' ap cm KHLN 4/2014 (3627 - 3633) B Vi?n KHLNVN - VAFS
ISSN 1859-0373 V vafs gov.vn
BIEN P H A P CONG NGHE XIJ LY DIEP LUC CUA QUA H 6 I TU'QI BANG HQI NU'O'C BAO HOA
NguyCn Van Duong, Vu Thi Hoang Phuong
Trung tdm Nghien cieu Ldm sdn ngodi gd. Vien Khoa hoc Ldm nghiep Viet Nam
Dua tren co so kign thirc ban dia va nhiJng dac tinh hoa hoc cua chdt diep luc thuc vat, mpt so thil nghiem sir dung hm nuoc bao hoa d l xii: ly mku diep luc cua qua hoi tuoi da duoc tiln hanh trong phong ihi nghiem va tren quy mo pilot Cac thang nhiet do cua hoi bao hoa dupc sir dung la: 110 ± 2 ^ ; 115 ± l^C: 120 ± 2''C; 125 ± 2"C va 130 ± 2''C.'Klt quk thir nghiem cho thay. I - thoi gian xu ly chat diep luc tren b l mat qua h6i tiroi ty le nghjch voi nhiet dp cua hoi bao hoa, 2 - nlu xir ly chua toi nhiet thi b l mat Tir khda: Hai nuoc bao _ qua h l i tuai se co mau xanh bpt, nhung nlu xir ly qua nhiel thi qua h6i tuoi hoa, xiJ ly diep lyc, qua h l i sg bj bien dang be mat, nhun va co mau den sSm. Trong dilu kien phong thi tuoi, tin that tinh dau. nghiem, iing voi cac thang nhiet dp noi tren, thoi gian xu ly chdt diep luc dupc xac dmh la 36 - 61 giay; con tren quy mo pilot, khao nghiem voi thiet bi cdl cong suat 400 kg/gia thoi gian xir lychdt diep luc dupc xac djnh la 70 - 90 giay. Luang tinh dau trong qua hoi tuoi bj ton thai do qua trinh xir ly chat diep luc bang hoi nuoc trong phong thi nghiem cung nhu tren quy mo pilot Cling da dirpc .xac dinh Tren quy mo phong ihi nghiem ty le t6n thdt tinh dau bang 3,71 - 4.02% long so linh dau chira trong qua hoi; con tren quy mo pilot con so nay la 3,85 - 4,27%. Mac dau lupng tinh dau bj ton that CO cao han so vai phuang phap chan qua nuoc soi (2,82 - 3,22%), nhung ham lupng tinh dau ciia san pham qua hoi kho sau khi xtr ly chat diep luc bang hoi nuac van con cao hon so voi yeu cau cua th| truang xuat khau
Key words. Saturated steam, cholorophyll treatment, fresh star anise fruit, essential oil loss.
Technological measures for treating chlorophyll of fresh anise fruit by using saturated steam
Based on indigenous knowledge and chemical characteristics of chlorophyll composition, we conducted experiments on using saturated steam to treat chlorophyll from fresh star anise fruit in laboratory and piloting. The fresh anise fruit were steamed at different temperature: 110 ± 2''C; 115 ± 2''C;
120 ± 2''C; 125 ± 2"C, and 130 ± 2"C. The results showed that: 1 - the time needed to treat chlorophyll on the surface of fresh star anise fruits inversely correlated with temperature of saturated steam used; 2 Underdone steaming the anise fruit surface retains light green color, while overheating leads lo distorting surface with mushiness and dark black color. Under laboratory conditions, corresponding to above mentioned temperature of saturated steam; chlorophyll ireatmeni process took from 36 to 61 seconds.
Under pilot conditions with an equipment of 400kg/hour, the time required for treatment is from 70 to 90 seconds. The loss of essential oil during chlorophyll treating process with using saturated steam was estimated at.
3.71 - 4,02% of total amount of essential oil in star anise fruit in laboratory, while this number was 3.85 - 4 27% at pilot scale Although the essential oil loss was higher than that in boiling water method - which was 2.82 - 3 22%, the essential oil content of dried star anise fruit after chlorophyll treatment by steaming is higher than that required for exporting.
3627
Tgp chi KHLN 2014 NguyenVan Dygng etai., 2014(4) I. DAT VAN BE
Viec xu ly mdu diep luc tren be mat qua hoi tuoi la mpt cong doan vd cCing quan trgng trong qua trinh san xudt qua hdi khd.
