LI CM N Tri qua thi gian hc tp ti trng v 3 thng lm n tt nghip ti Vin
nghin cu v ng dng Nha Trang, ti hon thnh bi n: Nghin cu trch
ly phlorotannin t rong Nu Sargassum Serratum v ng dng to sn phm
ung giu phlorotannin.
t c kt qu , trc ht ti xin by t lng bit n su sc n
PGS.TS Bi Minh L ngi tn tnh gip ti trong sut thi gian ti tin
hnh thc hin ti.
Ti chn thnh cm n qu Thy, C Khoa Cng ngh Thc Phm trng
i hc Nha Trang tn tnh dy d, ch bo ti trong sut thi gian hc ti
trng.
Xin gi li cm n n TS. Trn Th Thanh Vn, Th.S V Mai Nh Hiu,
Ks. Trn Nguyn H Vy cng cc anh ch cng tc ti phng th nghim ha phn
tch v trin khai cng ngh ca Vin tn tnh hng dn, gip ti trong sut
qu trnh thc hin n ny.
Ti xin gi li cm n n gia nh, bn b l ch da vng chc, ht lng
ng vin gip ti trong sut qu trnh hc tp cng nh thc hin ti.
Mt ln na ti xin chn thnh cm n!
Nha Trang, thng 6 nm 2012
Sinh vin thc hin
Hong Th Thy An
i
MC LC
MC LC ...............................................................................................................I
LI M U .........................................................................................................1
CHNG 1: TNG QUAN .................................................................................3
1.1. TNG QUAN V RONG BIN [1]. ............................................................3
1.1.1 c im, s phn b rong bin. ...............................................................3
1.1.2 Ngun li rong bin Bo v v pht trin ngun li rong bin Vit Nam.........4
1.1.3 Phn loi rong bin.....................................................................................7
1.1.4 Thnh phn sinh ha ca rong bin ............................................................8
1.1.5 Gi tr dinh dng v ng dng ca rong bin............................................8
1.1.6 c im sinh trng, pht trin v thi k thu hoch rong bin hp l cho
cng ngh ch bin. ...........................................................................................10
1.1.7 Tnh hnh s dng, ch bin rong bin Vit Nam..................................12
1.2 Qu trnh vn chuyn v cc bin php bo qun rong kh. ........................12
1.3 Gii thiu v rong Nu v rong M (Sargassum). .......................................13
1.3.1 c im. ................................................................................................13
1.3.2 S phn b [1].........................................................................................16
1.3.3 Thnh phn ha hc ca rong Nu. .........................................................18
1.4 Mt s quy trnh cng ngh sn xut cc cht t rong Nu.........................24
1.4.1 Cng ngh ch bin Mannitol t rong Nu [1].........................................24
1.4.2 Chit rt Iod t rong Nu [1] ....................................................................... 25
1.5 Tng quan v hp cht Phlorotannin (polyphenol). .....................................26
1.5.1 c im. ................................................................................................26
1.5.2 C ch oxi ha ca polyphenol................................................................27
1.5.3 Hot tnh sinh hc ca phlorotannin. .......................................................28
1.5.4 ng dng. ...............................................................................................29
1.6 Gii thiu v qu trnh trch ly. ...................................................................30
1.6.1 Bn cht. .................................................................................................30
1.6.2 Phm vi s dng ca qu trnh. ...............................................................30
1.6.3 Cc yu t nh hng n qu trnh chit................................................31
ii
1.6.4 Tng quan v dung mi chit. .................................................................32
1.6.5 Tm hiu dung mi chit trong ti. ......................................................34
CHNG 2: I TNG V PHNG PHP NGHIN CU..................37
2.1 i tng nghin cu. ................................................................................37
2.2 Ha cht v dng c th nghim. .................................................................37
2.3 Phng php nghin cu ............................................................................37
2.4 Quy trnh trch ly v thu nhn phlorotannin.................................................41
2.4.1 S quy trnh.......................................................................................41
2.4.2 Thuyt minh quy trnh.............................................................................42
2.5 Cc yu t nh hng n qu trnh trch ly Phlorotannin. ..........................43
2.5.1 Tin hnh kho st iu kin mi trng (pH) trch ly.............................43
2.5.2 Tin hnh kho st t l dung mi trch ly. ..............................................44
2.5.3 Tin hnh kho st nhit trch ly.........................................................45
2.5.4 Tin hnh kho st thi gian trch ly........................................................46
2.5.5 Tin hnh xc nh hiu sut trch ly .......................................................47
2.5.6 Th nghim xc nh nhit c c. ......................................................48
2.5.7 Th nghim xc nh thi gian ly tm ......................................................49
2.6 ng dng cao chit phlorotannin vo qu trnh to sn phm: nc ung
rong bin ng chai. ..............................................................................................50
CHNG 3: KT QU NGHIN CU V THO LUN ............................52
3.1 Kt qu xc nh mt s thnh phn ca rong nguyn liu. .........................52
3.2 Kt qu kh mi ca rong bin. ..................................................................53
3.3 Kt qu xc nh thng s thch hp ca qu trnh chit phlorotannin. ........53
3.3.1 Kt qu xc nh nh hng ca mi trng (pH) n kh nng chit. ....54
3.3.2 Kt qu xc nh nh hng ca t l NL/DM (khi lng/th tch) n
kh nng chit. ...................................................................................................55
3.3.3 Kt qu xc nh nh hng ca nhit n kh nng chit. .................58
3.3.4 Kt qu xc nh nh hng ca thi gian n kh nng chit. ................59
3.3.5 Xc nh hiu sut trch ly.......................................................................61
3.3.6 Kt qu xc nh thng s thch hp ca qu trnh c c........................63
iii
3.3.7 Kt qu xc nh thng s thch hp ca qu trnh ly tm........................66
3.3.8 xut quy trnh chit phlorotannin t rong Sargassum Serratum. .........67
3.3.9 ng dng cao Phlorotannin vo qu trnh to sn phm. .........................69
KT LUN V XUT KIN ....................................................................74
TI LIU THAM KHO .....................................................................................77
PH LC..................................................................................................................
iv
DANH MC BNG
Bng 1.1: Ngun li, sn lng thu hoch v tim nng sn xut rong bin [1]. ......5 Bng 1.2: Din tch cc vng c th qui hoch nui trng rong bin mt s tnh duyn hi Vit Nam [1]. ..........................................................................................6 Bng 1.3: Cc ging loi rong Nu tm thy v phn b. .......................................16 Bng 1.4: Tr lng rong M theo vng bin cc tnh...........................................17 Bng 1.5: Hm lng Mannitol 2 loi rong S.mcclurei v S.kjellmanianum ti Hn Chng Nha Trang 1979 (% so vi trng lng kh tuyt i)................................18 Bng 1.6: Hm lng axit Alginic trong cc loi rong Nu ...................................20 Bng 1.7: Hm lng axit amin mt s loi rong Nu vung bin Jeddah, Saudi Arabia (mg %).......................................................................................................22 Bng 1.8: Hm lng Iod trong cc loi rong Nu (% trng lng kh) Nha Trang Khnh Ha. ...........................................................................................................23 Bng 2.1: Cc mc cht lng ..............................................................................39 Bng 2.2: H s trng lng ca sn phm............................................................40 Bng 3.1 Thnh phn ha hc chnh ca rong nguyn liu ....................................52 Bng 3.2 nh hng ca nng dung dch H2O2 n kh nng kh mi............53 Bng 3.13: nh hng ca nhit n hm lng Phlorotannin v Carbohydrate trong qu trnh c c. ...........................................................................................64 Bng 3.14: Hm lng cc thnh phn (%) sau khi c c.....................................65 Bng 3.15 Kt qu nh gi cm quan dch chit. .................................................66 Bng 3.16: Ch tiu ha l v nht ca mt s sn phm nc ngt..................69 Bng 3.17: Kt qu nh gi cm quan dch chit theo t l dch cao b sung. ......69 Bng 3.18: Bng nh gi cm quan dch chit theo t l ng phi ch .............70 Bng 3.19: Kt qu ch tiu vi sinh theo thi gian thanh trng...............................71 Bng 3.20: Bng m t sn phm nc rong bin ng chai c b sung cao phlorotannin. .........................................................................................................71 Bng 3.21: Bng phn tch cc thnh phn ca sn phm sau khi b sung cao phlorotannin. .........................................................................................................72 Bng 3.22: Kt qu kim tra ch tiu vi sinh vt trong sn phm............................72
v
DANH MC HNH
Hnh 1.1: S hnh chit Mannitol bng phng php ha tan trong Alcol ..........25
Hnh 1.2: S quy trnh tng qut chit rt Iod t rong Nu...................................26
Hnh 1.3: Phloroglucinol (i) v phlorotannin [tetrafucol A (ii), fucodiphloroethol B
(iii), fucodiphlorethol A (iv), tetrafuhalol A (v), tetraisofuhalol (vi),
phlorofucofuroeckol (vii)] v hot tnh ca chng. ................................................27
Hnh 2.1: Rong M (Sargassum serratum) .............................................................37
Hnh 2.2: S quy trnh thu nhn phlorotannin t rong Sargassum Serratum. ......41
Hnh 2.3: S b tr th nghim xc nh nh hng ca pH ................................44
Hnh 2.4: s b tr th nghim xc nh nh hng ca t l dung mi n kh
nng trch ly. ..........................................................................................................45
Hnh 2.5: S b tr th nghim xc nh nh hng ca nhit ........................46
Hnh 2.6: S b tr th nghim xc nh nh hng............................................47
Hnh 2.8: S b tr th nghim xc nh nhit c c.....................................48
Hnh 2.9: S b tr th nghim xc nh thi gian ly tm ....................................49
Hnh 2.10: S quy trnh to sn phm nc ung rong bin ng chai...............50
Hnh 3.1a: Biu biu din nh hng ca pH trch ly n hm lng
phlorotannin trong qu trnh chit ..........................................................................44
Hnh 3.1b: Biu biu din nh hng ca pH trch ly n hm lng
carbohydrate trong qu trnh chit. .........................................................................55
Hnh 3.2a: Biu biu din nh hng ca t l NL/DM n hm lng
phlorotannin trong qu trnh chit...........................................................................56
Hnh 3.2b: Biu biu din nh hng ca t l NL/DM n hm lng
carbohydrate trong qu trnh chit. .........................................................................56
Hnh 3.3a: Biu biu din nh hng ca nhit chit n hm lng
phlorotannin trong qu trnh chit...........................................................................58
Hnh 3.3b: Biu biu din nh hng ca nhit chit n hm lng
carbohydrate trong qu trnh chit. .........................................................................58
vi
Hnh 3.4a: Biu biu din nh hng ca thi gian chit n hm lng
phlorotannin trong qu trnh chit...........................................................................60
Hnh 3.4b: Biu biu din nh hng ca thi gian chit n hm lng
carbohydrate trong qu trnh chit. .........................................................................60
Hnh 3.5a: th biu din hm lng phlorotannin trong cc ln trch ly ............61
Hnh 3.5b: th biu din hm lng carbohydrate trong cc ln trch ly...........62
Hnh 3.6a: th biu din hiu sut trch ly phlorotannin trong cc ln trch ly ....62
Hnh 3.6b: th biu din hiu sut trch ly carbohydrate trong cc ln trch ly...63
Hnh 3.7: S quy trnh chit rt phlorotannin t rong Sargassum Serratum
Khnh Ha. ............................................................................................................67
1
LI M U
X hi ngy cng pht trin, i sng con ngi ngy cng c nng cao.
Con ngi khng ch quan tm n nhng vn n, mc, n gin nh trc
y m cn c nhng yu cu cao hn. Khi i sng c nng cao, con ngi ngy cng quan tm hn n sc khe ca mnh. Do , nhng thc phm, vt dng c th gy hi cho sc khe dn b loi b v c thay th bng cc sn phm c sn xut t cc thnh phn chit xut t thin nhin. Nhu cu ca con ngi l mt trong nhng yu t quan trng thc y x hi pht trin v cng l ng lc thc y cc nh khoa hc, nh sn xut tm ti, sng to ra nhiu sn phm mi.
Vi s pht trin ca khoa hc, con ngi bit cch chit xut ra nhiu hp cht c ngun gc t nhin c li cho sc khe con ngi v ng dng chng vo trong i sng thng qua nhiu ngnh cng nghip nh: cng nghip thc phm, cng nghip xy dng, dt mayTrong , vic ng dng cc thnh tu khoa hc vo ngnh cng nghip thc phm ng vai tr quan trng v n nh hng trc tip n sc khe con ngi. Hin nay, c rt nhiu hp cht c chit xut t thin nhin c ng dng rng ri vo i sng.
Tht vy, sn phm ung khng cn n thun l gii kht m cn phi tt cho sc khe. V th vic nghin cu sn xut cc chit xut t thin nhin b sung vo ung lun c quan tm, v nhng cht c trch ly chnh l hp cht polyphenol (phlorotannin). Thnh phn ny c s dng trong thc phm nh mt loi thc phm chc nng nhm mc ch phng nga bnh do c tnh cht khng oxi ha mnh.
Vit Nam c h ng vt, thc vt v cng phong ph, c nhiu gen qu him c trng cho kh hu nhit i nng m. Mt trong nhng iu kin to nn s phong ph v giu c y chnh l vng bin nhit i rng vi b di hn 3200 km bao bc ht pha ng v nam t nc. Mt trong nhng ngun ti nguyn phong ph v c gi tr m vng bin ban tng cho chng ta l rong bin. Rong bin l loi thc vt bin qu gi c dng lm nguyn liu ch bin thnh cc sn phm c gi tr trong cng nghip v thc phm. T lu, rong bin c coi l i tng nghin cu ca nhiu nc trn th gii. nc ta tr lng rong bin
2
rt ln, l ngun ti nguyn bin v cng phong ph, rong bin chim v tr quan trng trong lnh vc kinh t bin Vit Nam. Ngnh rong bin c nhiu loi, mt trong nhng loi c nhiu tnh nng u vit c nhiu nh nghin cu nc ta quan tm ti l ngnh rong Nu m in hnh l rong M.
