TAP CHI KHOA HQC - BAI HOC BONG NAI, SO 04 - 2017 ISSN 2354-1482 N G H I E N c t r u THU NHAN D I C H T R I C H GIAU CAC HOfP C H A T PHENOLIC TtT QUA DAU T A M (MORUS ALBA)
TkS. Nguyin Tkj Nguyin Thdo^
TOM TAT
Ngdy nay, nhimg logi nu&c qud gidu cdc hogt chdt chdng oxy hda dang thu hut sy quan tdm dgc biit cua cdc nhd khoa hgc tren the gl&i. Trong nghien cicu ndy, cdc ky thugt tiich ly dnh hu&ng din hdm lugng cdc hogt chdt chdng oxy hoa trong nu&c ep ddu tdm dugc khdo sdt. Chung tdi da tiin hdnh nghien cuu cdc ky thugt hd tig qud tiinh tiich ly cdc hogt chdt chong oxy hda tren thit qud ddu tdm Morus Alba: Su dung sdng sieu dm vd chi phdm enzyme Pectinex Ultra SP-L. Kit qud cho thdy, du&i dieu ki?n tdi uu: ndng lugng siiu dm 10,36 W/g, nhiit dg siiu dm 63°C thu dugc dich Pich cd ham lupng phenolic tdng tdng 63,3% so v&i mdu ddi chieng; nong dg vd th&i gian tdi uu khi xu ly enzyme la 0,08% v/w vd 120 phut. Tiep do, cdc phuang phdp ndy dugc so sdnh ve hiiu qud tiich ly cdc hgp chdt chdng oxy hda bdng md hinh dgng hgc bgc 2. Theo mo hinh ndy, tdc do tiich ly phenolic tdng vd anthocyanin khi sie dyng ky thugt siiu dm tdng xdp xi 16,9 vd 21,5 ldn so v&i phuang phdp xic ly enzyme; hdm lugng phenolic tdng vd anthocyanin tiong mdu xie ly sieu dm cung cao han mdu ii che phdm ezyme ldn lugt Id 11,3% vd 15,9%.
Tir kkoa: Anthocyanin, Pich ly bang enzyme, thdng sd dgng hgc, ddu tdm. cdc hgp chdt phenolic, phuangphdp tiich ly bdng sdng siiu dm
l . D d t v S n d ^ Trich Iy la giai dogn mang tinh Nudc ep qua la ngudn cung cdp quyfit dinh den chat Iupng cua sdn phdm nMfiu logi dudng chdt phong phu cho nudc ep frai cay. Thdng thudng, dfi tang con ngudi nhu; dudng, acid huu co, hifiu suat ttich Iy thi dich qua dupc xu vitamin, khoang chdt vd chdt xo. Thfim ly vdi cdc chfi phdm enzyme [3]. Cdc vdo dd, cdc logi nudc ep frdi cay hign nghifin cdu da cho thdy vific dng dyng nay cdn dugc ua chudng hon bdi cdc cac chfi phara enzyme pectinase frong thanh phdn sinh hgc vd tdc dung dupc ly xd Iy thjt qua da ldm gia tang dang kfi cua chung dfin sue khde con ngudi [1]. cd hieu sudt thu hdi Idn chat Iugng dich Qua ddu tdm thuOc loai Morus alba. Id qud [4]. Bfin canh phuong phap trich ly ngudn nguyfin ligu ty nhien gidu cac truyfin thdng sd dyng chfi phdra hgp chdt phenolic vdi kha nang chfing enzyrae, frong vai ndra gdn day ky thuat oxy hda cao [1]. Trong sd cac hgp chdt sifiu ara dugc dng dung thanh cfing phenolic frong ddu tdm thi anthocyanin frong xd Iy dich qud nhdm nang cao la nhdm hogt chdt chdng oxy hda quan higu sudt va chdt Iugng nudc fip frai cay frgng [2L [5, 6].
'Tnrang D91 hoc Phii Ygn
TAP CHI KHQA HOC - BAI HOC DONG NAI, SO 04 - 2017 ISSN 2354-1482 Muc dich cua nghien cuu nay dd Id:
i) Khao sat dnh hudng ciia cac thdng sd sifiu dra dfin hdra Iupng cac hogt chdt chdng oxy hda frong dich trich dau tam;
2i) Tdi uu hda cac dieu kien sieu am cho ham Iupng hpp chdt phenolic frong dich dau tam dgt cao nhdt; 3i) Khdo sdt dnh hudng cua cac yfiu td ndng dp va thdi gian u enzyme pectinase den hara lugng phenolic thu dugc frong dich trich dau tdra; 4i) Tdi uu hda phuong phap xd Iy enzyme dfi thu hdm lugng phenolic cao nhdt; 5i) So sdnh higu qua trich Iy cac boat chdt chdng oxy hda frong dich qua ddu tara cua hai phuong phdp frfin.
