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

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

TRU ONG DAI HOC AN GIANG KHOA NONG NGHIEP & TAI NGUYEN THIEN 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 BANG NAM

M E N SACCHAROMYCES CEREVISIAE

C O 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

TRU'OfNG DAI HOC AN GIANG KHOA NONG NGHIEP & TAI NGUYEN THIEN NHIEN

BO MON CONG NGHE T H l / C PHAM

NGUYEN THI MY 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 NAM

M E N SACCHAROMYCES CEREVISIAE

C O DINH 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 VIEN 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

2.1.1 Buai 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

2.5 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 16

Chirong 3 Phirong tien va phirong phap nghien ciru 16

3.1 Phuong tien nghien cuu 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 24

Chirong 4 Ket qua va thao luan 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 pc_9

Bang22: Sir thay doi mat do te bao theo pH pc_10

Bang23: Sir thay doi mat do te bao theo ty le nam men pc_10

V

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_

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 pc_

0

vi

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

v i i

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

v i i i

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)

2.1.1.2 Thanh phan hoa hoc

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

"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, B2, 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 thi 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

- Cau tao, tinh chat, vai tro

Cellulose co cong thuc chung giong tinh hot (C6Hi0O5)n Trong phan tu cellulose, glucose la don vi co ban cau thanh va chung lien ket voi nhau bang lien ket 1,4-glucoside Moi phan tu cellulose chua 1.400 - 15.000 goc D-glucose (M = 2,5.104 -5.104)

D-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 (-CH3), acethyl (CH3CO-) 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 02 va H20

(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 ( C2 7H3 20 i4) 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

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

- 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 02 va H20 , con san pham ciia qua trinh

ho hap yem khi la C2H5OH va C02

(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 Nhd nhat

"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 (C6Hio05)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, B2 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

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 02

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 02: 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 02

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

2.2.2.3 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

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 02 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 02 trong rugu vang dat den 0,25% trgng lugng C 02 thi viec sinh san cua nam men bi dinh tre

- Ham lugng C 02 trong rugu vang dat den 1,5% trong lugng C 02 thi nam men khong con sinh san dugc nua

- Vdi ham lugng C 02 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

4 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:

11

* 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

4 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

+ 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 CaCl2 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 i2H2 20 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

H20 + C 02 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)

13

2.3.3 Natri bisulfit (NaHS0 3 )

Natri bisufit la mot hgp chit hoa hgc voi cong thuc la NaHS03, no la mot chat phu gia voi chi so E222

Theo Luang Due Phlm (2006), lugng S02 cho phep trong dich qua la tu 30- 120 mg/1

co tac dung chlng oxy hoa, diet tap khuan, men dai, khi len men tao dieu kien cho nlm men sinh ra mot ft glycerin lam hoan thien vi cho rugu vang

(Trln XuanHiln, 2010)

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

2.4.1 Qua trinh chan

Muc dich ciia qua trinh chan:

- Vo hoat enzyme va tieu diet mot so vi sinh vat, giup mau sac nguyen lieu khong bi xlu di, chin lam cho he thong cac enzyme peroxidase, polyphenoloxidase trong cac nguyen lieu rau qua bi dinh chi, khong tao thanh cac chat mau

- Thiiy phan protopectin thanh pectin, giup cac qua trinh xu ly sau do dugc de dang hon

- Lam thay doi thi tich, khoi lugng nguyen lieu de cac qua trinh che bien sau thuan lgi

- Loai tru cac chit khong thich hgp nhu cac chat gay ra vj dang va cac chat co vj khong thich hgp

- Tang do tham thau ciia chat nguyen sinh, lam cho djch bao thoat ra de dang, hoac dung djch de ngam vao te bao

- Tieu diet cac vi sinh vat bam ben ngoai nguyen lieu

(Dao Van Thanh, 2005)

2.4.2 Qua trinh ep

Tac dung ciia qua trinh ep la phan chia pha long ran trong vat lieu (tach chat long da dugc giai phong ra khoi te bao con nam trong vat lieu ra ngoai) Chat long la san pham can thu

