Thử nghiệm lên men rượu vang bưởi bằng nấm men saccharomyces cerevisiae

T R U ONG DAI HOC AN GIANG
KHOA NONG NGHIEP & TAI NGUYEN T H I E N NHIEN
BO MON CONG NGHE T H I / C PHAM

NGUYEN THI MY ANH
DH10TP

THtT N G H I E M L E N M E N R U O U V A N G BU'dl B A N G N A M
M E N SACCHAROMYCES

CEREVISIAE

CO DINH T R E N V O B l f d l

BAO CAO KHOA LUAN T O T NGHIEP DAI HOC

Nganh hpc: Cong Nghe Thirc Phhm
Can bo hirdng dan: ThS. Ho Thi Ngan Ha

KHOA HOC 2009 - 2013

TRUQNG DAI HQC
AN GIANG

THU VIEN

An Giang, Thang 5. 2013


TRU'OfNG DAI HOC AN GIANG
KHOA NONG NGHIEP & TAI NGUYEN T H I E N NHIEN

BO MON CONG NGHE T H l / C PHAM

NGUYEN THI M Y ANH
DH10TP

THU* N G H I E M L E N M E N R U 0 U V A N G BU'dl BANG N A M
M E N SACCHAROMYCES

CEREVISIAE

C O D I N H T R E N V O BU'dl

Do sinh vien: NGUYEN THI MY ANH thirc hien va de nap
Kfnh trinh hoi dong cham luan van tot nghiep xet duyet

Long xuyen, ngay 03 thang 5 nam 2013
GIAO V I E N HUONG DAN

ThS. Ho Thj Ngan Ha


Lbi cam on
Trong suot qua trinh thirc hien de tai nhb su tan tinh giup da cua quy thay co va cac ban,
de tai tot nghiep da hoan thanh. Co dugc ket qua nay, toi xin gui lai cam on den:
Co Ho Thi Ngan Ha, ngubi da true tiep huang dan va giup da toi trong suot thai gian
thirc hien de tai.
Cac thay co b bo mon Cong Nghe Thuc Pham, khoa Nong Nghiep & Tai Nguyen Thien
Nhien, Trubng Dai Hoc An Giang da cho toi nhung kien thuc quy bau trong thoi gian
hoc tap tai trubng.
Can bo thu vien, can bo phbng thi nghiem bo mon Cong Nghe Thuc Pham, khoa Nong

Nghiep & Tai Nguyen Thien Nhien, Trubng Dai Hoc An Giang, da tao dieu kien cho toi
hoan thanh tot de tai.
Cubi cung toi xin gui lbi cam on den cac ban sinh vien lbp Cong Nghe Thuc Pham, khoa
10, khoa Nong Nghiep & Tai Nguyen Thien Nhien. Trubng Dai Hgc An Giang da dpng
vien va giup do toi trong thoi gian thuc hien de tai tai phbng thi nghiem.
Toi xin chan thanh cam on!

Sinh vien thirc hien
Nguyen Thj My Anh


Muc luc
Noi dung

Trang

Lai cam an

i

Muc luc

ii

Danh sach bang

v

Danh sach hinh

viii

Tom lirgc

x

Chirong 1 Giai thieu

1

1.1. Dat van de

1

1.2. Muc tieu nghien cuu

1

1.3. Npi dung nghien cuu

1

Chirang 2 Lirac khao tai lieu

2

2.1. Giai thieu ve nguyen lieu
2.1.1. Buai

2

2

2.1.1.1. Giai thieu

2

2.1.1.2. Thanh phan hoa hoc

3

2.1.1.3. Cong dung cua qua bubi

5

2.1.2. Nam men Saccharomyces cerevisiae

6

2.1.2.1. Hinh dang te bao nam men

6

2.1.2.2. Kich thuoc te bao nam men

6

2.1.2.3. Cau tao te bao nam men

6

2.1.2.4. Cac hinh thuc ho hap cua nam men

7

2.1.2.5. Thanh phan hoa hoc va dinh dubng ciia nam men

7

2.1.2.6. Co che van chuyen cac chat dinh duong vao trong te bao nam men

8

2.1.2.7. Sinh duong cua te bao nam men

8

2.1.2.8. Cac hinh thuc sinh san cua nam men

9

2.2 Co so khoa hoc va cac yeu to anh hubng den qua trinh len men

10

2.2.1 Co so khoa hoc cua qua trinh len men ruou

10

2.2.2 Cac yeu to anh hudng den len men ruou vang

10


2.3. Ky thuat co dinh te bao

11

2.3.1. Phirong phap co djnh te bao nam men tren be mat chat mang

11

2.3.2. Phirong phap nhdt te bao vao he gel

11

2.4. Cac phu gia (hoa chat) sir dung trong nghien cuu

11

2.4.1. Duong saccharose

13

2.4.2. Acid citric

13

2.3.3. Natri bisulfit (NaHS0 3 )

14

2.5. Cac qua trinh, nguyen ly che bien va bao quan co lien quan

14

2.5.1. Qua trinh chan

14

2.5.2. Qua trinh ep

14

2.5.3. Qua trinh phoi che

15

2.6. Cac nghien cuu trudc day
Chirong 3 Phirong tien va phirong phap nghien ciru
3.1. Phuong tien nghien cuu

16
16
16

3.1.1. Dia diem va thoi gian nghien cuu

16

3.1.2. Nguyen lieu

16

3.1.4. Dung cu va thiet bi

16

3.2. Phuong phap nghien cuu

16

3.2.1. Phuong phap thu thap va xu ly so lieu

16

3.2.2. Quy trinh co dinh nam men Saccharomyces cerevisiae tren vo budi

17

3.2.3. Quy trinh len men ruou budi bang nam men co dinh

19

3.3. Noi dung nghien cuu

20

3.3.1. Thi nghiem 1: Khao sat anh hudng cua dp Brix, pH va ty le nam men
den qua trinh nhan giong nam men
20

3.3.2. Thi nghiem 2: Khao sat anh hudng cua mat do te bao nam men ban dau,
ty le vd budi va chieu day vd budi dung co dinh
21
3.3.3. Thi nghiem 3: Khao sat anh hudng cua dp Brix, pH va ty le men giong
den qua trinh len men chinh ruou vang budi bang nam men co dinh
22
3.4. Phuong phap phan tich
Chirong 4 Ket qua va thao luan

24
25


4.1. Thanh phan cua nguyen lieu

25

4.2. Anh hudng cua do Brix, pH va ty le nam men Saccharomyces cerevisiae thuan
den qua trinh nhan giong trong dich budi
26
4.3. Ket qua khao sat anh hudng cua do mat do te bao ban dau, lugng vd budi va
chilu day vd budi den qua trinh co dinh nam men
31
4.4. Anh hudng cua do Brix va ty le vd budi da co djnh nam men den qua trinh len
men chinh ruou vang budi
34
4.5. Thanh phan san pham

39

Chirong 5 Ket luan va kien nghi

40

5.1. Ket luan

40

5.2. Kien nghi

42

Tai lieu tham khao

43

Phu chuong

pc_l

Phu chuong A

pc_l

Phu chuong B

pc_2

Phu chuong C

pc_7

Phu chuong D

pc_9

IV


Danh sach bang

Bang 1: Thanh phan hoa hoc cua mui budi va vd budi

4

Bang 2: Thanh phan dinh duong cua nam men ( % )