Gn y, ngnh nui trng v ch bin rong bin ni ln nh mt ngnh cng nghip mi mang li mt s thnh tu nht nh. Nhiu cng trnh nghin cu v gi tr dinh dng cng nh dc hc t rong bin c cng b v ng dng rng ri trn ton cu. Ngi ta pht hin ra nhiu thnh phn qu c trong rong bin nh: Iod, Alginate, Fuccoidin, hp cht chng oxi ha (phlorotannin), cc axit bo,... rt c gi tr trong y hc, thc phm, dc phmgip cho mi quc gia gii quyt c vn nhp khu dc liu. Ngy nay, nhiu cng dng khc ca rong bin cn ang c cc nh nghin cu tip tc khm ph.
Xut pht t nhu cu ca x hi hin i, ng thi tn dng c ngun nguyn liu di do, cc nh khoa hc ca nc ta v ang tng cng nghin cu, chuyn ngun rong bin v ph thi t rong bin thnh cc sn phm c gi tr, bng cch sn xut ra cc loi thc phm khc nhau, tch chit ra cc thnh phn khc nhau c hot tnh sinh hc hoc hn hp cc thnh phn c hot tnh sinh hc gia tng gi tr rong bin Vit Nam.
gp phn vo xu th , ti thc hin ti Nghin cu trch ly phlorotannin t rong Nu Sargassum Seratum v ng dng to sn phm ung giu phlorotannin. ti gm cc ni dung:
1. Tm hiu mt s thnh phn ha hc ch yu ca nguyn liu rong Nu. 2. Kho st qu trnh trch ly phlorotannin. 3. Th nghim to sn phm ung giu phlorotannin. Bc u tip cn vi nghin cu khoa hc, trong iu kin kin thc cn
hn ch, iu kin c s vt cht, kinh ph nghin cu cn thiu thn, ngoi vic n lc ca bn thn, s gip ca gio vin hng dn cng cc anh ch ph trch phng th nghim ca Vin Nghin cu v ng dng cng ngh Nha Trang, ti hon thnh ti c giao. Tuy nhin ti khng trnh khi nhng thiu st, ti rt mong c s gp chn thnh ca cc thy c, cc bn c gi ti c hon thin hn. Ti xin chn thnh cm n!
3
CHNG 1: TNG QUAN
1.1. TNG QUAN V RONG BIN [1].
1.1.1 c im, s phn b rong bin. Rong bin hay to bin c tn khoa hc l marine algae, marine plant hay
seaweed. Rong bin l thc vt thy sinh c i sng gn lin vi nc. Chng c
th l n bo, a bo sng thnh qun th. Chng c kch thc hin vi hoc c
khi di hng chc mt. Hnh dng ca chng c th l hnh cu, hnh si, hnh phin
l hay hnh th rt c bit. Sn lng hng nm cc a dng cung cp cho tri
t hng 200 t tn rong. Nhiu nh khoa hc cho rng trn 90% carbon tng hp
hng nm nh quang hp trong mi trng lng, trong c 20% do rong bin tng
hp nn.
Rong bin thng phn b cc vng nc mn, nc l, ca sng, vng
trin su, Rong v rong Nu l hai i tng c nghin cu vi sn lng
ln v c ng dng nhiu trong cc ngnh cng nghip v i sng. i vi rong
Lc th loi to Chlorella c xp vo loi to k diu, c tc sinh khi cc
nhanh, ang c nghin cu phc v cho con ngi.
Rong bin sng bin, hp th mt lng thc n phong ph chy tri dt t
lc a ra, rong c nhiu tnh cht khng ging thc vt trn cn. Mt s yu t sinh
thi i vi ng vt sng trn cn l rt quan trng, song i vi rong bin li
khng quan trng nh m ca khng kh, lng ma. Nhng cc yu t sinh thi
bin c nh hng n i sng rong bin nh: a bn sinh trng, nhit , nh
sang, mui, PH, mui dinh dng, kh ha tan, mc triu, song, gi, hi lu.
Nhiu hp cht hu c trong rong bin c tc dng iu ha, kch thch sinh
trng i vi cy trng nh auxin, giberelin, cytokinin, mannitol v cc
oligosacaride khc. Ngy nay rong bin cn c sn xut thnh phn bn hu c
(phn bn l v phn bn gc).
4
1.1.2 Ngun li rong bin Bo v v pht trin ngun li rong bin Vit
Nam.
a. Ngun li rong bin th gii.
Ngun li rong bin trn th gii rt ln, song sn lng rong c khai thc
v s dng hng nm khng u (theo ti liu ca FAO v sn lng rong bin
hng nm trn th gii). Chu l khu vc cung cp rong . Trong ,
Philippines k t nm 1970 sau khi p dng thnh cng phng php pht trin
rong Eucheuma bng bao t chuyn ln hng u th gii v rong bin nguyn
liu, 85% lng nguyn liu sn xut Carrageenan v Furcellaran hng nm do
Philippins cung cp. Nam Triu Tin l nc cung cp nguyn liu sn xut Agar
vi khi lng ln nht trn th gii, chim 52%.
Ngun li rong Nu ch yu tp trung cc nc Chu u v Bc M.
Canada tp trung hn 75% khi lng rong nguyn liu sn xut Alginate , trong
khi khi lng rong Nu Chu ch khong 5%. Theo FAO c tnh mi nm
trn th gii rong Nu c khai thc dc b i Ty Dng k c bin en v a
Trung Hi [1].
Trn th gii Alginate c sn xut t rong Nu c sn lng ln hn Agar,
Carrageenan, Furcellanan c sn xut t rong . V sn lng rong Nu th khu
vc Bc M c sn lng ln nht, tip n l Chu u, M La Tinh v Chu .
i vi rong th sn lng ch yu tp trung ln ti Chu , n Chu M La
Tinh, ri n Chu u.
Vic chn loi rong no lm nguyn liu chnh sn xut cc loi keo rong
ph thuc vo nhiu yu t khc nhau. Mt trong cc yu t quan trng nht l tnh
cht n nh v ngun nguyn liu, hay ni mt cch khc l ph thuc vo kh
nng pht trin ca loi rong trong iu kin t nhin ca mi nc cng nh
cht lng keo rong c chit rt t loi rong .
5
Sn lng v ngun li rong bin trn th gii c th hin trn bng sau.
Bng 1.1: Ngun li, sn lng thu hoch v tim nng sn xut rong bin [1]. (n v: 1.000 tn)
Rong Rong Nu Khu vc Sn lng
thu hoch Ngun li
Sn lng
thu hoch Ngun li
Bc cc - - - -
Ty bc i Ty dng 35 100 6 500
ng bc i Ty dng 72 150 223 2.000
Trung tm ty i Ty dng - 10 1 1.000
Trung tm ng i Ty dng 10 50 1 150
a Trung Hi v bin en 50 1.000 1 50
Ty nam i Ty dng 23 100 75 2.000
ng nam i Ty dng 7 100 13 100
Ty n dng 4 120 5 150
ng n dng 3 100 10 500
Ty bc Thi Bnh dng 545 650 822 1.500
ng bc Thi Bnh dng - 10 - 1.500
Trung tm ty Thi Bnh dng 20 100 1 50
Trung tm ng Thi Bnh dng 7 50 153 3.500
Ty nam Thi Bnh dng 1 20 1 100
ng nam Thi Bnh dng 30 100 1 1.500
Nam cc - - - -
Tng cng 807 2.660 1.315 14.600
b. Ngun li rong bin Vit Nam nc ta c khong 794 loi rong bin, phn b vng bin min Bc 310
loi, min Nam 484 loi, 156 loi tm thy c 2 min (Nguyn Hu Dinh, 1998).
Trong c cc i tng quan trng l: rong Cu (Gracilaria), rong M
6
(Sargassum), rong ng (Hypnea), rong Mt (Porohyza) v rong Bn
(Enteromorpha).
Ngun rong trng bao gm ch yu cc loi rong nh: rong Cu ch vng
(G.verrucosa), rong Cu cc (G.acerosa), rong Cu (G.asiatica v G.heteroclada),
rong Sn (Alvarezii).
Trong G.verrucosa v G.asiatica c trng vng nc l (Blackish
water) t nm 1970 pha Bc, pha Nam t 1980 vi tng din tch 1.000 ha t
sn lng khong 1.500 n 2.000 tn kh/nm. Rong Cu cc (G.acerosa) cng
c trng vng thy triu, vnh, ao, a vi din tch khong 100 ha, sn lng
khong 150 n 200 tn kh/nm.
Rong Sn kapaphycus alvarezii c di trng vo vng bin nc ta nm
1993, loi rong ny c cht lng tt sn xut Carrageenan. Ngy nay trong nui
trng Thy sn, cc nh nghin cu ang kt hp vic nui trng rong bin vi cc
loi thy sn tm, c, nhuyn th nng cao hiu qu kinh t trn mt n v din
tch mt nc. y l phng php hu hiu va pht trin nui thy sn va
pht trin ngun li rong bin cc nc trn th gii ni chung v nc ta ni
ring.
Bng 1.2: Din tch cc vng c th qui hoch nui trng rong bin mt s tnh duyn hi Vit Nam [1].
(n v: ha) Din tch cc vng c th qui hoch nui trng
Vng qui hoch Rong Cu cc Rong Sn
Bnh nh 1.140 610
Ph Yn 1.750 2.580
Khnh Ha 5.050 8.160
Ninh Thun 390 2.030
Bnh Thun Cha qui hoch Cha qui hoch
B Ra Vng Tu 4.500 6.140
Tng cng 12.824 ha 19.520 ha
7
1.1.3 Phn loi rong bin
Ty thuc vo thnh phn cu to, thnh phn sc t, c im hnh thi, c
im sinh sn m rong bin c chia thnh 9 ngnh sau y:
1. Ngnh rong Lc (Chlorophyta)
2. Ngnh rong Trn (Englenophyta)
3. Ngnh rong Gip (Pyrophyta)
4. Ngnh rong Khu (Bacillareonphyta)
5. Ngnh rong Kim (Chrysophyta)
6. Ngnh rong Vng (Xantophyta)
7. Ngnh rong Nu (Phacophyta)
8. Ngnh rong (Rhodophyta)
9. Ngnh rong Lam (Cyanophyta)
Trong , ba ngnh c gi tr kinh t cao l rong Lc, rong Nu, rong .
* Ngnh rong Lc: c trn di 360 chi v hn 5.700 loi, phn ln sng
trong nc ngt, nt c trng ca loi rong ny l c mu lc, sn phm quang hp
l tinh bt. Rong c dng t bo n gin hoc phc tp, nhiu t bo dng hnh
phin hay dng si, chia nhnh hoc khng chia nhnh. Tr mt s trng hp rong
ch l mt t bo trn khng c v cn i a s c v ring l cht pectin hay
Cellulose.
* Ngnh rong Nu: c trn 190 chi, hn 900 loi, phn ln sng bin, s
chi, loi tm thy trong nc ngt khng nhiu lm. Rong c cu to nhiu t bo
dng mng gi, dng phin, dng si n gin, mt hng t bo chia nhnh, dng
nhnh hoc phn nhnh phc tp hn thnh dng cy c gc, r, thn, l. Rong sinh
trng nh (apical), gia, gc, cc lng. Ngoi ra, do cc t bo rong dng
phin chia ct sinh trng khuch tn gi l sinh trng b mt.
* Ngnh rong : Rong hay to l nhng loi rong bin khi ti c
mu hng lc, hng tm, hng nu. Khi kh ty theo phng php s ch chuyn
sang mu nu hay nu vng n vng. Trn th gii rong c s dng vi khi
lng ln phc v con ngi, mt s loi c hm lng cao v Agar,
Carrageenan, Fucellaran c s dng ch bin keo rong.
8
Phn ln rong c cu trc a bo, rong Gracilaria Verrucosa c di
nht. Tuy vy chiu di ca rong u ngn hn nhiu so vi rong Nu. Rong
c 2.500 loi, gm 400 chi, thuc nhiu h, phn ln sng bin, c cu to t
nhiu t bo, tr mt s t thuc dng mt t bo hay qun th. Rong c dng hnh
tr dp di, phin chia hoc khng chia nhnh. Phn ln chia nhnh kiu mt trc
(monopodial), mt s t theo kiu hp trc (symodial). Sinh trng ch yu nh,
gia t hay phn tn. c trng ca loi ny l cha nhiu sc t , gia cc t
bo c cha nhiu cht keo (Agar). Loi ny sinh trng vng bin su, ni thy
triu thp, su t 6m n 7m.
