Sir dung song sieu am trich ly polysaccharide

S dng sng siu m trch ly polysaccharide

1S dng sng siu m trch ly polysaccharide

LI M UHn mt na dn s trn th gii trng v s dng cy thng thc nh l ngun lng thc ch o nh: cy la, cy la m, i mch....Nhng thng tin khoa hc gn y nghin cu v pht hin lo ging cy lng thc ny l cha kha trong vic pht trin thc phm (Mutisya v cng s 2009). Polysaccharide v lignin c xem l nhng thnh phn chnh c trong cy lng thc c xem l nhng thnh phn chnh v quan trng trong vic ci thin sc khe (Yang v cng s 2008a) nh: y mnh s trao i cht, xoa du thn kinh, loi b chng mt ng...(Yang v cng s 2008b; 2009). Polysaccharide trch ly t ngun ng vt v thc vt c bit nh l ngun ph gia t nhin cho nhiu ngnh cng nghip, c bit l thc phm v dc phm (Forabosco v cng s 2006). Polysaccharide gi vai tr quan trng trong sinh trng v pht trin ca th bo v c nghin cu nhiu trong nhng nm gn y do c nhng c tnh sinh hc (Schepetkin v Quinn 2006).Rt t bo co khoa hc thc phm v trch ly polysaccharidc c trong cy lng thc, mt trong nhng l do l thiu cng ngh v phng php, phng php trch ly truyn thng bng hi nc, bng dung mi...thng khng mang li hiu qu cao, tn chi ph nng lng do trch ly nhit cao, thi gian di hiu sut thp (Li v cng s 2007). Do nhng hn ch , c mt nhu cu cho mt phng php tt hn m hiu qu ph v cc lin kt trong mt thi gian ngn v thu c nhiu polysaccharide. Nng lng siu m cho thy mt xu hng trin vng t c mc tiu nySng siu m l ng dng ca cc sng m thanh tn s v cng cao (khong 20-100 kHz) truyn qua cht lng hoc kh. Tc ng ch yu ca sng siu m l truyn v tng tc lm thay i tnh cht vt l v ha hc ca vt liu do tc dng xm thc .Xm thc gy ra cc b nhit cao v p lc cao, kt qu to ra nhiu gc t do, chng hn nh OH, H +, v H202, do tng cng cc phn ng ha hc. Hiu ng ca siu m gip tng cng s xm nhp ca cc dung mi v nhit vo t bo ngiiyn liu do ci thin tt kh nng truyn khi. Sng siu m cng c tc dng trong s ph v cc thnh t bo sinh hc to thun li cho vic gii phng dch cn trch ly.

PHN 1: GII THIU1.1. Polysaccharide v ng dngPolysaccharide l cc gluxit phc vi phn t rt ln gm nhiu on v monosaccharide lin kt vi nhau to nn. Polysaccharide khng c v ngt nh monosaccharide hay disaccharide, khng tan trong nc m ch to dung dch keo. y l nhm cht hu c ph bin v c khi lng ln nht trn tri t. Polysaccharid rt a dng v chng loi. Trong c the sinh vt c rt nhiu loi polysaccharide khc nhau, trong ph bin nht l tinh bt, glycogen, cellulose.1.1.1. Tinh btTinh bt l cht d tr rt ph bin thc vt. C nhiu trong cc m d tr nh ht, c. Tinh bt khng phi l n cht m l hn hp cc chui thng cc phn t amylose v chui phn nhnh l amilopectin. T l 2 nhm cht ny trong tinh bt quyt nh cc tnh cht l - ho ca chng, quyt nh cht lng ca chng ( do, n ...)S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

Amylose: Amylose l polysaccharide c to nn t cc phn t a.D.glucose. Cc a.D.glucose lin kt vi nhau bng lin kt (la - 4) glucozid to nn chui polysaccharide. Mi lin kt glucozit c to ra s loi mt phn t H20. Do ch c loi lin kt (la - 4) glucozid cu to nn amylose nn phn t amylose c cu trc mch thng.Nhm 7Trang 8

Nhm 7Trang 1

CH2OHCH2OH

ooonJ [/' \.o CH2OHHnh 1: Mch amylose

Amylose c to ra t 5000 - 1000 phn t a.D.glucose (c khi ch khong 250 - 300 phn t). Chui phn t glucose xon li vi nhau theo hnh xon l xo. S hnh thnh dng xon do hnh thnh cc lin kt hydro gia cc glucose to ra. Mi vng xon c 6 n v glucose v c duy tr bi lin kt hyro vi cc vng xon k bn.Khong khng gian gia cc xon c kch thc ph hp cho mt s phn t khc lin kt vo, v d nh iod. Khi phn t iod lin kt vo vng xon s lm cho cc phn t glucose thay i v tr cht t v to nn phc mu xanh c trng. Dng xon ca amylose ch to thnh trong dung dch nhit thng. Khi nhit cao chui xon s b dui thng ra v khng c kh nng lin kt vi cc phn t khc. Amyopectin: Amylopectin c cu to phc tp hn. Tham gia cu to amylopectin c khong 500.000 n 1 triu phn t a-D-glucose lin kt vi nhau. Trong amylopectin c 2 loi lin kt: Lin kt a (1 - 4) glucozid to mch thng. Lin kt a (1- 6) glucozid to mch nhnh.

Hnh 2: Mch amylopectinC khong 24 - 30 n v glucose trn mch s c mt lin kt a (1 - 6) glucozi to mch nhnh. Trn mch nhnh cp 1 li hnh thnh mch nhnh cp 2, c nh vy phn t amylopectin phn nhnh nhiu cp rt phc tp.Trong tinh bt t l amylopectin chim khong 80%, cn amylose chim 20%. T l ny thay i cc nhm sinh vt khc nhau.Tinh bt l nguyn liu d tr trong thc vt. y l dng d tr thch hp nht v tinh bt khng c kh nng thm qua mng t bo nn khng th tht thot ra khi t bo.1.1.2. GlycogenGlycogen l polysaccharide d tr ng vt, l tinh bt ng vt. cu trc ca glycogen ging tinh bt nhng mc phn nhnh nhiu hon tinh bt, c khong 8-12 n v glucose c mt lin kt a (1 - 6) glucozid to nhnh mi. ng vt v ngi, glucogen c d tr ch yu gan. S phn hu v tng hp glycogen c h thng cc hoocmon iu khin mt cch cht ch iu ho s n nh lng glucose trong mu lun l hng s 1%.1.1.3. CelluloseTrong cc hp cht hu c c trong c th sinh vt th cellulose c t l cao hn c. N l thnh phn chnh ca thnh t bo thc vt. Cng nh amylose, amylopectin, cellulose l cht trng hp t nhiu n phn. Thnh phn n phn ca cellulose l -D-glucose. Cc phn t -D-glucose lin kt vi nhau bng lin kt (1 - 4) glucozid thay nhau 1 "sp" v 1 "nga". S thay i v thnh phn v cu to ny dn n s khc bit v tnh cht gia cellulose v amylose. Phn t cellulose khng cun xon nh amylose m ch c cu trc dng mch thng, cu trc ny to iu kin hnh thnh cc lin kt hyro gia cc phn t cellulose nm song song vi nhau, to nn cu trc mng cellulose v vi si (micro fibrin) trong cu trc mng cellulose ca t bo thc vt. Cc si ny khng tan trong nc, rt bn v c hc nn to nn lp mng cellulose bn chc.