8

Bang 3: Cac phuong phap phan tfch

25

Bang 4: Thanh phan nguyen lieu dich budi

26

Bang 5: Su thay doi mat do te bao nam men trong djch budi theo thoi gian nhan giong .27
Bang 6: Gia trj mat do te bao nam men cue dai d cac gia trj do Brix, pH va ty le nam men
khac nhau

30
Bang 7: Su thay doi mat do te bao nam men co djnh tren vd budi theo thoi gian

31

Bang 8: Gia trj mat do te bao nam men co djnh tren vd budi sau 3 gio d cac gia trj mat do
te bao nam men ban dau, lugng vd budi va chieu day vd budi khac nhau
34
Bang 9: Su thay doi do Brix theo thoi gian len men

35

Bang 10: Do con san pham d cac gia trj do Brix va mat do nam men co djnh khac nhau 37
Bang 11: Anh hudng cua do Brix ban dau den gia trj cam quan san pham

38

Bang 12: Anh hudng cua mat do nam men co djnh den gia trj cam quan san pham

38

Bang 13: Anh hudng cua do Brix ban dau va mat do nam men co djnh den gia trj cam
quan san pham
39
BlUng 14: Thanh ph0n cdla sEn ph0m

40

Bang 15: Bang tra ty le duong nghjch dao

pc_4

Bang 16:Bang diem mo ta chi tieu do trong, mau sac va mui vj cua rugu

pc_7

Bang 17: Bang diem mo ta chi tieu muc do ua thich cua rugu vang budi

pc_8

Bang 18: Bang ANOVA mat do te bao theo do Brix, pH va ty le nam mem

pc_9

Bang 19: Su thay doi mat do te bao nam men theo thoi gian

pc_9

Bang 20: Sir tuong tac giua do brix, pH va ty le nam men bo sung den mat do te bao
nhan giong
pc_9
Bang21: Sir thay doi mat do te bao nam men theo do Brix
Bang22: Sir thay doi mat do te bao theo pH

pc_9
pc_10

Bang23: Sir thay doi mat do te bao theo ty le nam men

V

pc_10


Bang 24: Bang ANOVA the hien sir thay doi mat do te bao co dinh theo mat do te bao
ban dau, lugng vo budi va chieu day vd budi
pc_9
Bang 25: Su thay doi mat do te bao co dinh theo mat do te bao ban dau, lugng vd budi va
chieu day vd budi
pc_10
Bang 26:Su tuong tac giua mat do te bao nam men ban dau, ty le vd budi va chieu day vd
budi den mat do te bao nam men co dinh
pc_ 0
Bang 27: Sir thay doi mat do te bao co dinh theo mat do te bao ban dau

pc_

Bang 28: Sir thay doi mat do te bao co dinh theo lugng vd budi bo sung

pc_

Bang 29: Su thay doi mat do te bao co dinh theo chieu day vd budi

pc_

Bang 30: Bang ANOVA the hien sir thay doi do con giua cac mau

pc_

Bang 31: Sir thay doi do con theo ham lugng duong va ty le nam men

pc_

Bang 32:Su tuong tac giua do Brix va ty le nam men bo sung den do con sinh ra ciia san
pham
pc_
Bang 33: Bang ANOVA the hien diem cam quan ve mau sac theo do Brix

pc_

Bang 34: Sir thay doi diem cam quan san pham ve mau sac theo do Brix

pc_

Bang 35: Bang ANOVA the hien diem cam quan ve mau sac theo ty le nam men

pc_

Bang 36: Sir thay doi diem cam quan san pham ve mau sac theo ty le nam men

pc_

Bang 37: Bang ANOVA the hien diem cam quan ve mui vi theo do Brix

pc_

Bang 38: Sir thay doi diem cam quan san pham ve mui vi theo do Brix

pc_

Bang 39: Bang ANOVA the hien diem cam quan ve mui vi theo ty le nam men

pc_

Bang 40: Su thay doi diem cam quan san pham ve mui vi theo ty le nam men

pc_

Bang 41: Sir thay doi diem cam quan san pham ve mui vi theo ty le nam men

pc_

Bang 42: Sir thay doi diem cam quan san pham ve do trong theo do Brix

pc_

Bang 43: Bang ANOVA the hien diem cam quan ve do trong theo ty le nam men

pc_

Bang 44: Su thay doi diem cam quan san pham ve do trong theo ty le nam men

pc_

Bang 45: Bang ANOVA the hien diem cam quan ve muc do ua thich theo do Brix

pc_

Bang 46: Su thay doi diem cam quan san pham ve muc do ua thich theo do Brix

pc_

Bang 47: Bang ANOVA the hien diem cam quan ve muc do ua thich theo cac ty le nam
men
pc_
Bang 48: Su thay doi diem cam quan ve mire do ua thich theo ty le nam men
vi

pc_


Bang 49: Bang ANOVA the hien diem cam quan ve mau sac theo do Brix va ty le nam
men
pc_15
Bang 50: Sir thay doi diem cam quan ve mau sac theo do Brix va ty le nam men

pc_15

Bang 51: Bang ANOVA the hien diem cam quan ve mui vi theo do Brix va ty le nam
men
pc_15
Bang 52: Su thay doi diem cam quan ve mui vj theo do Brix va ty le nam men

pc_15

Bang 53: Bang ANOVA the hien diem cam quan ve do trong theo do Brix va ty le nam
men
pc_16
Bang 54: Su thay doi diem cam quan ve do trong theo do Brix va ty le nam men

pc_16

Bang 55: Bang ANOVA the hien diem cam quan ve mire do ua thich theo do Brix va ty
le nam men
pc_17
Bang 56: Sir thay doi diem cam quan ve mire do ua thich theo dp Brix va ty le nam men
bo sung
pc_17

vii


Danh sach hinh
Hinh 1: Buai Nam Roi

3

Hinh 2: Cau tao mot don vi ciia chuoi pectin

4

Hinh 3: Nam men Saccharomyces cerevisiae

7

Hinh 4: Chu ky sinh san cua nam men Saccharomyces

10

Hinh 5: Cau tao hoa hoc cua acid citric

14

Hinh 6: So do quy trinh tong quat co djnh nam men tren vo budi

18

Hinh 7: So dd quy trinh len men ruou vang budi bang nam men co djnh

20

Hinh 8: So do bo tri thi nghiem 1

21

Hinh9: So dd bo tri thi nghiem 2

23

Hinh 10: So dd bo tri thi nghiem 3

24

Hinh 11: Nguyen lieu Budi Nam Roi

26

Hinh 12: Su tang trudng ciia te bao nam men trong djch budi theo thoi gian nhan giong d
cac gia trj do Brix khac nhau
28