1.1.4 Thnh phn sinh ha ca rong bin
Theo Noris, Symeon, Williams trong 100 gam rong kh c [1]:
m : 24.5 g Provitamin A : 1.23 g
M : 0.95 g Vitamin B1 : 0.41 g
ng : 31.0 g Vitamin B2 : 2.07 g
Nhit lng : 30.3 Kcal Acid nicotinic : 5.1 mg
Fe : 32 mg Vitamin C : 1.0 mg
Mui khong : 30.3 g P : 440 mg
1.1.5 Gi tr dinh dng v ng dng ca rong bin.
Gi tr dinh dng ca rong bin l cung cp y cc khong cht c bit
l cc nguyn t vi lng, cc acid amin cn thit cho c th, cc loi vitamin, cc
carbohydrate c trng v cc hot cht sinh hc c li cho c th, ng thi c kh
nng phng v tr bnh. Theo s liu nghin cu ca Nht Bn trong rong
Laminaria c cha cc vitamin sau y (miligam %): tin vitamin A (caroten)-1.1;
A 622; B1 0.53; B2 0.41; acid nicotin- 1.6; acid folic 0.14; B12 0.0033 v
ascorbic 28. Rong bin c hm lng lipid rt thp (t hn 2%). Nhng acid
licozopentae kh cao ti 20 25% tng s lng cc acid bo, trong rong bin cn
tm thy nhiu fucosterol v nhiu nguyn t vi lng khc. Trong rong bin c
cha nhiu Iod. Iod hu c rt c gi tr trong y hc. Do vy rong Nu cn c
dng lm thuc phng chng v cha bnh bu c (Basedow) [1]. Th d 1 Kg
rong Laminaria cha mt lng Iod bng lng Iod c trong 100.000 lt nc bin.
9
Trong 10 gam rong kh loi Alginatearia esculenta cha mt lng vitamin E bng
trong 100 gam c ci ng, trong 10 gam rong kh Gracilaria sn phm cha mt
lng Canxi c trong mt cc sa [1].
Cc sn phm hu c t rong bin ngy nay c s dng ht sc rng ri
trong cc ngnh nh: thc phm, dc phm, m phm, cng nghip dt, nng
nghip, cng ngh sinh hc v nghin cu khoa hc.
Cc polysaccharide t rong bin c coi l nhng hp cht hu c khng
th thay th trong nhiu lnh vc cng nghip khi c s dng nh cht to ng,
lm c, cht n nh v cht n nh. Gi tr cng nghip ca rong bin l cung cp
cc cht keo rong quan trng nh: Agar, Alginate, Carrageenan, Fucryllanzan
dng cho thc phm v nhiu ngnh cng nghip khc. Khong 20% sn lng
rong bin th gii c dng sn xut cc loi keo rong, ch bin thc n cho vt
nui v lm phn bn, s cn li ch yu c dng lm thc n cho ngi (Ohno
v Critchley, 1997). Nm 1870 ngi ta iu ch x phng t cc cht K2O, Na2O
ly t rong bin (rong Nu), pht hin trong rong Nu c cha Iod, t ngi ta
dng nguyn liu rong Nu iu ch Iod [1].
Rong bin ngy cng c s dng rng ri lm thc phm. Nhu cu v rong
lm thc phm Chu chim ti 90% ton th gii cn Chu u ch chim 1%.
Tiu th rong nhiu nht l Nht, Nam Triu Tin, Trung Quc chim 70 90
nghn tn/nm, Bc M tiu th 240 tn/nm. Nh cc tnh cht vt l, rong c
ch bin cng vi u, nhiu loi ng cc v rau qu khc thnh cc mn n c
sc, dng t nhin hay qua s ch. Rong c s dng lm ph gia trong cc mn
n ch bin t c, gip xc, nhuyn th, gi ch, ko bnh, ung. Porpyra cn
gi l rong mt c gi tr thc phm cao nht v c cc nc phng ng rt a
chung. Rong mt ti c a vo ch bin cc mn n khc nhau vi tht, c
nh xo, nu canhhay nu ch gii kht.
Rong c c tnh y hc: Bi b c th v khong cht, tng sc khng t
nhin, iu ha s bin dng v cc ni tuyn, lm gim lng m, lm ti tr,
chng lo ha, chng vim ng rut, chng bu, chng khp, kch thch s tun
hon. Rong bin dng cha cc bnh thiu khong, bing n, vim thp khp,
10
bo ph, tim mch, thn kinh, bu cCc oligosaccharide c tc dng khng
nm bnh, c ch cc qu trnh pht trin ca t bo ung th, t bo HIV, cc bnh
thuc h tun hon cng nh h tiu ho ngy cng c pht trin trong nhiu loi
rong bin. V vy ngy nay rong bin c xp vo loi thc phm chc nng v
ngy cng c s dng rng ri khp th gii.
Theo nghin cu rong Lc Nht Bn Laminaria c cha nhiu cellulose, cc
glucid, acid Alginic, Fucoidin, cc mui ca acid Alginic. Tnh chng nhim x cao
ca acid Alginic v cc mui ca n c s dng rng ri. Ngoi ra Fucoidin v
Alginate ha tan trong nc cn lm gim cc tnh cht ng t trong mu v chng
to ra cc khi u. Rong Laminaria cn l ngun cung cp cc acid amin asparagin
v glutamine c c th con ngi hp th d dng. Trong cc t bo ca rong
Laminaria cn tm thy cc acid amin ng ng c th Laminin c tc dng gim
huyt p ca ng vt.
1.1.6 c im sinh trng, pht trin v thi k thu hoch rong bin hp l
cho cng ngh ch bin.
Qu trnh ln ln ca cy rong gm c nm thi k: Sinh trng pht trin
tch ly sinh sn tn li.
cui thi k tch ly, hm lng cc cht keo t cao nht v hon thin
nht v cu trc ca n. Do cn thu hoch cui thi k ny l tt nht. Nu thu
hoch rong non (cha tch ly ti a) hiu sut qui trnh gim, cht lng keo rong
gim. Nu thu hoch rong tn li cng phm phi cc nhc im trn. C th
xc nh c thi k ny theo cc ch tiu cm quan sau:
Rong ang thi k phn nhnh cp II mnh, chiu di nhnh trn 20 cm i
vi rong hi t nhin v hn 30 cm i vi rong nui trng. Khi lng c th t
t 2 n 3.5 gam.
T l rong kh/ rong ti t 1/8 n 1/10.
Vi rong Nu, thng quan st phao sinh sn ca n.
Kh nng khai thc Mannitol tp trung cao vo thng 3 v 4.
11
Thi im khai thc tt nht i vi rong Nu sn xut Alginic l vo
cui thng 4 khi rong thnh thc sinh dc v phng thch giao t vo nc
bin lu truyn ni ging cho th h sau.
Nu khai thc sm hn (thng 3 chng hn) th nn bng cch ct cha li
gc 20 cm rong c th ti pht trin v hnh thnh c quan sinh sn.
Qua kt qu phn tch hm lng cc cht axit Alginic, Mannitol v Iod
trong cc loi rong Nu tm thy vng bin Qung Nam Nng n Ninh
Thun (Trn Th Luyn, Nguyn Anh Tun v cng tc vin, 1998) cho thy:
Hm lng axit Alginic tch ly trong cc loi rong khc nhau c s sai khc
nhau r rt. Hm lng axit Alginic cao nht thng vo thng 4 l lc cc loi
rong trng thnh, phng thch giao t v kch thc ca cy rong l ln nht
sau t thng 5 tr i th c hin tng hm lng axit Alginic gim dn theo s
tn li ca rong.
Hm lng axit Alginic trong 5 loi rong Nu dao ng trung bnh t 23.5
37.05% trng lng kh tuyt i. Hm lng ny cao nht vo thng 4, ng vo
thi k rong trng thnh.
Hm lng Mannitol cng bin i tng t nh axit Alginic,cao dn theo s
sinh trng ca rong v cng t gi tr cao nht lc rong trng thnh, phng
thch giao t vo thng 4.
Hm lng Mannitol trong 5 loi rong Nu vng bin Khnh Ha c phn
tch, c hm lng trung bnh vo khong 6.3 11.35% trng lng rong kh tuyt
i. Trong loi S.mcclurei c hm lng ln hn c. Hm lng ny thng cao
vo khong thng 3, 4.
Hm lng Iod trong cc loi rong Nu c phn tch c dao ng trung bnh
t 0.07 0.09% trng lng kh tuyt i. Trong loi Turbinaria ornate v loi
S.kjellmanianum c hm lng cao. Thng hm lng Iod tp trung cao vo cc
thng ma ng cn cc thng ma h th hm lng lng ny thp.
Cc loi rong c hm lng axit Alginic v Mannitol cao l Sargassum
mcclurei, Sargassum kjellmanianum, Sargassum quinhoneness Dai, Sargassum
12
polycystum. Cao nht l loi Turbinaria ornate. Trong loi Sargassum mcclurei
c tr lng ln nht, v Turbinaria ornate c tr lng khng ng k.
T cho thy nn khai thc rong vo thng 4 v u thng 5 l lc rong
Nu trng thnh, c kch thc ln nht, hm lng axit Alginic v Mannitol
cao nht. Mt khc lc ny rong phng thch cc giao t vo nc bin do vy ta
va thu va bo v c li ch lu di, trnh c nn hy dit ngun li.
1.1.7 Tnh hnh s dng, ch bin rong bin Vit Nam. Mc d c thin nhin u i v bin nhng s u t pht trin nui
trng, ch bin khai thc rong bin cn hn ch v cha c hiu qu. Ngnh cng
nghip ch bin rong bin cha pht trin, hin nay ch mi c nh my c hp H
Long Hi Phng sn xut vi cng sut nh. Nm 1985 B Thy sn xut khu
c 150 tn v nm 1986 c 100 tn rong kh cho Nht Bn. Nhu cu Alginate
v Agar ngy cng tng, c nhiu c s cng nghip phi mua Alginate ca Nht
Bn vi gi kh cao. Trong thi gian ti nn cng nghip cng pht trin th nhu cu
v Alginate, Agar v cc keo rong khc s cn tng gp bi. Nu c u t v
pht trin ng mc, cng ngh rong bin s mang li hiu qu ln cho nn kinh t
nc nh.
Rong bin l ngun nguyn liu qu, c kh nng gip cho c th phng
chng c mt s loi bnh. Do vy nhiu nc trn th gii ginh khon ngn
sch kh ln cho vic nghin cu ng dng sn xut thc phm t rong bin.
nc ta, thc phm t rong bin cha thc s c ch , l mt vn cn ang
b ng. Mt s c s ch bin nh ti gia nh nh: lm gi, nu thch, ng sng,
mt, ko, ch rong bin,Tuy nhin cc sn phm ny cha nhiu, cha ph bin,
rt t ngi dn bit n cc loi thc phm c bit ny. Do cn phi c k
hoch pht trin mnh hn tin ti cc sn phm rong bin phi phong ph hn,
c sn xut theo quy m cng nghip trong iu kin v sinh am ton thc phm
cao phc v tiu dng ni a v xut khu.
1.2 Qu trnh vn chuyn v cc bin php bo qun rong kh. Trong qu trnh thu hi, ch bin v thng mi rong bin thng phi vn
chuyn rong bin vi khi lng kh ln. Trong qu trnh vn chuyn rong kh
13
thng ng rong thnh kin tng cng kho cha v phng tin vn chuyn.
Kin rong phi c ng gi bng dy ai dc, ngang c gn nhn hiu ghi tn sn
phm, c s sn xut, khi lng tnh. Trong khi ch i, rong phi c trn
cc sn g cch mt t, cch tng 20 cm. Hoc c th ct rong thnh cc mnh c
chiu di 3 n 5 cm ri ng gi vo bao ti hoc bao nylon. Vn chuyn rong
bng cc phng tin c mi che. Phng tin phi kh sch, khng vn chuyn
rong kh cng vi cc loi hng ha ti sng, t nh tm, c,
Mt s hin tng h hng ca rong:
Trng thi cy rong b thay i: rong gin, mn. Gin l do sy nhit kh
cao, rong mn l do s ch nc ngt khng ng k thut, hm lng mui cn
nhiu. Cc loi vi sinh vt nh cellulomonas, Aspegillus, Streptococcus,
Pseudomonas v Penicilium hot ng mnh phn hy cellulose v cc cht keo
rong.
Rong hao ht trng lng do m cao.
Rong h cc b: do tri rong xung nn nh m khng tn nhit, xut hin s
t pht nhit nm mc pht trin.
Cc bin php bo qun rong kh.
Rong cha phi thng thong, lu thng khng kh. Khng kh trong kho c
m 80%. Ngy kh ro phi m ca kho gim m ca kho.
Cc kin rong c trn cc gin cch mt t 15 20 cm. Gia cc gin
c li i li thng xuyn kim tra, bc xp, to thong tn nhit.
Pht hin rong m phi a i ch bin ngay. Khi rong mc phi loi b
phn mc, ra, sy li.
Cc kin rong phi c sp xp theo cht lng v thi gian sn xut, rong
nhp kho trc phi a sn xut trc. Rong kh ng tiu chun, bo qun ng
ch thi gian ti a l 1 nm.
1.3 Gii thiu v rong Nu v rong M (Sargassum).
1.3.1 c im. Ngnh rong Nu (phaeophyta) c khong 190 loi, trn 900 loi phn ln l
sng bin, s ging loi tm thy trong nc l v nc ngt khng nhiu lm.
14
Rong M Sargassum l mt ging To ln thuc h rong M Sargassaceae ca
ngnh rong Nu sng tri ni trong nc. Thn cy c dng tr gn trn rt ging
vi thc vt bc cao c mu t xanh oliu n nu ( mu nu m, nu vng). Mu
sc khc nhau cc ging loi ph thuc vo thnh phn v t l ca cc loi sc t
c trong rong. i vi rong c lm kh s c mu nu m [2], [19]. Thn rong
di ngn ty loi v ty iu kin mi trng. Thng gp t vi chc cm n vi
ba mt hay hn (6- 8 m). Rong m l loi rong to mc thnh bi, gm vi trc chnh
quanh nhnh, nhnh mang phin c dng ca l, phin c rng mn ging nh l m
do c tn l rong l m hay gi tt l rong M. Cc loi rong M u c phao,
phao nhiu t to nh khc nhau, hnh dng ca phao l hnh cu hay tri xoan,
ng knh ca phao nh khong 0.5 0.8 mm, phao ln khong 5 10 mm. Phao
c th mang cnh hoc khng.
