MICROENCAPSULATION OF ANTIOXIDANT IN FOOD1. Mc ch cng ngh vi baoBn cnh nhng qu trnh ng gi bnh thng th cng ngh bao vi bin nhng th tng nh khng th thnh c th, y l mt gii php bao gi hu hiu gip chuyn i cc hp cht dng lng, kh sang dng bt ng thi bo v hot tnh ca cc hp cht ny trong mt cu trc rt nh c mng bao bc nhm hn ch tc ng ca mi trng bn ngoi (nh sng, nhit , m, oxy ), gip bin i v bo v cc hp cht c hot tnh sinh hc cao nh enzyme, t bo (probiotic), cht thm, cht mu thc phm ng thi l mt bin php hu hiu nng cao gi tr s dng ca chng. Trong , chng oxy ha l mt mc tiu kh l quan trng ca ng dng cng ngh ny trong ngnh thc phm do kh ngn cch vi mi trng bn ngoi vn bt li cho sn phm thc phm, gim thiu c vic h hi ca sn phm thc phm, gim thiu c tc hi ca nhng ph gia bo qun thc phm i vi sc khe con ngi. V d nh vic phn lp vitamin khi nhng nh hng xu ca oxy, gim s tht thot hi nc khng mong mun ca vt liu nhni khi vic bao gi vi nang cn c s dng che nhng khuyt im ca vt liu c bao gi. V d nh bao gi poplyphenol gip cho hp cht ny c kh nng n nh hot tnh sinh hc v ngn nga nhc im mi kh chu ca hp cht polyphenol.2. Gii thiu v cng ngh vi baoBao vi l ng gi cc vt liu c kch thc rt nh vo trong mt lp v bao cc mng, lp v ny s gi v bo v cht c vi bao khng b bin i lm gim cht lng v hn ch tn tht, cht c vi bao ny c th c gii phng trong mt iu kin c bit. Cc cht c vi bao c gi l cht nn, nhn hay vt liu ct li. Cc cht bao c gi l v, vt liu ph hay mng bao ph.Mng vi bao bao gi nhng git cht lng nh hay nhng ht c kch thc nh hn mng bao. Thng thng kch thc nhng ht nh c th dao ng t di 1 micromet n hn 1 milimet. Ty thuc vo mc ch bao nang, tnh cht ha l ca cht c bao gi, thnh phn ca cht bao gi v cc k thut s dng bao vi nang khc nhau, m ta c th thu c cc dng bao gi khc nhau: n nhn, a nhn, loi ma trn, nhiu lp bao gi.Tuy nhin hai hnh thi ch yu thng thy l n nhn, mt nhn bao ph bi 1 lp v. V hnh thi th hai l a nhn tp hp, trong c nhiu nhn trong 1 lp v. Loi ma trn th vt liu nhn phn phi ng nht trong vt liu bao ph. Thm vo cng c nhng loi mt nhn vi nhiu lp v hay chng cng c th c hnh thc cm ca vin bao nang.

H1: Hnh thi ca cc loi vin nang siu nh (Gibbs v mt s cng s, 1999)Bao vi nang l mt cng ngh tin tin v c ng dng kh ph bin trong nhiu lnh vc nh: Thc phm, dc phm, m phm, nhng sn phm chm sc c nhn, nng nghip, th , cng nghip ha cht, cng ngh sinh hcRing ngnh thc phm th lnh vc s dng cng ngh ny nhiu nht l ngnh sn xut sa bt.3. Vt liu v phng php ca cng ngh mng vi bao3.1 Vt liu c bao gi ( nhn): L nhng sn phm trong nhiu lnh vc c th tn ti trng thi rn ( c th c trn vi cc phn t hot ng, cht n nh, cht lm long), lng ( bao gm c pha phn tn hay cc cht ha tan), kh, vt liu nhn c xc nh v phn loi c th cng vi chc nng s dng ca chng c th c nhng phng php bao gi v vt liu bao gi ph hp. 3.2 Vt liu bao gi ( v): Vic la chn vt liu bao gi phi da vo nhiu yu t nh: tnh n nh, bn c hc, tnh tng thch vi sn phm thc phm, gim bin ng, iu kin mi trng, tha mn mc ch cng nh yu cu v phng php ng gi g l tt nht ph hp vi mc ch . Cc thuc tnh ca vt liu bao gi in hnh nh: s gn kt, tnh thm, m hp ph, tnh ha tan, tnh n nh, phi c xem xt r rang trong vic la chn vt liu bao ph l thch hp nht. Lp bao ph b mt hay vt liu nhn u nh hng n quyt nh tnh cht ca vt liu bao ph. Trong thc t c kch thc v hnh dng ca vi bao nang u ph thuc vo vt liu nhn v phng php s dng chun b cho qu trnh vi bao. Bn cnh trong ngnh thc phm th vt liu bao gi phi m bo khng nguy hi n c th, sc khe con ngui v c th tiu ha c v cng c th cung cp dinh dng hay c li cho c th. Gelatin l vt liu c s dng lm bao nang ph bin, bn cnh vt liu polymer tng hp cng c s dng nh polyvinyl alcohol , ethylcellulose, polyvinyl chloride , Maltodextrin, tinh bt, chitosan, glucan, gum, protein.3.3 Phng php bao gi vi bao nang: C rt nhiu phng php bao gi nh: sy phun, tch pha ng tch, bao gi bng liposome, phun lnh, vi bao gi bng kh nn, p n, gi phc phn t, ng kh, ng kt tinh..trong sy phun l phng php s dng kh ph bin trong lnh vc thc phm . Vi bao gi bng phng php sy phun c s dng kh thnh cng trong ngnh cng nghip thc phm trong nhiu thp k qua v c s dng sm nht trong tt c cc phng php bao gi khc do chi ph thp, thit b c sn. Phng