Hinh 13: Su tang trudng cua te bao nam men trong djch budi theo thoi gian nhan giong d
cac gia trj pH khac nhau
28
Hinh 14: Su tang trudng ciia te bao nam men trong djch budi theo thoi gian nhan giong d
cac ty le nam men khac nhau
29
Hinh 15: Su thay doi mat do te bao nam men co djnh tren vd budi theo thoi gian cd djnh
d cac gia trj mat do te bao ban dau khac nhau
32
Hinh 16: Su thay doi mat do te bao nam men co djnh tren vd budi theo hoi gian cd djnh d
cac ty le vd budi khac nhau
33
Hinh 17: Su thay doi mat do te bao nam men co djnh tren vd budi theo thoi gian cd djnh
d cac chieu day vo budi khac nhau
33
Hinh 18: Su thay doi do Brix theo thoi gian len men khi dieu chinh do Brix ban dau khac
nhau
36
Hinh 19: Su thay doi do Brix theo thoi gian len men khi dieu chinh mat do nam men cd
djnh khac nhau
36
Hinh 20: San pham ruou vang budi

20

Hinh 21: Quy trinh cd djnh nam men saccharomyces cerevisiae tren vd budi de nghj

42

Hinh 22: Quy trinh san xuat ruou vang budi de nghj

43

viii


Hinh 23: Dich birdi dang len
Hinh24:Rirgu vang budi


Tom liroc
Co dinh nam men saccharomyces cerevisiae tren vo budi la phuong phap nham giu cac
te bao nam men tren vd budi. Ben canh dd, len men ruou vang budi bang nam men
Saccharomyces cerevisiae co djnh tren vd budi nham tang hieu suat thu hoi va tinh sach
san pham. Ruou vang budi la mot trong nhung loai ruou cd gia trj dinh duong cao do
dupe len men tir djch ep budi bdi nam men Saccharomyces cerevisiae. Ruou vang budi
thu dupe khong qua chung cat, co huang thorn budi tir nhien, dp con nhe va la loai ruou
giau chat dinh duong.
De tim ra cac thong so thich hop cho qua trinh cd djnh nam men Saccharomyces
cerevisiae tren vd budi va len men ruou vang budi bang nam men cd djnh nham nang cao
hieu suat thu hoi va tao san pham cd gia trj dinh duong cao, gia trj cam quan tot, chiing
toi tien hanh khao sat cac thi nghiem sau:
- Khao sat anh hudng ciia dp Brix, pH va ty le nam men Saccharomyces cerevisiae thuan
trong qua trinh nhan giong den kha nang sinh trudng va phat trien ciia nam men.
- Khao sat anh hudng ciia mat dp te bao nam men ban dau, lupng vd budi va chieu day
vd budi den hieu suat cd djnh nam men tren vd budi.
- Khao sat anh hudng ciia dp Brix va mat dp nam men cd djnh den qua trinh len men
chinh ruou vang budi.
Sau thoi gian nghien cuu va tien hanh thi nghiem, ket qua dat dupe nhu sau:
- Vdi ham lupng ban dau ciia djch len men la 22°Bx, ty le nam men bo sung la 0,3%, ket

hop vdi pH bang 4 thi qua trinh nhan giong nam men Saccharomyces cerevisiae dai mat
dp cao nhat.
- Djch budi sau khi nhan giong dupe pha loang vdi mat dp te bao dat 40.107tb/ml, lupng
vd budi bo sung la 15% so vdi djch nude budi, chieu day la 0,75cm thi mat dp te bao
nam men cd djnh tren vd budi la cao nhat.
- Djch budi len men vdi ham lupng chat kho hoa tan ban dau la 22°Bx va mat dp te bao
cd djnh la 5.106 tb/ml thi san pham len men tot nhat, dp con sinh ra cao, san pham dat gia
trj cam quan cao.

X


Chirong 1
G i o i thi^u
1.1. Dat van de
•

Rugu vang la mot loai thuc uong len men truyen thong co nguon goc tu phuong Tay.
Hien nay, cac san pham ruou vang da trd nen pho bien tren toan the gioi vi nhung tac
dong co loi den sue khoe ciia con ngudi. Khac vdi ruou trang va cac loai ruou pha che,
ruou vang la loai thuc uong len men tiyc tiep tu nude qua. Khi qua trinh len men ket
thuc, ngudi ta khong chung cat ma de l&ng trong tu nhien, gan loc va hoan thanh san
pham. Chinh vi le dd, tren the gidi co rat nhieu cong trinh nghien cuu nham nang cao
hieu qua kinh te va chat lugng rugu vang va mot trong nhQng phuong phap cd trien
vong nhat hien nay la su dung nam men co dinh. Rugu vang von cd nguon goc tir qua
nho, nen co ten goi la "Vin" hoac "Wine", ngay nay ngudi ta md rong y nghla ciia
rugu vang la ruou khong chung cat tir cac loai nude qua. Budi la mot loai trai cay
ngon, rat dugc ua chuong va trong pho bien d nude ta. Thit budi cd chua nhieu nude
va mot lugng duong tuong doi ldn, dac bigt la ham lugng vitamin C va chat khoang
kha cao, nen cd the dung de san xuat loai ruou vang vira ngon lai vira dem lai nhieu lpi

ich cho sue khoe.
Nam men Saccharomyces cerevisiae la chung nam men dugc sir dqng pho bien trong
qua trinh len men rugu vang.Trong qua trinh san xuat ruou vang, nam men thudng bi
loai bd sau khi ket thuc qua trinh len men. Nam men sau khi lo$i bd khong the tdi sir
dung gay lang phi. Hon the nua, nam men phan tan trong dung dich, nen khong the
loc bd het triet de, trong qua trinh bao quan, phan nam men con sot lai se l&ng xuong
day gay anh hudng den trang thai ciia san pham.
Do do, viec nghien cuu de tai "Thu nghiem len men rugu vang budi bang nam men
Saccharomyces cerevisiae co dinh tren vd budi" se giup giam chi phi cho qua trinh len
men do nam men cd the tai sir dung nhieu lan, va tao dugc sir on dinh ve hoat tinh ciia
nam men cung nhu nang cao chat lugng san pham ruou vang. Ben canh do, khi cd
dinh nam men tren vd budi con tan dung dugc phe lieu vd budi gdp phan nang cao
hieu qua kinh te. Muc tieu ciia phuong phap nay la giu cac te bao nam men tren mot
chat mang, nham t&ng hieu suat thu hoi va giam chi phi tinh sach. Khi sir dung nam
men cd dinh de len men ruou vang se han che su phan tan ciia nam men trong dung
dich giiip qua trinh lpc dugc tuong doi tri?t de nen it lam anh hudng den gia tri cam
quan ciia san pham khi bao quan.
1.2. Muc tieu nghien cu u
- Tim ra quy trinh co dinh nam men Saccharomyces cerevisiae tren vd budi.
- U'ng dung ndm men cd dinh tren vd budi vao qua trinh len men chinh rugu vang
budi.
1.3. Noi dung nghien cuu
- Khao sat anh hudng ciia do Brix, pH va ty le nam men Saccharomyces cerevisiae
thuan trong qua trinh nhan giong den kha nang sinh trudng va phat trien ciia nam men.
- Khao sat anh hudng ciia mat do te bao nam men ban dau, lugng vd budi va chieu day
vd budi den hi?u suat co dinh nam men tren vd budi.
- Khao sat anh hudng ciia do Brix va mat do nam men co dinh den qua trinh len men
chinh rugu vang budi.