2. Thyc nghiem 2.1. Nguyin lieu
Ddu tdm: Qud ddu tdm (Morus alba) diing frong ngMfin cdu nay dupc thu mua vao thang 2 td nha vudn d Da Lgt. Qua dugc xu ly bang may cha hifiu Panasorac MJ - 170, Malaysia. Phdn thit qua thu nhgn dupc hda tan vdi nudc theo ti lfi 1:1 tinh theo ti frgng, sau dd hfin hgp dugc xu Iy tifip vdi che phara enzyrae hoac sdng sieu am vd thu nhdn nudc fip qud.
Che phdm pectinase: Pectinex Ulfra SP-L cd ngudn gdc td ndm mdc A.
aculeatus, dupc sdn xuat bdi cdng ty Novo Nordisk Ferment (Thyy Si). Hoat tinh cua che phdm 4.193 don vi polygalacturonase/raL. pH tdi uu va nhiet do tdi uu ciia chfi phdm ldn lupt Id 4,0 vd 50°C.
2.2. Phuangphdp thi nghidm
Mdi ngMgra thuc dupc thyc hifin vdi 40 g radu ddu cha frong becher (lOOmL).
2.2.1. Anh hu&ng cua cdc diiu kien siiu dm vd tdi uu hda cdc diiu kiin xic ly song siiu dm den hdm lugng chdt chdng oxy hda trong dich ep ddu tdm
Phan nay gdm 4 thi ngMem:
* TM nghifim I: Cfing sudt sifiu am dupc thay ddi tu 0 dfin 13,3 W/g hfin hgrp dau cha, frong difiu kifin nhiet dd sifiu am la 30°C vd thdi gian 2 phut cho I mdu.
* TM nghidm 2: Nhiet do sieu dm dugc khdo sdt td 30 dfin 80°C, vdi cdng sudt va thdi gian sieu am la 9,38 W/g hdn hpp ddu cha va thdi gian 2 phut cho 1 mdu.
* Thi nghifim 3: Thdi gian sifiu dm thay ddi tu 0 dfin 10 phut, vdi cdng sudt va nhifit do sifiu dm Id 9,38 W/g ddu chd vd nhifit do 60°C.
* TM nghiem 4: Vdi muc tieu tim ra cdc difiu kien xu ly sieu dm tdi uu, chiing toi chgn hai thdng sd cdng suat va nhiet dg sifiu dm dfi tifin hanh thi nghifim theo phuong phap quy hogeh thuc nghiera true giao 2 yfiu td, cau tnic cd tara vdi cac ham muc tifiu la ham lupng cdc hgp chat phenolic frong dich dau tam. Chiing tdi sd dyng phan mfim Modde 5.0 dfi thifit kfi thi nghifim va xu Iy ket qud.
Trong phdn thyc nghiera nay, thdi gian sifiu dra dupc cd djnh frong 6 phut, cdc budc tifip theo dupc tifin hdnh khdo sdt tuong ty nhu fren. Mdu ddi chiing
122
TAP CHf KHOA HOC - BAI HOC B 6 N G NAI, SO 04 - 2017 ISSN 2354-1482 dugc chudn bi tuong ty cdc tM nghifim
fren dfi so sanh hdm Iupng chdt chfing oxy hda frong nudc ep dau tdm ttirdc vd sau khi xd Iy sdng sifiu dm. Sau khi xu ly sifiu am, hdn hgp ddu cha dugc ly tam vdi tdc do 10.000 vdng/ phut frong thdi gian 15 phdt bdng tMfit bi ly tara lanh (Satorius, Thuy SI) vd dich qud sau ly tdm dupc mang di phdn tich.
2.2.2. Anh hu&ng cua cdc dieu kiin il enzyme vd tdi uu hda cdc dieu kiin xu ly enzyme din hdm lugng chdt chdng oxy hda trong dich ep ddu tdm
Gdm 3 thi nghifim:
* Thi nghifim 1: Ham Iugng Pectinex Ulfra SP-L khdc nhau dupc cho vao cac cdc chua mdu: 0; 0,03;
0,05; 0,07; 0,09; 0,11 va 0,13 % v/w (khdi lugng enzyme/khdi lugng thit qua) vdi nhifit dd xd Iy 50 °C frong thdi gian 60 phut.
* Thi nghiem 2; Ndng dp Pectinex Ulfra SP-L 0,07% dupc cho vdo cac cdc mau va lan lupt u frong thdi gian tu 30 dfin 150 phut.
* Thi nghifim 3: Thi nghifim nay dupc bd tri nhdm khdo sdt sy tuong tac giiia hai yfiu td ndng dp che phara enzyme pectinase va thdi gian xu Iy enzyme va sy anh hudng ddng thdi cua hai yeu td nay dfin ham Iugng cac hpp chat phenolic frong dich trich dau tam.