(b)Starch: 1-4 linkage of a glucose monomers(c)Cellulose: 1-4 linkage of p glucose monomers

Hnh 3 : Cu trc lin kt p (I - 4) glucozid1.2 Sng siu m1.2.1. nh nghaSiu m (ultrasound) l sng c hc hnh thnh do s lan truyn dao ng ca cc phn t trong khng gian c tn s ln hn gii hn trn ngng nghe ca con ngi (16-20kHz). Ngoi ra, sng siu m c bn cht l sng dc (longitudinal wave) hay sng nn (compression wave), ngha l trong trng siu m cc phn t dao ng theo phng cng vi phng truyn ca sng.

IiifrasoundSoundUltrasoundBumble bee150 HzMiddle c256 HzMosquito1500 HzGrasshopper7 kHzUp per-ranging bats70 kHz

Human healing16Hz- 16kHzPower ultrasounds20 kHz - 100 kHz Cleaning Plastic welding Sono chemistryExtended range100 kHz-2 MHzSonochemistryHigh frequency2 MHz - 10 MHz Medical diagnostic Chemical analysis

Hinh 4: Phn loi cc loi sng theo tn s1.2.2. Bn cht ca sng mCc mi trng cht n hi (kh, lng hay rn) c th coi nh l nhng mi trng lin tc gm nhng phn t lin kt cht ch vi nhau. Lc bnh thng, mi phn t c mt v tr cn bng bn. Neu tc ng mt lc ln mt phn t A no bn trong mi trng ny, n s ri khi v tr cn bng bn. Do tng tc to nn bi cc mi lin kt vi cc phn t' bn cnh, mt mt phn t A b ko v v tr cn bng, mt mt n cng chu tc dng bi lc tc ng nn phn t A s di chuyn qua li quanh v tr cn bng, c ngha l phn t A thc hin chuyn ng di dng dao ng. Hin tng ny tip tc xy ra i vi cc phn t khc ca mi trng. Dng dao ng c, c tnh cht lp i lp li, lan truyn trong mi trng n hi c gi l sng n hi hay sng c, ni mt cch khc, sng l mt hin tng vt l trong nng lng c dn truyn di dng dao ng ca cc phn t vt cht ca mi trng truyn sng.v bn cht, sng m l sng c hc, do n tun theo mi quy lut i vi sng c, c th to ra sng m bng cch tc ng mt lc c hc vo mi trng truyn m.Vd 1: Tc ng mt lc lm rung ln m thoa, gy ra cho cc phn t trong khng kh b nn li hay dn ra ty theo hng chuyn ng ca m thoa, phn t u tin b tc ng s nh hng n phn t k tip ... v c th m c s lan truyn sng ra mi hng (v cng nh th m tai ngi bt k v tr no xung quanh m thoa u nghe c m vang ca m thoa). Hin tng ny tng t nh khi ta th mt vin si vo gia lng h ang lng sng, vin si s to ra nhng gn sng c hnh dng cc vng trn ng tm lan ta ra xung quanh m tm ca chng l v tr m vin si ri xung h nc.Vd 2: nh vo mt trng; tc ng dng in lm rung mng loa; n bay trong khng kh.1.2.3. Cc i lng c trng ca sng

Hnh bn di l hnh biu din ca sng, n l mt tp hp ca cc ln nn v dn thay i tun t theo dng hnh sin, trong cc nh sng th hin p lc cao nht cn cc y sng th hin p lc thp nht.wuvelenth V = umpitudeli a ve

Hnh 5: th biu din dao ng ca sng m Cc i lng c trng ca sng bao gm: Chu k T = (s) l khong thi gian m sng thc hin mt ln nn v mt ln dn. Tn s f = (Hz) l s chu k thc hinc trong 1 giy. Vn tc truyn ca sng m l qungng m sng mtruyncsau mtn v thi gian di bc sng X = (|im): l qung ng m sng truyn c sau khong thi gian bng 1 chu k (X = V.T = v/f). Trn hnh v, ta thy bc sng X l khong cch gia hai nh hoc hai y nm k nhau.1.2.4. Phn loi sng mPhnloi theo phng dao ng: da vocch truyn sng,ngita chiasngcra lmhai loi: sng dc v sng ngang. Sng ngang l sng m phng dao ng ca cc phn t ca mi trng vung gc vi tia sng. Sng ngang xut hin trong cc mi trng c tnh n hi v hnh dng. Tnh cht ny ch c vt rn. Sng dc l sng m phng dao ng ca cc phn t mi trng trng vitia sng. Sng dc xut hin trong c mi trng chu bin dng v th tch,do n truyn c trong cc vt rn cng nh trong mi trng lng v kh.Sng siu m ng dng trong siu m chn on thuc loi sng dc.Phnloi theo tn s: sng m c chia theo di tn s thnh 3 vng chnh. Sng m tn s cc thp, hay cn gi l sng h m (Infrasound): f < 16 Hz.Vd: sng a chn. Sng m tn s nghe thy c (Audible sound): f= 16 Hz - 20 kHz Sng siu m (Ultrasound): f> 20kHzCc ngun sng siu m c trong t nhin: Di, mt vi loi c bin pht sng siu m nh hng ... Ni chung cc sng ny nm trong vng tn s 20 - 100 kHz. Sng siu m ng dng trong y hc c tn s t 700 KHz n 50 MHz trong siu m chn on s dng cc tn s t 2 MHz n 50 MHz.1.2.5. Phm vi ng dngSiu m l mt lnh vc ang c nghin cu v c tim nng pht trin trong ngnh cng ngh thc phm. Sng siu m c tn s t' 20kHz n trn 25MHz thng c ng dng rng ri trong nhiu lnh vc. C 2 lnh vc c ng dng chnh trong cng nghip thc phm: Tn s cao v nng lng thp: siu m chun on, trong khong tn s MHz. Phn ny c s dng nh mt k thut phn tch m bo cht lng, qui trnh iu khin v kim tra khng lm ph hu cu trc, iu ny c ng dng trong xc nh tnh cht thc phm, o tc dng chy, kim tra bao gi thc phm...( Floros & Liang, 1994; McClements,1995; Mason, Paniwnyk & Lorimer, 1996; Mason 1998).S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

Nhm 7Trang8Nhm 7Trang 12

Nhm 7Trang 11

Tn s thp v siu m nng lng cao: Phn ny c ng dng rng ri nh mt quy trnh h tr trong hng lot cc lnh vc nh: kt tinh, sy, bi kh, trch ly, lc, ng ho, lm mm tht, qu trnh oxi ho, qu trnh tit trng ... (Floros & Liang, 1994;Gennano et al.,1999; Mason,1998; Mason et al.,1996; McClements, 1995).Bng 1 : Mi vi ng dng ca sng siu m trong cng ngh thc phmng dng cc hiu ng c hc ng dng hiu ng ha hc v ha sinh

Qu trnh kt tinh cht bo, ng...Dit khun

Bi khX l dng chy (nc thi)