Chirong 2
Liro'c khao tai lieu
2.1. Tong quan ve nguyen lifu
2.1.1. Biroi
2.1.1.1. Giai thieu
Theo tu dien Bach Khoa Nong Nghiep (1991), budi la loai cay an qua thupc ho cam
quyt (Rutaeae), co ten khoa hoc la Citrus Grandis (L.) Obseek. Qua budi la loai co
kich thudc ldn nhat trong so cac loai qua citrus.
Budi xuat hi^n tu mien Dong Nam Chau A, dugc du nhap vao Trung Qudc khoang
100 nam trudc cong nguyen, tu do budi dugc trong nhieu d Trung Qudc va cac nude
khac dac biet la d mien Nam Thai Lan, Nhat Ban, An Do, Indonesia, Hungari,...
Theo Pham Hoang Ho (2000), budi cd hai loai: Citrus grandis Obseck var.grandis la
budi ngpt thong thudng nhu budi Nam Roi, Bien Hoa va Citrus grandis Obseck
var.racemosa la budi dang trong tot d Da Lat va cac noi cd khi hau tuong tu.

Hinh 1: Biroi nguyen lieu
Budi NSm Roi la giong budi dac san ciia tinh VTnh Long, dugc ngudi tieu dung danh
gia cao va cd gia tri kinh te ldn. Tong dien tich budi Nam Roi la 9.200ha, phan bo
chinh d VTnh Long (dien tich 4.500 ha, cho san lugng 31.300 tin, chiem 48,06% ve
dien tich va 54,03% ve san lugng ca nude), tiep theo la tinh Hau Giang (1.300ha) va
mot so tinh mien Dong Nam Bo.
Theo Nguyen Minh Chau (2009), cay budi Nam Roi 10 nam tudi cd chieu cao khoang
7 - 8m. Thoi gian trong tu thang 4 den thang 1 nam sau, thoi gian ra hoa thu hoach qua
khoang 210 - 220 ngay. Dac diem ciia budi Nam Roi la cd hinh qua le, trpng lugng
trung binh tu 1,0 - 1,4 kg, khi chin vd qua cd mau vang xanh, thit qua mau vang, min,
ddng nhat. Mui va vach mui de tach, an gidn, hoi nggt. Ty le an dugc tren 55%, do
Brix tu 9 - 12%. Cay budi Nam Roi cho nang suat kha cao, khoang 280-300
kg/cay/nam (cay tren 10 nam tudi).

2

2.1.1.2. Thanh phan hoa hoc
Bang 1: Thanh phan hoa hoc cua mui biroi va vo budi
Thanh phan

Mui budi

Vd budi

Nude (%)

88,30

79,32

Fructose (%)

0,56

0,72

Glucose (%)

0,62

3,67

Saccharose (%)

0,83

1,60

Acid (%)

5,60

0,28

Tinh dlu (%)

Vlt

2,00

Caroten (mg%)

vlt

0,03

Vitamin C (mg%)

55,00

140,00

Vitamin B] (mg%)

0,07

0,05

Vitamin B 2 (mg%)

0,05

0,02

Vitamin PP (mg%)

0,34

1,27

Pectin (%)

1,12

7,05

Cellulose (%)

0,52

4,44

Chit khoang (%)

0,46

0,95

"Nguon: Tran Xuan Hien, Tran Phuong Lan, Nguyen Duy Tan, 2002"
Nude budi chua nhieu chat bd duong nhu cac loai duong trai cay, dam, beo, acid
tannic, beta-caroten va cac chat khoang nhu phospho, sat, canxi, kali, magie. Ngoai ra,
trong nude budi con chua nhieu vitamin (Bj, B 2 , C), trong do ham lugng vitamin C
kha cao, gap khoang 10 lan so vdi qua le, vdi 152g mui budi co the cung cap 130%
nhu cau vitamin C hang ngay cho co the.
4- Pectin
- Cau tao, tinh chat

Hinh 2: Cau tao mot don vi cua chudi pectin
Pectin ton tai d hai dang la protopectin khong tan va pectin hoa tan. Dudi tac dung cua
acid hay enzyme pectinase hoac khi dun soi, protopectin chuyen thanh pectin hoa tan.
Do do, thanh phan pectin gitr vai tro quan trgng trong qua trinh chin ciia qua. Khi qua
3


con xanh va dang phat trien, protopectin phan tan d thanh te bao vdi ti le kha cao lam
cho qua cung. Khi qua bat dau chin, protopectin chuyen dan sang dang pectin hoa tan
dudi tac dung ciia acid huu co va enzyme protopectinase trong qua, qua cang chin
cang mem, pectin hoa tan tang cao, protopectin khong hoa tan se giam din. Khi rau
qua bj nau chm, cac thanh phan protopectin khong hoa tan trong nude se bj thiiy phan
thanh pectin hoa tan, ket qua la tao do mem cho rau qua.
Pectin la mot polysaccharide mach thang chua tir 300 din 1.000 don vj
monosaccharide. Acid D-galacturonic la monosaccharide chii yeu ciia pectin. Ngoai ra
trong thanh phan ciia pectin con chua mot so loai duong trung tinh. Trong lugng phan
tu ciia pectin trong khoang tir 50.000 din 150.000 daltons. Nhom methyl trong phan tir

acid galacturonic ciia pectin co the bj methyl hoa, dua tren mire do methyl hoa ngudi
ta chia ra hai loai pectin: pectin co nhom methyl trong phan tu acid galacturonic bj
methyl hoa hon 50% ggi la pectin co do methyl hoa cao hay HMP (High Methoxyl
Pectin), ngugc lai pectin co do methyl hoa d phan tu acid galacturonic nhd hon 50%
ggi la pectin cd do methyl hoa thap hay LMP (Low Methoxyl Pectin). Pectin co do
methyl hoa thap (< 50% do ester hoa) co t h i tao gel thuan nghjchd pH (3,0 - 4,5) khi
co sir hien dien cua ion canxi, trai lai pectin co do methyl hoa cao co the tao gel nhanh
d nong do dudng khoang 65% (duong sucrose) d pH thap (< 3,5) va khong can sir hien
dien cua ion canxi nhung qua trinh tao gel khong thuan nghjeh. Pectin co do methyl
hoa thap se tao gel cham hon pectin co do methyl hoa cao hon.
Pectin la mot loai chat xo, tan trong nude, lam tang do nhdt, khong tan trong ethanol,
pectin co trong nhieu loai qua, song d cui va vd hat budi co ty le cao va de chiet xult
nhat.
Pectin la ester cua acid pectic. Dudi tac dung cua enzyme pectinase, pectin bj thiiy
phan den cac thanh phan don gian hon la dudng va acid tetragalacturonic. Pectin hoa
tan dudi tac dung cua enzyme pectinase hay kiem loang se giai phdng nhom methyl
tao rugu methylic va acid pectic tu do. Acid pectic phan irng vdi ion canxi tao pectat
canxi. Acid pectic tir do khong co kha nang tao gel ke ca khi co dudng.
(Trln Xuan Hiln, 2010)
- Tac dung
+ Keo dai thai gian tieu hoa thuc an trong mot, tang hap thu duong chat.
+ Giam beo (do tao cam giac no bung keo dai).
+ Giam hap thu lipid, giam cholesterol toan phan trong mau.
+ Khong che tang dudng huyet d ngudi co benh tieu dudng.
+ Chdng tao bon, cam mau va sat thing
± Cellulose
Cellulose thudc loai polysacharide cao phan tu khong co tinh chat dudng, la thanh
phan chinh cua te bao thuc vat. Cellulose tham gia chu yeu trong cau tao mang, thanh
te bao thuc vat lam cho cac mo thuc vat co tinh ben co hgc, tinh dan hoi va tao thanh
bg xuong cho tat ca cac loai cay. Cellulose dugc hinh thanh trong cay nhd qua trinh

quang hgp.