Chiing tdi thyc Mfin qua trinh tdi uu hda hai yfiu td bdng md hinh trye giao cdp 2 cd tdm xoay vdi 5 thi nghifim d tam, sd dung phdn mem Modde 5.0 dfi thifit kfi va xd Iy sd lieu thuc ngMfim.
Trong phdn thyc nghigra nay, cdc budc tifip theo dupc tifin hdnh khao sdt tuong bf nhu frfin. Mdu ddi chdng dupc chudn bi tuong ty cdc thi nghifim frfin de so sanh ham lugng chdt chdng oxy hda frong nudc ep ddu tdra trudc va sau khi xd Iy enzyrae.
2.2.3. So sdnh cdc thdng so dgng hgc cua qud trinh trich ly dich qud bang phuangphdp ho trg enzyme vd sieu dm tir md hinh dgng hoc bgc hai
Trong thi nghifim nay, phenolic tdng vd anthocyanm dupc chpn la nhung thdnh phan muc tieu frong dich ttich ddu tam giau cac hgp chdt chdng oxy hda. Cac difiu kifin xu ly enzyrae pectinase va sdng sifiu am da dupc tdi uu hda dfi thu nhdn dich trich ddu tdra gidu cac hgp chat chdng oxy hda.
Trong phuong phdp hd frg trich Iy bang chfi phdm enzyme pectinase, ndng dd Pectinex Ulfra SP-L Id 0,08% w/w dupc cho vdo cdc becher chda mdu. pH cua dich qua dugc difiu chinh tdi 4,0.
Nhifit dp frich ly dugc khdng che d 50'*C bdng bfi difiu nhigt (Memmert, Ddc). Ham lupng cdc boat chdt dugc xac dinh trong khoang thdi gian tii 0 dfin 140 phut.
Trong phuang phap xu 1;^ sifiu am dich qua, hdn hgp dau tdm dupc xu ly vdi cdng suat sieu am la 10,36 W/g, nhifit dd xd ly dich qua la 6'i°C va thdi gian sieu dm dupc khdo sat tu 0 dfin 8 phut. De xac dinh hang sd tdc dp trich Iy cac hpp chat chdng oxy hda cua dich trich ddu tam, chiing tdi dp dung quy
TAP CHI KHOA HOC - BAI HQC BONG NAI, SO 04 - 2017 ISSN 2354-1482 Mat ttich ly cua md hinh bac hai [7,8].
Mo hmh bac hai dang chung dupc bifiu difin nhu sau:
^ = f c ( C . - C , ) ^ l ) Trong dd:
k: Hang sd tdc dp trich ly theo md hinh bgc 2 (L g'^ phut"')
Ce: Khd ndng trich Iy (ddy Id ndng dp chat chiet d trang thai can bang frong dich trich) (g L"')
Ct: Ndng dd chdt ehifit frong dich trich tgi thai diera t.
Quy Mat trich ly cua md hinh bac 2 ndm frong difiu kifin bifin t = 0 den t va Ct = 0 dfin Ct, cd thfi dupc vifit theo phuong frinh dudng thang nhu sau:
Tdc dp trich ly ban ddu, h (L g"
phlit"') la C|/t khi t tien dfin 0 va dupc xac dinh bdi phuong trinh sau:
h = kC^ (4) Tdc dp trich Iy ban dau h (L g"' phut"'), khd nang trich ly Cg (g L"') va hang so tdc do trich ly k (L g"' phut"') se dugc xac dinh tu dd thi dudng thang frfin hai trye tpa dp t va t/Ct-
2.2.4. So sdnh hdm lugng cdc hogt chdt vd hogt tinh chdng oxy hoa cda dich qud ddu tdm thu dugc bdng phuangphdp hd trg enzyme vd sieu dm
Cac ky thuat hd frp frich Iy dich qua ddu tdm bdng enzyme va sieu am dugc tien hanh dudi cdc difiu kifin tdi im.
Ddi vdi phuong phap trich Iy bang
enzyme, ndng do Pectinex Ultra SP-L la 0,08% w/w dupc cho vdo cac becher chda mlu; pH cda dich qua dugc dieu chinh tdi 4,0; nhifit dg vd thdi gian trich l y I d 5 0 ° C v a I 2 0 p h u t .
Ddi vdi ky thuat trich ly bdng sdng sifiu dm, dich qud dupc sieu dm dudi cdng sudt 10,36 W/g d dieu kien nhigt do la 63 °C va frong thdi gian trich ly la 6 phut.
Mdu ddi chdng khdng xu ly enzyme ldn sifiu dm ciing dugc xu ly dudi cac dieu kign tuong tu.