Djch ep la mot he keo phuc tap gom thanh phan chii yeu la mot so chat hoa tan ke ca mot it chit khong tan Yeu clu dung djch co do tinh khiet cao Do tinh khiet la ti le giua ham lugng chat tan chii yeu va tong cac chat tan trong dung djch dugc tinh bang

% chat ran thu dugc la san pham dac con it nuoc

Qua trinh ep la mot qua trinh co hgc, chii yeu la bien doi ve vat ly nhu bien doi ve cau tnic, trang thai lien ket, ti le hai pha long - ran, hoac long - dac, su giam do xop, tang

su ket dinh giua cac phan tu

Khong co su thay d l i dang k l v l hoa hgc, sinh hoa, tuy nhien co the co su ton that vitamin, cac hoat chat dugc giai phong ra khoi te bao, cac enzyme cung co kha nang giai phong ra khoi te bao, co kha nang oxy hoa manh hon, kha nang bao quan lau dai

va tot hon do khong con co do hong khong khi, khi bao quan it bj bien doi

(Dao Van Thanh, 2005)

2.4.3 Qua trinh phoi che

Nham dieu chinh do Brix va pH den muc thich hgp de nam men co the phat trien tot trong dung dich

2.5 Cac nghien ciru trirdc day

- Do Duong Phuong Thao (2005) khi "nghien cuu che bien san pham vo buai tarn duong" da nit ra ket luan: Doi vdi cong doan xu ly the va dang, vo budi dugc chan trong thai gian 5 phut, xa 2 lan se co vi the va dang thap nhat

- Nguyen Thi Huyen Trang (2011) khi "nghien cuu che bien rugu vang budi" da nit ra ketluan:

+ Vdi lugng dudng ban dau ciia dich len men la 22°brix, ty le nam men bo sung la 0,3%, ket hgp vdi dieu chinh pH bang 4 thi san pham len men tot nhat, do con sinh ra cao nhat

+ Dich qua sau khi len men dugc tien hanh lgc trong vdi ham lugng agar xu ly la 0.5g/1 thi san pham cd mau sac va do trong tot nhat

+ Nham tang gia trj cam quan ciia san pham thi ty le dudng bo sung la 0,3% va pH dugc dieu chinh ve gia trj la 4,5 giup san pham cd vj chua nggt hai hoa, hau vj luu lai tot nhat va dat gia trj cam quan cao

- Phan Ngoc My Hda (2010) khi "nghien cuu cd djnh nam men Saccharomyces

cerevisiae tren ba mfa de san xuat rugu dau tarn" da nit ra ket luan:

+ Mat do nam men ciia dung djch la 15.107de co djnh dem lai ket qua tot

+ Chieu dai ba mfa dung de co djnh la 2 cm

- Nguyen Minh Dung (2009) khi " khao sat anh hudng cua cac yeu to pH va S02 den ddng hgc qua trinh len men chinh rugu vang nho sir dung nam men cd djnh tren chat mang Bacterial cellulose" da nit ra ket luan:

+ Mat do te bao nam men sir dung de len men rugu vang nho la 1.109 tb/1

+ Thai gian len men san pham rugu vang nho la 14 ngay dem lai ket qua tot

15

Chirong 3 Phirong tien va phirong phap nghien eihi

3.1 Phirong tien nghien ciru

3.1.1 Dja diem va thoi gian nghien ciru

Dia dilm nghien cuu: Phong thi nghiem Bo Mon Cong Nghe Thuc Pham, Khoa Nong Nghiep & TNTN, Trudng Dai Hoc An Giang

Thai gian nghien cuu: thang 12/2012 din thang 5/2013

3.1.2 Nguyen lieu

- Budi Nam Roi dugc mua tai sieu thi Metro

- Dudng saccharose tinh luyen (RE) dugc mua tai sieu thi Metro

- Nam men Saccharomyces cerevisiae

3.1.3 Hoa chit

- Acid citric

- Na2C03

- Natri bisulfit (NaHS03)

Va cac hda chat phan tich khac

- Can dien tu, can phan tich

- Kinh hien vi va budng dem nam men

Va mot so dung cu thong thudng khac

3.2 Phirong phap nghien ciru

3.2.1 Phuong phap thu thap va xxx ly so lieu

Cac thi nghiem dugc tiln hanh vdi ba lan lap lai Khi khao sat cac cong doan dau, co dinh cac thong so ky thuat ciia cong doan sau dua tren so lieu tham khao Chon cac thong s i ky thuat t l i uu cua thi nghiem trudc sir dung cho cac thi nghiem d cdng doan sau