4


- Cau tao, tinh chat, vai tro
Cellulose co cong thuc chung giong tinh hot (C6Hi 0 O 5 ) n . Trong phan tu cellulose, Dglucose la don vi co ban cau thanh va chung lien ket voi nhau bang lien ket 1,4glucoside. Moi phan tu cellulose chua 1.400 - 15.000 goc D-glucose ( M = 2,5.104 5.104).
Trong phan tu cellulose co nhieu goc -OH d dang tir do, nhung cung co vai nhom -OH
ma hydro cua no dugc thay the bang mot so goc hoa hgc nhu goc methyl (-CH 3 ),
acethyl (CH 3 CO-) hinh thanh nen dan xuat ete hay ester ciia cellulose hay goc co nito
tao dan xuat nito.
Cellulose trong tir nhien ton tai dudi dang sgi va khong hoan toan nguyen chat. No
thudng lien ket chat che vdi cac thanh phan khac nhu chat beo, hemicellulose,
pentozan, cac chat nhira va cac mudi vo ca,...
Cellulose khong tan trong nude, khong tan trong cac dung moi huu co nhu ete, rugu.
Trong dieu kien thudng no cung kha ben doi vdi cac dung dich kiem loang, acid loang
va cac chat oxi hoa yeu. Con ngudi khong the tieu hoa dugc cellulose trong khau phan
vi khong co cac enzyme can thiet de phan hiiy chiing. Tuy nhien, mot so loai vi khuan
co kha nang phan hiiy cellulose thanh C 0 2 va H 2 0 .
(Trln Xuan Hiln, 2010)
- Tac dung
Trong dinh dudng, cellulose co y nghia rat quan trgng trong viec phong ngira ung thu
ruot ket - cellulose giu vai tro nhat dinh trong dieu hoa he vi khuan co fch d ruot va tao
dieu kien tot nhat cho chiic phan tong hgp cua chiing. Cellulose co tac dung kich thich
nhu ddng ruot, vi the chiing dieu hoa bai tiet.
Gan day nhieu nghien cuu cho thay cellulose tao dieu kien bai tiet cholesterol ra khdi
co the, vi vay cellulose co vai tro nhat dinh trong phong ngira xo vira ddng mach.
Cellulose phong ngira hinh thanh sdi mat, giam dugc ham lugng md trong mau.
Cellulose con tac ddng den miic dudng huyet, giam bdt tac dung dira vao insulin ciia
benh nhan tieu dudng, ngan ngira sir thira dinh dudng va beo phi.

4 Cac thanh phan gay dang trong vo budi (naringin va hisperdin)
Nhieu nghien cuu cho thay naringin va hisperdin la hai chat chii yeu gay ra vi dang
trong vd budi. Trong mang bao ciia mui budi va gan budi co chua hgp chat narinhin
( C 2 7 H 3 2 0 i 4 ) . Khi chin thi chat narinhin trong thit qua dudi tac dung ciia enzyme
peroxidase bi thiiy phan thanh dudng (glucose va ramnose) va narinhinen khong co vi
dang (Nguyen Van Tiep va ctv, 2000).
2.1.1.3. Cong dung ciia qua buai
Qua budi co nhieu hoat chat sinh hoc quy va la mot vi thudc chua dugc nhieu chiing
benh.
Mui budi: Co vi nggt, chua, tinh mat, khong doc, co tac dung trj ho, trj dau dau, giai
rugu, nude budi co chiia thanh phan gan giong nhu insulin, giup ha dudng huyet, tot
vdi benh nhan tieu dudng, cao huyet ap, an budi thudng xuyen giiip giam can.

5


Cui budi: Vi ngot ding, tinh am, tac ddng vao ty, th§n va bang quang, cong dung hoa
dam, tieu thirc, ha khi va lam khoan khoai long ngirc, tri cac benh nhir viem loet ngoai
da, phu nir mang thai ndn nhieu, san khi, chung ho hen d ngudi gia, cham tieu,...
(Viet Linh, 2004)
2.1.2. Nam men Saccharomyces cerevisiae
Giong Saccharomyces quan trgng nhat la loai Saccharomyces cerevisiae, dugc dung
nhieu trong cong nghiep thuc pham. Mot so chiing nam men diing trong cong nghiep
san xuat banh mi, mot so khac dung trong cong nghifp rugu, bia, san xuat glycerol
ho&c enzyme invertase.
2.1.2.1. Hinh dang te bao nam men
Nam men cd nhieu hinh dang khac nhau, thudng chiing cd hinh cau, hinh elip, hinh
bau due va ca hinh dai. Hinh dang te bao nam men hinh nhu khong on dinh, no phu
thudc vao tudi ciia nam men va phu thudc vao dieu kien nudi cay.

1 c;

i
-

l)il

c

Hinh 3: Nam men Saccharomyces cerevisiae
(Bui Thi Quynh Hoa, 2001)

2.1.2.2. Kich thieac te bao nam men
Te bao nam men thudng cd kich thudc rat ldn, gap 5 - 10 lan kich thudc te bao vi
khuan.
Kich thudc trung binh ciia te bao nam men: dai 8 - 10 pm, rong 2 - 7 pm. Kich thudc
nay cung thay doi, su khong ddng deu thay d cac loai khac nhau, d lira tudi khac nhau
va d dieu kien nudi cay khac nhau.
(Bui Thi Quynh Hoa, 2001)
2.1.2.3. Cau tao te bao nam men
Te bao nam men cung nhu nhieu loai te bao khac dugc cau tao chii yeu tir cac phan co
ban sau:
- Thanh te bao: Thanh te bao nam men dugc cau tao tir nhieu thanh phan khac nhau.
Trong do dang ke nhat la: glucan, manan, protein, lipid va mot so thanh phan nhd khac
nhu kitin.
- Mang nguyen sinh chat: Gdm cac hgp chat phuc tap nhu protein, phospholipid,
enzyme permase.
6

