tra cht lng sn phm

4.3.4.1 Kt qu kho st hm lng protein tng ca sn phm

Kt qu kho st protein tng ca bnh chun v bnh ht bp gim


ngha (p

54

4.3.4.2 Ch tiu vi sinh

Kt qu kim tra vi sinh trn mu bnh ht bp gim

Bng trn cho thy sn phm bnh ht bp gim m bo cht lng v vi sinh vt.

Kt qu xt nghim c nh km phn ph lc.[7.5]

4.3.4.3 Ch tiu cm quan

Sn phm bnh ht bp gim l mt sn phm thc phm mi, cha c mt trn

th trng. V vy, yu t cm quan i vi sn phm l rt quan trng. Vic tin hnh

th nghim phn tch cm quan s nh gi vic ngi tiu dng c chp nhn sn

phm ny hay khng nu sn phm c a ra th trng. Thng qua php th th

hiu cho im bi 60 ngi cm quan, ta c kt qu nh gi cm quan cho hai mu

bnh chun v bnh b ht bp gim.


ngha (p

55


5%, bnh ht bp gim khng nh hng n cc tnh cht cm quan nh hnh thi,

mi v so vi bnh chun v c nh hng n mu sc so vi bnh chun. Bng im,

kt qu x l ANOVA v LSD c trnh by phn ph lc.

V c 4 ch tiu, hnh thi, mu sc, mi v th cc mc a thch vn thp

hn so vi bnh chun. Ta nhn thy:

Hnh thi: vn cn nhiu ngi khng thch nhng m en trm b mt bnh,

mt s khc li thch hnh thi ny v n khng n iu nh bnh chun. Tuy im

a thch ca bnh ht bp gim nh hn so vi bnh chun ( 6.773

56

Mi: bnh c ht bp gim c nh gi cao v mi v c s im v mc

a thch tng ng vi bnh chun (7.267 v 7.333), tuy c s chnh lch nhng

khng c ngha xt theo kt qu x l s liu ANOVA mc ngha 5%. Ta nhn

thy, thnh phn nguyn liu ht bp gim b sung to c mi c trng cho sn

phm, v c ngi tiu dng nh gi cao.

V: Bnh c b sung ht bp gim c im thp hn so bnh khng b sung ht

(7.233

57

Hnh 4. 13 Quy trnh ch bin bnh ht bp gim

Bt m, mui,

bt ni, vani

Trng g, ng,

b, shortening

Nho trn

Trn u

nh u

t = 3 pht

To hnh

Ph du

Nng

ngui

Bnh cookie

T = 150oC; t = 13 pht

t = 20 pht

Bt ht bp

gim loi v

58

CHNG 5: KT LUN V KIN NGH

5.1 Kt lun

Bi nghin cu ng dng nguyn liu ht bp gim b sung vo sn phm

bnh cookie, nhm nng cao gi tr s dng ht bp gim, l mt loi ht hin nay

c thi b nhng c gi tr dinh dng cao v cha thnh phn khng oxy ha cng

nh c kh nng lm gim cholesterol.

Nghin cu cho thy ht c thnh phn v kh cao l 37.905%. Ht c x l

bng phng php sy trc khi c nghin ry cho hiu sut loi v cao (37%).

Hm lng protein v lipid c trong ht bp gim loi v ln lt l 24.963 v

26.065 %, cao hn so vi ht bp gim khng loi v.

Bn cnh , nghin cu cng cho thy vic b sung ht bp gim vo bnh

cookie c nh hng n cu trc bt nho, cng nh cu trc ca sn phm. Sau khi

kho st, t l b sung thch hp l 10% nguyn liu ht bp gim. T l b 40% l ph

hp bnh c cu trc v gi tr cm quan tt hn.

Thnh phn dinh dng ca bnh cookie c b sung ht bp gim cao hn so vi

bnh khng b sung (protein tng 14.22%). Theo kt qu nh gi cm quan th sn

phm c th p ng th hiu ngi tiu dng.