Ph btiu chnh s sinh trng ca t bo

Trch ly cc cht thmsng

H tr lc v sy tch mBin i hot tnh enzyme

Lnh ngTit trng thit b trong cng nghip

Khuy trn v ng ha

Ket t cc ht bi l lng

Lm mm tht

1.2.5.1. Bo qun thc phm

V hot vi sinh vtCng nghip ch bin thc phm thng tp trung ch yu vo qu trnh v hot (inactivation) hoc tiu dit cc vi sinh vt v enzyme nhm mc ch ko di thi gian bo qun sn phm. Rt nhiu phng php vt l c p dng vo mc ch ny, trong phng php dng nhit cao l ph bin v hiu qu tiu dit vi sinh vt cao nht. Th nhng vic s dng nhit cao c th gy ra mt s bin i bt li i vi sn phm nh lm tht thot mt s cht dinh dng v lm gim cc tnh cht cm quan ca thc phm. Do , yu cu t ra cho cc nh nghin cu k thut thc phm l tm ra cc gii php mi, cc phng php vt l khc thay th hoc h tr mt phn phng php nhit trong qu trnh thanh trng v tit trng sn phm.Qu trnh siu m kt hp vi p sut (manosonication-MS) c thc hin bi mt s tc gi nh Sala v cng s (1995), Manas v cng s (2000) trn cc i tng vi sinh vt gy bnh cng cho thy nhng kt qu rt kh quan. Cc nghin cu ny cho thy ti nhit thng qu trnh x l siu m khng hiu qu vi L. monocytogenes (vi thi gian cht nhit l D = 4.3 pht). Bng phng php siu m kt hp vi p sut (MS), gi tr D ca vi khun ny gim xung cn 1.5 pht. Khi gia nhit n 50c, hiu qu ca qu trnh x l khng ng k nhng nhit cao hn th hiu qu x l li tt hn rt nhiu.Mt im ng lu i vi k thut siu m so vi k thut thanh trng nhit truyn thng l phng php nhit, kh nng v c ch khng ca vi khun l yu t quan trng cn c quan tm trong qu trnh x l. Nhng vi k thut MTS v MS, kh nng khng nhit ca vi khun hu nh khng c. Do , k thut ny mang li nhiu trin vng hn bi hiu qu x l ca n khng ph thuc vo iu kin x l v kh nng chng chu nhit ca vi khun trong thc phm so vi qu trnh nhit. Bn cnh , nghin cu ca Pagan v cng s (1999) cho thy rng s tn thng ca t bo bi nhit l thun nghch nhng tn thng gy ra bi qu trnh x l MTS l bt thun nghch.Khuy trn, ng ha v nh haPhng php s dng sng siu m cng cao l mt phng php hiu qu trong vic khuy trn cc phn t nh, tng kh nng truyn khi. C ch v phng php tc ng ca sng siu m c Penn v cng s (1959) gii thch rng sng siu m v s h tr ca my khuy nh s to bt gn b mt ca cht rn c th gim lp bin truyn khi v do lm tng s truyn khi.C ch qu trnh to nh tng: Khi tc dng sng siu m vo cht lng, s to ra l trng xut hin khi p sut ca sng t n mt gi tr xc nh ti thiu no , gi tr ny c gi l ngng to l trng. Trong h thng du/nc, qu trnh nh ha xy ra khi t n mc ngng ny. Sng siu m c th cung cp mt nng lng cho vic hnh thnh b mt mi, v th n c th lm cho qu trnh nh ha xy ra ngay c khi khng dng cht nh ha. Nen bong bng b v ra gn lp bin ca 2 cht lng khng tan ln th sng va chm c to ra c th cung cp s o trn cc lp rt hiu qu (Mason, 1996). Vi s h tr ca sng siu m, kch thc ht nh tng s nh hon rt nhiu so vi kch thc t c bi qu trnh khuy trn c hc cng iu kin. Do , h nh tng c to thnh bng phng php ny thng n nh hn so vi nhng phng php thng thng. Bn cnh , khi t kch thc nh vy th qu trnh nh ha thng i hi t hoc c th khng cn cht hot ng b mt.Qu trnh ph btTrong mt s trng hp, s to bt c xem l qu trnh khng mong mun trong ch bin thc phm v d nh bt sinh ra trong qu trnh ln men c th lm gim nng sut bn ln men, gy tp nhim, gy tr ngi cho cc qu trnh downstream sau ny. Do , vic loi bt hay ph bt l yu cu rt cn thit trong qu trnh ch bin. C rt nhiu phng php ph v h bt nh cc phng php ha hc (dng cht ph bt) v phng php c hc (thay i p sut nhanh, dng lc ct, lc nn, lc p, lc ht v lc ly tm). Vic dng sng siu m cng cao cng c xem l phng php ph bt hiu qu v sch bi v n khng tc ng trc tip vo cht lng. C ch ph bt ca sng siu m c gii thch nh sau: Chn khng c to nn trn b mt bt bi p sut m thanh cao, S va chm ca cc dao ng p sut trn b mt bt, S cng hng ca cc bong bng bt to nn s ma st lm nhp cc bng bt vi nhau, Qu trnh to l hng (cavitation) bi sng siu m, S tn nh hay s phun t' b mt mng cht lng, Dng chy m (ascoustic streaming) (Boucher v Weiner, 1963; Gallego 1999). Qu trnh lc v phn ring bng membraneThng thng, cc loi mng lc c s dng t' cc dng mng lc n gin n cc loi mng membrane kch thc rt nh ng vai tr nh l vch ngn ch cho php cc ht c mt kch c nht nh i qua. Nhng cc phng php lc truynthng thng gp phi hin tng fouling gy tt mng lc kt qu phi thay thng xuyn v v sinh lin tc.C 2 c trng ca tc dng ca sng siu m m qua ta c th ci thin k thut lc: Sng siu m s lm kt t cc ht mn (lc nhanh hn), Sng siu m s cung cp mt ng nng (gy chuyn ng rung) cho h thng gi cc h huyn ph v v vy cho php ta tch ra cht ha tan.nh hng tc ng ca cc tc dng ny c dng x l trong lc chn khng ca cng nghip pha trn nh bn than m khng cn tn nhiu thi gian v vic x l kh khn, ng dng ca sng siu m trong qu trnh lc (hay cn gi l lc acousti) hm lng m trong hn hp c th gim nhanh chng t 50% xung cn 25%, ngc li cch lm truyn thng ch c th lm gim xung cn 40%. Ngoi ra, qu trnh siu m cng gp phn lm gim nht dch lc gip lm tng lun lng dng permeat.S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

i vi qu trnh phn ring bang membrane, x l sng siu m tp trung vo vic lm sch b mt mng membrane v gim hin tng fouling. Tc nghn mng membrane c biu hin bng vic gim ng k lu lng dng permeate do s bt kn v s hp ph ca cc i phn t b gi li trn b mt membrane. Bn cnh cc k thut lm sch membrane bng phng php thy lc, c kh v ha hc, lm sch bng sng siu m gii quyt rt tt vn nghn mng v phc hi ng k lu lng dng permeate trong qu trnh x l membrane. Mt s tc gi th nghim sng siu m trong vic khc phc tnh trng tt nghn mng v thu c mt s kt qu kh quan. Vic s dng tia nc khng u kt hp dng chy rung ng (to bi siu m) gip vt qua s gim tc dng permeat ca membrane (Kobayashi v cng s, 2003). Trong nhng qu trnh ny, sng siu m gy ra nhng ch gy ti lin kt cht ch gia cn bn v membrane trong thi gian x l ngn. Ngoi ra, gim hin tng nght mng ca cc membrane polysufone v polyacrylonitrile trong qu trnh siu lc v vi lc, c th khc phc bng cch dng sng siu m. Theo nghin cu, siu m tn s 28 kHz, 45 kHz v 100 kHz c hiu qu n vic gim Nhm 7Trang12Nhm 7Trang 14

