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

Chia sẻ: Bút Màu | Ngày: | Loại File: PDF | Số trang:6

Thêm vào BST

Báo xấu

76
lượt xem 9
download

Download Vui lòng tải xuống để xem tài liệu đầy đủ

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

Chủ đề:

Bình luận(0) Đăng nhập để gửi bình luận!

Lưu

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

TAPCHiKHOAHOC V A C 6 N G 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 H O N G 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 ^ 6000. . d . T 33 00 i rich 50 00 - b 32 00 f I : d \ • " a 31 00 a> Q. 40 00 - 3 be c 30 00 •? - 30 00 - "b 29 00 c 5- I . 28 00 = d 20 00 a f 27 00 1 10,00 26 00 ' 25 00 o.oo - 24 00 30 40 50 60 70 Th(7i gian Inch ty (phut) ' • ' i Hieu suit Inch ly —% DPPH quet 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 - 50 00 1 a 58 00 a T *3 ^^ s" t b 1 40 00 1 , 1 66 00 v,^b * 35 00 .§ * b • 30 00 " •; C 54 00 • C "^ c ' d ; 25 00 1 ^ 52 00 15 00 1 60 00 10 00 • 500 48 00 25 3 35 4 45 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 00 - 40 00 2 57 00 1- A, ' c 35 00 f £ o Q. 30 00 ? Q. 55.00 b ,o '^ 54 00 25 00 c 5 53 00 r a 20 00 ^ =• 52 00 15 00 - =-• 51 00 1000 I 50 00 5.00 70 80 90 000 Nhi$l ao Irich ly CC) 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.