Hnh 5. 1 Sn phm bnh cookie ht bp gim

59

5.2 Kin ngh

Do y l sn phm bnh c ch bin quy m gia nh nn c nhng thng

s khng iu chnh c nh kch thc bt ht bp gim. V vy, nu bnh c p

dng vo quy m sn xut th ngh s dng my nghin nhiu trc c kch thc

bt nh mn. Bn cnh , ht bp gim l mt ngun x di do m ch yu l t v

ht, nu xay c kch thc nh mn v c th tm cch x l loi cc thnh phn

khng dinh dng th c th lm sn phm bnh t ht bp gim khng cn loi v.

60

CHNG 6: TI LIU THAM KHO

[1] Robert, S.M. (1996) Roselle production manual (Hibiscus sabdariffa). [Online].

http://www.herbs.org/africa/hibiscus_production_manual.html

[2] El-Adawy, T.A & Khalil, A.H, "Characteristics of roselle seeds as a new source

of protein and lipid," Journal of Agricultural and Food Chemistry, no. 42, pp.

1896-1990, 1994.

[3] Ngoc Yen Tran-Thi, Maria Yuliana, Novy S. Kasim, Nhan Thi Hong Le, Der-Yen

Lee and Yi-Hsu Ju, "Subcritical water extraction of phenollic- rich product from

defatted roselle seed," Journal of Chemical Engineering of Japan, vol. 45, pp.

911-916, 2012.

[4] R.Mohamed, J. Fernandez, M. Pineda, and M. Aguilar, "Roselle (Hibiscus sabdariffa) Seed Oil Is a Rich Source of -Tocopherol," Journal of Food Science, vol. 72, pp. 207-211, 2007.

[5] K.I. Emmy Hainida, I. Amin, H. Normah, N. Mohd.-Esa & Zaiah A., "Effects of

defatted dried roselle (Hibiscus sabdarifaa L.) seed powder on lipid profiles of

hypercholesterolemia rats," Journal of the Science of Food and Agriculture, no.

88, pp. 1043-1050, 2008b.

[6] L Vn Vit Mn, Li Quc t, Nguyn Th Hin, Tn N Minh Nguyt, Trn Th Thu Tr, Cng ngh ch bin thc phm. H Ch Minh, 2011.

[7] Manley, Duncan, Technology of Biscuits, Crackers and Cookies. Woodhead

Publishing Ltd., 1998.

[8] Manley, Duncan, Biscuit, cracker and cookie recipes for the Food Industry.

Woodhead Publishing Ltd and CRC Press LLC, 2001.

[9] P. . Bnh, "Bp gim tr bo ph-x va ng mch v huyt p cao," Khoa hc ph thng, vol. 159, p. 13, 2009.

[10] Chen, H.h, Tsai, P.J, S.H, Su, Y.M, Chung, C.C & Huang, T.C, "Grey relational

analysis of fried roselle (Hibiscus sabdariffa L.)," Journal of Food Processing and

Preservation, no. 29, pp. 228-245, 2005.

[11] Maganha, E.G, Halmenschlager, R.d.C, Rosa, R.M, Henriques, J.A.P>, Ramos,

A.L.L.d.P & Saffe, J., "Pharmacological evidences for the extracts and secondary

metabolites from plants of the gems Hibiscus," Food Chemistry, no. 118, pp. 1-

10, 2010.

61

[12] Abu-Tarboush, H.M & Ahmed, S.A.B & AL Kahtani, H.A, "Some nutritional and

functional properties of karkade (Hibiscus sabdariffa) seed products," Cereal

Chemistry, no. 74, pp. 352-355, 1997.

[13] Morton, J. F., "Roselle," in Fruits of Warm Climates. Miami, Florida, 1987, pp.

281-286.

[14] Al-Wandawi, H., Al-Shaikhly, K. & Abdul-Rahman, M., "Roselle seeds: Anew

protein source," Journal of Agricultural and Food Chemistry, no. 32, pp. 510-512,

1984.

[15] Mungole, A. & Chaturvedi A., "Hibiscus sabdariffa L. a rich source of secondary

metabolites," Int J Pharm Sci Rev Res, no. 6, pp. 83-87, 2011.

[16] Yagoub, A.E.G.A, Mohamed, B.E, Ahmed, A.H.R & EL tinay, A.H, "Study on

furundu, a traditional Sudanese fermented roselle (Hibiscus sabdariffa L.) seed:

Effect on in vitr protein digestibility, chemical composition, and functional

properties of the total proteins.," Journal of Agricultural and Food Chemistry, no.