Nhm 7Trang 13

nght mng. Vi phng php ny, nng lng sng siu m c iu khin gn mng bn bng k thut phn x (Latt v cng s, 2006).Qu trnh syQu trnh sy kt hp sng siu m c th tin hnh nhit thp hn nhng phng php truyn thng, iu ny lm gim kh nng gy oxi ha v h hng nguyn liu bi cc phn ng ha hc nhit cao. Khi dng sng siu m c cng cao tc ng n vt liu cn sy, n di chuyn xuyn sut mi trng rn to ra mt lot cc qu trnh nn v dn nhanh v lin tc, tng t nh mt ming xp cao su khi n b bp v th ra nhiu ln. Nhng lc ny cao hn sc cng b mt vn duy tr m bn trong cc mao qun ca vt liu, t c the gip hi m di chuyn d dng. Thm vo , sng siu m to ra cc l hng c xem l c li cho vic di chuyn hi m mnh m. Sng siu m c the c dng tng tc truyn nhit gia cht rn c gia nhit b mt v cht lng, mt qu trnh quan trng trongQu trnh trch lyK thut c in trong qu trnh trch ly cht tan ca nguyn liu da vo vic la chn chnh xc cc loi dung mi trch ly c ha tan thch hp kt hp vi s dng nhit v/hoc khuy o. Qu trnh trch ly hp cht hu c cha trong thn cy v ht bng dung mi c ci tin ng k bng cch s dng nng lng sng siu m trong qu trnh tch chit. C ch ca sng siu m gip lm tng kh nng trch ly ca cc qui trnh trch ly truyn thng l da trn:To ra mt p lc ln xuyn qua dung mi v tc ng n t bo vt liu Tng kh nng truyn khi ti b mt phn cchPh v thnh t bo trn b mt v bn trong ca vt liu, gip qu trnh thot cht tan c d dng.Siu m nng lng cao c p dng trong qu trnh trch ly ng t c ci ng (Chendke v Fogler, 1975). Siu m h tr cho qu trnh trch ly cn c ngdng trong sn xut cc hp cht dc nh helicid, berberine hydrochloride, v berberine t nhng loi cy Trung Quc (Zhao et al.,1991). Helicid, thng c trch ly bng phng php trch ly ngc dng trong ethanol, nhng khi s dng sng siu m th lng helicid thu nhn cao hn 50% trong khong thi gian ch bng mt na phng php c in nhit thng.Kt tinhSng siu m l ngun nng lng c cho l c kh nng iu khin c cc ht nhn mc bo ha thp hn so vi cch lm thng thng. Sng siu m c th lm cc phn ng din ra nhanh hn v ng u hn, sn phm kt tinh c ci tin hn, gim thiu s kt t v c th kim sot c qu trnh kt tinh. Sn phm to ra bi kt tinh dng sng siu m t c kt qu cao hn so vi cch lm thng thng.PHN 2: C S KHOA HC2.1. Trch ly:Trch ly l dng nhng dung mi hu c ha tan cc cht khc, sau khi ha tan, ta c hn hp gm dung mi v cht cn tch, em hn hp ny tch dung mi ta s thu c cht cn thit. C s l thuyt ca qu trnh trch ly l da vo s khc nhau v hng s in mi ca dung mi v cht cn trch ly. Nhng cht c hng s in mi gn nhau s d ha tan vo nhau. Phng php ny c th tin hnh nhit thng (khi trch ly) v c th ly c nhng thnh phn qu nh sp, nha thm trong nguyn liu m phng php chung ct khng th tch c. V th, cht lng ca tinh du sn xut bng phng php ny kh cao.Bn cht ca qu trnh trch ly l qu trnh khuch tn nn ngi ta thng da vo cc nh lut khch tn ca FICK gii thch v tnh ton.Cht lng ca sn phm thu c bng phng php trch ly ph thuc rt nhiu vo dung mi dng trch ly, v th dung mi dng trch ly cn phi m bo cc yu cu sau: Nhit si thp d dng tch sn phm ra khi dung mi bng phng php chng ct, nhng khng c thp qu v s gy ton tht dung mi, d gy chy v kh thu hi dung mi (kh ngng t), Dung mi khng tc dng ha hc vi sn phm, nht ca dung mi b rt ngn thi gian trch ly ( nht nh khuch tn nhanh), Dung mi ha tan nguyn liu ln nhng ha tan tp cht b, Dung mi khng n mn thit b, khng gy mi l cho tinh du v c bit khng gy c hi,S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

Nhm 7Trang15Nhm 7Trang 20

Nhm 7Trang 21

Dung mi phi r tin v d mua.Tuy nhin, khng c loi dung mi no t c tt c yu cu trn, v d: ru, axton ha tan tinh du tt nhng ha tan c nc v ng c trong nguyn liu na v nh vy tinh du s c mi caramen sau khi dng nhit tch dung mi. Neu s dng te tilic dng lm dung mi trch ly th dung mi ny ha tan nha v sp tt nhng c v d sinh ra hn hp n.Hin nay, ngi ta thng dng dung mi l te 70c thnh phn ch yu l cc hidro cacbon--du ha, nhit si 45c no nh pentan, hexan v ln mt t heptan. te du ha cn c tinh ch trc khi sn xut. te du ha c em i ct li e ly nhng 70c a vo trch ly. te du ha d phn c nhit si t 45c chy n, c, do trong sn xut cn thc hin nghim tc cc qui tc v an ton lao ng v phng cha chy.2.2. Sng siu m:Sng siu m s dng trong trch ly c ba tc ng sinh hc sau:2.2.1. RungChuyn ng sng siu m to ra l rt nhanh, tc ng ln cc m, ging nh massage nh. Tt c cc tc ng khc ca sng (nhit v to bong bng) u da trn tc ng rung ny. .