Qua tim hieu thuc te san xudt cua ngudi san xuat hoi tai cac tinh Lang San va Quang Ninh thdy rang, de san phdm qua hoi khd co dugc mau ndu dd, hop vdi yeu cau va thi hieu cua khach hang, trudc khi phai khd qua hdi nhdt thiet phai xir ly mau diep luc tren be mat cua nguyen lieu qud hoi tuai. Cd 3 phuang phap dugc ngudi dan six dung Id: (1) Chdn hdi qua nudc soi; (2) Phoi ti; (3) Sd\ LI (Nguyin Van Dudng, 2011).
Phuang phap chan hoi qua nudc sdi la phuang phap cd truyen da cd tir lau. Khi dugc chan qua nudc soi dting ky thudt, qua hdi se co mdu nau do, trdng rdt '"bat mat". Nhung nhugc diem ca ban cua phucmg phap nay la lao ddng vat va, nang sudt thap. Bdi \d\ hau nhu tai nhii'ng dia phucmg cd nliieu hdi d Lang Scm va Quang Ninh phuang phap nay da hi ngudi dan 'iang quen".
Phuang phap phoi it la rai deu mdt Idp qua hoi tuai mdi hai tren sdn xi mang hoac tren vai bat vao budi sang cua nliung ngay ndng to, sau 5 - 6 gid thi phu mot Idp ni Idng mau trang len tren be mat qua hdi. Dudi tac dung CLia birc xa mat trdi, sau mgt khoang thdi gian chimg 4 - 5 gid, chdt diep luc mau xanh tren be mat cua qua hdi chuyen sang mau vang nau. Phuang phap nay hien vdn dugc ngudi dan d nhieu nai nhu Trang Dinh, Binh Gia, Tan Doan, Diem He... su dung. iTu diSm ca ban cua phuomg phap nay la tdn it cdng, nhimg nhugc di^m la phu thudc hoan toan vao dieu kien thdi tiet.
Cdn ddi vdi phuang phap sdy it - qua hdi tuai thu hai \ e dugc cho vao bao tai. \kp d6ng cac bao tai tren 2 - 3 thanh go dai khoang 1,5 - 2,5m. Phia dudi de 1 - 2 chau than cui hay
than cam chay am i. Ca khdi baatai hdi dugc triim kin bang bat, duy tri nhiet do 30 - 40''C trong vdng 1 2 - 1 8 gid, cho den khi thay toan bd qud hdi chuyen sang vang nau. l/u diem ciia phuang phap nay la it tdn cdng, mpt me u cd the so che tir 1 - 3 tan qud tuoi, nen hien nay phucmg phap nay da dugc nhieu co sd san xuat hdi d Lang Som dp dung. Tuy nhien phuang phap nay cdn cd mdt sd nhugc diem;
1 - mau sac qua hdi khdng dong nhat, phdn ldp qua phia dudi sat chdu than hi chuyen mau nau sam cdn ldp qua nam phia tren lai chua dii nhiet de khir dugc chdt diep luc; 2 - sdn pham rdt de bj am khoi, dac biet la khi sir dung Clii hoac than cam.
Tren ca sd nhirng kien thiic ban dia da thu thap dugc ciing vdi nhung hieu biet ve dac tirJi hoa hpc ciia chat diep luc trong thuc vat, Du an SXTN: ''ifng dung liin hp ky thugt, xdy dung md hinh .sdn xudt qud hdi khd vd tinh ddu hdi ddm hdo tieu chudn xudt khdu" da trien khai nghien cuu xir ly mau diep luc bdng hai nudc bao hda tren quy md phdng thi nghiem va quy md pilot.
Uu diem cua viec su dung hai nudc bao hoa la xir Iy nhanh, nang sudt cao, chii ddng trong sdn xudt va khdng bi le thuoc vao di6u kien thdi tiet.
II. V^T LIEU, NOI DUNG VA PHUONG PHAP NGHIEN CUtJ
2.1. Vat lieu nghien ciiu
Ddi tugng nghien cuu la qud hdi tuai dat dp chin, thu hai vao thang 9 (duong lich) tren dia ban huyen Van Quan, tinh Lang San. Lira chpn qua cd dudng kinh tdi thiau 2,5cm, canh khdng giap, khdng bi sau benh.
Thiet bi nghien ciai tren quy md phdng thi nghiem: Ndi cung cdp hai SEB (Phap); Tu sdy CO ban Memmert, seri D06866 GMbH (Dire); Bd xac dinh ham lugng tinh ddu da nang (Dire); Bd xac djnh ham dm Dean -
Nguyen Van DworiQ et at. 2014(4) Tgp chi KHLN 2014 Stark; Nhiet kg, khoang do 0 - 200''C; Cdn
phdn tich Denver (My).