Rong l m l nhng loi rong mc nhng vng bin m nng, trn nn
vi, san h cht, ni sng mnh v nc trong, nht l ven cc o.Chng mc t
pha trn ca mc nc trung bnh thp ca con nc thng n su t 2 4 m.
Sinh trng trung bnh t 2.000 4000 b/m2, c ni n 7.000 g/m2 nh Hn
Chng, Nha Trang.
Rong M l loi c kch thc c th ln v tr lng cao nht trong cc loi
rong bin Vit Nam. Rong M mc trn tt c cc loi vt bm cng, trn cc vch
dc ng, cc bi tng, cc vng c ngm hay rn san h ngm, nhng
thch nghi nht l trn vt bm san h. Cu trc ca cc qun th rong M trn
cc vt bm khc nhau r rt. Trn cc b dc ng, chng phn b thnh ai
hp di mc triu thp n su khong 0.5 m. cc b bin tng nm trn
nn ct hay cui, chng mc thnh qun th dy, phn b tng i u, mt
khi rong trng thnh c th t 10 c th/dm2, cho nn vo ma pht trin ca
chng rt t cc loi rong bin khc c th mc chen c vo trong qun th rong
ny.
a s cc loi rong u thch mc ni c sng mnh. cc o, b pha
ng chng mc dy v phong ph hn b pha Ty. cc bi hng ra bin
khi, chng pht trin mnh v sinh lng cao hn nhiu so vi cc bi rong trong
15
cc vng, vnh yn sng. Cc bi rong trn b bin dc, thm san h cht, vi
ng vai tr quan trng trong ngun li ca rong M, nhiu vng rng 30 50 ha
hay hng trm ha, ko di vi chc km, thng gp ven bin min Trung, nht l
t Qung Ngi n Bnh Thun.
Ma v rong M c s sai khc cht t ty thuc tng loi, ni phn b, ty
cc iu kin mi trng sng,nhng nhn chung qui lut v ma v kh r rt.
Chng tng trng rt mnh t thng 2 n thng 3, a s cc loi c kch thc ti
a vo thng 3, 4 v hnh thnh cc c quan sinh sn, sau s b sng nh tp vo
b v tn li. n thng 7 hu ht cc loi rong u tr tri. Mt s loi mc ln
cao hoc phn b ln cao (vng triu thp) nh: S.mcclurei, S.polystum pht trin v
tn li sm (thng 4). Trong khi cc loi mc vng di triu nh S.binderi,
S.microcystum,mc chm hn, n thng 6, 7 i ni vn cn cc qun th rong
ny. Mt vi loi thch nghi trong cc vng, vnh yn sng c th tn ti v pht
trin tt vo thng 7 nh S.polycystum v S.longicaulis.
Rong trng thnh v phng thch giao t vo cc thng 3, 4, 5, vo thi
im ny, kch thc ca rong t n ti a v sinh lng cao nht. Mt khc hm
lng axit Alginic cng cao nht. Cc c im ny rt quan trng, ph hp v c
li cho vic khai thc ngun li t thng 4 tr i. Vic khai thc ng ma v hon
ton c kh nng bo v ngun ging t nhin, gip cho rong ti pht trin li vo
ma sau. Ngoi ra vic khai thc bng cch ct gc rong tng 10 cm gip cho mt
s nhnh cn st li vn tip tc pht trin to ra cc c quan sinh sn.
Cc bi rong M mc trn thm san h cht c din tch rng ln, mt
dy, sinh lng cao (trn 12 kg rong ti/m2) rt quan trng vi ngun li, tm thy
cc tnh Qung Ninh, Qung Ngi, Bnh nh, Khnh Ha, Ninh Thun v Bnh
Thun. Cc bi rong rng ln nm gn trc giao thng rt thun li cho vic khai
thc v vn chuyn. Sn lng hng nm c tnh c th t 10.000 tn rong ti
[1].
16
1.3.2 S phn b [1]. Bng 1.3: Cc ging loi rong Nu tm thy v phn b.
a phng STT Loi rong Q. Nam
Nng Bnh nh
Khnh Ha
Ninh Thun
1 Sargassum mcclurei
2 Sargassum graminafolium (rong M tro l nhnh)
3 Sargassum phamhoangii (mt loi rong mi tm thy Vit Nam)
4 Sargassum siliquosum
5 Padina australis (rong cnh qut) 6 Sargassum crassifolium
7 Sargassum patens var. Vietnamese Dai
8 Sargassum quinhonense Dai
9 Sargassum polycystum 10 Sargassum kjellmanianum
11 Sargassum microcystum 12 Sargassum congkinhii
13 Turbinaria ornate (rong ci bp)
14 Padina tetrastromatica (rong qut 4 lp)
Rong Nu phn b ti vng bin Qung Nam Nng khng nhiu so vi
vng bin Khnh Ha v Ninh Thun. Qung Nam Nng tuy c nhiu trin
dc, bi ci, bi san h cht nhng c chiu ngang rt hp (1 n 10 m) nn din
tch phn b rt nh, tr lng kh cao. Khi lng rong ti trung bnh q0 = 2 4
kg/m2, c bit c ni t n 7 kg/m2 nh vng C Lao Chm, trin o Hi Vn.
Din tch rong M mc ti ch vng bin Qung Nam Nng khong 190.000
m2 , tr lng rong mc ti ch c th thu c vo thng 4 khong hn 800 tn
rong ti. y l kt qu khng ln i vi mt vng bin c iu kin t nhin
thun li cho s pht trin ca rong M. Kt qu ny rt nh so vi cc va rong
17
M khc nm ri rc ven bin min Trung. Rong t kch thc v sinh lng cao
nht vo cui thng 3 v u thng 4. Sau rong sng cm c thm mt thi gian
na ri tn li vo thng 7.
Din tch c rong mc ti ch ca tnh Bnh nh khong hn 40.000m2 , tr
lng rong ti c tnh hn 100 tn/nm. Sinh lng cao nht vo cui thng 4 v
u thng 5. Din tch c rong phn b rt b so vi cc tnh khc, sinh lng trung
bnh q0 khong 2.5 kg/m2.
Cc vng c rong mc l Bi Xp, Ghnh Rang, Hn Kh.Trong vng
Hn Kh l vng c chiu di bi rong khong 10 km, rong mc khng u di
rong hp, c tr lng cao nht. Tr lng rong ca tnh Bnh nh thp nht trong
cc tnh iu tra. Hin nay s rong ny hng nm t mc, t tn li, khng c k
hoch no khai thc s dng, cn rt lng ph. Vng bin Khnh Ha l vng c
din tch rong M mc cao nht trong cc tnh iu tra, tng din tch c rong ln
ti 2.000.000m2, tr lng c th khai thc c hng nm c th c tnh hn
11.000 tn rong ti. Khnh Ha c nhiu vng rong nh Hn Chng, Bi Tin,
bn o Cam Ranh, Hn Tre v mt s o khc.
Bng 1.4: Tr lng rong M theo vng bin cc tnh.
STT A IM DIN TCH (M2) THNG TR LNG RONG
TI (tn)
1 Qung Nam Nng 190.000 4/97 860
3/97 106 4/97 124 2 Bnh nh 42.750 5/97 129 3/97 11.002 4/97 7.930 3 Khnh Ha 2.000.000 5/97 6.046 3/97 7.650 4/97 6.180 4 Ninh Thun 1.500.000 5/97 4.650 3/97 18.750 4/97 15.724
Tng cng 3.732.750
5/97 10.825
18
1.3.3 Thnh phn ha hc ca rong Nu. a. Sc t
Sc t trong rong Nu l dip lc t (Chlorophyl), dip hong t
(Xantophyl), sc t mu nu (Fucoxanthin), sc t (Caroten). Ty theo t l cc
loi sc t m rong c mu t nu vng nu nu m vng lc. Nhn chung sc
t ca rong Nu kh bn [1].
b. Gluxit
Monosacaride [1].
Monosacaride quan trng trong rong Nu l ng Mannitol c Stenhouds
pht hin ra nm 1884 v c Kylin (1913) chng minh thm. Mannitol c cng
thc tng qut: HOCH2 (CHOH)4 CH2OH. Mannitol tan c trong Alcol, d
tan trong nc c v ngt. Hm lng t 14% 25% trng lng rong kh ty
thuc vo hon cnh a l ni sinh sng. Hm lng Mannitol trong 2 loi rong
Nu c cc nh nghin cu Vin Hi Dng hc Nha Trang xc nh trn bng
1.5.
Bng 1.5: Hm lng Mannitol 2 loi rong S.mcclurei v S.kjellmanianum
ti Hn Chng Nha Trang 1979 (% so vi trng lng kh tuyt i)
Hm lng Mannitol trung bnh (%) ca thng Loi rong
1 2 3 4 5 6 Ghi ch
S.mcclurei 11.3 14.6 15.79 16.73 16.36 9.37 Thng 6 rong
bt u tn li
S.kjellmanianum 10.12 10.53 12.40 13.82 6.95 Thng 5 rong
bt u tn li
Hm lng Mannitol bin ng theo thi gian sinh trng trong nm ca
rong kh r rt, tng dn t thng 1, tp trung cao vo ma h (thng 4) ri sau
gim i: Theo Kylin (1993) v Vedrinski (1938) cho thy hm lng Mannitol t
19
25% v ma h ri b phn hy dn trong cc thng ma ng ch cn 4% 6%.
Vit Nam, theo kt qu nghin cu ca cc nh khoa hc vin Hi Dng hc
(1979) v i hc Thy sn (1997 1998) hm lng Mannitol cng theo quy lut
ny. Thng 4 l hm lng Mannitol cao hn c, Mannitol trong loi S.mcclurei c
hm lng cao nht, vo thng 4 t 15.9% so vi trng lng kh. Hm lng
Mannitol ca cc loi rong cc vng bin Qung Nam Nng, Bnh nh,
Khnh Ha, Ninh Thun dao ng t 7% 15.95% (vo thng 4 hng nm).
Trong qu trnh bo qun rong kh c hin tng xut hin cc im m
trng trn thn cy rong, l hn hp ng Mannitol theo t l : mui 60%
80%, Mannitol 20% 40%. Rong bo qun khng tt, m cao lm cho Mannitol
b ph hy. Cng dng ca Mannitol: dng trong y hc cha bnh cho ngi gi
yu; trong quc phng dng iu ch thuc n theo t l hn hp Mannitol vi
Hydrogen v Nito. Ngoi ra Mannitol cn dng iu ch thuc st trng (Mannit
vi kim loi c tc dng st trng cao). Do c kh nng ny m ngy nay mt s tc
gi cho thy c kh nng sn xut thuc tr su c bn cht sinh hc (bo v thc
vt) t rong bin.
Polysaccharide
Alginic: Alginic l mt polysaccharide tp trung gia vch t bo, l thnh
phn ch yu to thnh tng bn ngoi ca mng t bo rong Nu. Alginic v cc
mui ca n c nhiu cng dng trong ngnh cng nghip, y hc, nng hc v thc
phm. Hm lng Alginic trong cc loi rong Nu khong 2% 4% so vi rong
ti v 13% 15% so vi rong kh. Hm lng ny ph thuc vo loi rong v v
tr a l mi trng m rong sinh sng. Theo cc ti liu tng kt ca Miyake
(1995) cho thy hm lng Alginic trong cc loi rong Nu c cc vng bin Lin
X c l 13% 40%. Theo ti liu phn tch cc chuyn gia B Thy sn cho thy
hm lng Alginic trong cc loi rong Nu Hi Phng l 22% 40%, trong khi
, rong Nu vng bin Ph Yn Khnh Ha c hm lng Alginic cao hn
hn. Theo s liu phn tch ca cc nh nghin cu vin Hi Dng hc th hm
lng Alginic ca hai loi rong Nu c trnh by trn bng 1.6.
20
Bng 1.6: Hm lng axit Alginic trong cc loi rong Nu
(% so vi rong kh tuyt i).