Hnh 6: Thit b to siu m (sng siu m), thanh titan c ngm vo trong dung dch phn ng truyn ng thng qua s rung.2.2.2. NhitChuyn ng do sng siu m l nguyn nhn chnh to ra tc dng nhit. Siu m c th to nhit cao nh nhit ca b mt mt tri v p sut ln nh p sut di lng i dng. Trong mt vi trng hp sng siu m c th lm tng tc phn ng ln gn mt triu ln.2.2.3. S to v v bt (cavitation)Lch s ca ngnh m ha hc pht trin sau nhng nm 1800. 1984, trn con tu chin cao tc, Sir John I. Thomycroft v Sydney w. Bamaby pht hin con tu lac d di v chn vt tu b n mn nhanh chng. H tm hiu v thy c nhng bng kh ln hnh thnh trn chn vt ca tu khi tu ang chy, s hnh thnh v v ca nhng bng kh, bng cch tng kch thc ca chn vt v gim vn tc quay ca chn vth hn ch c s n mn. V th pht hin ra c c ch cavitation (tm gi l "s to v v bt")Sng siu m c chiu di sng khong 10cm - 10-3cm, vi chiu di sng ny th khng to nng lng tng tc trc tip ln lin kt ha hc (khng th lm t lin kt ha hc).Tuy nhin, s chiu x siu m trong mi trng lng li sn sinh ra mt nng lng ln, do n gy nn mt hin tng vt l l cavitation, qu trnh ny ph thuc vo mi trng phn ng (mi trng ng th lng rt khc so vi cavitation b mt tip xc rn-lng).Siu m c chiu x qua mi trng lng to ra mt chu trnh dn n, n gy ra p sut chn khng (negative pressure) trong mi trng lng. Hin tng cavitation xy ra khi p sut chn khng (negative pressure) vt qu so vi bn ko (local tensile strength) ca cht lng, bn ny thay i ty theo loi v tinh khit ca cht lng ( bn ko l ng sut ti a m cht lng c th chu c khi ko). Thng thng s to-v bt l mt qu trnh to mm, bt ngun t nhng ch yu trong cht lng nh mt l hng cha kh phn tn l lng trong h hoc l nhng vi bt tn ti thi gian ngn trc khi s to-v bt xy ra. Hu ht cc cht lng u c nhng ch yu ny hnh thnh nn cavitation.Nhng vi bt ny qua s chiu x ca siu m th s hp thu dn nng lng t sng v s pht trin. S pht trin ca bt ph thuc vo cng ca sng. cng sng cao, nhng bt ny s pht trin nhanh thng qua tng tc qun tnh. Neu chu k gin n ca sng nhanh, bt kh c gin ra na chu k u v na chu k cn li l nn bt, nhng bt cha kp nn th li c gin tip, c th bt ln dn ln v v. cng m thp hn bt kh cng hnh thnh theo qu trnh chm hn.S nn kh to ra nhit. Mt v d d thy l khi bm lp xe p, nng lng c hc l s nn kh to ra nhit lm nng ng bm.Trong cht lng chiu x siu m, s nn kh cng din ra khi cc bt b v vo trong di p lc ca cht lng bnngoi, s v ny sinh ra mt lng nhit ti im gi l s ta nhit ti mt im (hot-spot). Tuy nhin trong mi trng xung quanh l lng lnh v s gia nhit nhanh chng c dp tt, nn n tn ti trong thi gian ngn. Hot-spot l yu t quyt nh ca m ha hc trong mi trng ng th.

Hnh 7: Nn, to bt v ph v btS dng sng siu m nng lng cao trong cng ngh thc phm ngy cng c kho st t m. Phn ln cc nghin cu u p dng tn s sng trong khong t 20 kHz n 40 kHz.Khi sng siu m c truyn vo mi trng cht lng, cc chu trnh ko v nn lin tip c to thnh. Trong iu kin bnh thng, cc phn t cht lng rt gn nhau nh lin kt ha hc. Khi c sng siu m, trong chu trnh nn cc phn t gn nhau nhau hn v trong chu trnh ko chng b tch ra xa. p lc m trong chu trnh ko mnh thng cc lc lin kt gia cc phn t v to thnh nhng bt kh nh.Trong sut chu trnh ko/nn bt kh ko gin v kt hp li cho n khi t c cn bng hi nc bn trong v bn ngoi bt kh. Din tch b mt bt kh trong chu trnh ko ln hn trong chu trnh nn v vy s khuych tn kh trong chu trnh ko ln hn v kch c bt kh cng tng ln trong mi chu trnh. Cc bt kh ln dn n mt kch c nht nh m ti nng lng ca sng siu m khng duy tr pha kh khin cc bt kh n tung d di. Khi cc phn t va chm vi nhau mnh lit to nn s sc sng trong lng cht lng, kt qu l hnh thnh nhng im c nhit v p sut rt cao (5000c v 5xl04kPa) vi vn tc rt nhanh 106 c/s.

~

kokokoko

t kch tlmc ti abt kl I11 (ln5000 c 2000 atsllll tlnl bt klbt kl v tung

Hnh 8: C ch cavitation ca sng mTrong Mi Trng Lng-Rn khi s to-v bt xy ra gn b mt phn cch lng-rn th n khc so vi trong h ng th. Trong h ng th th qu trnh v bt th bt vn dng hnh cu i xng. Tuy nhin, ranh gii phn cch rn lng th s v bt dng rt bt i xng v to ra mt s phun cht lng vi tc rt cao.

Hnh 9: Hnh nh mt bng kh trong mi trng lng chiu x siu m v gn b mt rn. S c mt ca b mt rn l ngiiyn nhn ca s v bt i xng, hnh thnh mt vi cht lng bn vo b mt rn vi tc rt cao. (L.A. Crum)C ch tc ng ca nng lng siu m trn h thng cc cht mi trng lng ch yu cho l do s to l hng v cc lc ny c mt nh hng nguy kch ln h thng sinh hc. S to l do sng m c chia tng qut thnh 2 loi: loi tm thi v loi bn vng. Dans bons bons si trong nc cha y kh hay hi nc, tri qua s dao ng khng u nhau v cui cng n tung. iu ny sinh ra nhit v p xut ti ch cao s phn hy cc t bo sinh hc v lm bin tnh cc enzyme hin din. Cc bong bng n tung vo trong cng sinh ra cc lc bin dng cao v cc tia lng trong dung mi cng c th c nng lng ph hy mng t bo mt cch c hc. C ch tc ng kiu ny cng tng c s dng quy m nh trong vic tay u ngun nc b nhim bo t vi sinh. Dang l n inh lin quan n nhng bt si m dao ng theo mt dng u cho nhiu chu trnh m thanh. Cc bt si cm ng cc vi dng c th gy ra stress trong cc cht lng xung quanh ln s hin din ca vi loi. Tc dng ny do cung cp mt lc ln m khng c s no ca cc bt si. Dng to l trng ny quan trng trn mt lot cc ng dng ca siu m trong cng ngh sinh hcTh nng ca s gin n' bt c chuyn thnh ng nng ca vi phun cht lng, n hnh thnh v di chuyn vo pha trong, m xuyn qua bng kh. Nhng vi ny bn vo b mt rn vi mt lc rt ln, qu trnh ny to ra mt l thng ti v tr b tc kch, lm tng din tch b mt tip xc ca pha rn. y l nguyn nhn chnh dn n s mi mn kim loi nhanh chng chn vt tu, cc tua bin nhng ni m s to-v bt xy ra lin tc.ooor- - r-ooo

000901** ?

