Báo cáo "Nghiên cứu trích li Polyphenoltừ chè xanh vụn. Phần1: Các yếu tố ảnh hưởng đến quá trình trích li polyphenol " pdf

TAPCHiKHOAHOC
VAC6NG
NGHE Tap 47, so L 2009 Tr. 81-86
NGHIEN
CU'U TRICH Ll POLYPHENOL TU CHE XANH VUN
PHAN
1. CAC Y^U T6 ANH HU'6'NG O^N QUA TRJNH TRICH Ll
POLYPHENOL
VU
HONG
SON,
HA DUYEN TU
1.
GIOI
THIEU
Cac hgp chat polyphenol phan bd rdng rai trong thuc vat va dugc dac biet chu y nghien ciru
trong vai thap ky gan day. Polyphenol ciia che xanh ddng vai trd la mdt chat chdng oxy hda tu
nhien va ire che su phat trien ctia vi sinh vat. Nd cd tac dung ngan ngira benh ung thu [10], benh
ve dudng tim mach [6], benh tieu dudng, benh Alzheimer, benh Parkison [7], lam giam su
nhiem ddc do kim loai, do phdng xa
Polyphenol che xanh dugc trich li bang nhieu
kT
thuat khac nhau: trich li truyen thdng bang
dung mdi nudc, trich li bang bd Soxhlet. trich li cd hd trg vi sdng, trich li diing sieu am, trich Ii
bang ddng chat Idng sieu tdi ban. Qua trinh trich li polyphenol chju anh hudng ciia nhieu yeu td:
Beata Druzynska ciing cdng su [3] da cho thay hieu suat trich li va boat tinh chdng o.xy hda cua
polyphenol che xanh phu thudc nhieu vao dung mdi va thdi gian trich li; Yuko Yoshida [11] va
Pham Thanh Quan [8] trong nghien ciru ciia minh deu cho thay ham krgng va boat tinh sinh hgc
cua polyphenol thu dugc tir djch trich li che xanh phu thudc dang ke vao pH, ti le dung mdi /
nguyen lieu, cimg nhu loai dung mdi, lhdi gian trich li va nhiet do trich li. Ngoai ra vdi kT thuat
trich li cd hd trg vi sdng deu cho hieu suat trich li cao ban phuang phap trich li truyen thdng [5,

8],
tuy nhien phuong phap nay chi phii hgp vdi quy md nhd. Mac dii nhieu kT thuat trich li mdi
dugc phat trien, nhung phuong phap trich li cd dien bang nudc van dugc irng dung rdng rai do
uu diem ndi trdi ve hieu qua kinh te cao.
Trong nghien ciru nay, chimg ldi da lien hanh khao sat cac yeu td anh hudng den qua trinh
trich li polyphenol bang nudc lir che xanh viin nham hoan thien cdng nghe khai inac ngudn
polyphenol tir che xanh.
2.
DOI TUONG VA PHU^ONG PHAP NGHIEN
CLTU
2.1.
Nguyen lieu
Nguyen lieu dimg trong nghien ciru la che vim dugc lay tir ca sd san xuat che xanh d viing
Phil Hd (Phil Thg) vao vu Ddng. Mau che dugc bao quan trong 2 Idp tui polyetylen kin d nai
khd rao. thoang mat. diing lam nguyen lieu de nghien ciru.
2.2.
Thiet bj, hoa chat
Dung mdi va hda chat sir dung dat do tinh khiet phan tich do Trung Qudc va Dire (Merck)
san xuat. Cac thi nghiem dugc tien hanh tai phdng thi nghiem Phan tich chat lugng thuc pham.
Vi^Mi cdng ngh(; sinh hgc va cdng nghe thuc pham, Dai hgc Bach khoa Ha Ndi.
81
2.3.
Cac phu'o'ng phap phan tich
2.3.1.
Chudn bi dich chiet che
a. Mau dich che xdc
dinh
polyphenol tdng
sd
Ket hgp phuong phap xac djnh tdng lugng chat tan theo Voronxop [1] va phuang phap