Loi rong Thi gian thu mu
(thng/nm)
a im thu
mu
Phm vi dao ng ca hm
lng
Hm lng
trung bnh
S.mcclurei 11/77 4/78 Hn Chng 26.41 43.36 33.24 - 1/79 6/79 - 29.89 39.30 35.61 - 5/1978 Sn Hi 40.06 - S.kjellmanianum 11/77 4/78 Hn Chng 31.60 43.64 37.03 - 1/79 6/79 - 37.64 44.77 40.39 S.polycystum 3/1978 - 42.747 - - 11/77 4/78 35.17 41.00 38.47 S.congkinhii 3/1978 Hn Chng 34.82 - - 5/78 4/79 Sn Hi 39.11 43.50 41.30 S.microcystum 3/1978 Hn Chng 39.60 - S.feidmanii 3 4/1979 Sn Hi 36.41 41.93 39.17 Turbinaria ornata
3 5/1979 -
39.14 47.16 43.75
Hm lng Alginic c cc loi rong min Trung Vit Nam l kh cao, dao ng t 12.3% 35.9% so vi trng lng kh tuyt i, ty thuc vo loi v vng a l. Trong loi rong S.mcclurei v Turbinaria ornate c hm lng
Alginic cao nht khong 35.9% 39.4% rong kh tuyt i. Nu so snh cc vng bin th rong bin vng bin Khnh Ha c hm lng Alginic cao hn c (t 26.2% 39.4% rong kh tuyt i) [1]. Axit Fucxinic: c tnh cht gn ging vi axit Alginic. Axit Fucxinic tc dng vi axit Sunfuric to hp cht c mu ph thuc vo nng axit Sunfuric. Chng hn:
Axit Fucxinic + H2SO4 0.1% : cho sn phm mu xanh. Axit Fucxinic + H2SO4 10% : cho sn phm mu xanh tm Axit Fucxinic + H2SO4 25% : cho sn phm mu tm Axit Fucxinic + H2SO4 25% : cho sn phm mu Axit Fucxinic + H2SO4 > 50% : cho sn phm mt mu
21
Nh c tnh cht ny m Fucxinic c ng dng vo sn xut t si mu, phim nh mu. Mui ca Fucxinic vi kim loi gi l Fucxin. Fucxinic tc dng vi Iod cho sn phm mu xanh [1]. Fuccoidin: L loi mui gia axit Fuccoidinic vi cc kim loi ha tr khc nhau nh: Ca, Cu, Zn. Fuccoidin c tnh cht gn ging vi Alginic, nhng hm
lng thp hn Alginic. Fuccoidin hay Fucoidan l mt polysaccharide sulfate ha d hp, trong fucose chim t 18.6% 60% [18], sulfate chim t 17.7% 39.2%, ngoi ra cn c mt cc thnh phn ng khc nh: galactose, glucose, mannose, xylose, rhamnose, v acid uronic. Hm lng fucoidan trong cc loi rong Nu khong 2 9% so vi
rong kh. Hm lng ny ph thuc vo loi rong v v tr a l mi trng m rong sinh sng [18]. Laminarin: Laminarin l tinh bt ca rong Nu. Laminarin thng dng bt khng mu, khng mi v c hai loi: loi ha tan v loi khng ha tan trong nc.
Laminarin c hm lng t 10% 15% trng lng rong kh ty thuc vo loi rong, v tr a l v mi trng sinh sng ca rong Nu. Thng th vo ma h hm lng Laminarin gim v phi tiu hao cho qu trnh sinh trng v pht trin ca cy rong. Cng dng ca Laminarin l dng cho thc phm v chn nui [1].
Laminarin c hnh thnh t cc gc D- glucans kt hp vi nhau bng cc lin kt - 13 v mt t lin kt - 16, gc ng cui mch ca mt s phn t c th c cc gc manitol (M series) hoc vn l glucose (G series) [17]. Cellulose: l thnh phn to nn v cy rong. Hm lng Cellulose trong rong Nu nhiu hn rong . Cng dng: Dng cho cng nghip giy, trong cng nghip xy dng (l ph gia kt cu xi mng) [1]. c. Protein
Protein ca rong Nu khng cao lm nhng kh hon ho. Do vy rong Nu c th s dng lm thc phm. Protein ca rong Nu thng dng kt hp vi Iod to Iod hu c nh: MonoIodInzodizin, DiIodInzodizin. Iod hu c rt c gi tr trong y hc. Do vy rong Nu cn c dng lm thuc phng chng v cha bnh bu c (Basedow). Hm lng protein rong Nu vng bin Nha Trang dao ng t 8.05% 21.11% so vi trng lng rong kh. Hm lng cc axit amin cng ng k v c gi tr cao trong Protein ca rong bin. Theo ti liu nghin cu ca
22
chuyn gia rong bin quc t, hm lng axit amin mt s loi rong Nu vng bin Jeddah, Saudi Arabia c trnh by trn bng 1.7 [1].
Bng 1.7: Hm lng axit amin mt s loi rong Nu vung bin Jeddah,
Saudi Arabia (mg %).
Axit amin (mg %)
S.vulgare S.enerve C.barbata T.murrayana P.vikersiae
Asp 12.70 12.86 13.3 12.2 12.4
Thr 3.23 3.25 1.7 2.2 3.4
Ser 5.90 6.60 3.4 3.6 6.7
Glu 16.50 18.03 24.2 21.2 15.1
Pro Nd Nd 2.7 3.6 2.9
Gly 6.20 6.91 1.4 1.3 2.7
Ala 5.78 5.91 1.3 1.5 3.0
Val 4.77 5.21 1.5 1.4 0.3
Cys 0.72 0.66 2.5 2.9 5.2
Met 0.53 0.76 0 0 0.7
Tre 4.06 4.13 4.9 4.7 5.6
Leu 7.98 8.08 6.3 7.6 9.1
Tyr 2.56 2.67 5.7 6.2 3.5
Nd = not determined (khng xc nh)
d. Hn hp Phenolic Theo Ragan v Glombitza, hp cht rt ph bin trong rong Nu thuc nhm
hp cht polyphenolic l phlorotannin. Phlorotannin l cht chuyn ha th cp,
xut hin ch yu cc m, ti nng c th ti 20% so vi khi lng tnh
ca rong bin. Schoenwaelder 2002, ch ra mt s chc nng ca chng nh tng
tnh lin kt v chc cho thnh t bo. Phlorotannin hp th bc sng UV, ch
yu l UVC v mt phn UVB, vi cc i ti 195 nm v 265 nm [9].
e. Cht khong Hm lng cc nguyn t khong trong rong Nu thng ln hn nc bin.
Chng hn: I2 ca rong Nu ln hn trong nc bin t 80 n 90 ln. Hm lng
23
Ba ln hn trong nc bin 1.800 ln. Mt s loi rong Nu cn c kh nng hp
th mt s cht phng x, do vy c th dng rong Nu xc nh nhim phng
x ca mt vng a l no . Hm lng khong ca cc loi rong Nu Nha
Trang dao ng t 15.51 46.30% ph thuc vo ma v, thi k sinh trng.
Chiu hng tch ly khong theo Wort cho thy lng khong ti a v
ma ng. Theo s liu ca cc nh nghin cu Vin Hi Dng hc cng nhn xt
theo quy lut . Chng hn hm lng khong tng s ca loi S.mcclirei bin
ng theo ma r rt cao nht vo thng 12/1977 l 42.805% ri li gim dn v
thp nht vo thng 3/1978 l 21.1% sau li tng dn vo thng 7/1978 l
33.75%.
Bng 1.8: Hm lng Iod trong cc loi rong Nu (% trng lng kh) Nha Trang
Khnh Ha.
Loi rong
Thi gian thu mu
a im ly mu
Phm vi dao ng ca hm
lng
Hm lng trung bnh
S. mcclurei 11/77 4/78 Hn Chng 0.06 1.13 0.09
1 6/1979 -- 0.05 0.08 0.07
S. Kjellmanianum 11/77 4/78 -- 0.05 0.15 0.09
1 5/1979 -- 0.05 0.11 0.07
S.polycystum 11/78 5/1979 Sn Hi 0.05 0.11 0.08
S. congkinhii 5/1979 -- 0.1 --
S.feldmanii 3 4/1979 -- 0.12 0.13 -- Turbinaria ornata 3 5/1979 -- 0.1 0.16 0.15
Hm lng Iod trong mt s loi rong Nu dao ng 0.05% 0.16% so vi
rong kh tuyt i. Hm lng ny c phn thp hn rong Nu vng bin Hi Phng trung bnh trong khong 0.25% 0.34% v cng thp hn rong Nu vng Vin ng (pha Bc Lin X c) c hm lng trung bnh 0.24%. S bin i hm lng Iod kh r rt, thng vo ma ng rong Nu c hm lng Iod cao hn ma h.
24
1.4 Mt s quy trnh cng ngh sn xut cc cht t rong Nu. 1.4.1 Cng ngh ch bin Mannitol t rong Nu [1].
Rong kh
Rong ti
X l ct nh L= 23 cm
Sy s b W = 30%,
T0 = 50 600C
Alcol thu hi
Chit Mannitol T0C = 80 850C
X l ct nh L = 2 3 cm
Alcol 960 T l
v/w = 56/1 rong
Sn xut alginate
Dch chit B rong
Phn tch
Chng ui alcol Lc li
Kt tinh, T0 = 2 40C
Chng ui dung mi
Ha tan
C c, w = 50%
C c Kt tinh Lm kh Bao gi
(5 6 ln)
25
Hnh1.1: S quy trnh chit Mannitol bng phng php ha tan trong Alcol 1.4.2 Chit rt Iod t rong Nu [1].
Ra sch
Rong Nu
X l qua formol
Ct nh (1 1.5 cm)
Chit Iod
Lc tch
Dch chit 3 ln B rong
Nc 800C, pH = 7. Thi gian: 10 15 pht
C c Ch bin alginate
Cao rong
nh hnh Bao gi
Cht bo qun
Sy kh
Ra
Hnh 1.2: S quy trnh tng qut chit rt Iod t rong Nu.
26
1.5 Tng quan v hp cht Phlorotannin (polyphenol). 1.5.1 c im.
Theo Ragan M. A [9] th phlorotannin c nh ngha nh sau: chng l polyme sinh hc c hnh thnh t gc phloroglucinol (1,3,5 trihydroxybenzen) v cc gc ny lin kt vi nhau bng nhiu cch khc nhau. Chnh v vy m chng to nn nhiu cu trc khc nhau v i lc c trng lng phn t ln n 650 KDA. Cho n nay, trn th gii c mt s cu trc ca cc hp cht thuc nhm phlorotannin t rong Nu c xc nh v nhiu dch chit th ca chng c kho st hot tnh sinh hc. Tuy nhin, rt t cng trnh cng b mt cch y cc cu trc ca tt c cc dn xut ca phloroglucinol trong dch chit
phlorotannin th c chit t mt loi rong c th v hot tnh ca chng v cc cng trnh ny ch c cng b trong 10 tr li y.
Cc nh khoa hc Hn Quc [10] cng a ra cu trc y ca cc dn xut ca phloroglucinol chit t loi rong Ecklonia cava bao gm:
27
Hnh 1.3: Phloroglucinol (i) v phlorotannin [tetrafucol A (ii), fucodiphloroethol B
(iii), fucodiphlorethol A (iv), tetrafuhalol A (v), tetraisofuhalol (vi),
phlorofucofuroeckol (vii)] v hot tnh ca chng.
1.5.2 C ch oxi ha ca polyphenol. Trong c th con ngi thng xuyn din ra nhiu hot ng hoc xy
dng hoc ph hy. C nhng cht tng nh l thc phm chnh ca t bo nhng
ng thi cng lm hi t bo. C nhng phn t gy ra tn thng th cng c
nhng cht khng li hot ng ph phch ny. Gc t do, oxygen v cht chng
oxi ha l mt v d.
Theo cc nh khoa hc th gc t do c th l th phm gy ra ti hn 60
bnh, Chng tn cng ln cc phn t protein, lipid, ADN,dn n cc bnh nan
y nh thoi ha thn kinh, ung th, tim mch, tiu ng, V vy ch n nhiu
hoa qu v t cholesterol s lm gim ung th, km hm v gim cc gc t do. Cc
cht chng oxi ha t tri cy hoc sn phm chit xut gip bo v, ngn cn qu
trnh oxi ha. chng li tc hi ln do cc gc t do gy ra, c th con ngi
c trang b mt h thng cc cht chng oxi ha. Cht chng oxi ha l cc cht
28
c kh nng ngn nga, chng li v loi b tc dng c hi ca cc gc t do trc
tip hoc gin tip. Cht chng oxi ha c th phn ng trc tip vi gc t do hot
ng, to ra nhng gc mi km hot ng hn, ngn cn cc chui phn ng dy
chuyn do cc gc t do khi mo. Cht chng oxi ha cng c th to phc gin
tip vi ion kim loi chuyn tip c ch enzim xc tc trong phn ng sinh gc t
do nhm ngn s hnh thnh gc t do trong c th.
Polyphenol c coi l cht chng oxi ha hu hiu nht hin nay (hu hiu
gp 100 ln vitamin C v gp 25 ln vitamin E) [5].
S oxi ha ca cc hp cht polyphenol c ngha rt ln trong s sinh tng hp
nhiu cht t nhin nh licnhin, alkaloid v melanin. S to thnh cc hp cht ny
c th gii thch bng c ch gc t do, trong giai on u ca hp cht
monomerphenol xut hin cc gc phenol. giai on sau, xy ra s ghp i cc
gc t do vi s to thnh mi lin kt C-C hoc C-O-C ph thuc vo kiu ghp
i [5].
Kh nng khng oxi ha mnh ca polyphenol c gii thch da trn s
lng ln cc nhm hydroxyl trong cng thc chng , n cho ghp tip nhn
electron mt cch d dng (polyphenol l cht nhn cc gc t do), tc l chng c
kh nng dp tt cc qu trnh to ra gc t do.
1.5.3 Hot tnh sinh hc ca phlorotannin. Hot tnh sinh hc ca phlorotannin c cng b nhiu nht l hot tnh
chng oxi ha. Hot tnh ny c nghin cu thng qua kho st kh nng qut cc
gc DPPH (2,2-diphenyl-1-picrylhydrasyl), gc hydroxyl (OH), cc anion nh
superoxide anion (O2-), kh st (III), to phc chelat vi cc ion ha tr (II) v oxi
ha lipid ca chng.
Cc nh khoa hc Mexico [11] xc nh kh nng qut cc gc DPPH,
anion O2- v hot tnh kh ca hn hp cc cht thuc nhm phlorotannin c
chit t mt s loi rong Nu sinh trng ti vng bin nhit i ti Mexico. H
thu cc phlorotannin bng chit lnh, s dng dung mi l dichloromethanol :
methanol (2:1) trong 20 gi. Kt qu thu c cho thy tt c tng phlorotannin
c chit t cc loi rong (Lobophora variegate, Padina gymnospora, Dictyota
29
cervicornis v mt s loi rong thuc chi Sargassum, chi Turbinaria) u c hot
tnh chng oxi ha vi gi tr EC50 ca gc DPPH tng ng l nh sau: Lobophora
variegate: 0.32 0.01 mg/ ml, Padina gymnospora: 3.45 mg/ml, chi Sargassum: t
6.64 7.14 mg/ml, chi Turbinaria: 8.85 mg/ml v chi Dictyota: 6.42 mg/ml. Ngoi
ra tng phlorotannin chit t loi Lopophora variegate cn th hin kh nng qut
gc anion O2- v tnh kh mnh.