- Nhan: Te bao nam men co nhan that, nhan co hinh bau due hay hinh cau,chira protein
va acid nucleic.
Nhung thanh phan khac nhu: Khong bao, volutin, ty lap the, ribosom.
(Bui Thi Quynh Hoa, 2001)
2.1.2.4. Cac hinh thuc ho hap cua nam men
O nam men, ho hap la qua trinh kha phuc tap, no xay ra theo hai chieu hudng khac
nhau. Vi the, ngudi ta phan ra thanh hai loai ho hap: hieu khi va yem khi.
- Giong nhau:
+ Ca hai dang ho hap deu sinh ra nang lugng, nang lugng nay dung de cung cap cho
co the song hoat ddng va mot phan thai ra ben ngoai.
+ San pham trang gian ban dau deu giong nhau, nghia la tao ra acid pyruvic.
+ Qua trinh chuyen hoa cua hai kieu ho hap deu cd sir tham gia cua nhung he enzyme
oxy hoa gan giong nhau.
- Khac nhau:
+ Ho hap yem khi la dang ho hap khong cd sir tham gia ciia oxy, con ho hap hieu khi
thi ngugc lai.
+ San pham ciia qua trinh ho hap hieu khi la C 0 2 va H 2 0 , con san pham ciia qua trinh
ho hap yem khi la C 2 H 5 OH va C 0 2 .
(Trln Thi Thiiy Trang, 2003)
2.1.2.5. Thanh phan hoa hoc va dinh duang cua nam men
Thanh phan hda hgc va dinh dudng ciia nam men phu thuoc vao chiing giong, moi
trudng, trang thai sinh ly cung nhu dieu kien nudi cay. Men ep chua 75% nude va 25%
chat khd. Cac chat khd ciia nam men bao gdm cac thanh phan sau:
Bang 2: Thanh phan dinh dudng ciia nam men ( % )
Thanh phan

Ldn nhat

Trung binh

Protein

75

55

30

Glucid

40

32

24

4

Lipid
Tro (Khoang)

Nhd nhat

1 1

9

5

"Ngudn: Luang Dire Pham, 1998"

- Protein chua trong nam men rugu thudng cd dii cac acid amin khong thay the dugc.
Ve gia tri dinh dudng thi protein nam men tuong duong protein ddng vat nhung gia tri
hon protein thuc vat. O nhiet do cao va binh thudng, dudi tac dung ciia protease cd san
trong nam men, protein se bien thanh pepton, peptid va acid amin.
- Gluxit ciia nam men chii yeu la glycogen (C 6 Hio0 5 ) n , day la chat du tra ciia te bao,
theo thanh phan cau tao thi glycogen giong nhu amylopectin nhung khac la khdi lugng
phan tu ldn hon. Ham lugng ciia no trong te bao nam men tuy thuoc trade het vao moi
trudng dinh dudng. Trong moi trudng du dudng, lugng glycogen tang dang ke. Trong


giai doan dau len men, nong do dudng con cao nen nam men chua nhieu glycogen.
Khi lugng dudng giam, nam men se su dung glycogen de duy tri sir song. Dudi tac
dung cua a-amylase, glycogen se bien thanh maltose va dextrin.
- Chat beo la thirc an du tra ciia nam men va chua chii yeu trong nguyen sinh chat.
Trong nam men con chua cac chat tuong tir chat beo nhu leucithin.
2.1.2.6. Ca che van chuyen cac chat dinh duang vao trong te bao nam men
Nam men hoan toan khong co co quan dinh dudng rieng biet, cac chat dinh dudng ma
chiing sir dung chu yeu dugc van chuyen qua thanh te bao theo hai con dudng co ban
sau:
- Con dudng thu nhat la tham thau bi ddng: Tren thanh te bao nam men cd nhung 16
nhd, nhung 16 nay cd tac dung lam cho cac chat dinh dudng van chuyen vao trong te
bao tir moi trudng ben ngoai nhd ap suat tham thau. Ngugc lai, chat thai trong qua
trinh trao doi chat cung dugc thai qua nhung 16 nay.
- Con dudng thu hai la hap thu thirc an mot each chii ddng: Cac thanh phan dinh
dudng khong cd kha nang xam nhap vao te bao thi lap tire cd he permease hoat hda.
Permease la mot protein hoat dong, chat nay se lien ket vdi chat dinh dudng hinh
thanh hgp chat va hgp chat nay chui qua thanh te bao vao trong, tai day chiing tach ra
va permease lai tiep tuc lam cong viec van chuyen.
(Bui Thi Quynh Hoa, 2001)
2.1.2.7. Sinh duang ciia te bao nam men

Nam men tiep nhan thirc an bang con dudng hap thu chgn lgc tren be mat ciia te bao
va sau dd khuech tan vao ben trong. Mang va ldp bao bgc nguyen sinh chat ciia te bao
trong trudng hgp nay ddng vai tro la ldp mang ban tham ngan each, dieu khien cac
chat dinh dudng vao te bao va thai ra moi trudng xung quanh nhung san pham ciia
hoat ddng song. De cho te bao de hap thu, cac chat dinh dudng phai la nhung chat cd
phan tir lugng thap va hda tan vao trong nude, mot phan cac chat dinh dudng chuyen
hda thanh cac hgp chat cao phan tir nhu: protein, glucid, lipid,... trong te bao va xay
dung thanh te bao mdi.
Nam men cung giong nhu cac co the thuc vat khac can cac nhu cau dinh dudng nhu:
oxy, carbon, nito, kali, magic
- Oxy, hydro, cacbon: Oxy, hydro cung cap cho te bao nam men tir moi trudng. Nguon
cung cap carbon la cac loai dudng khac nhau. 6 nhung giai doan nhat dinh, nam men
con sir dung nguon carbon ciia acid amin.
- Nito: Nam men khong cd enzyme ngoai phan giai protein, cho nen khong the phan
tach albumin ciia moi trudng thanh chat cd kha nang hap thu va phai cung cap d dang
hda tan, cd the la dang vo co hoac huu co. Dang huu co thudng dugc su dung la acid
amin, pepton amid, ure. Dang vo co la cac mudi amon khir nitrat, sulfat.
- Cac vitamin: De dam bao cho sir song, nam men can cac vitamin nhu Bj cd trong
thanh phan ciia coenzyme cacboxylase, B 2 d dang ester phosphoric, acid nicotic cd
trong cozymase,... Biotin va acid paraamino benzoic la nhung chat kich thich cho sinh
trudng ciia nam men (Nguyen Dinh Thudng, 2000).
- Chat khoang: Chat khoang cd anh hudng to ldn den hoat dong song cua te bao nam
men. Trade het la phospho, cd trong thanh phan ciia nucleoprotein polyphosphate ciia
8


nhilu enzyme va ciia san pham trang gian ciia qua trinh len men rugu. Chiing tao
thanh m l i lien k i t co nang lugng horn. Lira huynh tham gia vao thanh phan ciia mot so
acid amin, albumin, sinh to va mot so nguyen to vi lugng nhu magie, sat co anh huang
din qua trinh sinh ly, sinh hoa cua nam men. Magie tham gia vao nhieu phan ung

trang gian ciia su len men. Sat tham gia vao thanh phan enzyme ciia sir ho hap va cac
qua trinh khac. Nam men can nhieu kali, no thuc day sir phat trien cua nam men tham
gia vao sir len men rugu, tao dieu kien hoi phuc phosphoric hoa ciia acid pyruvic.
Mangan dong vai tro tuong tu magie.
2.1.2.8. Cac hinh thuc sinh san cua nam men
Khi nghien cuu dac tinh di trayln ciia nam men tai Dan Mach (1935), ong Carlsberg
phat hien, cac loai thuoc gilng Saccharomyces co the bien doi giua hai dang don boi
va nhi boi.