Thiet bj nghien curu tren quy md pilot; Ndi hoi, cong sudt 200kg hoi/gid; Jhik bi xir ly diep luc, cdng sudt 400kg/me; May do dp dm cdm tay MD - 7822 (My): Can nhiet Omron (Nhdt Bdn); Van dieu ti^t hoi (Han Qudc).
2.2. Noi d u n g nghien cuu
- Xac dinh thdi gian xir ly mdu diep luc tren be mat qua hdi tuai bang hoi nudc bao hda tren quy md phdng thi nghiem.
- Tren co sd kit qua thu dugc tir phdng thi nghiem se tien hanh thu nghiem xac dinh thdi gian xir ly mau chdt diep luc tren hk mat qua hdi tuai bang hod nudc bao hoa tren quy md pilot.
Cac thang nhiet dp ciia hai bao hda dugc sir dung la: 110 ± 2"C; 115 ± 2"C; 120 ± 2°C;
1 2 5 ± 2 " C v a l 3 0 ± 2 " C ;
Khoi lugng mdu qua hdi tuoi xit ly trong phdng thi nghiem: 0,5kg/mdu;
Khoi lugng mau qua hdi tuoi xir ly tren quy mo pilot: 400kg/me.
- Xac dinh lugng tinh ddu hdi bi tdn that do xu ly mau diep luc bang hoi nudc bao hda.
- Xac dinh ham lugng tinh ddu ciia sdn phdm qua hdi khd tir nguyen lieu qud hdi tuoi da dugc xii Iy mau diep Iuc bang hai nudc bao hda.
2.3. P h u o n g p h a p nghien cuu
Co sd khoa hoc ciia vdn de xir ly chdt diep luc bang hai nudc bao hda:
Trong tu nhien chdt diep Iuc thuc vat tdn tai d 6 dang khac nhau:
Diep luc td a (C55H7205N4Mg), Diep luc td b (C55H7o06N4Mg), Diep Iuc td cl (C35H3o05N4Mg), Diep luc td c2 (C55H2a05N4Mg), Diep luc td d (C54H7o06N4Mg) va Diep luc td f (C55H70O6N4).
Trong dd phd bien nliat la Diep Iuc td a vd b;
cdn Diep luc td d va f thi rdt hi^m, chi dirge tim thdy trong mdt sd loai tao bi6n. Ham lugng diep luc td trong thuc vat vao khoang 0, 7 1, 3 % trgng lugng khd cua cay.
Chlorophyll lan trong nhieu dung mdi hiiu ca nhung khdng tan trong nudc. Nhiet dp chdy mem ciia chlorophyll a nam trong khoang 117 - ! 2 r C va cua chlorophyll b 124 - 125"C.
Dudi tac dung ciia nhiet dp, anh ndng mat trdi (quang hda). hoa chat va cdc enzym chdt diep luc de hi chuyen hda d trong va ngoai t^ bao thanh mpt loat cac dan xuat khac nhau nhu pheophytin, pheophorbide, pyropheophytin, pyropheophorbide, chlorophyllide, pyrochlorophyll, caroten, hydroxychlorophyll... Cac ddn sudt nay co mau rat khac nhau, tir khdng mau, qua mau xanh diiu, mau ca rot rdi tdi mau nau sdm (Kephart John C , 1995). Can cir vao nhiing dac tinh tren ciia diep luc chung toi da chpn khung nhiet dp tir 110 - HO'^C de xir Iy mau ciia diep Iuc bang hai nudc nham lam cho qua hdi kho cd dupc mau dap irng yeu cau ciia thj trudng.
- Phuang phap thi nghiem:
+ Danh gia mau sac qua hdi tuoi da dugc xii ly mdu diep luc bang cam quan.
+ Dp am ciia nguyen lieu dugc xac dinh tren thiet hi Dean Stark vdi dung mdi khong phdn cue;
+ Ham lugng tinh dau ciia qud hdi tuoi trudc va sau khi xir ly chdt diep luc dugc xac djnh tren thiet bi chung cdt tinh ddu thi nghiem cua Dire; tinh theo % so vdi khdi lugng khd kiet ciia qua hdi, theo cdng thiic:
lOOxm,,,
Trong do- mtd la khdi lugng tinh ddu hoi chung cat duoc; mni la khdi lugng nguyen lieu mau qua hdi dem chung cdt; w la khdi lugng
Tap chi KHLN 2014 Nguyen Van Difdng etai., 2014(4) nudc chiia trong nguyen lieu qua hdi. Ca 3 dai
lugng nay dugc tinh theo gam.