9i

Hnh 10: nh c chp bi my quay vi phim cm ng laser tc cao. S to- v bt gn b mt phn cch rn lng, mt vi rt nh c hnh thnh, bn vo b mt rn vi vn tc xp x 400Km/gi (111 m/s) (Werner Lauterbom thuc i hc Technische Hochschule Darmstadt ca c).S bp mo ph hy bng kh ph thuc vo b mt rn. Do vy, nu s dng bt mn cho vo pha lng v s dng siu m th s khng thy s hnh thnh vi (jet). Trong trng hp lng v bt th s to-v bt hnh thnh lin tc to ra sng kch thch (shock waves) c th gy ra s va chm mnh gia cc ht. Sng kch thch ny c th lm cho nhng ht kim loi va chm nhau vi tc cao v sinh ra nhit gy nng chy ti im va chm, nn nhng ht ny b dnh vi nhau.2.2.4. Cc yu t nh hng n kh nng hnh thnh v v bngNhiu yell t nh hng n qu trnh v hiu qu trch ly bng sng siu m. Chng bao gm cc thng s lin quan n m trng nh: tn s sng m, cng m, mt nng lng m; nguyn liu th: cu trc, mc ph v, loi v s lng cc cht trch ly; c tnh vt l dung mi, cng nh s x l vi cc yu t: thi gian, nhit , p sut,...Cng d siu m gy bt li, v n gy ra nhiu hiu ng ph nh hng dn s c mt ca trng m nh hiu ng nhit (nhit tng), xm thc, s tn sc, vvnh hng ca siu m l khng th tch ri c lin quan gia ta nhit cng vi mi trng xt nghim. Hin tng gy ra s tng nhit ca nguyn liu x l l: ma st ca b mt ranh gii v giao din, s hp th ca nng lng siu m v trong trng hp cng cao, xm thc.Hu nh 75% nng lng m truyn bi chuyn i nng lng sng siu m sau c th chuyn i thnh nng lng nhit ca h thng x l l nguyn nhn ca s gim cng nh hng ca sng m trong nhiu lnh vc qu trnh. V vy, theo di cc thay i nhit trong h thng th nghim cng vi tm kim nhit ti u cho qu trnh trch ly rt quan trng trong x l bng sng siu m.Mt s thng s nh l tn s v bin ca sng siu m, nhit v nht ca mi trng nh hng n mc to bong bng kh. S hnh thnh cc l hng hay bng kh c th b gii hn tn s cao hn 2,5 MHz. Kch thc bong bng kh thu c tn s thp hn 2,5 MHz l ti a v do nhng bong bng kh ny s to ra nng lng ln khi v. Siu m vi bin cao hn s hnh thnh hin tng si bong bng vi cng mnh hn. Bong bng c hnh thnh nhanh hn nhit cao hon do tng p sut hi v gim sc cng. Tuy nhin sc cng hi cao hon s lm yu i cng n bong bng. nht ca cht lng cng nh hng n hin tng si bong bng. Trong mi trng c nht cao, s lan truyn ca cc phn t trong trng siu m b cn tr v do lm gim mc si bong bng. Trong trng hp ny, siu m c tn s thp hn v nng lng cao hn c kh nng xuyn thu vo thc phm tt hon l siu m c tn s cao hon.2.2.5. u v nhc im ca sng siu m u im: Thi gian trch ly nhanh Hiu sut trch ly cao hn so vi mt s phng php trch ly thng thng.Sn phm trch ly cht lng tt. Thit b d s dng, an ton v bo v mi trng. Sng siu m c tn s ln hn 20 Khz tc l hon 20000daong trong mtgiy xung ng truyn qua mi trng vt cht (kh, lng, rn) vo tn trong t bo, ng thi n cn lm tng nhit . Nhng tc ng lm tng vn tc ha tan, khuch tn hot cht vo dung mi, v vy rt ngn thi gian trch ly. Mt khc, n cn lm gim s tiu hao nng lng Lm tng tc ha tan cht phn ng, lm tng tc phnngvdo rtngn thi gian phn ng. Sn lng sn phm thu c cao hn. Nguyn liu s dng r tin hn. Lng ha cht c hi (acid sulfuric) s dng t hn.Nhuc im: Ch c th p dng vi qui m nh. Nhit si ca cc dung mi t c rt nhanh, c th gy nPHN 3: NG DNG3.1. Ti u ha ca siu m Khai thc polysaccharides t mm cy la min Trung Quc s dng m hnh thng k RSM3.1.1. Phng phpNgm, gy mm v chun b bt la min:Sau khi loi b v v ht hng, ht la min (1000 g) c ra sch bng vi nc v sau ngm trong nc tro trch ly. Ht ngm trong 24 gi 30c vi nc ngm thay i khong 6gi/ ln. Sau khi ngm, ly ht b vo ti ay v ct li vo ch ti. Gy mm tin hnh khong thi gian khc nhau (3, 5 v 6 ngy) v nhit gy mm 25c. Sau sy bng tc nhn kh l nng 40c trong 24 h chm dt qu trnh ny mm . Loi b r mm, ht em xay v sy kh. Bt em sng qua ry 70 mesh. Bt sau cm ng gi trong ti polyethylene t trong hp nha c np y bo qun trong t lnh 4c phn tch sau Trch ly polysaccharides t mm cy la min Trung Quc bng siu m:Quy trnh trch ly polysaccharides t t mm cy la min Trung Quc bng siu m thc hin trong mt t bo nghin siu m. Cn 2g bt ( chun b trn) cho vo cc, thm nc ct vo cc sao cho 100ml, sau t thit b to sng siu m vo tip xc v trch ly ti thi gian khc nhau..Nc c s dng m bo nhit ca trch ly l di 50c.

Hnh l: Thit b siu m n gin

S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

Hnh 12: Thit b to sng siu m phng th nghim Nhm 7Trang26Nhm 7Trang 28

Nhm 7Trang 27

Xc nh lug polysaccharidesSau khi trch ly bng siu m, ly tm 10.000 vng / pht trong 20 pht thu dch ly tm v cc cn khng ha tan c trch ly 2-3 ln nh cp trn. C c dch ly tm s dng mt thit b bay hi quay ti 55c trong chn khng. Dung dch sau c c trn ethanol khan, t l 1:4 (nng cn 80%) v gi qua m ti 4c. Sau , hn hp c ly tm 10.000 vng / pht trong 20 pht, ra sch su ln bang ethanol khan v kt ta thu c trch xut th. Ta em sy kh 50c cho n khi trng lng khng i .T l polysaccharides (%) c tnh nh sau:Khi lng dch trch th% Polysaccharides =77 X 100Khi lng nguyn liu ban u3.1.2. Kt qu v tho luny l phng php m t mi quan h gia cc phn ng v mc th nghim ca tng bin v cc loi tng tc gia hai bin th nghim. Cc hnh dng ca th cong, trn hoc hnh bu dc, cho bit s tng tc ln nhau gia cc bin c ng k hay khng. Cc cung trn biu hin tng tc gia cc bin tng ng l khng ng k, trong khi l ng cong hnh elip cho thy tng tc gia cc bin tng ng l ng k. Cc mi quan h gia cc bin c lp v ph thuc c minh ha trong ng cong ba chiu ca cc phn ng v hai ng cong 2 chiu m t lng polysaccharide trch ly, m t trong cc ng cong ba chiu trong khi bin khc gi mc s khng. R rng l lng polysaccharides l nhy cm vi s thay i nh ca cc bin th nghim (nng lng sng siu m, thi gian trch ly v t l nc v nguyn liu).

UP

Hnh 13: th 2D v 3D th hin mi tng quan gia %polysaccharide, cng sut sng siu m v thi gian trch ly

Polysaccharides (%)UP

Hnh 14: th 2D v 3D th hin mi tng quan gia %polysaccharide, cng sut sng siu m v t l nc /nguyn liuCc mi quan h tng tc ca nng lng siu m vi thi gian trch ly v t l nc v nguyn liu v lng polysaccharides c th hin trong hnh 13 v hnh 14, tng ng v ch ra rng ba bin c tt c nh hng ng k kh nng trch ly polysaccharides. Theo hnh 13 v hnh 14, Cng sut sng siu m v thi gian trch ly tc ng tch cc n thu nhn polysaccharides, trong khi lng polysaccharides thay i cht t khi t l nc vt liu trong khong 25-35 ml/g. Lng polysaccharides tng nhanh chng tng cng vi s gia tng cng sut sng siu mv t n gi tr cao nht ti 600 w. Tip tc nng cng sut sng siu m lng polysaccharides gim nh. Cn trch ly thi gian lu hn tc ng tch cc vo vic trch ly polysaccharides v t 4 pht khi cng sut sng siu m khng i (600 W). iu ny cho thy rng mun thu lng polysaccharides nhiu hn th cng sut sng siu m cao hn, thi gian trch ly lu hn v t l t l nc v nguyn liu thp hon. Cc thng s thit lp c xem l trch lypolysaccharides cao ti cng sut sng siu m cao hn do s gia tng hin tng si bt v hnh thnh nhiu bong bng do tng kh nng truyn khi.