phan tich polyphenol chuan [4], tien hanh chuan bj mau nhu sau: can chinh xac lugng che vun
(khoang 3 g) da nghien nhd, chuyen vao binh cau 250 ml (cd lap sinh ban), them 150 ml nudc
cat, chinh pH = 3,5 bang HCl 1 N, trich li trong
1
gid. Lgc djch che, cd quay chan khdng, djnh
mirc ve 100 ml. Dich chiet che dugc bao quan lanh, trong Ig kin, dimg cho phan tich tdng lugng
polyphenol.
b. Mau thi nghiem
Can chinh xac (khoang 3 g) che vun da nghien nhd, chuyen vao binh cau 250 ml (cd lap
sinh ban) va tien hanh trich li trong be dieu nhiet d cac dieu kien xac djnh ve thai gian, nhiet do,
ti le dung mdi/nguyen lieu va pH. Lgc djch che, cd quay chan khdng, djnh mirc ve 100 ml. Djch
chiet che dugc bao quan lanh, trong Ig kin.
2.3.2. Dinh lugng polyphenol tdng
sd
Djnh lugng polyphenol tdng sd duac tien hanh theo phuang phap Folin-Denis (AOAC
952.03-2000) [2]. ,,, .,
2.3.3.
Hogt tinh chdng oxy hda-khd nang quel goc tu do DPPH
Hoat tinh chdng oxy hda ciia polyphenol dugc xac djnh dua tren kha nang quet goc tu do
DPPH (2,2-diphenyl-l-picrylhydrazyl) [9]. Cac mlu djch chiet che dugc chu4n bj cd ham lugng
polyphenol (tuong duang axit gallic) 100 ppm.
2.4.
Xir li so lieu
Mdi thi nghiem dugc tien hanh lap 4 lan. So sanh su khac biet ve gia trj trung binh bing
thuat loan phan tich phuong sai (ANOVA) theo md hinh
1
ygu to. So lieu dugc xir li bang phan
mem thdng ke SPSS 11.5.
3.
KET QUA VA THAO LUAN

3.1.
Anh hudng cua thoi gian trich li
^
rich
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3
I
6000.
. d
50 00
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40 00 -
30 00
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20 00
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: d\
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30 40 50 60 70
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31 00 a> Q.
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28
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f
27 00
1
26
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Th(7i gian Inch ty (phut) ' • ' i Hieu suit Inch ly
—%
quet DPPH
Hinh
1.
Anh hudng cua thdi gian dSn hieu suit trich li va hoat tinh chdng oxy hoa ciia polyphenol
82
Tien hanh trich li cac mau che tir 30 den 70 phut d pH 3,5, ti le dung mdi/nguyen lieu 10/1
(v/m),
nhiet do trich li 90"C. Hieu suat trich li va boat tinh chdng oxy hda ciia polyphenol dugc
the hien d hinh 1.
Qua hinh 1, ta thay khi thdi gian trich li tang, hieu suat trich li tang va Idn nhat dat 56,75%
tai 60 phiit, sau dd bat dau giam. Phan tich ANOVA 1 yeu td chi ra thdi gian trich li cd anh
hudng rd d6n hieu suat trich li (F = 3816,3, p < 0,0001, a = 0,05), hieu suat trich li khac nhau d
tirng thdi gian trich li dugc bieu dien bang cac chir cai khac nhau tren cot. Quy luat tuang tu
ciing quan sat thay khi khao sat boat tinh chdng oxy hda, tang dan va ldn nhat dat
32,11%

tai 60
phiit, sau dd giam dan (F =
40,43,
p < 0,0001, a = 0,05). Ket qua nay phii hgp vdi nghien cuu
ciia Beata Druzynska [3]. Theo thdi gian trich li, djch che dan dat do bao hda, ddng thdi trong
djch che chua nhieu cac catechin cd hoat tinh cao nhu EGCG (epigallocatechin gallat), EGG
(epicatechin gallat), EGG (epigallocatechin). Khi keo dai thdi gian trich li cac catechin bj oxy
hda va triing ngung lam giam ham lugng va boat ti'nh. Do vay thdi gian trich li thich hgp tir
45 - 60 phut.
3.2.
Anh hudng ciia pH trich li
Cac mau che dugc trich li d pH tir 2,5 den 4,5, thdi gian 60 phut, ti le dung mdi / nguyen
lieu 10/1 (v/m), nhiet do trich li 90°C. Cac polyphenol la nbting chat chdng oxy hda manh, de bj
oxy hda d pH cao. Do vay d pH thap cac htrp chat polyphenol dugc bao ve tdt ban va cho hieu
suat trich li cao ban. Ket qua nghien ciiu dugc the hien d hinh 2.
60 00 -
58
00
66 00
54
00
52 00
60 00
48
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10 00
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2 5 3 3 5 4 4 5
pH
r |
Hi«u 9U^ (rich ly
•—^ qu6t DPPH
Hinh
2.
Anh hudng ctia pH den hieu suat trich li va hoat tinh chong oxy hoa cua polyphenol
Anh hudng ciia pH den hieu suat trich li la rd ret (F = 221,9, p < 0,0001, a = 0,05), khi
pH > 3,5 hieu suat trich li bat dau giam, dat 58,9% (pH = 2,5) va giam xudng 52,49%