52, pp. 6143-6150, 2004.

[17] Parkouda, C., Diawara, B. & Ouoba, L I.I, "Technology and physico-chemical

characteristics of bikalga, alkaline fermented seeds of Hibiscus sabdariffa,"

African Journal of Biotechnology, no. 2008, pp. 916-922, 2008.

[18] K.I. Emmy Hainida, I. Amin, H. Normah, N. Mohd.-Esa, "Nutritional and amino

acid contents of differently treated Roselle (Hibiscus sabdariffa L.) seeds,"

Elsevier Ltd, no. 111, pp. 906-911, 2008a.

[19] Amin, I., Hainida, K.I.E & Halinatul, S.M.N, "Roselle (Hibiscus sabdariffa L.)

seeds -nutritional composition, protein wuality and health benefits," Global

Sciene Books, no. 2, pp. 1-16, 2008.

[20] Abu-Tarboush, H.M & Ahmed, S.A.B, "Studies on karkade (Hibiscus sabdariffa):

Protease inhibitors, phytate, in vitro protein digestibility and gossypol content,"

Food Chemistry, no. 56, pp. 15-19, 1996.

[21] Fagbenro, O.A, Akande, T.T, Fapohunda, O.O & Akkegbejo-Samsons, Y.,

"Comparative assessment of roselle (Hibiscus sabdariffa var. sabdariffa) seed

meal and kenaf (Hibiscus sabdariffa var altissima) seed meal as replacement for

soy meal in practical diets fro fingerlings of nile tiapia, Oreochromis niloticus,"

The 6th International Symposium of Tilapia in Aquacutule, Manila, The

Philipines, pp. 277-288, 2004.

[22] Anhwange, B.A, Ajibola, V.O & Okibe, F. G, "Nutritive value and anti-

nutritional factors in Hibiscus sabdariffa," Journal of Fisheries International, no.

62

1, pp. 73-76, 2006.

[23] Atta, M.B & Imaizumi, K, "Some characteristics of crude oil extracted from

roselle (Hibiscus sabdariffa L.) seeds cultivated in Egypt," Journal of Oleo

Science, no. 51, pp. 457-461, 2002.

[24] Rao, P.U., "Nutrient composition and biolody evaluation of mesta (Hibiscus

sabdariffa) seeds," Plant Foods for Human Nutrition, no. 49, pp. 27-34, 1996.

[25] Khalid S. Al-Numair, Saif Eldein B.Ahmed, "Biological evaluation of karkade

(Hibiscus sabdariffa) seed protein isolate," Journal of Food, Agriculture &

Environment, vol. 6, pp. 155-161, 2008.

[26] K.L. Nyam, C.P. Tan, O.M. Lai, K. Long , Y.B. Che Man, "Physicochemical

properties and bioactive compounds of selected seed oils," Food Science and

Technology, no. 42, p. 13961403, 2009.

[27] Sarojini, G, Rao, K.C, Tulpule, P.G & Lakshminaryana, G., "Nutritional

evaluation of refined, heated and hydrogenated Hibiscus sabdariffa seed oil,"

Journal of the American Oil Chemists' Society, vol. 62, no. 993-996, 1985.

[28] Isaac Bamgboye, O. I. Adejumo, "Mechanical properties of Roselle (Hibiscus

sabdariffa L) seeds," Agricultural Science Research Journals, vol. 1, pp. 178-183,

2011.

[29] Ahmed, W.K.A &Hudson, J.F.B, "The fatty acid composition of Hibiscus

sabdariffa seed oil," Journal of the Science of Food and Agriculture, no. 33, pp.

1305-1309, 1982.

[30] Ahmad, M.U., Husain, S.K, & Osman, S.M, "Hibiscus sabdariffa seed oil: a re-

investigation," Journal of the Science of Food and Agriculture, vol. 30, no. 424-

428, 1979.

[31] Matthaus, B., Vosmann, K, Pham, L.Q, "FA and tocopherol composition of

Vietnamese oilseeds," Journal of the American Oil Chemists Societ, vol. 80, no.

1013-1020, 2003.