+ Ty le tdn thdt tinh ddu cua qua trinh xir Iy chat diep luc bdng hoi nudc vdi lugng tinh dau thdt thoat khi xir ly chdt diep luc theo phuang phap cd truyen ia chdn qua nudc sdi dugc tinh theo cdng thirc:
1 0 0 ( a | - a , ) a,
Trong do: a[ la ham lugng tinh ddu ciia mau qua trudc khi xii ly, %; az la ham lugng tinh dau cua mdu qua sau xir ly, %.
+ Ham lugng tinh dau cua sdn phdm qua hdi khd sau say dugc xac dinh theo TCVN 7039: 2002.
+ Miic dp lap lai cua cac thir nghiem tren quy md phdng thi nghiem: 3 ldn. Ldy kSt qua trung binh.
III. KET QUA VA NHAN XET
3.L Xac djnh thoi gian xir ly mau diep luc cua qua hoi tuoi bang hoi nuffc bao hoa trong phong thi nghiem
Ban^ 1. Ket qua xac djnh thdi gian xir ly chat diep luc bang hai nudc bao hda
trong phong thi nghiem No
1 2 3 4 5
Nhi?t dp hoi (°C) 110±2 115±2 120 ± 2 125 ± 2 130 ± 2
Thoi gian XLF ly. giay (s)
61 53 47 41 36
Ghi chu
3.2. Xac dinh thoi gian xii- Iy man diep luc bang hoi nuoc bao hoa tren quy md pilot Dua tren nhiing k§t qua thu dugc tir phdng thi nghiem, cac thir nghiem vk xir ly mau diep luc bang hoi nudc bao hoa da dupc lien hanh tren thiet hi cua Du an SXTN: "iTng dung ti^n bd
ky thudt, xay dung md hinh sdn xudt qua hdi khd va tinh dau hdi xuat khdu" dat tai thon Chg Bai 2, xa Yen Phiic, huyen Van Quan, Lang San, ket qua nhu sau:
Bang 2. Ket qua xac dinh thdi gian xir ly chdt diep luc bang hoi nudc bao hda tren quy mo
pilot TT
1 2 3 4 5
Nhiet dp hoi (°C) 110±2 116±2 120 ± 2 125 ± 2 130 + 2
Thoi gian XLF iy, giay (s)
90 87 82 76 70
Ghi chu
Nhdnxel-
Qua trinh xtj ly mau diep Iuc bang hai nuoc bao hoa dien ra rat nhanh, trong khoang nhiet dp tir 110 - 130°C, thai gian khir la 36 - 61 giay tren quy mo phong thi nghiem va 70 - 90 giay tren quy mo pilot;
Tren quy mo phong thi nghiem cung nhu tren quy mo pilot, thoi gian xCr ly mau diep luc tren b l mat cua qua hSi tuai phu thupc vao nhiet dp ciia hoi; trong khoang nhiet dp thit nghiem, nhiet dp cua hai cang cao thi thoi gian xir ly cang ngan.
Do thao tac timg me, nen cong doan chilm nhieu thoi gian nhjt trong qua trinh xti ly mau diep luc bang hai nuoc bao hoa tren quy mo pilot la viec nap lieu va ra lieu.
3.3. Xac dinh ty le ton that tinh dau Qua trinh xir ly mau diep luc cung lam mk di mpt lupng tinh dau co trong qua h5i, mirc dp ton that tinh dau phu thupc vao phuang phap xit ly. Trong cac phucmg phap nhiet (phoi il, sky u, chan qua nuoc soi), t6n thit tinh d4u con phu thupc vao nhiet dp va thcji gian xir ly.
Ty le t6n thit tinh d i u duac tinh bang % giua khoi lupng tinh dau m i t di trong qua trinh xir
j^liHygfl^n Du-gng etai. 2014(4) Tap chi KHLN 2014 ly vdi tdng khdi lugng tinh ddu chiia trong
mau qua hdi tuoi trudc khi xii Iy.
T\' le tdn that tinh dau trong qua trinh khu mau diep Iuc bang hoi nudc bao hda dugc so sanh vdi ty Ie tdn thdt tinli ddu khi xir ly bdng phuong phap chdn qua nudc sdi d ap sudt thudng (100"C).