(pH = 4,5). Ta cung nhan thay dieu tuang tu d boat tinh chdng oxy hda, dat
43.81%
(pH = 2,5)
va giam cdn 27,77% (pH = 4,5). Sir anh hudng ciia pH trich li den boat tinh chdng oxy hda ciia
polyphenol la rat rd (F = 2483,3, p< 0,0001, a = 0,05). Dieu nay cung thay trong nghien ciru cua
Yuko Yoshida [11], d pH cao lugng catechin chinh nhu EC (epicatechin), EGG, EGG, EGCG se
giam, lugng catechin cdn lai nhu C (catechin), GC (gallocatechin), CG (catechin gallat) va GCG
(gallocatechin gallat) se tang. Nhu vay pH thich hgp cho trich li tir 2,5 - 3,5.
3.3.
Anh huong cua ti le dung mdi/nguyen lieu
Tuan tu trich li cac mau che vdi ti le dung mdi/nguyen lieu tir 5/1 den 20/1 (v/m), thdi gian
60 phiit, d pH 3,5, nhiet do trich li 90°C. Trong qua trinh trich Ii, hgp chat polyphenol tir che se
chuyen vao pha nirdc do sir khuech tan, do vay hieu suat trich li se tang khi tang ti le dung
mdi/nguyen lieu. Ket qua nghien ciru dugc tht§ hien d hinh 3.
83
Hinh
3.
Anh hudng ciia ti le dung moi/nguyen lieu den hieu suat trich li va boat tinh
chong oxy hoa ciia polyphenol
Khi ti le dung mdi/nguyen lieu tang de thay hieu suat trich li tang: ti le 5/1 cho hieu suat
48,08%),
ti le 20/1 cho hieu suat cao 77,53%o. Ti le dung mdi/nguyen lieu cd anh hudng rat Idn
den hieu su4t trich li (F = 14804,9, p < 0,0001, a = 0,05). Hoat tinh chdng oxy hda cua
polyphenol cung tang: tir 27.76% (ti le 5/1) len 38,28% (ti le 15/1), giira ti le 15/1 va 20/1 khdng
thay sir khac biet ve boat tinh chdng oxy hda. Tuy nhien su khac nhau ve boat tinh chdng oxy
hda d cac ti le dung mdi/nguyen lieu ciing rat ldn (F = 782,9, p < 0,0001, a = 0,05). 6 ti le dung
mdi / nguyen lieu thap lugng catechin tu do, EC, EGG Idn, nhung khi tang ti le dung mdi /
nguyen lieu thi lugng cac chat gallat ciia catechin (EGG, EGCG) tang manh lam tang boat tinh,
theo nghien ciru cua Yuko Yoshida [11]. Khi ti le dung mdi/nguyen lieu
>15/1,

boat tinh chong
oxy hda ciia polyphenol khdng ddi, hieu suat cd tang them, nhung djch che bj loang gay nhieu
khd khan cho viec tinh che thu hdi che pham polyphenol. Do vay ti le dung mdi/nguyen lieu
thich hgp tir 10/1 - 15/1.
3.4.
Anh hudng cua nhiet do
Cac mau che dugc trich li d nhiet do tir 60°C den 100"C, thdi gian 60 phuL pH 3,5, ti le
dung mdi/nguyen lieu 10/1 (v/m). Trong qua trinh trich li, tang nhiet do se giiip qua trinh khuech
tan hgp chat polyphenol tir che vao pha nudc dugc nhanh va triet dk. KSt qua nghien ciru dugc
the hien d hinh 4.
58
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57 00
1-
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Nhi$l ao Irich ly CC)
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20 00
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1000 I
5.00
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3 Higu Suit Inch ty
-% quel DPPH
FTinh
4.
Anh hudng ciia nhiet do dkn hieu sudt trich li
va hoat tinh chong oxy hoa ciia polyphenol
De nh^n thiy khi nhiet do tang, hieu suat trich li tang: d 60''C cho hieu suat 52,67%, lOOT
cho hieu suat 57,23%). Su anh hudng ctia nhiet do dgn hieu suk trich li la rat rd rang (F =
775,1,
84
p < 0,0001, a = 0,05). Trong quang nhiet do tit 60°C - 80''C, boat tinh chong oxy hoa cua
polyphenol hau nhu khdng ddi, khi nhiet do Idn hon 90°C boat tinh bk dau giam (F = 147,9,
p < 0,0001, a = 0,05), dieu dd dugc bieu dien bang cac chir cai tren dudng cong trong hinh 4. Do
vay nhiet do trich li thich hgp tir 80°C - 90''C.