2.3. Phwffng phdp phdn tick Phenolic tdng duoc xac dinh bang phuang phdp quang phd sd dung thudc thd Folin-Ciocalteu [9]. Ket qua thyc nghifim dugc bifiu difin bdng duong lugng mg acid gallic fren lit dich qud (rag GAE L"'). Ham Iupng anthocyanin tdng dupc xac dinh bang phuang phdp pH-vi sai [9]. Hoat tinh chdng oxy hda cua dich trich dugc danh gid bang phuang phdp FRAP (Ferric Reducing Ability of Plasma) va phuang phap ABTS (2,2'-Azmobis-(3-ethyl Benzo Thiazoline-6-Sulfonic acid)) [10, II].
Ket qua dupc bieu difin dudi dgng milimol Trolox tren lit dich trich (mM TE/L).
2.4. Phwang phdp xw ly so li^u Tdt cd cac nghiera thdc dupc tifin hanh lap lgi 3 Idn. Ket qua frmh bay la gid tri trung binh. Nhiing gid tri tmng binh dugc xera !d khac biet cd y nghia khi p<0,05. Phan tich phuang sai (ANOVA) dugc tifin hdnh frfin phdn
124
TAP CHI KHOA HQC - DAI HQC BONG NAI, SO 04 - 2017 ISSN 2354-1482 mfim Statgraphics plus version 3.0.
3. Ket qua vd ban ludn
3.1. Anh kw&ng cua cdc dieu kifn sieu dm vd toi wu koa cdc Miu ki^n xw ly song sieu am den hdm lwffng ckdt chong oxy kda trong dich ep dau tam
Theo ngMfin cuu cua chiing tdi [12], khi tang cdng sudt sifiu am, hogt tinh chdng oxy hda cda dich ddu tdm tang theo vd dgt eye dgi d cdng sudt 9,38W/g. Khi dd, boat tinh chdng oxy hda tang Idn lugt 19,2% (theo phuong phap FRAP) va 14,1% (theo phuang phap ABTS) so vdi mau ddi chiing khdng xu Iy sieu am.
Hoat tinh chdng oxy hda tang len cung vdi su gia tdng hpp chdt phenolic (frong do bao gdra cd anthocyanin) vd vitamin C frong dich frich, chiing td rdng sdng sieu ara lara tang ham lupng cdc cdu td cd hogt tinh sinh hpc frong dich qua khi sd dung cdng suat sieu dm phu hpp. Nhdn dinh nay cua chung tdi phu hgp vdi kfit qua dupc cfing bd bdi Le vd cdng sy (2012) [5]. Cdc tdc gia nay ting dung sdng sieu am dfi hd frg ttich ly vitamin C vd cdc hap chat phenolic td qud so ri. Theo cdc tac gid nay, sdng sieu dm da lara gidra kich thudc thjt qua, gia tang tdc do khuay frdn, cdi thifin qua trinh truyen khdi vd ddy nhanh tdc do trich Iy cdc hogt chdt frong dich qua. Tuy nhifin nang lugng sifiu dm qua cao se Idm gidm ham Iupng cac hogt chdt trong dich qua. Difiu ndy cd thfi do sy xudt hien cdc goc hydroxyl, cac gdc ndy phan ung vd Idm bifin ddi
cdc thanh phan phenolic va vitamin C frong dich qua [13].
Cac yfiu td nhifit dfi va thdi gian sieu ara cung lan lugi dupc khdo sdt.
Theo ket qua thu dugc tu [12], khi nhifit dg sifiu ara vugt qua dO^C thi ham lugng phenolic tdng va anthocyanin trong dich qua giam dan. Mason &
Lorimer (2002) [14], da phat bifiu rang, nhiet do qua cao sfi Idm gidm cudng dp nd va Clia cac bgt bdng do dp sudt hai cao. Them vdo dd, nhiet dg cdng cao cdng ddy nhanh tdc do phdn huy vitamin C vd cdc hpp chdt phenolic. Khi xd ly thit qud ddu tdm vdi thdi gian sifiu dm khdc nhau thi hdm lupng cdc hoat chdt cung bifin ddi ddng kfi vd 6 phut la khodng thdi gian sifiu dm cho hdm lupng cdc hpp chdt phenolic cao nhdt, kfit qua nay ciing tuong tu vdi nghien cuu cua Le va cdng sy (2012) [5] khi trich ly cac hgp chdt phenolic td trdi sa ri.