De dam bao tdn thdt tinh ddu trong qua trinh xir ly mau diep luc bang hoi nudc bao hda van
nam trong gidi han cho phep; nghia la ham lugng tinh ddu con Iai trong san phdm qua hdi khd \'an con cao hon so vdi yeu cdu ciia nhirng thi trudng cao cdp nhu EU, Bdc My va Nhat Ban (8,0%), chung toi da ti^n hanh cdc thi nghiem chung cdt tinh ddu vdi cac mau qud hdi tuoi ca trudc va sau khi xir ly diep luc bang hoi nudc bao hoa. Kk qua thir nghiem d bang 3.
ang 3. Ty le tdn thdt tinh ddu trong qua trinh xir ly chdt diep Iuc bdng hai nudc bao hoa tren quy md phong thi nghiem
T T
1 2 3 4 5
Nhi?t do hoi bao hoa (°C)
110±2 115±2 120 ± 2 125 ± 2 130 ± 2
Ham iLFp-ng tinh d i u
(%)
T r i F o c XLF ly a i 15,02 14,39 14.87 15,48 15.25
Sau XLF ly 02 14,47 13.85 14.30 14,87 14,64
Ty lp ton that tinh d i u
(%)
1 0 0 ( a i - 0 2 ) : Oi 3,82 3,71 3,85 3,91 4,02
Nhdn xet: ton thdt mpt Iirgng tinh ddu bdng 3,71 - 4,02%
Qud trinh xir Iy chdt diep Iuc bdng hoi nudc '^'^O' '^^'"g ^'"h ddu chira trong qua h6i.
bao hda tren quy md phdng thi nghiem da Iam
Bang 4. Ty le tdn thdt tinh ddu trong qua trinh xir ly chdt diep Iuc bang hoi nudc bao hoa tren quy md pilot
TT
1 2 3 4 5
Nhipt dp hoi bao hoa (°C)
1 1 0 ± 2 115±2 120 ± 2 125 ± 2 13012
Ham iiFong tmh dau (%) Tru'oc XU" iy
a, 15,32 14,71 15,65 15,17 14,91
Sau XLF ly 02 14,70 14,14 14,98 14,57 14,87
Ty lp ton t h i t tinh d i u {"/.) 100(ai -02) : a i
4,07 3,85 4,27 3,96 4,18
Nhdn xet:
Qua trinh xir ly chat diep luc bang hai nudc bao hda tren quy md pilot da lam tdn that mgt lugng tinh dau bang 3,85 - 4,27% tdng khdi lugng tinh ddu chira trong qua hdi. Khi chdn
qua nudc soi, ty le nay la: 2,82 3.22%
(Nguyen Van Duang, 2011).
Ty Ie tdn that tinh dau khi xii ly chat diep Iuc bang hai nudc bao hda tren quy md pilot cao han so vdi tren qu\ md phong thi nghiem.
Tap chi KHLN 2014 Nguyin Van Dugng ef a/. 2014{4) Xde djnh ham lugng tinh ddu hdi cua san
phdm qua h6i kho sau khi da dugc xir Iy chdt diep Iuc bang hoi nudc bao hoa.
Sau khi xir ly chdt diep luc bang hoi nudc bao hda, qua hdi dugc dua vao say kho trong tii say CO ban Memmert, seri D06866 - GMbH (quy mo phdng thi nghiem) va Id sdy hdi gian
tiep cua Du dn (quy md pilot) tai Yen Phuc, Van Quan, Lang Son den do am 13,0%.
Cac sdn phdm qua hdi khd nay sau do da dugc tien hanh chung cdt tai phdng thi nghiem d^
xac dinh hdm lupng tinh dau. Ket qua thu dugc d b a n g 5.
Bang 5. Ham lugng tinh ddu cua sdn phdm qua hoi khd sau khi dugc khu bd chdt diep luc bang hoi nudc bao hda
TT 1 2 3 4 5
Nhiet dp cua hoi bao hoa (°C) 11012 115±2 120 ± 2 126 ± 2 130±2
Ham tu'ong tinh dau {%) Miu o phong thi nghipm
13,34 12,75 13,12 13,70 13,51
M i u XLF iy 6 piiot 13,46 12,94 13,70 13,34 13,59
Nhu da ndi d phdn phuang phdp, ham lupng tinh ddu trong bai nay dupc tinh theo % so vdi khdi lupng nguyen lieu kho kiet, each tinh toan nay dugc diing phd bien trong cac tai lieu khoa hpc, mot so lac gid con gpi ddy la hdm lugng linh ddu tuyet doi (absolute content).