[32] Rukmini, C., Vijayaraghavan, M & Tulpule, P.G, "Nutritional and toxicological

evaluation of Hibiscus sabdariffa oil and Cleome viscosa oil," Journal of the

American Oil Chemists' Society, no. 59, pp. 415-419, 1982.

[33] Norhaizan Mohd-Esa, Fong Shin Hern, Amin Ismail, Chew Lye Yee,

"Antioxidant activity in different parts of roselle (Hibiscus sabdariffa L.) extracts

and potential exploitation of the seeds," Food Chemistry, no. 122, p. 10551060, 2010.

63

[34] Amin, I. & Chew, L.Y., "Antioxidative effects of extracts of cocoa shell, roselle

seeds and a combination of both extracts on the susceptibility of cooked to lipid

oxidation," Joural of Food Technology, no. 4, pp. 10-15, 2006.

[35] Kosakowska, O., Weglarz, Z., Sidky, M., Przybyl, J, "Sterols and fatty acids in

the seeds of Roselle (Hibiscus sabdariffa L.) cultivated in Egypt," Kerla Polonica,

vol. 51, pp. 19-23, 2005.

64

CHNG 7: PH LC

7.1 Cc phng php phn tch ha hc

7.1.1 o kch thc ht

Ht c o kch thc : Chiu di (a), chiu rng (b) v chiu dy (c) theo hnh

Hnh 7. 1 o kch thc ht

7.1.2 Xc nh thnh phn ht

Ngm ht vi nc trong vng 30', sau bc v v tch ring hai thnh phn v

v nhn. Ta sy v v nhn n khi lng khng i nhit 1050C.

Tnh ton thnh phn da trn m ht, khi lng lc u v sau khi sy n khi

lng khng i ca v v ni nh.

7.1.3 Xc nh hm lng m

Nguyn tc: Dng nhit lm bay hi lng nc t do trong mu.

Tin hnh

Sy cc n khi lng khng i: Cc c ra sch, p kh, sy nhit

100-1050C trong khong 1 gi, ly ra lm ngui trong bnh ht m cn sy tip

nhit trn lm ngui trong bnh ht m cn n khi no gia 2 ln cn lin

tip, sai khc khng qu 5.10-4g.

Cn chnh xc 1g mu ( c chun b) trong cc s ( c sy kh n

khi lng khng i). Chuyn cc vo t sy, sy 1050C lin tc trong 3 gi.

Ly mu ra ngui trong bnh ht m cn trn cn phn tch sy tip tc

nhit 1001050C n khi lng khng i nh trn.

65

Tnh kt qu

m (hm lng nc) ca nguyn liu c tnh theo cng thc sau:

XH2O =

100(%)

Trong :

XH2O : m (hm lng nc) ca bn nguyn liu (%).

G1 : Khi lng cc sy v mu trc khi sy (g).

G2 : Khi lng cc sy v mu sau khi sy (g).

G : Khi lng cc sy (g).

7.1.4 Xc nh hm lng ng kh

nh lng ng kh bng phng php quan ph so mu.

Nguyn tc

Phng php ny da trn c s phn ng to mu gia ng kh vi thuc

th acid dinitrosalicylic (DNS). Cng mu ca hn hp phn ng t l thun vi

nng ng kh trong mt phm vi nht nh. So mu tin hnh bc sng

540nm. Da theo th ng chun ca glucose tinh khit vi thuc th DNS s tnh

c hm lng ng kh ca mu nghin cu.

Tin hnh:

Cn chnh xc 3g mu, em mu trch ly bng nc nng 800C v trch nhiu

ln. Thm HCl 0.1N vo dch trch n pH =4.5. Sau em lc, dch lc c nh 3

git methyl red v cho t t tng git NaOH 5% n khi xut hin mu hng nht. Sau

em hn hp i lc qua giy lc ta thu c dung dch trong. Tip theo a dung

dch ny vo bnh nh mc v nh mc ln 100ml. Ta c dung dch mu.

Dng ng chun: chun b dy ng nghim theo bng sau (ml):

STT C 1 2 3 4 5 Mu

Dd chun (mg) 0.2 0.4 0.6 0.8 1

Dd mu (ml) 1

Nc ct (ml) 3 2.8 2.6 2.4 2.2 2 2

Thuc th DNS (ml) 1 1 1 1 1 1 1

66

cc ng nghim vo ni cch thy dang si ng 5 pht.