Hot tnh khng vi sinh vt ca phlorotannin chit t loi rong Ecklonia
kurome ti Nht Bn c Koki Nagayama v CS kim nh [12]. th hot
tnh khng vi sinh vt ca phlorotannin, nhm tc gi s dng phng php chit
phlorotannin bng cn methanol. Hn hp thu c sau khi chit bng cn c
chit li vi ethyl acetate v cui cng c tch trn sc k bn mng. Tt c cc
phn on thu c u th hot tnh trn 25 chng vi sinh vt kim nh thuc 02
nhm Gr(+) v Gr(-). Kt qu l tt c cc phn on u th hin hot tnh khng
25 chng vi sinh vt em th.
Trn c s phlorotannin th chit t loi rong Ecklonia cava cc nh khoa
hc Hn Quc xc nh c nhiu hot tnh sinh hc khc ca chng. Tt c cc
dn xut ca phloroglucinol phn lp c (tetrafucol A, fucodiphloroethol B,
fucodiphlorethol A, tetrafuhalol A, tetraisofuhalol, phlorofucofuroeckol) u th
hin hot tnh c ch cc enzyme Matrix metalloproteinase (MMP), Alpha-
glucosidase, alpha- amylase v c ch qu trnh gii phng histamine [13, 14, 15].
Kt qu ny nh hng cho vic s dng chng h tr iu tr cc bnh tiu
ng, thp khp, vim nhim kinh nin, chng d ng.
1.5.4 ng dng. Polyphenol l nhng cht chng oxi ha, do chng c ng dng trong
nhiu lnh vc. ng dng c quan tm mnh m nht hin nay l v kh nng
dc l.
Bn cnh kh nng ngn chn c hiu qu cc qu trnh oxy ha, c bit
l qu trnh oxi ha lipid. Nhm cht ny c quan tm s dng trong cc sn
phm thuc cc lnh vc khc nhau nh m phm, thc phm v dc phm.
30
Ring trong ngnh thc phm, do c im xut pht t thin nhin, m bo tnh
an ton nn chng c s dng ch yu nh mt cht ph gia chng oxi ha, nhm
thay th cho cc ph gia tng hp thng dng nh: BHA (Butyl hydroxyl anisol),
BHT (Butyl hydroxyl toluene), nhng cht ny d gy tc dng ph khng c li
cho sc khe ngi s dng. Polyphenol ch yu c ng dng lm bn cht
bo trong cc sn phm bnh, ko,
Ngoi ra, polyphenol (trong ch, rong bin, ) cn c s dng nh mt
loi thc phm chc nng nhm tng cng kh nng phng v cha bnh ca c
th [5].
Phlorotannin trong rong Nu cn c hot tnh khng khun [6], khng nm bnh, c
ch cc qu trnh pht trin ca t bo ung th, t bo HIV, cc bnh thuc h tun
hon nh iu ha lng ng huyt trong c th v cc bnh v ng tiu ha.
1.6 Gii thiu v qu trnh trch ly. 1.6.1 Bn cht.
Bn cht ca qu trnh trch ly (qu trnh chit) l s rt cht ha tan trong
cht lng hay cht rn bng mt cht ha tan khc (gi l dung mi) nh qu trnh
khuch tn gia cc cht c nng khc nhau [4].
Trch ly cht ha tan trong cht lng c gi l trch ly lng, cn trch ly cht ha
tan trong cht rn l trch ly cht rn.
1.6.2 Phm vi s dng ca qu trnh. Trong cng ngh thc phm nhm mc ch sau:
Khai thc l mc ch ch yu. Ph bin l trch ly cc nguyn liu dng rn
nh: ht du, cc nguyn liu tinh du nh l, r, cy, hoa hoc qu; trch ly cc loi
c nh c ci ng, trch ly ma. Cng vi mc ch ny c th phi hp vi qu
trnh khc nng cao hiu sut thu sn phm. V d nh phi hp vi qu trnh p
trong sn xut ma ng [4].
Trch ly cn nhm mc ch chun b cho cc qu trnh tip theo, v d nh
ngm cc loi ht (cc loi u, ng, thc,) trc khi ch bin; ngm cc loi c
(sn, khoai,) lm yu cc lin kt trong vt liu, ng thi trch ly mt s phn t
vo dung mi ngm (v d: ha tan HCN khi ngm c sn) [4].
31
Vi mc ch thu nhn sn phm nh tch penicillin t dung dch ln men
sn xut nc chm bng phng php m trch ly, hoc trch ly trong qu trnh
sn xut c ph ha tan, trch ly khi ngm qu, ngm tm cc loi thuc b v thuc
cha bnh, [4].
1.6.3 Cc yu t nh hng n qu trnh chit. Thc cht qu trnh trch ly l qu trnh khuch tn. V vy s chnh lch
nng gia hai pha (gradient nng ) chnh l ng lc ca qu trnh. Khi chnh
lch nng ln, lng cht trch ly tng; thi gian trch ly gim ta thc hin bng
cch tng t l dung mi so vi nguyn liu.
Qu trnh trch ly polyphenol (phlorotannin) hin nay c thc hin bng
cc loi dung mi. Nguyn tc ca trch ly bng dung mi da trn s thm thu
dung mi vo t bo, cht cn trch ly ha tan vo dung mi v khuch tn ra ngoi
t bo. Qu trnh trch ly bng dung mi c u im l thit b n gin, c th x
l mt lng ln nguyn liu v c th s dng quy trnh lin tc. Cc yu t nh
hng n qu trnh trch ly bng dung mi:
La chn dung mi trch ly: Dung mi trch ly l dung mi ha tan c hp
cht cn trch ly. Cc polyphenol (phlorotannin) l cc hp cht phn cc nn ch
yu s dng cc dung mi phn cc nh: nc, ethanol, acetone, ethyl acetate
Din tch tip xc gia nguyn liu v dung mi. Cn tng din tch ny
lm tng hiu qu ca qu trnh. Vi cc nguyn liu rn cn tng din tch tip xc
gia chng v dung mi. iu ny thc hin bng cch nghin nh, thi nh, bm
nh vt liu. N cn lm ph v cu trc t bo, thc y qu trnh tip xc trit
gia dung mi v vt liu. Tuy nhin kch thc v hnh dng ca vt liu khi lm
nh cng c gii hn v nu chng qu mn s b lng ng ln lp nguyn liu, lm
tc cc ng mao dn hoc b dng dung mi cun vo mixen (hn hp) lm cho
dung dch c nhiu cn gy phc tp cho qu trnh x l tip theo [4].
Khuy trn: Khuy trn gip tng cng hiu qu trch ly, do tng cng
qu trnh truyn khi.
pH: Polyphenol (phlorotannin) rt bn pH acid v km bn pH bazo. Khi
thc hin trch ly pH thp s trnh c hin tng oxy ha polyphenol v tng
32
hiu qu qu trnh trch ly. Tuy nhin, cng c nghin cu cho rng nh hng ca
pH khng lm nh hng nhiu n hiu qu trch ly, ch cn m bo pH trung
tnh hoc thp hn.
Tnh cht ca vt liu cng nh hng ln n hiu sut trch ly. Vt liu l
hn hp lng- lng hoc hn hp rn lng cng vi mt dung mi hoc tp hp
mt s loi dung mi. Chng c ha tan khc nhau, nng cc cht khc nhau
v c tc dng tng h, khuch tn vo nhau. Nh khi trch ly u nu m
nguyn liu gim, tc trch tng ln, v m tc dng vi protein v cc cht
ho nc khc ngn cn s dch chuyn ca dung mi thm su vo trong nguyn
liu, lm chm qu trnh khuch tn [4].
Nhit c tc dng tng tc khuch tn v gim nht, phn t cht
ha tan chuyn ng d dng khi khuch tn gia cc phn t dung mi. Tuy nhin
nhit l mt yu t c gii hn. V khi nhit qu cao c th xy ra cc phn
ng khc khng cn thit (lm oxi ha polyphenol cn trch ly), gy kh khn cho
qu trnh cng ngh [4]. Do trong ton b qu trnh nhit khng nn vt qu
800C.
S dng cht khng oxy ha h tr: Vic s dng cc cht khng oxy ha b
sung nh acid ascorbic, acid citric, c xc nhn lm tng hiu qu trch ly cng
nh lm gim s oxy ha polyphenol.
Yu t thi gian cng nh hng n qu trnh trch ly. Khi thi gian tng
ln, lng cht khuch tn tng, nhng thi gian phi c gii hn. V khi t
c mc trch ly cao nht, nu ko di thi gian s khng mang li hiu qu
kinh t.
1.6.4 Tng quan v dung mi chit.
Dung mi:
Dung mi l pha c nng thp. Dung mi l chit cc hp cht ra khi
nguyn liu v thay i ty theo bn cht ca mi loi nguyn liu. C s la
chn mt dung mi chit l tnh phn cc ca hp cht cha trong nguyn liu v
ca dung mi.
Dung mi phn cc v khng phn cc [6].
33
Qu trnh hnh thnh mt l ty thuc vo c tnh ca cht tan v dung mi.
hnh thnh mt dung dch trc ht phi c s ph v cc dy ni lin kt trong
hp cht tan v trong dung mi hnh thnh dy ni lin kt mi gia cht tan v
dung mi.
hiu v tnh phn cc ca dung mi, ta c th so snh gia 2 cht ete v
nc:
Hng s in mi ca nc 200C l 80.4 trong khi ca ete l 4.34.
Nguyn t hydro ca phn t nc c kh nng lin kt vi mt nguyn t
mang in m ca mt hp cht khc, hnh thnh dy ni lin kt hydro trong dung
dch nc, trong khi ete etylic khng c s lin kt ny.
Dy ni hydro hnh thnh nh hng n tnh ha tan ca hp cht i vi
dung mi.
Nc c tc dng va nh mt acid va nh mt bazo, cn ete ch l bazo
rt yu v khng hot ng nh mt acid.
Do nhng c tnh trn, nc c xem nh mt dung mi phn cc mnh
cn ete l mt loi dung mi khng phn cc. Cc dung mi phn cc mnh ngoi
nc ra cn c cc ancol bc thp nh: methanol, ethanol, propanol, Cc dung
mi khng phn cc ngoi ete cn c cc hydrocacbua nh ete du, benzene,
toluene, hexan,cc cht nm gia hai nhm ny gi l cc cht phn cc yu hoc
va nh ethyl acetate, clorofoc, acetone, diethyl clorua.
Khi la chn dung mi cn p ng c cc yu cu sau y [4].
Phi c tnh ha tan chn lc, tc l ha tan tt cc cht cn tch m
khng c ha tan hoc ha tan rt t cc cht khc. y l tnh cht rt c bn
khng th thiu c khi la chn dung mi.
Khng c tc dng ha hc vi cc cu t ca dung dch.
Nu trch ly lng yu cu khi lng ring ca dung mi khc xa vi
khi lng ring ca dung dch. Tuy nhin cng c loi thit b trch ly dung dch
c khi lng ring rt gn nhau.
Khng ph hy thit b, dng c.
Khng b bin i thnh phn khi bo qun.
34
Khng c khi thao tc, khng to hn hp n vi khng kh v kh
chy.
R tin, d kim.
Dung mi phi c trch ly ra sau qu trnh ly bng phng php
un nng, chng ct hoc sy. Sau khi tch khng li mi v l v khng gy c
cho sn phm. Trong cng ngh thc phm dung mi trch ly ph bin l nc (nh
trch ly c ci ng, trch ly ma sau khi bm nh, trch ly c ph, ngm nc
tinh ch cc loi tinh bt,). Vn quan trng cn gii quyt l cht lng nc
thc phm. Bn cnh dung mi trch ly c th l dung dch ng trong qu trnh
ngm cc loi qu, tm cc loi hng,; c khi dung mi l mt s dung dch ha
cht c nng rt long nh: dung dch CuSO4 1%, dung dch nc vi long.
Cc cht tan trong nc v dung mi phn cc [6].
Cc cht in ly nh cc mui v c u tan trong dung mi phn cc. Cht phn
cc: Cc hp cht hu c ni chung khng ion ha nhng nu chng c cha cc
nhm hoc nguyn t mang in m c th hnh thnh dy ni hydro vi phn t
nc th chng s tan c trong nc. Nhng nhm c kh nng to dy ni hydro
nh: -OH, CO, NO, NH2 v cc halogen gi l nhm phn cc. Cng c nhiu
nhm phn cc th phn t y cng d ha tan trong nc. Nhng nu mch hydro
cacbon ca phn t cng di th ha tan cng gim.
Thc nghim cho thy, mt nhm phn cc trong phn t c kh nng hnh
thnh lin kt hydro vi phn t H2O s lm cho phn t y tan c trong nc
nu s cacbon ca mch khng qu 5 hoc 6 nu phn t c thm mch nhnh. Nu
phn t c nhiu nhm phn cc (2 nhm tr ln) th t l ny gim xung. Mt
nhm phn cc cho 3 hoc 4 cacbon trong mch th phn t y tan c trong nc.
1.6.5 Tm hiu dung mi chit trong ti.
Nc.
Phn t nc c cu to t mt phn t Oxy v hai phn t Hydro, m i
electron trong mi trng lin kt ny b ko lch v pha Oxy nn phn t nc c
tnh phn cc, do nc d lin kt vi cc nguyn t, phn t v cc cht khc.