T l bao nlm men co hai gioi tinh a va a. Cac te bao don boi sinh ra a va a dugc hinh
thanh qua nguyen phan bang each nay choi. Chiing ket hgp vdi nhau thanh bao tir
ludng boi aa. Khi gap dilu kien dinh dudng kern, chiing giam phan tao nang chua 4
bao tir: 2a va 2a. Sau do, te bao sinh san theo kieu vo tinh hoac huu tinh.
Hinh 4: Chu ky sinh san cua nam men Saccharomyces
(1) : Qua trinh sinh san vo tinh (nay choi)
(2) : Qua trinh sinh san huu tinh (giao hgp)
(3) : Qua trinh tao nang chua 4 bao tir
Qua trinh sinh san ciia nlm men lien quan chat che den sir nay choi. Choi tach khdi te
bao me khi cd kich thudc blng t l bao me va bit dau sinh san. Thai gian the hg la chu
ky sinh san dugc tinh la khoang thai gian giua hai lan phan chia. Thai gian the he ciia
nam men Saccharomyces cerevisiae la 2 gid. Qua trinh nay choi dien ra dong thai vdi
su bit dlu ting hgp ADN. Qua trinh nay lien quan den hien tugng lam mem vd te bao
blng enzyme lytic, enzyme nay tac dung len polysaccaride ciia thanh vd te bao. Tir
chii mdi hinh thanh cac vat lieu mdi ciia te bao ldn dan len, hinh thanh vach ngan
chitin, mannan, glucan. Choi tach ra va de lai seo.
(Luang Dire pham, 2006)

9

2.2. Co so* khoa hoc va cac yeu to anh hirdng den qua trinh len men rirmi
2.2.1. Co* so khoa hoc cua qua trinh len men rirou
Len men la mot qua trinh trao ddi chat dudi tac dung cua cac enzyme tuong ung ggi la
chit xiic tac sinh hoc. Tuy theo san pham tich tu sau qua trinh len men ma ngudi ta
chia lam nhieu kilu len men khac nhau. Tuy nhien co hai hinh thuc len men chinh la
len men yem khi (ki khi) va len men hieu khi.
Len men ruou la qua trinh len men yem khi vdi su co mat cua nam men, chiing se
chuyen hoa dudng thanh ethanol va C 0 2 .
Qua trinh len men ruou dugc chia lam hai thai ky chinh:
- Thai ky phat tri I n sinh khoi: giai doan nay vdi su co mat ciia oxy, te bao nam men
phat trien sinh khoi.
- Thai ky len men chuyln dudng thanh rugu va C 0 2 : giai doan nay nam men hap thu
cac chat dinh duong va su dung cac enzyme san co ciia minh thuc hien xiic tac sinh
hgc trong qua trinh trao doi chat de duy tri su song, tao thanh rugu va C 0 2 .
2.2.2. Cac yeu to anh hudng den qua trinh len men ruou
2.2.2.7. Oxy
Hau het cac chiing nam men trong len men rugu vang thuoc giong Saccharomyces.
Chiing la nhom vi sinh vat ki khi tuy tien. Khi trong moi trudng co dii lugng oxy, nam
men phan hiiy dudng de dung lam nguon nang lugng va tham gia cau tao te bao tang
sinh khoi.
Trudng hgp thieu oxy (ki khi), nam men su dung phan oxy hoa tan trong moi trudng
de sinh trudng va chii yeu la len men.
Trong qua trinh len men giai doan dau, yeu cau oxy cao nhat de nam men sinh san,
phat trien tang sinh khoi. Neu co giai doan nhan giong thi cung can phai cung cap oxy
bang each lac hoac sue khi.
2.2.2.2. Nhiet dp
Nhiet do len men cd anh hudng den doi song ciia nam men, den qua trinh len men va
chat lugng ciia san pham.
Nhieu cong trinh nghien cuu ve san xuat rugu vang da xac dinh dugc khoang nhiet do
len men rugu vang trang thich hgp la 15 - 30°C, neu len men d nhung thang do thap

hon thi cang tot. Con len men rugu vang do (nude qua lan vdi xac qua) phai chiet xuat
cac chat thorn va polyphenol tir vo qua nen can thang do cao hon, thudng la 25°C.
Nhiet do len men cao, thoi gian ciia qua trinh len men ngan, do con co the thap, dudng
sot con nhieu va huang vj ciia san pham cd khi khong tot.
2.2.2.3. Ham luang duang
Dizlcmg la nguon dinh dudng quan trgng, anh hudng true tiep den hoat dong ciia nam
men va qua trinh len men. Dudng cung cap nang lugng va carbon cho nam men hoat
dong, dang glucose la thich hgp nhat vi tat ca cac loai men deu dong hoa dugc. Ti le
dlzldng cang cao thi tao thanh nhieu ethanol, cho nen them dudng vao nude qua la mot
bien phap rat pho bien.

10


Moi trudng co nong do dudng tir 10 - 25% thuan lai cho su len men. Khi nong do
dudng tir 25% trd len thi su len men khd khan va cham. Dung dich dudng co nong do
rat cao se tao ra ap suat tham thau ldn gay pha hiiy trang thai sinh ly binh thudng cua
nam men, thai gian len men se keo dai, sir dung dudng khong triet de, hieu suat tao
thanh ruou giam, lugng rugu tao ra khong nhieu. Ngugc lai, mdi trudng len men cd
nong do dudng qua thap se khong du co chat cho nam men hgat ddng.
2.2.2.4. pH cua moi truang
Trong thuc te, khi len men nhung dich qua chua thudng dugc rugu vang ngon. Ddi vdi
dich qua thudng co dd pH tir 2,8 - 3,8. Khoang pH nay nam men van hoat ddng dugc.
Vung pH tdi thich ciia nam men la 4 - 6.
Trong san xuat rugu vang ngudi ta thudng chuan bi mdi trudng nude qua cd do pH
bang 3,0 - 3,5.
2.2.2.5. Anh huang cua CO2
Ham lugng C 0 2 hinh thanh trong qua trinh len men thudng han che manh su sinh san
ciia nam men vang. Theo nghien cuu ciia Miuler-Thurrau, khi:
- Ham lugng C 0 2 trong rugu vang dat den 0,25% trgng lugng C 0 2 thi viec sinh san

cua nam men bi dinh tre.
- Ham lugng C 0 2 trong rugu vang dat den 1,5% trong lugng C 0 2 thi nam men khong
con sinh san dugc nua.
- Vdi ham lugng C 0 2 1,5% d nhiet dd 15°C se co ap suat la 7,7 atm, nam men van
song va tiep tuc len men ki khi.
2.2.2.6. Anh huang ciia ethanol
San pham ciia qua trinh len men ki khi la ethanol. Ethanol kirn ham hoat ddng song
ciia te bao nam men, tuy nhien muc dd kim ham khac nhau ddi vdi cac chiing, noi nam
men khac nhau. V i du, ddi vdi S.ellipsoideus cd the chiu dung dugc 18%V ethanol
nhung ddi vdi Kl.apiculata chi chiu dung dugc tir 4 - 6%V ethanol. Kha nang chiu
dung ethanol ciia nam mdc, vi khuan kem hon nhieu so vdi nam men. Dieu nay thuc
su cd y nghia ldn trong san xuat, boi vi khi qua trinh len men ki khi bat dau xay ra thi
nhung san pham ethanol hinh thanh trong moi trudng cd tac dung kim ham manh me
nam mdc, vi khuan (ludn cd di kem trong dich nho) va sau dd la uc che nhung nam
men dai di lan vdi S.ellipsoideus, de roi phai nhudng mdi trudng cho nam men vang
hoat ddng.
(Le Nggc Tu va ctv, 2002)
2.3. Ky thuat co djnh te bao
2.3.1. Phirong phap co djnh te bao tren be mat chat mang
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Phuang phap gan te bao len be mat chat mang