Polysaccharides (%)I (17.1516.816.4516.1RWMExtract time

Hnh 15: th 2D v 3D th hin mi tng quan gia %polysaccharide, thi gian trch ly v t l nc /nguyn liu35.00.Yield (%)

Tuy nhin, lng polysaccharide gim l kt qu tng thm cng sut sng siu m. Cc kt qu tng t t c tng t- theo Li cng s (2007) v cho rng mt phn ca polysaccharides c th b phn hy v to thnh cc gc ng t do. Qua cng thy rng, s tng tc gia cng sut sng siu m v 2 thng s trch ly cn li khng nh hng ng k n lng polysaccharidcs thu c, bong bng bt ca nng lng sng siu m l yu t chnh nh hng n kh nng trch ly polysaccharides. Cc nh nghin cu cng ch ra rng s tng tc gia cc cng sut sng siu m v thi gian trch ly, cng sut sng siu m v t l nc v nguyn liu khng gy nh hng ng k kh nng trch ly polysaccharide, trong cng sut sng siu m c tc ng ng k. Hnh 15 cho thy thi gian trch ly v t l nc /nguyn liu l khc nhau. Ket qu l ng cong cao lng polysaccharide cng caoth thi gian trch ly lu hn. Cc ng cong trch ly tng i thng ti nhng khong thi gian trch ly thp, mang li hiu qu trch ly polysaccharide thp khi t l nc /nguyn liu thay i trong khong 25-35 ml/g. Tuy nhin, lng polysaccharide gim khi tng dn t l nc/nguyn liu ti thi gian di hn. Ket qu ny ch ra rng thi gian trch ly khc nhau nh hng n lng polysaccharide thu c t l ca nc /nguyn liu l khc nhau, v cc tng tc cng ng k gia thi gian trch ly v t l nc / nguyn liu.Lng polysaccharides thu c nhiu hn ti thi gian trch ly lu hn v t l nc /nguyn liu thp. hnh 15 s tng tc ca thi gian v t l nc / nguyn liu c nh hng ng k lng trch ly polysaccharide, l cng vi kt qu nghin cu khc (Rodrigues v cng s, 2008;. Wang v cng s, 2009.). Ket lun ny l khng ph hp vi nhng quan st thu c t Li v cng s (2007).Li cho rng iu ny khng gy tng tc quan trng nh hng n lng trch ly polysaccharide ti cng sut sng siu m khng i. iu ny mu thun c th l do s khc bit ln trong cc thng s ca in m. Trong nghin cu ny, cng sut sng siu m (> 500 W) l ln hn so Li v cng s 2007 (60W)3.1.3. Kt lun:Cng ngh siu m c thc hin trch ly polysaccharides t mm cy la min Trung Quc tng sn lng khai thc. Gi tr thc nghim ca lng polysaccharides thu c dao ng t 11,01-17,48%.Cc iu kin trch ly ti u cho polysaccharides c xc nh nh sau: cng sut sng siu m 600 w, thi gian trch ly 4 pht, t l nc /nguyn liu 30ml/g3.2. Tin hnh trch ly xylan ca bp bng sng siu m3.2.1. Gii thiu

S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

Cc nh nghin cu s dng cc cng ngh truyn thng v hin i trch ly xylan. Neu xylan c th c trch ly t li bp cha lignocellulosic trc khi n c dnh cho sn xut ethanol, iu ny s thm mt gi tr ln cho nn kinh t nhin liu nng lng sinh hc .Nhm 7Trang 32

Xylan trong li bp l hp cht ca lignin v carbohydrates khc thng qua lin kt ng ha tr, lin kt ny bn kh b tc ng bi cc phn ng ha hc v enzyme. V vy, cc nguyn liu cn c tin x l ph v lin kt ny l cc polysaccharide lm cho phn ng vi enzyme v ha hc d xy ra. Mt s phng php tin x l c tin hnh ph v cc lin kt ha tr gia xylan v carbohydrate khc trong li bp. Thng thng trch ly xylan l mt qu trnh tn thi gian v sinh ra mt s sn phm khng mong mun nh furfural v lm gim ng.Garrote v cng s trch ly 28% xylan t li bp 170c bng nhit bng cch trn nc v li ng s dng su tua bin cnh qut.Yang v cng s pht hin x l li bp bng axt sulfuric long tng cng kh nng trch ly xylan. H thu c cc t l trch ly: 19,9%, 39,4% v 52,9% tng ng hp 135c, 140 c v 150c. Ket qu ca h ch ra rng s gia tng nhit hp mang li kt qu t l trch ly cao hn. Tuy nhin, s gia tng nhit hp cng gim nng ng.Ket qu trch ly nng kim trong dch trch ly cao [6], nng kim x l thp v tin x l axit cng c tin hnh trch ly cc xylan. Mt s cc phng php c s dng thnh cng cho xylose, xylitol hoc sn xut butancdiol. Tuy nhin, trch ly bng kim v trch ly bang acid l khng thch hp cho vic sn xut cc xylooligosaccharides, v gy ra n mn nghim trng v nhim, to ra mt lng ln cc xylose trong dch thy phn.Do nhng hn ch ca cc phng php tin x l thng thng, c mt nhu cu cho mt phng php tin x l tt hn m hiu qu c th ph v cc lin kt trong mt thi gian ngn v thu c nhiu xylan. Nng lng siu m cho thy mt xu hng trin vng t c mc tiu nySng siu m l ng dng ca cc sng m thanh tn s v cng cao (bnh thng trong khong 20-100 kHz) truyn qua cht lng hoc kh. Tc ng ch yu ca sng siu m l truyn v tng tc lm thay i tnh cht vt l v ha hc ca vt liu do tc dng xm thc ca n. Xm thc gy ra cc b nhit cao v p lc cao, kt qu to ra nhiu gc t do, chng hn nh OH, H +, H202, do tng cng Nhm 7Trang31cc phn ng ha hc. Hiu ng ca siu m gip tng cng s xm nhp ca cc dung mi v nhit vo t bo nguyn liu do ci thin kh nng truyn khi. Sng siu m cng c tc dng trong s ph v cc thnh t bo sinh hc to thun li cho vic gii phng dch boNng lng siu m c chng minh nng cao ng k t l trch ly protein, hp cht dc liu v sn phm thc phm nng nghip khc. Cc ng dng ca siu m cng ci thin ng k sn xut pectin v nng sut cng nghip sn xut cn thuc thuc t tho mc. Trch ly polysaccharides t thc vt cng c tng cng bi cc ng dng ca siu m.Hromadkova v cng s chng minh rng 36% ca xylan c trch ly t li bp bng dung dch NaOH 5% 60c trong 10 pht bng sng siu m. Xylan c s dng trong xt nghim min dch, v kt qu cho thy rng cc tnh cht min dch ca xylan b nh hng bi sng siu m, nhng gim khng ng k trong cc phn ng sinh hc trong cc th nghim lm sngWang v Zhang cng nghin cu tc dng ca sng siu m vo trch ly xylan t li bp. Trong nghin cu ny, cn lng NaOH khc nhau so vi li bp ha tan vi t l 1:25 s dng trch ly vi sng siu m thc hin mc cng sut 200 w trong 30 pht 60c. Cc nghin cu gi rng, tng thi gian x l siu m, t l trch ly tng ln cho n khi t 30 pht v quan st c khng tng ng k sau . T l trch ly cng c tng ln khi cng sut sng siu m tng ln.Cc ti liu nghin cu cho rng, ng dng siu m c tim nng ci thin qu trnh trch ly xylan t ph phm nng nghip. Thng thng qu trnh x l bang acid long c pht hin bi Yang v cng s cng thu c t l trch ly cao hn chp nhn vi mc mt ng. Do , nghin cu ny ngh hiu qu ca kt hp acid long v x l siu m nng cao trch ly xylan3.2.2. Nguyn liu v phng phpNguyn liuCc vt liu cha lignocellulosic c s dng trong nghin cu ny l bt li bp.Cc bt li bp l sn phm ca hng Mt. Pulaski M, c nghin mn 0.8 mmbng my nghin ba. Theo cc nh cung cp,qua phn tch HPLC thnh phn xylan nguyn cht trong li trung bnh l 32,6%.Thit b siu m v cng sng mB hai u d siu m:a. Model S3000 (Misonix Inc, NY) vi cng sut 350 w, tn s sng m dao ng tronn khong 20 kHz,b. Model IL 1000-6/2 (cng ty TNHH Saint-Petersburg, Nga), lm vic tn s 22 kHz,cng sut 1000 wMt nng lng sng m (AED) c kho st cho c hai my siu m s dng trong nghin cu ny. Cng siu m ca my ph thuc vo khi lng v th tch mu ly phn tch. i vi cc mu phn tch, nhit (T) c ghi li bng mt nhit k xem l mt hm ca thi gian. T l tng nhit (AT/At) c tnh khong 30s/ln. Mt nng lng sng m_cho mi my c tnh bng cng sut trung bnh chia cho th tch nc s dng trong th nghim. Ket qu Mt nng lng sng m cho c hai my c tm tt trong bng 2Bng 2 : Mt nng lng sng mUnit 1 (Ultrasonic Technique, Inlab Ltd, St. Petersburg, Russia)Unit 2 (Misonix Model S3(X)0 ultrasonic liquid processor)