4.
KET LUAN
Qua trinh trich li polyphenol tir che xanh vun bang dung mdi nudc chju anh hudng manh
ciia cac yeu td nhu: thdi gian trich li, pH trich li, ti le nudc/nguyen lieu va nhiet do trich li. Da
xac djnh dugc khoang anh hudng cua cac yeu td chinh tac ddng d^n qua trinh trich li polyphenol
lir che xanh vyn nham thu dugc che pham polyphenol vdi hieu suat va boat tinh chong oxy hda
cao.
Cu the tien hanh qua trinh trich li trong khoang: thdi gian tir 45 dkn 60 phuL pH tir 2,5 d^n
3,5,
ti le nudc/nguyen lieu (v/m) tir 10/1 den 15/1 va nhiet do trich li tir 80°C den 90°C.
TAI LIEU THAM KHAO
1.
Vu Thy Thu, Doan Hiing Tien, Dd Thj Gam. Giang Trung Khoa - Cac hgp chat hda hgc
cd trong che va mdt sd phuang phap phan tich thdng dung trong san xuat che d Viet Nam,
NXB Ndng Nghiep, 2001.
2.
AOAC - Official Method 952.03, 2000.
3.
Beata Druzynska, Agnieszka Stepniewska, Rafal Wolosiak - The influence of time and
type of solvent on efficiency of the extraction of polyphenols from green tea and
antioxidant properties obtained extracts. Acta Sci. Pol., Technol. Aliment 6(1) (2007) 27-
36.
4.
Hara Yukihiko - Process for the production of a natural antioxidant obtained from tea
leaves, US patent 4.673.530, 1987.
5.
Jae-Moon Rho, Jae-Kun Chun - Automatic operating system for microwave assisted
extraction of food. Food Engineering Progress 5 (2) (2001) 125-129.
6. Nakachi Kel, Kazue Imai and Kenji Suga - Epidemiological Evidence for Prevention of
Cancer and Cardiovascular Disease by Drinking Green Tea, Department of Epidemiology,

Saitama Cancer, Center research institute: 818 Komuro, Ina, Saitama 362, Japan, 1997.
7.
Pan T., Jankovic J., Le W. - Potential iheurapeutic properties of green tea polyphenol in
Parkinson's disease. Drug aging 20 (2003)
711
-721.
8. Pham Thanh Quan, Tong Van Hang, Nguyen Hai Ha, Do Nguyen Tuyet Anh, Truong
Ngoc Tuyen - Extraction of polyphenols from green tea using microwave assisted
extraction method. In: Proceedings of the 9th conference on science and technology. Ho
Chi Minh City University of Technology, October 2005, pp. 42-45.
9. Qin Yan Zhu, Robert M. Hackman, Jodi L. Esunsa, Roberta R. Holt, and Carl L. Keen -
Antioxidative activities of Oolong tea, J. Agric. Food Chem. 50 (2002) 6929-6934.
10.
Xu Y., Ho C.T., Amin S.G., Han C, Chung F.L. - Inhibition of tobacco-epecific
nitrosamine-induced lung tumorigenesis in A/J mice by green tea and its major polyphenol
as oxidants, Cancer Res. 52 (1992) 3875-3879.
1 1. Yuko Yoshida, Masaaki Kiso, Tetsuhisa Goto - Efficiency of the extraction of calechins
from green lea. Food Chemistry 67 (1999) 429-433.
85
SUMMARY
STUDY ON POLYPHENOL EXTRACTION FROM DUST GREEN TEA
PART
1.
THE INFLUENCE FACTORS ON POLYPHENOL EXTRACTION
Traditionally, green tea extract is obtained by water or organic solvent extraction. In this
paper, polyphenol extraction was carried out by using water extraction from dust green tea,
harvested from Phu Ho, Phu Tho province. The aims of the study is to investigate the influence
factors on the efficiency of
the
extraction of polyphenols (a functional group with many precious

biological activities) from dust green tea. Tea extract was analysed for the content of total
polyphenols by Folin-Denis method and the antioxidant activity of this extract was determined
by DPPH free radical scavenger activity. This work was focused on researching of several main
influence factors on the extraction of polyphenols from green tea including extraction time, pH,
solvent/material ratio and extraction temperature. The range of these factors to get high yield of
both polyphenols and antioxidant activity were 45 - 60 min; 2,5 - 3,5; 10/1 - 15/1 and SOT -
90°C,
respectively.
Dia
chi:
Nhdn bdi ngdy 22 thdng
3
ndm
2008
Trudng Dai hgc Bach Khoa Ha Ndi.