Sau khi khdo sat sy dnh hudng cua tdng dieu kifin sifiu dm dfin ham Iugng cdc hoat chat trong dich trich dau tdra, cdng suat sifiu dm 9,38 W/g vd nhifit do xd ly 60°C dupc chpn la hai yeu td trung tam cua rad hinh true giao cd tam xoay vdi hdm muc tifiu Id hdm lugng cdc hpp chat phenolic. Theo [12] chung tdi thu dupc phuang frinh hdi quy ve hdm Iugng cac hpp chat phenolic frong dich qua ddu tdm nhu sau:
Y = 1344 + 26,8592X,+ 11,5543X2 29,5045Xi^ - 42,0084X2^ + I7,4999Xi.X2(l)
125
TAP CHl KHOA HQC - BAI HQC BONG NAI, SO 04 - 2017 ISSN 2354-1482 Trong dd: Y, Xt, X2 ldn lugt Id hdm
lupng cac hgp chdt phenolic (ragGAE/L), cdng suat sifiu dm vd nMfit do sieu dm.
Phuong trinh hdi quy dugc bifiu difin frfin \mc tga do khdng gian 3 chifiu:
II
Hinh 1: Anh hu&ng cua cong sudt sieu dm (Xi) vd nhiet do (X2) din hdm lugng cdc hgp chdt phenolic (Y)
trong dich qud ddu tdm
Md hinh cho thdy, sy thay ddi cdng sudt vd nhifit do sieu dm dd lam bien ddi ham lupng phenolic tdng thu dugc frong dich trich. Td phuong'frinh hdi quy, ndng do phenolic tdng dgt tdi da la 1.353 rag GAE/L kM cdng sudt 10,36 W/g va nhiet dg sifiu dra la 63°C. Dfi kifim tra do cMnh xdc cua md hinh, chiing tdi da thyc Men cdc thi ngMgra kifira chdng dudi cac dieu kien dd tdi uu.
Kfit qud dgt dupc nhu sau: Hdra Iugng trung bmh cua cdc hpp chdt phenolic thu dupc sau 3 lan lap lgi Id 1363 mg GAE/L ling vdi cdng suat sifiu dm la 10,36 (W/g) va nMfit do sifiu am la 63 "C; gid tri tM nghigm rdt gdn vdi gia tri tien doan td phuang trinh hdi quy (1).
Ci phuong phap thyc ngMfim cd difin, cdc difiu kign dupc chgn la cfing sudt sifiu am 9,38 W/g, nhi^t do 60°C vd thdi gian 6 phiit. Khi dd, chiing tdi nhgn thdy hdm Iupng cdc hgp chdt phenolic frong dich qua tang 58,3% so vdi mau ddi chung khdng qua xu ly sieu am. Sau khi tifin hdnh tdi uu hda bang phuong phdp quy hogeh thyc nghifim, chiing tdi nhdn thdy hara Iupng cdc hpp chdt phenolic ttong dich qud tang dfin 63,23% so vdi mau ddi chdng. Kfit qud nay tang 8,5% so vdi phuang phdp thyc nghiera cd difin. Nhu vgy, phuang phdp tdi uu bdng quy hoach thyc nghigm dd Idm tang hieu qud xd ly sieu dm frfin dich qua dau tam.
Kfit qua chiing tfii thu dugc cung tuong ty vdi ket qua nghifin ciiu cua Nguyen va Le (2012) [15] kM tdi uu hda cdng sudt va thdi gian sifiu am dfi tang hifiu qud trich Iy dich qua dda; hay ket qud nghifin ciiu cua Chen vd cgng su (2012) [16] khi tdi uu hda ti lfi nudc phdi frdn, nhiet dO vd thdi gian sieu am dfi tdng hieu qud trich ly polysaccharide td bOt ndm Boletus edulis.
3.2. Ank kw&ng cda cdc diiu kiin u enzyme Pectinex Ultra SP-L vd toi wu koa cdc Meu kien ATK" ly enzyme den kdm lwong chdt ckong oxy hoa tiong dfck ep ddu tdm
Ham lupng vd hogt tinh cua cdc chdt chdng oxy hda frong dich qua ddu tdm bidn ddi dang ke khi xu Iy hdn hpp ddu chd vdi nhiing ndng dp enzyme vd thdi gian d khdc nhau. Chiing tdi da thu
TAPCHI KHOA HOC - DAI HQC DONG NAI, SO 04 - 2017 ISSN 2354-1482 dupc kfit qua td [17], d nfing dd enzyrae
0,07% v/w ham Iupng cdc boat chdt chdng oxy hda frong dich trich ddu tdm dgt cao nhdt, cu thfi phenolic tdng vd anthocyanin tang so vdi mau ddi chdng Idn lupt Id 36,9% vd 78,5%. Difiu nay dupc ly gidi la do che phdm enzyme da phdn buy cdc pectic ma cac ca chdt ndy tap trung chu yeu d thanh vd cdc phien giua cua te bao thit qua [16]. Do dd, qua trinh trich Iy cac hpp chdt chdng oxy hda tai te bdo chat cua thit qua dugc cai thi$n. Nhu vdy, ndng dg thich hgp cua Pectinex Ulfra SP-L cho xu Iy thit qua la 0,07% v/w.