- Vat lieu: Thiiy tinh xdp, cellulose, than, cac oxide kim loai, cao lanh,...
- Nguyen tac thuc hien: Thong qua cac lien ket cong hoa tri, lien ket tinh dien, luc
Vandewalls. Cac phuong phap gan nay cu the dua tren nhung nguyen tac sau:
+ Gan te bao bang lien ket ion: dua vao su tich dien trai dau giua te bao va chat mang.
+ Gan te bao bang lien ket cdng hda tri: cd the xay ra hai trudng hgp:
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* Trudng hop 1: Chat mang co chua cac nhom co the tham gia true tiep vdi nhom
amin cua protein vi sinh vat.
* Trudng hop 2: Phai hoat hoa chat mang bang each gan len chat mang nhung chat co
kha nang phan ung . Tiep theo do, la tao lien ket giua cac nhom tren chat mang vdi te
bao vi sinhvat.
- Uu va nhugc diem: Phuong phap nay co the tao dugc nhung lien ket hoa hgc manh
giua te bao va chat mang. Tuy nhien, de tao ra cac moi noi dong hoa tri nay thudng ton
cong va dac tien.
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Phuang phap hap phu

- Vat lieu: Su dung cac chat co hoat tinh be mat manh nhu: cellulose, agarose,
polyacrylamide, chitin, nylon, thiiy tinh...
- Nguyen tac thuc hien: Dua vao co che hap phu. Co the xay ra cac trudng hgp sau:
+ Thu nhat, chat mang co nhieu 16 xop, te bao vi sinh vat bam vao cac Id xdp va toan
bd be mat chat mang.
+ Thu hai, ddi vdi chat mang khong co Id xdp (thiiy tinh), te bao se bam tren be mat
chat mang.
+ Thu ba, khi chat mang tich dien (nhua trao ddi ion), chiing se tao lien ket ion.
- Phuong phap thuc hien: te bao vi sinh vat dugc phdi trdn vdi chat mang trong mdi
trudng long, khuay trdn trong dieu kien thich hgp, sau do rua ba de loai bd phan te bao
vi sinh vat du.
- Uu va nhugc diem: Phuong phap nay de thuc hien, don gian. Tuy nhien, lien ket vat
ly rat yeu nen vi sinh vat de tudt khoi chat mang.
2.3.2. Phirong phap nhot te bao vao he gel
- Vat lieu: Co the su dung cac loai sau:
+ Ion gel: cac polymer ma te bao gan ket vdi nhau tao thanh mang ludi bang lien ket
ion.

+ Covalent gel: polymer gan vdi nhau bang lien ket cdng hoa tri, tao thanh mang ludi.
+ Non-covalent gel: polymer gan vdi nhau thudng bang lien ket hydro.
+ Cryogel: la cau true gel polymer mdi dugc tao bdi phuong phap lanh ddng cac tieu
phan polymer cd phan tu lugng cao hay thap.
+ Aginate la vat lieu lay tir rong bien, cd kha nang tao gel tot, rat tot de bao gdi
enzyme hay te bao.
- Nguyen tac thuc hien: Trong he gel, cac polymer se tao thanh mang ludi bao bgc te
bao. Mang ludi cd 16 nhd den muc te bao khong the ra ngoai, nhung du ldn de co chat
va san pham chui vao.
+ Ddi vdi chat mang tao lien ket ion, trdn chung huyen phu te bao va hdn hgp chat
mang da dien tich va dung djch da dien tich trai dau.
+ Vdi chat mang polymer nhu covalent: trdn huyen phu te bao vi sinh vat vdi cac
monomer rdi dem trung hgp, hoac trdn chung vdi polymer de tao lien ket giua cac sgi
polymer.
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+ Doi voi gel aginate: Dau tien gel alginate dugc dun soi va de ngugi den 30°C. Sau
do, khuay trgn alginate va huyen phu te bao voi ty le 1:1, khuay nhe 30 vdng / phut,
trong 5 - 1 0 phut. Tao hinh, co dinh trong dung dich CaCl 2 . Tiep theo, rua nuoc vo
trung. Cuoi ciing bao quan lanh.
- l / u & nhugc diem: Phuong phap nay co hieu suat cao, te bao ft bi rua troi. Tuy
nhien, vi nam trong khuon gel nen khong chju dugc khuay trgn. Cac te bao trong
khuon gel phan bo khong dong deu, cac te bao nam tren be mat se tham gia len men.
Dong thai san pham trao doi chat lam truang nd hat gel, gay be vd.
2.4. Cac phu gia (hoa chat) sir dung trong nghien cihi
2.4.1. Duong saccharose
2.4.1.1. Cau tao va tinh chat
Saccharose co cong thuc cau tao la C i 2 H 2 2 0 n , d dang tinh the trang, dugc cau tao tir
hai phan tu dudng dan la glucose va fructose. Saccharose rat pho bien trong giai thuc

vat, dac biet chiem ti le cao trong cay mia (14 - 20%), trong cu cai dudng (16 - 20%).
Saccharose de tan trong nude, ket tinh tir dung dich nude se cho nhung tinh the ldn.
Nong do saccharose trong dung djch nude co the xac djnh bang phan cue ke hay
dudng ke.
Saccharose de bj thuy phan trong moi trudng acid hay ngay ca vdi acid yeu nhat nhu
H 2 0 + C 0 2 tao thanh D-glucose va D-fructose. Hien tugng nay ggi la sir nghjch dao
dudng. Saccharose cung de bj thiiy phan dudi tac dung ciia enzyme saccharase.
2.3.1.2. Tac dung ciia duang
- Tao vj nggt cho san pham, lam tang gia trj cam quan ciia san pham.
- Kim ham su phat trien ciia mot so loai vi sinh vat co hai.
- Cung cap co chat cho nam men len men rugu.
(Trln XuanHiln, 2010)
2.3.2. Acid citric
- Nguon goc: ton tai trong rau qua, trai cay nhung nhieu nhat trong cac loai trai cay
thuoc hg cam, quit. Trong cong nghiep, acid citric dugc san xuat tu ri dudng bang
phuong phap len men acid citric.
- Cau tao hoa hgc:

Hinh 5: Cau tao hoa hoc cua acid citric
- Dac tinh: Acid citric la mot acid huu co yeu. khong mau hay mau vang, khong mui,
vj chua, de bj thiiy phan bdi nhiet do, hoa tan tot trong nude va ethanol.
(Trlii XuanHiln, 2010)

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