Change in temperature (AT)/ C166.5

Duration of time (At)/s3030

AED/W mL'10.450.18

X l SO b li bp bng phng php thng thngMu li bp lOg c ngm trong axt sulfuric long (H2SO4 2%, t l 1:10 khi lng / th tch) 50 c trong 24 gi (hnh 1). Cht trch ly c tch bng lc. Lng acid d lng c ra sch bng nc trc khi hp. X l s b ph v cc lin kt ha tr gia lignin v xylan trong li bp, v gii phng xylan.Nhm 7Trang33Hnh 16: So snh 2 phng php: x l thng thng v x l s dng sng siu mNgm li bp trong dung dch H2SO4 2% ti 10,20,30 v 60 pht vi mt sng m ln lt 0.18W/mL v 0.45 W/mLNgm li bp trong 24 gi bng dung dch H2S4 2% 50c

Trch lyB em hp 110,118 v 121cTrch lyTrch ly

X l SO b li bp bng sng siu mCn lOg li bp ngm trong axt sulfuric long (H2S042%, t l 1:10 khi lng / th tch) vng chc t l cht lng) sau chiu sng siu m trong 10, 20, 30 hoc 60 pht mt nng lng sng m l 0,45 w / mL v 0,18 w / ml. Cc mu cm lc v ra sch bng vi nc trc khi hp (Hnh 16).Hp muMu c t trong mt ng bng thp khng g em hp trong ni hp. Hp trong 30 pht ti nhit 110, 118, hoc 121 c (Hnh 16). (Yang v cng s.) v nhng khong nhit ny c xem trch ly ti a xylan v gim thiu vic gim ng v cc sn phm khng mong mun khc. Sau khi hp, mu trn vi 100 ml nc 16000 rad/ pht trong 2 pht. i vi phn tch ha hc, cht lng thu c sau khi trch ly em lc. Cc mu lc em phn tch ha hc s hin din ca xylan. Phn tch ha hc ca cc cht trch lyS dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

S dng sng siu m trch ly polysaccharide

Xylan thu c dau cc qu trnh trn cm i xc nh bng cch o tng s ng ha tan. Theo Yang v cng gii thch rng: tng s ng ha tan trong cht Nhm 7Trang34Nhm 7Trang 38

Nhm 7Trang 37

chit bao gm xylan ha tan v xylooligosaccharides, nhng lng xylooligosaccharides l rt thp v cellulose ha tan trong li bp l khng ng k trong qu trnh x l s b v trch ly, tng s ha tan ng l mt phng php tng i chnh xc nh lng xylan trong mu. Mt khc, xylooligosaccharides cng sn phm thun li ca qu trnh trch ly, bi v sau khi enzyme chuyn i xylan, cc sn phm ch yu l xylooligosaccharides. Do , thu c c xylan hoc xylooligosaccharides nh nhau trong qu trnh trch ly. Bi v iu ny, trong nghin cu ny s lng nh cc xylooligosaccharides c tnh vo dch trch ly n gin khi xc nh xylan. Do , lng xylan c tnh bng cch o hm lng ng tng s ha tan trong nc lc, nh th hin di y :Lng xylan trong dch trch lyLng xylan c trong dch trch(%) = T7"7T- z I 77T~ x '()()vLng xylan trong nguyn liu3.2.3. Kt qu v tho lunTrch ly xylan ny sau khi x l s b (truyn thng) 24 h v hp 30 pht, lp th nghim nh trn cc nhit khc nhau (110, 118, v 121C) nh bng 3. Khong, 29,1% xylan u tin bp c trch ly (Bng 2). Hp mang li hiu qu trch ly nhiu xylan hn v d: t l trch ly c 7,3%, 8,2% v 8,8% ti 110, 118, v 121c. iu ny cho thy hp nng cao trch ly xylan, c th v hai l do sau y: Nhiu lin kt cng ha tr ca lignin v carbohydrate khc b ph hy trong qu trnh hp, do lm tng kh nng trch ly Mc d li bp c ra sch bng nc trc khi hp nhng vn cn c mt s H2SO4 st li v nhit cao acid ny thy phn vn c th din ra.Tuy nhin, trc y phng php ny c th ng mt vai tr ln trong trch ly xylan.Extraction duc to 24 h pretreatmentStcamint temperature t:Extraction due to 30 min steamingTotal extraction

29.10.5%1107.30.3%a*36.40.3a

29.10.5%1188.20.3%b37.30.3b

29.10.5%1218.80.2%b37.90.2b

Average37.2

Bng 3: Cc thng s ca phng php trch ly truyn thngThng k Turkey ch ra rng t l trch ly do hp ti 118 and 121 c khc nhau ng k vi t l trch ly ti 110 c (p