Cac s i lieu thu thap se dugc ve dd thi bang chuong trinh Microsoft Excel va xir ly thing ke blng phuong phap phan tich ANOVA sir dung phan mem Portable Statgraphics Centurion 15.2.11.0 vdi su kiem tra muc dd y nghia cua cac nghiem thirc qua LSD d dd tin cay 95 % (P = 0,05)

3.2.2 Quy trinh co djnh nam men Saccharomyces cerevisiae tren vo biroi

Got vo xanh, cat nho

Rua chat mang

Duong, acid citric/ Na2C03

NaHS03 (0,01%, 30 phut)

Nam men

Pha loang < Djch budi

Nude vo trung

Nam men co dinh tren vd budi

Hinh 6: Quy trinh co djnh nam men tren vo biroi du* kien

TRUC3NG DAI HQC

AN GIANG

T H l J V I E N

17

Thuyet minh quy trinh:

- Rua: Budi sau khi mua ve dugc dem rua sach be mat vd ben ngoai nham giam ty le nhiem ban va nhiem khuan trudc khi dua vao sir dung

- T&ch vd: Sau do, budi dugc dua vao cong doan tach vd

- Ep: Phan thjt mui budi dugc ep lay dich qua

- Phoi che: Dich budi dugc pha loang vdi ty le dich budi : nude la 1:1, sau dd dieu chinh do brix bang each bo sung dudng, dieu chinh pH bang each bd sung acid citric hoac Na2C03 de tao dieu kien thich hgp cho nam men phat trien

- Thanh trung: Can thanh triing dich budi bang NaHS03 0,01% trong 30 phut de tieu diet cac vi sinh vat tap

- Nhan giong: Bd sung nam men Saccharomyces cerevisiae thuan vao dich budi va

tien hanh nhan giong d dieu kien nhiet dd thudng

- Pha loang: Dung dich nude budi pha loang huyen phu nam men de dat mat dd nam men theo yeu cau

- Got vd xanh, cat nhd: Phan vd qua dugc ggt bd phan xanh, giu* lai phan thit trang, cat nhd thanh tung mieng vudng cd kich thudc 1cm x 1cm

- Chan - Xa: Vd budi dugc chan trong 5 phut va xa hai lan bang nude sach de loai bd

vi the dang, sau dd vat rao

- Say: Vd budi sau khi vat rao dugc say d 70°C den khoi lugng ban dau de dd am ludn

3.2.3 Quy trinh len men rircru biroi bang nam men co dinh

Hinh 7: Quy trinh len men nrou vang biroi bang nam men co djnh du* kien

Thuyet minh quy trinh:

Budi sau khi mua ve dem rua sach, tach vd, mui budi ep lay nude Nude budi dugc pha loang theo ty le dich budi : nude la 1:1, phoi che vdi dudng va acid citric hoac

Na2C03 d l dung dich dat do Brix va pH theo yeu cau Sau do, dich budi dugc thanh trung bang NaHS03 0,01% trong 30 phut Bo sung nam men co dinh vdi mat do theo yeu cau de tien hanh len men Sau khi qua trinh len men ket thuc, tien hanh lgc thu thanh pham

19

3.3 Noi dung nghien cuu

3.3.1 Thi nghiem 1: Khao sat anh hirdng cua dp Brix, pH va ty le nam men

Saccharomyces cerevisiae thuan den qua trinh nhan giong nam men trong dich

biroi

a Muc dich

Nhlm xac dinh do Brix va pH cua dich nude budi cung nhu ty le nam men S

cerevisiae thuan bo sung thich hop de nam men sinh trudng va phat trien tot

b Bo tri thi nghiem:

- Thi nghiem dugc bo tri vdi ba nhan to:

Nhan td A: Do Brix djch budi (°Bx)

Thanh triing < NaHS03 (0,01%, 30 phut)