Khi keo dai thdi gian xd ly vdi enzyrae len den 90 phiit ham lugng cdc hpp chat phenolic frong dich qua ddu tdm dgt cao nhdt, tang Ifin 46,8%i so vdi mdu ddi chdng. Neu tifip tyc tdng thdi gian xu Iy enzyme td 90 phut dfin 150 phut thi hdm lupng cac hop chat phenolic khdng bifin ddi ro r$t (p <
0,05). Do dd, 90 phut la thdi gian thich hgp cho xu ly enzyme ddi vdi hdn hap ddu tdm. Thdi gian xd ly enzyme pectinase ddi vdi hdn hop ddu tdra thi dai hon so vdi khi xd ly thit qud so ri (60 phut) [18].
Dya ttfin kfit qud thu dugc, chdng tfii tifip tyc lya chpn ndng dp Pectinex Ulfra SP-L 0,07 %v/w va thdi gian xd ly enzyme 90 phut Id hai yfiu td trung tam cua md hinh trye giao cd tara xoay.
Theo [17] chung tdi thu dupc phuang ttinh hdi quy vfi hara Iugng cdc hop
chat phenolic ttong dich qua dau tara nhu sau:
Y = 1600 + 35.91X1 + 36.22X2 - 53.14X1^-15.62X2^2)
Trong dd: Y, X,, X2 ldn lugt la hara Iugng cdc hpp chdt phenolic (ragGAE/L), ndng dg chfi phara enzyme va thdi gian xd Iy.
Phuong trinh hfii quy dugc bifiu difin ttfin trye tpa do khdng gian 3 chifiu nhu sau:
Hinh 2 Anh huong cua ndng do chi phdm enzyme (Xj) vd th&i gian xu ly (X2) din hdm lugng cdc hgp chdt phenolic (Y) tiong dich qud dau tdm
Md hinh cho thay, sy thay ddi ndng do enzyme hay tiidi gian xd Iy da Idra bifin ddi hdm lupng phenolic tdng thu dugc frong dich trich dau tam. Td phuang trinh hdi quy, ndng dg phenolic tdng dat tdi da la 1.631 mg GAE/L khi ndng do che phara enzyme vd thdi gian xu Iy Id 0,08%v/w vd 120 phut. Dfi kifim tra do chinh xac cua md hinh, chiing tdi da thyc hifin cac thi nghiera kifim chdng dudi cac dieu kien da tdi uu. Kfit qua ham Iugng trung binh cua cdc hgp chdt phenolic thu dupc sau 3 ldn lap Igi la 1659 mg GAE/L, gid tri thi nghiera rdt gan vdi gia fri tifin doan td
TAP CHI KHOA HOC - DAI HQC DQNG NAI, SO 04 - 2017 ISSN 2354-1482 phuong ttinh hdi qui (2). Ndng dO
phenolic tdng frong cdc radu xu ly enzyrae dudi difiu kifin toi iru tang 51,2% so vdi radu ddi chiing vd tang hon 7,1% so vdi cdc mdu xu ly enzyrae theo phuong phap cd difin.
3.3. So sank cdc tkdng so Mng hgc cua qud trink trick ly dich qua bang pkwang pkdp ko tra enzyme vd siiu dm tie mo hinh dgng kgc bgc hai
Trong phdn nay, chiing tdi tifin hdnh xd ly hdn hgp dau tam bdng sdng sifiu dm hoac che pham pectinase, td do xdc dinh ham lugng cdc hpp chdt phenolic vd anthocyanin tai cac khodng thdi gian khac nhau frong qua trinh xu ly, kfit qud thu dupc nhu hinh sau:
flm (pb&t)
Hinh 3; Su thay ddi ndng do phenolic tong vd anthocyanin trong djch
Pich ddu tdm theo thai gian khi xu ly bdng sdng sieu dm vd enzyme pectinase
18,0 ' 1 - '*•"
a l - 10.0 g'^ 80 f^ 6.0 5 4.0
2.0
• phenolics n
" anthocyanins y^
>"
/ /
o / ^ • - ' ^
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Thjli gian silu Bm (phAl)
ThM gian I D ly eniyme (phdt)
Hinh 4: Gid tri nghich ddo toe do Pich ly (t/Ct) ddi v&i phenolic tdng vd anthocyanin theo th&i gian trong (a) phucmg phdp tiich ly bdng siiu dm vd (b) phucmg phdp tiich ly bdng enzyme
Hinh 3 thfi hi^n ndng dp phenolic tdng va anthocyanin cua dich trich frong sudt thdi gian trich Iy bang phuang phdp sieu dm vd sd dung chfi phdm enzyme pectinase. Tat cd cdc mdu dugc xd ly bdng sdng sifiu ara hay che phdm enzyrae dfiu cho thay ham lupng cac hpp chdt phenolic va anthocyanm cao hem so vdi mdu ddi chiing khdng xd ly cac ky thudt ttich ly.