Con tren thi trudng giao dich, ciing nliu trong cac tieu chudn quy djnh ddi vdi sdn phdm qud hoi khd, ham lupng tinh ddu dugc sir dung la hdm lirgng tinh ddu tuang ddi (relative content). Day la ty le % giOa khoi lugng tinh ddu vdi khoi lugng qua hdi khd (khdng phdi la
khd kiet, ma van cdn chira mpt lugng dm nhdt dinh nao dd). Cdng thirc chuyen ddi giiia ham lugng tinh dau tuyet ddi sang ham lupng tinh dau tuang ddi la: Qr = a^ (100 - Wr): 100.
Trong do: Wj la ham lugng nudc ciia qua hoi khd. Ham lupng nudc cua san phdm hoi kho dugc nhii'ng thi trudng cao cdp quy dinh khdng vugt qua 13,0%. Kit qua chuyin d6i ham lugng tinh dau tuyet d6i (ttg) d bang 5 sang ham lupng tinh ddu tuong ddi (ttr) dugc dua vdo bang 6.
Bang 6. Ham lugng tinh ddu tuong ddi ciia sdn phdm qua hdi khd sau khi dugc xir ly chdt diep luc bdng hoi nudc bao hda
T T
1 2 3 4 5
Nhiet dp cija hoi bao hoa (°C|
110 + 2 115±2 12012 125 ± 2 130 ± 2
Ham iupng tinh d i u tu'ong ddi (%}
M i u o phong thi nghiem 11,61 11,09 11,41 11,92 11,75
iVIIu XLF iy a piiot 11,71 11,26 11,92 11,61 11,82 Nhgn xel •
San pham qua hoi kho thu dupc tir qua h6i tuoi sau khi da xu ly diep luc bang hai nuac
bao hoa a cac thang nhiet dp khac nhau tren quy mo phong thi nghiem cung nhu tren quy mo pilot v i n con chira mot ham luong tinh dau dam bao dimg cho xuat khiu.
J % j y t ! i y a n Duong etai, 2014(4) Tap chi KHLN 2014 IV. K E T LUAN
- Qua trinh xir ly chdt diep luc tren be mat qua hdi tuoi bang hai nudc bao hda dien ra rat nhanh. Vdi cdc thang nhiet dd trong khoang tir 108 - 132''C, thoi gian xir ly chdt diep luc la 36 - 61 gidy tren quy mo phdng thi nghiem va 70 - 90 gidy tren quy md pilot;
- Thdi gian xir ly chat diep Iuc bang hoi nudc bao hda ty le nghich vdi nhiet dp hoi;
- 0 khodng nhiet dp hoi khdo nghiem tir 108 - 132''C, ty le tdn that tinh ddu trong qua trinh
khir bd chdt diep luc bang hoi nudc bao hoa tren quy md phdng thi nghiem bang 3,71 4,02% tdng sd tinh ddu chira trong qua hoi;
con tren quy md pilot con sd nay la 3,85 - 4,27%.
- Mac dii cd ton thdt tinh ddu do qud trinh xu ly chdt diep luc bang hai nudc bao hoa tren quy md phdng thi nghiem cung nhu tren quy md pilot, cac mdu san pham qua hdi kho vdn con chira mpt ham lugng tinh ddu cao hon so vdi yeu cdu xudt khdu.
TAI LIEU T I U M KHAO
1. Nguyen Van Duang, 2011. Bao cao tong Icet de tai "Tliigt ke, che tao va chuydn giao he thflng chirng ck tinh dau hoi quy mo nho".
2. Nguyin VSn Dan, Nguyin Viet Tiru, 1995 Phirong phap nghien ciiu hoa hoc cay thuflc, Nxb. Y hoc.
3 Vij Nggc Lfl va dong tac gia, 1996. NhiJiig cay tinh dau Viet Nam: Khai thac, che bien, iing dung Nxb. Khoa h o c & K y thuat HaNoi.
4 Tieu chuSn Viet Nam TCVN 7039' 2002
5. Kephart, John C . 1995. "Chlorophyll derivatives-Their chemistry? Commercial preparation and uses" Journal of Ecological Botany 9: 3.
6. http://en.wikipedia,org/wiki/Chlorophyll.
7. Mednhicop F. A., 1976. Chlorophyll, tinh chat hoa hoc va irng dung, Nxb. Cong nghiep rung Mafxcova.
Ngu-oi t h a m d m h : G S . T S . H a C h u C h i r