Mt khc cc phn t nc lin kt vi nhau bng cc lin kt Hydro (lin kt km
35
bn) nn cc phn t, cc nguyn t hoc cc cht khc d b gy lin kt to
nn cht mi [19].
Nc s dng l nc c cung cp t nh my nc ca thnh ph. Nc
t cc tiu chun cho php ca nc dng trong sinh hot v ch bin thc phm
ca Vit Nam theo tiu chun ca B y t.
Phng php chit xut.
Chit xut (trch ly) l mt qu trnh tch chit hon ton cc cht c trong
hn hp. Cc cht ny c ha tan khc nhau trong mt dung mi hoc trong
nhng h dung mi khc nhau. Qu trnh chit xut l mt qu trnh phc tp, c
th xy ra c l nh hin tng khuch tn, ha tan, thm thu, thm tch,ca
cht tan vo dung mi.
Phng php chit xut l bao gm c vic chn dung mi, dng c chit v
cch chit. Mt phng php chit xut thch hp ch c th c hoch nh khi
bit r thnh phn ca cc cht cn chit trong nguyn liu ra. Mi loi hp cht c
ha tan khc nhau trong tng loi dung mi. V vy khng th c phng php
chit xut chung p dng cho tt c cc nguyn liu.
Phng php thc hin qu trnh trch ly:
Cc cng on ch yu ca qu trnh trch ly l: Cho hn hp cn trch ly
tip xc vi dung mi ri tch cc pha, sau tch v thu hi dung mi v tin hnh
phn tch ring.
Phng php ngm: Nguyn liu c ngm vi dung mi trong bn chit
nhit phng, thnh thong o trn. Thi gian ngm ty thuc vo loi nguyn
liu.
C th thc hin qu trnh trch ly gin on hoc lin tc; trch ly mt hoc
nhiu bc, dung mi c th chuyn ng cng chiu hoc ngc chiu.
C th chit nhit thng hoc chit nng. Hai cch chit nhit
thng l ngm kit v ngm phn on. Phng php ngm kit cho kt qu tt
hn v chit c nhiu hot cht v t tn dung mi, nht l khi p dng cch chit
ngm kit ngc dng. Khi chit nng, nu dung mi l cc cht bay hi th p
36
dng cch chit lin tc hoc chit hi lu. Nu dung mi l nc th sc hoc hm
phn on.
Phng php ngm kit v phng php ngc dng: c thc hin trong
bn chit c van iu chnh dch chit chy xung theo mong mun sau khi
ngm nguyn liu vi dung mi mt thi gian nht nh. Dch rt ra t bn th nht
dng ngm nguyn liu bn th hai, tip tc thc hin cho n bn chit sau
cng. Phng php ny c s dng rng ri trong sn xut.
37
CHNG 2: I TNG V PHNG PHP NGHIN CU
2.1 i tng nghin cu. i tng nghin cu l loi
rong M (Sargassum serratum) mc
t nhin vng bin Nha Trang
Khnh Ha. Rong khi thu nhn
c ra qua loi b cc cht
bn c hc nc bin v lm kh
n m bo qun.
Hnh 2.1: Rong M (Sargassum serratum)
2.2 Ha cht v dng c th nghim. Ha cht: Cc loi ha cht s dng cho ton b qu trnh thc hin cc th nghim u l ha cht tinh khit t tiu chun dng cho phn tch do Trung Quc sn xut. Dng c th nghim: S dng cc thit b hin c ca phng th nghim ha phn tch, trin khai cng ngh ti Vin nghin cu v ng dng cng ngh Nha Trang nh: cc thy tinh, bnh tam gic, a thy tinh, bnh nh mc, giy lc, bnh cu, cn, t sy, bp in, my so mu, thit b ly tm, my c quay, t lnh, 2.3 Phng php nghin cu a) S tin hnh nghin cu.
Kho st phng php o
La chn nguyn liu
Kho st qu trnh trch ly
Thu nhn phlorotannin
ng dng trong sn phm
Phng php Folin - Ciocalteu
Rong kh
38
b) Cc phng php phn tch ha hc v vt l. Xc nh hm lng m bng phng php sy (ph lc 1)
Xc nh hm lng protein bng phng php Kjeldadl (ph lc 2).
Xc nh hm lng lipid tng theo phng php Bligh v Dyer hn hp chloroform/methanol (ph lc 3).
Xc nh hm lng Iod theo phng php chun (ph lc 4).
Xc nh hm lng tro ton phn (ph lc 5).
Xc nh hm lng x th theo Crudefibre v nh lng carbohydrate (ph lc 6).
Xc nh hm lng Fucoidan (ph lc 7).
Xc nh hm lng Alginate (ph lc 8).
Xc nh hm lng phlorotannin trong dch chit (ph lc 9). c) Phng php cm quan.
Tin hnh nh gi cm quan sn phm ung theo phng php cho im cht lng theo TCVN 3215- 79.
Phng php ny c s dng nh gi tng qut mc cht lng ca
mt sn phm so vi tiu chun hoc so vi mt sn phm cng loi trn tt c cc ch tiu cm quan: mu sc, mi, v, trng thi. Tnh trng cht lng ca mi ch tiu c nh gi bng im. Gi tr im tng theo mc tng ca cht lng. Ty theo sn phm v quc gia m thang im s dng rt khc nhau (thang 10, 20, 50, thm ch l 100). Do cc ch tiu c vai tr i vi cht lng chung ca sn phm mc khc nhau nn cc gi tr cho c i vi mi ch tiu c nhn thm mt gi tr tng ng gi l h s trng lng. Cc ch tiu c vai tr ln hn th c h s trng lng cao hn. Vic xc nh h s trng lng cho mi ch tiu ca mi loi sn phm l rt kh. Cc h s ny thng c xc nh theo kinh nghim, phng php iu tra kt hp vi phng php chuyn gia trn c s thng k. Khi nh gi cht lng cm quan bng mt hi ng th im cht lng ca ch tiu no l im trung bnh ca mi thnh vin nhn vi h s trng lng ca n. Tng im ca cc ch tiu l im cht lng sn phm. im ny quyt nh mc cht lng ca sn phm c nh gi.
39
Vit Nam, phng php nh gi cm quan sn phm thc phm thc hin
theo Tiu chun Vit Nam TCVN 3215 79. y l tiu chun s dng h im 20 xy dng trn mt thang thng nht 6 bc 5 im (t 0 n 5) trong im 0 ng vi cht lng sn phm b hng, cn t im 1 n im 5 ng vi mc khuyt tt gim dn. im 5 sn phm coi nh khng c sai li v khuyt tt no, trong tnh cht ang xt, sn phm c tnh tt c trng v r rt cho ch tiu . Tng h s trng lng ca tt c cc ch tiu c nh gi cho mt sn phm bng 4. Qu trnh nh gi phi c thc hin trong phng phn tch cm quan t yu cu. Vic chun b mu phi ph hp vi tng loi sn phm theo quy nh cht ch. Hi ng phi gm t 5 n 12 ngi chuyn gia c hiu bit v sn phm c nh gi. Hi ng c ch tch v th k lnh o hi ng trong qu trnh lm vic.
Khi nh gi, cc thnh vin lm vic c lp, cho im vo phiu v np
cho th k sau gi lm vic.
Th k hi ng s tng kt im ca cc thnh vin v t tnh ra im cht
lng ca sn phm. Theo h im 20, cht lng sn phm c chia ra 6 mc
theo bng sau:
Bng 2.1: Cc mc cht lng
Mc im im trung bnh cha c trng lng
Tt 18.6 20.0 Cc ch tiu quan trng nht 4.7
Kh 15.2 18.5 Cc ch tiu quan trng nht 3.8
Trung bnh 11.2 15.1 Mi ch tiu 2.8
Km 7.2 11.1 Mi ch tiu 1.8
Rt km 4.0 7.1 Mi ch tiu 1.0
Hng 0.0 3.9 Sn phm t cht lng khi im trung bnh cha c trng lng ca mt
ch tiu bt k phi t nh nht l 2.8 v im cht lng khng nh hn 11.2. Nu
hi ng thng nht nh cho mt ch tiu no 0 im th im chung bng 0 v
sn phm coi nh hng. Nu thnh vin no cho im lch qu 1.5 im trung bnh
cha c trng lng ca hi ng th im ca thnh vin b loi.
40
Bng 2.2: H s trng lng ca sn phm
im cht lng Ch tiu
5 4 3 2 1 0
Trng thi
Sn phm ng nht trong sut, khng c
bt
Sn phm trong, khng
bt
Sn phm hi c
Sn phm c, c cn
Sn phm cn nhiu, nc c.
Sn phm qu nhiu
cn, c vng, mc ni trn b
mt.
Mu sc
Trong sng, c trng cho sn phm ung
rong bin. Mu nc vng sng ng, hp
dn.
Trong sng, kh snh, c trng cho sn
phm ung rong bin. Mu
nc tng i.
Trong sng, c trng ca sn phm.
Mu nc hi nht.
B c, khng c trng cho sn phm,
c cn bn.
c ti, nhiu cn
bn
Sm en do qu nhiu cn bn. Mu ca sn phm h hng.
Mi
Thm t nhin, hi ha, hp dn, d
chu, c trng cho sn phm, khng c
mi l hoc mi do
khuyt tt. Mi thm mnh v
bn.
Thm t nhin, gy n tng kh hi
ha v hp dn c trng
cho sn phm.
Mi thm tng i, c thong
mi l.
Km thm, l mi l v
mi do khuyt tt, khng c trng cho sn phm.
L r mi l v cc mi do
khuyt tt.
Mi tanh kh chu ca sn
phm hng.
V
Ngt du, c trng cho sn
phm, hi ha gia v
v mi. Sn phm ngon, hp
dn.
Ngt du, c trng cho sn
phm, kh hi ha gia v v mi. Sn phm
tng i hp dn.
Ngt du, c cm gic xut hin v
khc.
Ngt du, nhng c
ln v khc.
C v l hoc do cc khuyt tt khc gy cm gic kh chu.
V ca sn phm hng.
41
d) Phng php phn tch vi sinh Ch tiu vi sinh vt l ch tiu rt quan trng nh gi cht lng v v sinh
an ton thc phm. i vi sn phm nc ung rong bin ng chai: Xc nh tng s vi sinh vt hiu kh bng phng php TCVN 4884:2005. Xc nh Colifom v E. coli bng phng php TCVN 6848:2005. Xc nh tng s nm men, nm mc bng phng php TCVN 5166:1900. Xc nh S.aureus bng phng php TCVN 4830-1:2005. Xc nh Strepstococcuss faecalis bng phng php TCVN 6189-2:1996. Xc nh P.aeruginosa bng phng php 3347/2001/Q. Xc nh Cl.perfringens bng phng php TCVN 4991:2005. e) Phng php x l s liu.
X l s liu theo phng php thng k. Mi th nghim u tin hnh 3 ln, v kt qu l trung bnh cng ca cc ln th nghim.
S liu c x l v th trn phn mm MS. Excel. 2.4 Quy trnh trch ly v thu nhn phlorotannin. 2.4.1 S quy trnh
Hnh 2.2: S quy trnh thu nhn phlorotannin t rong Sargassum Serratum.
Cht chit
Ra sch
Ct nh
Trch ly
B
Dung mi
Rong kh
Lc
C c
Ly tm
42
2.4.2 Thuyt minh quy trnh
Nguyn liu:
Thu mua rong kh c x l v c ngun gc r rng. Mc ch ca vic
la chn rong kh: hm lng m trong rong nh, gp phn quan trng trong vic
c ch s pht trin ca vi sinh vt sng trn rong, c ch qu trnh sinh tng hp
v chuyn ha trong rong. T rong c bo qun tt hn, m bo cho qu
trnh thc hin khng gp gin on v vn nguyn liu. ng thi, khi hm
lng m trong rong nguyn liu gim, tc trch ly tng ln v m tc dng
vi protein v cc cht ho nc khc ngn cn s dch chuyn ca dung mi thm
su vo trong nguyn liu, lm chm qu trnh khuch tn.
Ra sch.
Rong s c ra sch nhm loi b tp cht v mui bm dnh trn rong,
to iu kin cho qu trnh chit v lc c thc hin d dng.
Ct nh.
Sau khi ra sch, rong c lm ro s b ri ct vi kch thc thun li
cho qu trnh chit rt. Lm nh rong nhm mc ch tng din tch tip xc ca
rong nguyn liu v dung mi, ng thi lm ph v cu trc t bo rong, to iu
kin thun li cho cc cht ha tan trong dung mi. Tuy nhin, ta khng nn xay
hoc nghin rong qu nh, bi kch thc bt rong qu nh, bt kn l ca giy lc
lm cn tr qu trnh lc.
Trch ly Phlorotannin.
Phlorotannin l hp cht hu c c kh nng tan trong mt s loi dung mi
phn cc. Nc l dung mi phn cc nn c s dng trch ly cc cht phn
cc c trong rong, c th l phlorotannin. Cc yu t nh mi trng chit, nhit
, t l nguyn liu: dung mi, thi gian chit u c nh hng n kh nng ha
tan ca phlorotannin trong qu trnh chit. V vy ti cng on chit ny ta s tin
hnh cc th nghim nghin cu nh hng ca mt s yu t n kh nng chit
phlorotannin.
Lc
Sau khi chit, tin hnh lc nhm thu hi nhng cht ha tan c trong
dung mi. ng thi loi b c nhng tp cht khng tan khc (cn, b rong).