Td cdc sd lifiu thyc nghifim nay, gia tri nghich dao tdc do trich Iy tgi cac thdi difim khac nhau dupc tinh todn vd hinh 4 rad ta phuang trinh dang tuyfin tinh
TAPCHI KHOA HQC - DAI HQC DONG NAI, SO 04 - 2017 ISSN 2354-1482 cua md hinh ddng hgc bde 2 ciia
phuong phap trich Iy cdc hogt chdt chdng oxy hda cd hd trp cua sdng sifiu dm va che phdra pectinase.
Bdng I cho thdy cdc thdng sd dpng hgc cua qua trinh ttich ly cac hpp chdt chdng oxy hda tu qud ddu tdm. Khd nang trich ly Ce ddi vdi cdc hpp chdt phenolic va anthocyamn cda cd hai phuong phdp xd Iy tuong duong nhau.
Tuy nhien, gia fri hang sd tdc dp trich Iy k cua phuong phap xd Iy bdng sdng sifiu am cao hon so vdi phuong phdp xu Iy bdng chfi pham pectinase xdp xi la 16,9 ldn ddi vdi cac hop chat phenolic vd 21,5 ldn ddi vdi anthocyanin. Tuong ty, tdc do trich Iy ban dau h cua cdc hogt chat khi sd dung ky thuat sieu am cdng cao hon nhifiu so vdi phuong phap xd Iy chfi pham pectinase. Difiu ndy chung td phuang phap trich ly cd hd ttp cua sdng sieu dm da tgo difiu kifin thudn lgi cho qua ttinh trich Iy cac boat chat cd ttong qud ddu tdra vd thdi gian trich ly ngan hon so vdi phuong phap su dyng che phdm enzyme pectinase.
Ket qud ndy tuong ty nhu ket lugn cua Khan va cdng sy (2010) [19] vd Pan va cpng sy (2011) [20] kM nghien cdu qud trinh frich Iy polyphenol td vd qua
cam vd vd qud lyu. Tuy nhifin, mdc dp tang cua cdc thdng sd ddng hgc frong nghien cuu cua cdc tac gid nay thap hon nhieu so vdi kfit qud cua chiing tdi. Sy khac bigt ndy cd thfi la do ham Iugng cdc hpp chdt phenolic frong dau tam cao hon nhifiu so vdi cac hpp chdt phenolic frong vd cam hay vd lyu, ddng thdi cdc hgp chat phenolic trong thit qud dfi trich ly hon so vdi frong vd qua.
Xet vfi ham lugng cac hoat chdt thu dupc frong dich qua kM tifin hdnh so sanh hai phuang phap xd Iy frfin, d bdng 2 cho thay cd hai phuong phap deu giiip cdi thifin ddng kfi ham Iupng cdc hogt chdt frong dich trich. Theo do, ham Iugng cdc hgp chat phenolic va anthocyanin frong djch qua dau tdm frong trudng hgp xu Iy sdng sieu am tang cao ban so vdi trudng hgp xu Iy enzyme lan lugt 11,3% va 15,9%. Ky thuat xu ly sieu dm ddi vdi thit qud ddu tdm cho hifiu qua trich ly cdc hgp chat phenolic va anthocyanin frong dich trich cao hon so vdi phuong phap su dung chfi phdm pectinase. Do vay hogt tinh chdng oxy hda cua cac radu khi xu ly vdi sdng sifiu am ciing cao ban so vdi cdc mdu xd ly vdi chfi pham enzyme.
TAP CHI KHOA HQC - BAI HQC BONG NAI, SO 04 - 2017 ISSN 2354-1482 Bang 1: So sdnh cdc thdng sd ddng hgc cua qud tiinh tiich ly cdc hgp chdt phenolic vd anthocyanin tic ddu tdm khl cd sy ho tig cua sdng siiu dm vd cki phdm pectinase
Hop chat
Hop ch4t phenolic Anthocyanin
Phmrag phdp trich ly Xu 1^ sieu am Xu ly pectinase Xii ly sieu am Xii ly pectinase
Khd nSng trich ly, C, (grt.)