Ly ra, lm lnh n nhit phng ri em i o mt quang bc sng

540nm vi mu i chng (C) l nc ct. Ghi kt qu.

Hnh 7. 2 ng chun o hm lng ng kh

Tnh ton

Trong :

m- lng mu em th ngh nghim (g)

V- th tch nh mc dung dch th nghim (100ml)

X-nng ng kh trong dung dch mu tnh theo glucose

f- h s pha long mu

7.1.5 Hm lng ng tng

Nguyn tc

Phng php s dng phenol - acid sulfuric m c dng xc nh nng

ng trong mt dung dch. Acid sulfuric m c s ct cc polysaccharide thnh

cc monosaccharide, cc monosaccharide ny s b kh thnh cc cht trung gian,

y = 1.1715x - 0.1201

R = 0.9991

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 0.2 0.4 0.6 0.8 1 1.2

h

p t

hu

Nng ng kh, mg/ml

67

v di s hin din ca phenol, nhng cht trung gian ny s to thnh nhng sn

phm mu vng v hp th bc sng 490nm. Cng mu t l thun vi lng

ng trong mu.

Tin hnh

Dng ng chun: Ht t 10 70 L dung dch ng chun vi bc nhy

10 L vo 7 ng nghim khc nhau ht thm 1 mL dung dch phenol 5% lc u

thm 5 mL acid sulfuric 96% lc u ngui v nhit phng o

hp thu bc sng 490nm.

o mu:

Cn chnh xc 3g mu, em mu trch ly bng nc nng 800C v trch nhiu

ln. Thm HCl 0.1N vo dch trch n pH =4.5. Sau em lc, ht 1 mL dch lc

pha long vo ng nghim thm 1 mL dung dch phenol 5% lc u thm

5 mL acid sulfuric 96% lc u ngui v nhit phng o hp thu

bc sng 490 nm.

Tnh ton

Dng ng chun hp thu khi lng ng saccharose. Khi lng

ng tng (x) tng ng vi saccharose ca dch chit c ni suy t hp thu

ca mu phn tch tng ng.

Nng ng tng c tnh theo cng thc

Trong :

m- lng mu em th ngh nghim (g)

V- th tch nh mc dung dch th nghim (100ml)

x-nng ng tng trong dung dch mu tnh theo saccharose

68

f- h s pha long mu

Hnh 7. 3 ng chun o hm lng ng tng

7.1.6 Phng php xc nh lng nit tng

Nguyn tc

Khi t nng vt phm em phn tch vi H2SO4 m c, cc hp cht hu c b oxy

ha. Carbon v hydro to thnh CO2 v H2O. Cn nit sau khi c gii phng ra di

dng NH3 kt hp vi H2SO4 to thnh (NH4)2SO4 tan trong dung dch. ui NH3 khi

dung dch bng NaOH ng thi ct v thu NH3 bng mt lng d H2SO4 0.1N. nh

phn lng H2SO4 0.1N cn li bng dung dch NaOH 0.1N chun, qua tnh c

lng nit co trng mu nguyn liu th nghim.

Tin hnh

- V c ha mu: cho 1g mu xc nh vo ng Kieldal, thm vo 10ml dung dch

H2SO4 m c v xc tc HClO4. a ng vo my v c ha mu.

Sau khi v c mu xong, ta nh mc dung dch ny ln 100ml.

y = 0.0106x + 0.0035

R = 0.9991

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 10 20 30 40 50 60 70 80

h

p

th

u

Nng ng tng, mcg/ml

69

- nh m bng my Kjeldahl: Ht 10 ml mu nh mc vo ng, ri a vo my

Kjeldahl nh m. ng thi, a vo mt erlen c cha thuc th H2SO4 0.1N

thu mu.

Mu ny sau em i chun bng NaOH 0,1N n khi xut hin mu hng nht.

Tnh ton

Hm lng nit tng s (Nt) c trong mu:

Trong :

N- hm lng nit tnh bng phn trm khi lng

a- s mL dung dch chun H2SO4 0.1N em hp th NH3

b- s mL NaOH 0.1N tiu tn cho chun

m- khi lng mu em v c ha, g

V- tng th tch nh mc dung dch v c ha (100mL)

v- th tch dung

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