43
C c
Sau khi lc, dch rong c em i c c, nhm mc ch loi b bt dung
mi trong dch lc nh qu trnh bay hi dung mi bi nhit v p sut, to iu
kin thun li cho cng on sau. Qu trnh c c ph thuc vo nhit , thi
gian, ch khuy o, p sut ca thit b,Trong qu trnh c c, dung mi
trong dch rong bay hi nn mu sm li, th tch dch gim dn. Nu c c nhit
v thi gian khng thch hp s gy hao ht hoc lm bin tnh cht tan cn
chit. V vy khng nn c c nhit qu cao v thi gian di.
Sau khi c c, dch chit c em i phn tch thnh phn ri qua cng
on ly tm.
Ly tm
Sau qu trnh c c, tin hnh ly tm dch rong nhm loi b ht cc tp
cht hoc b rong cn st li sau khi lc v c c. Bn cht ca qu trnh ly tm l
tch d dng cc phn t khc nhau v kch thc v trng lng (khi lng ring)
trong dch chit, di tc dng ca lc ly tm v trng lc ca Tri t (lc ly tm
ln hn trng lc rt nhiu).
2.5 Cc yu t nh hng n qu trnh trch ly Phlorotannin.
Kho st qu trnh trch ly Trch ly nhm mc ch tch phlorotannin ra khi rong bng cch s dng
dung mi ha tan da trn c s chnh lch nng .
Trong qu trnh chit, vic la chn ra loi dung mi chit thch hp nht
ha tan tt cht tan cn xc nh l mt yu t rt quan trng. Qua bn cht ca mt
s loi dung mi v ca cht tan, ta thy dung mi c th ha tan tt phlorotannin l
cc dung mi c tnh phn cc, v vy ti chn dung mi l nc..
Phng php kho st: khi kho st mt yu t no (nhit , thi
gian) th cc yu t cn li c nh. Yu t no kho st xong th s c c nh
gi tr ti u tip tc kho st n cc yu t khc.
2.5.1 Tin hnh kho st iu kin mi trng (pH) trch ly. Khi lng mu cho mi th nghim l 10(g). Tin hnh ngm rong trong
dung mi l nc.
44
Chun b 11 mu th nghim theo cc pH nh sau: 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0, 7.0, 8.0.
Khi tin hnh th nghim ta c nh cc thng s: T l nguyn liu: dung mi l 1:20 Nhit trch ly l 700C Thi gian trch ly l 120 pht.
Dch chit thu c em i xc nh hm lng phlorotannin v carbohydrat. T la chn pH chit thch hp.
Hnh 2.3: S b tr th nghim xc nh nh hng ca pH
n kh nng trch ly (chit).
2.5.2 Tin hnh kho st t l dung mi trch ly. Vic la chn t l nguyn liu: dung mi (NL/DM) c nh hng ln ti
qu trnh chit. Nu lng dung mi qu t qu trnh chit s khng trit , lng
cht ha tan bn trong nguyn liu cn nhiu (do chnh lch nng cht tan nh).
Ngc li nu lng dung mi qu ln, kh nng chit trit hn, lng cht tan
ha tan nhanh hn, tuy nhin li nh hng n chi ph dung mi v ko di thi
gian thc hin cng on c c. V vy cn la chn t l dung mi sao cho thch
hp nht.
Trch ly
1.0 1.5 2.0 2.5 3.0 3.5 4.0 5.0 6.0 7.0 8.0
o OD
Chn pH ti u
45
Chun b 10 mu th nghim theo cc t l khi lng nguyn liu: dung mi
nh sau: 1: 5, 1: 10, 1: 15, 1: 20, 1: 25, 1: 30, 1: 40, 1: 50.
C nh cc thng s:
pH c xc nh th nghim 2.5.1
Nhit trch ly: 700C.
Thi gian trch ly: 120 pht.
Dch chit thu c em xc nh hm lng phlorotannin v carbohydrate.
T la chn t l nguyn liu: dung mi thch hp.
Hnh 2.4: s b tr th nghim xc nh nh hng ca t l dung mi n kh
nng trch ly.
2.5.3 Tin hnh kho st nhit trch ly. Nhit c nh hng n kh nng ha tan cc cht trong rong nguyn
liu vo mi trng chit. Khi nhit tng cc phn t khuch tn cng mnh,
nht gim, lng cht tan vo mi trng chit cng nhiu. Tuy nhin nu nhit
qu cao c th lm bin tnh mt s hp cht c hot tnh sinh hc hoc lm hao ht
mt lng cht tan d bay hi khc. Nu nhit qu thp, lng cht tan khuch
tn ra mi trng b hn ch. V vy cn xc nh nhit chit thch hp.
Trch ly
1: 5 1: 10 1: 15 1: 20 1: 25 1: 30 1: 40 1: 50
o OD
Chn t l dung mi ph hp
46
Chun b 7 mu th nghim theo cc nhit nh sau: 400C, 500C, 600C, 700C,
800C, 900C, 1000C.
C nh cc thng s:
PH c xc nh th nghim 2.5.1
T l nguyn liu: dung mi c xc nh th nghim 2.5.2
Thi gian trch ly: 120 pht.
Dch chit thu c em xc nh hm lng phlorotannin v carbohydrate.
T la chn nhit trch ly thch hp.
Hnh 2.5: S b tr th nghim xc nh nh hng ca nhit
n kh nng chit.
2.5.4 Tin hnh kho st thi gian trch ly. Th nghim nhm xc nh thi gian chit ti u thu c hm lng
phlorotannin cao nht. Thi gian chit phi hp l, nu ko di thi gian chit lng
cht ha tan dung mi ht, ng thi s nh hng n thi gian thc hin v chi
ph cho ton b qu trnh.
Chun b 12 mu th nghim theo cc thi gian nh sau: 20, 40, 60, 80, 100,
120, 140, 160, 180, 200, 220, 240 (pht).
Trch ly
600C 500C 400C 700C 800C 900C 1000C
o OD
Chn nhit ti u
47
C nh cc thng s:
pH c xc nh th nghim 2.5.1
T l nguyn liu: dung mi c xc nh th nghim 2.5.2
Nhit trch ly c xc nh th nghim 2.5.3
Dch chit thu c em xc nh hm lng phlorotannin v carbohydrate.
Hnh 2.6: S b tr th nghim xc nh nh hng
ca thi gian n kh nng chit.
2.5.5 Tin hnh xc nh hiu sut trch ly Tin hnh trch ly mu iu kin ti u kho st trn. Sau khi trch ly
1 ln xong th tin hnh lc thu ly dch lc. Phn b tip tc c s dng trch
ly li (ln 2, 3, 4) cc iu kin tng t nh trch ly ln 1.
Vic trch ly c lp li 4 ln trn cng mt mu. o OD ca dung dch sau mi
ln trch ly. T so snh vi hm lng ban u tnh c hiu sut trch ly.
C nh cc thng s:
pH c xc nh th nghim 2.5.1
T l nguyn liu: dung mi c xc nh th nghim 2.5.2
Nhit trch ly c xc nh th nghim 2.5.3
Trch ly
80 60 20 40 100 120 140 160 180 200 220 240
o OD
Chn thi gian ti u
48
Thi gian trch ly c xc nh th nghim 2.5.4
Dch chit thu c em xc nh hm lng phlorotannin v carbohydrate.
Hnh 2.7: s b tr th nghim xc nh nh hng ca s ln chit
2.5.6 Th nghim xc nh nhit c c. Qu trnh c c l tch bt lng dung mi c trong dch chit to iu
kin thun li cho cc cng on sau. Ta cn xc nh nhit c c thch hp
nhm hn ch nh hng ca yu t nhit n cht tan cn chit.
B tr th nghim:
Hnh 2.8: S b tr th nghim xc nh nhit c c.
Trch ly
1 ln 2 ln 3 ln 4 ln
o OD
Chn s ln trch ly
C c
40 50 60 Nhit c c (0C)
Xc nh hm lng phlorotannin, Carbohydrate
La chn nhit c c thch hp
70
49
Cch tin hnh:
Sau khi dch rong c lc, ta chia dch rong thnh 4 th tch bng nhau
(khong 500 ml) ri tin hnh c c ti cc nhit 400C, 500C, 600C v 700C
bng thit b c quay (iu kin chn khng ti nhit 400C). Lm th nghim ny
khi la chn c cc yu t nh hng n qu trnh chit nh: loi dung mi,
t l nguyn liu: dung mi, nht chit v thi gian chit.
2.5.7 Th nghim xc nh thi gian ly tm Qu trnh ly tm l tch ht cn (b rong) cn st li trong dch chit v
cc cn mui hnh thnh trong qu trnh c c . Dch chit thu c s trong hn,
sng mu hn. Ta cn xc nh thi gian ly tm thch hp tch trit cn trong
dch rong, ng thi tit kim c thi gian v chi ph thc hin qu trnh.
B tr th nghim:
Hnh 2.9: S b tr th nghim xc nh thi gian ly tm
Cch tin hnh: Dch rong sau khi c c tch bt dung mi c chia thnh
5 mu v tin hnh ly tm tc 5000 vng/ pht ti cc mc thi gian: 5 pht,
Thi gian ly tm (pht)
5 10 15 20 25
Kim tra trong ca dch rong
La chn th nghim thi gian ly tm
50
10 pht, 15 pht, 20 pht, 25 pht. Sau kim tra trong bng cm quan v la
chn thi gian ly tm thch hp.
2.6 ng dng cao chit phlorotannin vo qu trnh to sn phm: nc
ung rong bin ng chai.
S quy trnh
Hnh 2.10: S quy trnh to sn phm nc ung rong bin ng chai.
Nguyn liu
Trch ly
Lc
Phi ch
Gia nhit, bi kh
Bo n
Rt chai, y np
Thanh trng, lm ngui
Thnh phm
Cao hlorotannin
Dch ng
Chai, np
Natribenzoat
B
51
Thuyt minh quy trnh
Nguyn liu: S dng nguyn liu rong kh sch, khng ln tp cht v cc
loi khc, khng b h hng, m mc,loi rong s dng c cha hm lng
Phlorotanin cao v mt s thnh phn khong cht c li cho sc khe.
Trch ly: Tch chit cc thnh phn c trong rong nguyn liu.
Lc: Nhm loi b phn b v cc cu t l lng gy c, lm trong dch
trch ly.
Phi ch: Dch trch ly c phi trn cng vi cao phlorotannin, dung dch
ng.
Gia nhit, bi kh: To iu kin thun li cho qu trnh vo chai, do ui ht
khng kh ra khi chai. giai on ny c b sung Natribenzoate nhm mc ch
bo qun sn phm.
Rt chai, y np: s dng bao b thy tinh th tch 300ml vi chiu cao l
20 cm. Np chai lm bng st, c m km v c sn lp vecni chng r, m bo
phi to kn cho chai thy tinh.
Thanh trng, lm ngui: Tiu dit cc vi sinh vt gy h hng sn phm, ko
di thi gian bo qun.
Bo n: Pht hin cc sn phm khng t cht lng trc khi a ra th
trng.
52
CHNG 3: KT QU NGHIN CU V THO LUN
3.1 Kt qu xc nh mt s thnh phn ca rong nguyn liu. Trong n ny ti la chn rong Nu Sargassum Serratum lm nguyn liu
chit phlorotannin. V y l loi rong c tr lng ln v phn b rng ri ti
vng bin Vit Nam.
nh gi s b cht lng ca rong Sargassum Serratum, ti tin hnh
xc nh mt s thnh phn ha hc ca nguyn liu ny v kt qu phn tch c
ch ra trn bng 3.1 nh sau:
Bng 3.1 Thnh phn ha hc chnh ca rong nguyn liu
STT Thnh phn Hm lng (% cht kh)
1 Phlorotannin 0.8
2 m 11.5
3 Tro 35.1
4 Protit th 4.7
5 Lipid 0.7
6 It 0.1
7 Alginate 25.9
8 Laminaran 0.1
9 Fucoidan 1.7
Nhn xt: T kt qu trong bng 3.1 ta thy, thnh phn ha hc chnh ca
rong Sargassum Serratum bao gm cc cht c hm lng ln nh alginate, khong
v cc thnh phn khc chim t 0.1% n 11.5% nh protein, fucoidan,
phlorotannin, cc cht tan trong cn nh lipid, iot. Nhng thnh phn ny c th tan
trong cc loi dung mi phn cc, khng phn cc. Nn khi chit phlorotannin s
xy ra ng thi qu trnh chit cc cht trn, dch chit thu c bao gm
phlorotannin v cc cht i km, s c mt ca nhng cht ny trong dch chit
chim mt hm lng ng k. V vy tng hm lng phlorotannin chit v
gim cc cht i km, ta tin hnh la chn mt s thng s thch hp c th
chit c hm lng phlorotannin l nhiu nht.
53
3.2 Kt qu kh mi ca rong bin. Trong n ny ti s dng ngay dch chit c c phi ch to nc
ung, do , sn phm ung s c mi tanh ca rong bin do s c mt cc dn xut ca pyridine nh 2,4-di-isopropenylpyridine. y ti s dng tc nhn kh mi l cht H2O2 v tin hnh th nghim nh sau: Nhit kh mi : Nhit phng Thi gian kh mi :10 pht Thay i nng dung dch H2O2 :0,1%; 0,3%; 0,5%; 0,7%; 0,9 % v 1,2 %. Kt qu thu c nh sau: Bng 3.2 nh hng ca nng dung dch H2O2 n kh nng kh mi
Dung dch H2O2
0,1 % 0,3 % 0,5 % 0,7 % 0,9 % 1,2 %
Cm quan (mi) Mi tanh Mi tanh Mi tanh nh Mi thm c trng ca rong bin,
khng c v tanh
Da trn s liu dn trn bng 3.2, ti chn iu kin kh mi l ng
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