1,39 1,36 0,45 0,39
T6C d$ trich ly ban d^u, h (gL'phiif') 11,76 0,66 2,79 0,10
H^ng s6 toe do trich ly, k ( L g ' p h i f ' )
6,09 0,36 13,76 0,64
R' 0,996 0,999 0,995 0,998 Bang 2: Hdm lugng cdc hogt chdt vd kogt tinh chdng oxy hda cua dich tiich ddu tdm
thu dugc tie phuang phdp siiu dm vd xu ly enzyme
Phirong phap trich ly Mau doi chung
Xu ly sieu am Xii ly pectinase
H^m liTQrng cdc hgp ch^t Phenolic
(mg GAE/L) 1375 + 35' 1530 ±38°
910 + 24*
Anthocyanin (mg/L) 477 ± 2 0 ' 553 ± 14' 234 ±18"
Hoat tinh chong oxy hda FRAP
(mM TE/L) 13,62 ±0,19' 14,04 ±0,17' 8,19 ±0,12*
ABTS (mM TE/L) 11,88 ±0,25' 12,33 ±0,17' 7,10 ±0,16"
4. Ket lu$n
Cd hai phuang phap hd frp trich ly bdng sdng sifiu dm va chfi pham pectinase Id nhting phuong phdp trifin vgng nhdm cdi tMfin gia tri dinh dudng cua nudc qud ddu tara thfi hifin qua sy gia tang hara Iupng cac hgp chat phenolic, anthocyanm vd hoat tinh chdng oxy hda ciia dich qud. Tuy nMfin khi sd dyng phuang phdp sieu am cho thdy nhifiu thuan lgi ban so vdi phuong phdp xu Iy enzyme nhu thdi gian xd ly ngan hon, ddng tiidi hieu sudt thu hdi cdc hpp chdt phenolic va anthocyanin cao hon. Nhu da trinh bdy, chfi phdm pectinase chi phdn cdt pectin frong cdu
true md thyc vat dfi ldm giam kich thudc nguyfin lieu vd hd frp cho qud trinh trich ly phenolic vd anthocyamn.
Trong khi dd sdng sieu am c6 thfi phdn cat tdt ca cdc polymer ttong cau tnic tiidnh te bao va ldp ket dinh gida cac tfi bao frong md thyc vat nen sy pha huy tfi bdo se trifit dfi han; td dd, cdc chat chdng oxy hda td ndi bdo se dupc giai phdng ra ngoai nhifiu hon. Do dd, sy phdn cdt khdng chpn Igc cdc polyraer frong thit qud bdi sdng sieu am se cho hieu qua trich ly cdc hpp chdt phenohc cao hon sy phan cat chgn lgc cua enzyme pectinase.
TAP CHl KHOA HOC - BAI HpC BONG NAI, S6 04 - 2017 ISSN 2354-1482 TAI L i p u THAM KHAO
1. Song, W.; Wang, H.J.; Bucheli, P.; Zhang, P.P.; Wei, D.Z.; Lu, Y.H., Journal of Agriculture and Food Chemistry (2009), 57, 9133-9140
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4. Horvath-Kerkai, E. and Steger-Mate, M. Manufacturing fruit beverages and concentrates. In Sinha, N., Sidhu, J., Barta, J., Wu, J. and Cano, M. P. (Eds).
Handbook of fruits andfivit processing Oxford: Wiley-Blackwell (2013), 215-228 5. Le, H.V. va Le, V.V.M., Intemational Joumal of Food Science and Technology (2012), 47,1206-1214
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FoodChemistry (2010), 119, 851-858
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TAP CHI KHOA HOC - BAI HQC BONG NAI, SO 04 - 2017 ISSN 2354-1482 STUDY ON EXTRACTION OF PHENOLIC COMPOUNDS FROM
MULBERRY JVICKS (MORUS ALBA)
ABSTRACT
Nowadays, fhiit juice with high antioxidant level has attracted great attention.
In this study, techniques of extiaction which effected on the antioxidant level in mulberry juice was investigated. We researched the supported-technologies on antioxidant exPactionfor mulberry mash treatment: Using ultiasound and pectinase preparation Pectinex Ultia SP-L. The results show that, under the optimal conditions: sonication power and time were 10.36 W/g of fruit mash and 63 °C, respectively, the total phenolic content in the mulberry juice was 63.3% higher than that in the control sample; the optimal concentiation of pectinase preparation and biocatalytic time were 0.08% v/w and 120 min. respectively. Next, these methods were compared the efficiency for antioxidant on the basis of kinetic model of second- order extraction. According to this model, the extraction rate constant of total phenolics and anthocyanins in ultiasound-assisted extraction (UAE) increased approximately 16.9 and 21.5 times, respectively, in comparison with that enzyme- assisted extiaction (EAE); the level of phenolics and anthocyanins of mulberry juice from the ultiasonic treatment were 11.3% vd 15.9%, respectively, higher than those Jrom the enzymatic treatment
Keywords: anthocycmins, enzyme-assisted extraction, kinetic parameters, mulberry, phenolics, ultiasound-assisted extiaction
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