Xac dinh mat do te bao nam men

Hinh 8: So* do bo tri thi nghiem 1

c Tien hanh thi nghiem

Chon loai budi Nam Roi tuoi, do chm vira phai, sau do tach vd ep lay nude Moi mau sir dung 100ml dich nude ep budi Djch budi dugc pha loang, bo sung dudng saccharose d l dat do Brix 19%, 22%, 25% va dilu chinh pH lan lugt ve cac gia trj 3,5; 4,0; 4,5 Sau do, tiln hanh thanh trung blng NaHS03 va phoi trgn nam men theo cac ty

le 0,2%; 0,3%; 0,4% Nhan gidng d dilu kien nhiet do thudng

d Chi tieu theo doi

- Xac djnh mat do t l bao nam men tren mot don vj djch huyen phu sau moi 6 gid nhan gidng

3.3.2 Thi nghiem 2: Khao sat anh hirdng cua mat do tl bao nam men ban dau,

ty le vo budi va chieu day vo budi dung co djnh

a Muc dich

Nhlm xac djnh mat do te bao nam men ban dau va ty le vd budi cung nhu chieu day

vd budi dimg cd djnh nam men de qua trinh cd djnh dat hieu suat cao

b Bd tri thi nghiem

- Thi nghiem dugc bd tri vdi ba nhan td:

Nhan td D: Mat dd nam men ban dau (te bao / ml)

c Tien hanh thi nghiem

Vd budi dugc ggt bd phan xanh, cat nhd thanh tirng mieng vudng vdi chieu dai x chieu rdng la 1 x 1 cm, chieu day dao ddng trong cac khoang 0,5cm; 0,75cm va 1,0cm Sau

do, vd budi dugc chan trong 5 phut va xa hai lan bang nude sach, ep rao, say khd rdi tien hanh tiet trung d 121°C trong 20 phut Djch budi sau khi nhan gidng se dugc pha loang de dat dugc cac mat dd nam men ban dau la 20.107 tb/ml, 40.107 tb/ml va 60.107 tb/ml Phoi trdn vd budi vao djch huyen phu nam men lan lugt theo cac ty le 10%, 15%, 20% de cd djnh Sau khi cd djnh, vdt vd budi ra khoi djch huyen phu nam men

va rua bang nude vd khuan

d Chi tieu theo ddi

- Xac djnh mat dd te bao nam men cd djnh tren mot don vj khoi lugng vd budi cu sau mdi gid cd djnh

21

Vo budi Dich budi

Nam men cd dinh tren vd budi

Hinh 9: So* do bo tri thi nghiem 2

3.3.3 Thi nghiem 3: Khao sat anh hirdng cua do Brix dich birdi va mat do nam

men co dinh den qua trinh len men chinh riron vang birdi

a Muc dich

Nham xac dinh do Brix dich budi va mat do nam men cd dinh bd sung thich hop cho qua trinh len men

b Bd tri thi nghiem:

- Thi nghiem dugc bd tri vdi hai nhan td:

Nhan td G: Dd Brix dich budi (°Bx)

Hinh 10: So* do bd tri thi nghiem 3

c Tien hanh thi nghiem

Chon loai budi Nam Roi tuoi, do chin vira phai, sau do tach vd ep lay nude Mdi mau

su dung 200ml dich nude ep budi Dich budi dugc pha loang theo ty le dich budi : nude la 1:1, bd sung dudng saccharose de dat dd Brix 16%, 19%, 22%, 25% va dieu chinh pH bang 4,0 Sau dd, tien hanh thanh trung bang NaHS03 0,01% trong 30 phut

va bo sung nlm men d l dat cac mat dd 105tb/ml; 106tb/ml; 107tb/ml; 108tb/ml Len men d dieu kien nhiet dd thudng trong 14 ngay, tien hanh lgc va hoan thien san pham

d Chi tieu theo ddi:

- Theo ddi qua trinh len men bang each xac djnh dd Brix cir sau mdi 24 gid len men, xac djnh ham lugng dudng va dd con khi ket thuc qua trinh len men

- Danh gia cam quan san pham

23

3.2.4 Phirong phap phan tich

Bang 3: Cac phirong phap phan tich

cni tieu Jrnirong pnap pnan nen

Dung dung dich NaOH 0,1N de trung hoa het cac

ftpn man hnno nhst hpn vfrno