php ny c s dng t nm 1930 bao gi mi thm bng vt liu bao gi l gum acasia (Shahidi & Han, 1993).Bn cnh mc ch loi m cho sn phm, to trng thi bt mn sau khi sy th sy phun cng l mt phng php ng gi cc thnh phn thc phm nh hng v, cht bo, carotenoids bi c im ca phng php ny l sy cc dung dch, huyn ph trong trng thi phn tn, do , chng ta c th ng nht hn hp vt liu bao gi v vt liu c bao gi mt cch d dng. Qu trnh phun sng dung dch c to ra bi p lc hay lc ly tm, to ra dng ht sng c kch thc rt nh 1 m 100 m ph hp vi qu trnh bao gi vi bao. S trao i nhit m xy ra ngay trong lng th tch cc git cht lng, khi chng c phun dng sng kt hp vi dng kh nng ( s dng khng kh hoc kh tr nh nit) c th l phun cng chiu, ngc chiu hay s dng c 2 phng php ny.Cc bc ca qu trnh vi bao bng phun sng: Chun b h nh tng:Yu cu trong giai on ny l hn hp vt liu bao gi v vt liu c bao gi phi dng dch, to mi h nh tt v n nh. Ty vo hot ng ca vt liu bao gi m c hay khng vic s dng cht nh ha. Bn cnh nu h nht cao s dn n hnh thnh cc ht di, kch thc ln v nh hng xu n tc sy. Phu sng dng nhp liuPhun sng dng nhp liu vo bung sy, s dng my phun bao gm phun kh nn, phun vi p lc, vi phun a. Ty vo mc ch, yu cu cng nh l tnh cht ca h nh tng m ta chn kiu phun ph hp vi cc thng s ph hp. Ti y, dng nhp liu phun sng c tip xc vi dng khng kh nng vi nhit thng t 150 C 200 C, bc hi xy ra ngay lp tc. Tuy nhin khng qu cao bi nu nhit cao s dn n nht v kch thc ht gim nhng gy ra s bay hi v lm bin cht ca mt s sn phm nhy nhit. Nhng nu nhit thp s dn n tc bay hi thp, mng vi bao dy, m cao v km linh ng.. S thot m dng nhp liuThng thng th thi gian cho s thot hi nc khong 5s 100s, tuy nhin, thng s thi gian cho quy trnh sy tt l khong 15 20s, dng nhp liu s i chuyn theo hnh l xo thi gian lu trong thit b l ln nht v qu trnh bc hi nc l ti u nht, sn phm thu c dng bt mn c ngun gc t cc git ban u. Ty thuc vo thnh phn vt liu, nc, v kh m cc ht thu c c th l c hoc rng. Kch thc, hnh thi ca ht c lin quan n m v nhit cho qu trnh sy phun. Tri vi nhit u vo khng kh, ti ca thot kh ngi ta khng th c kim sot trc tip v n ph thuc vo nhit khng kh u vo, v nhit u ra khng kh cho qu trnh vi bao sy phun cc thnh phn thc phm nh hng v l tng l 50C80 CVt liu bao gi c nghin cu v ngh cho vi bao gi bng sy phun: Cacbohydrat nh tinh bt, siro ng, maltodextrin, y c xem l vt liu bao gi tt v ph hp vi phng php sy phun v nht thp vi nng cht rn cao, c kh nng ha tan tt nhng thiu tnh cht b mt chung cn thit cho cho hiu qu vi bao cao, do hiu qu vi bao cao th thng phi b sung thm protein v gum. Ngoi ra th polysaccharide u tng l cht nh ha vt tri hn c gum Arabic, y l mt cht to gel c th n nh nh tng theo hng keo t v kt dnh.Gum c s dng vi bao vi c 2 tnh cht l lm vt liu bao gi v n nh h nh tng. Gum arabic l mt polymer gm D-glucuronicacid, L-rhamnose, D-galactose, L-arabinose v, vi khong 2% protein (Dickinson, 2003).Protein c coi l vt liu vi bao gi tt nht ca pp sy phun, cc protein thng c s dng cho vic vi bao gi thc phm l Whey protein, gelatin.Mt s thnh phn thc phm vi bao gi bi sy phun nh: Hp cht mi l thnh phn rt d bay hi trong thc phm. Qu trnh vi bao ca nhng hng v k nc c vai tr quan trng trong ngnh hng liu v cc ngnh cng ngh thc phm, n gip cho hng liu n nh thnh phn ha hc cng nh kim sot kh nng pht tn ca hng liu. V d nh vi bao gi bng phng php sy phun hng liu L-menthol vi vt liu bao gi l maltodextrin v gum Arabic nng cao.Cht bo l thnh phn rt kh phn tn trong cc sn phm thc phm, ngoi ra nhng cht bo cha bo ha s d dng b oxy ha lm gim cht lng ca sn phm thc phm, cht bo c th lm dung mi ha tan cc cht k nc nh cc hp cht thm d bay hi, do , vic vi bao gi cht bo s cho ta nhng li ch nh:lm chm qu trnh t oxy ha ngn nga to hng v kh chu v sinh ra cc hp cht c hi, kim sot ha tan hng liu, bo v cht ha tan b mt v chng thy phn enzyme. Vt liu tng ph hp bao gi cht bo l gum Arabic, maltodetrin hay tinh bt bin tnh.Bn cnh nhng u im th phng php sy phun vi bao cng tn ti nhng nhc im sau: Hn ch vic la chn vt liu bao gi v vt liu c bao gi, ch s dng c cc loi cht bao ha tan trong nc mt mc nht nh v sy phun c th nhp liu phi dng lng, xy dng m hnh ton hc ca sy phun l kh kh khn v rt nhiu thng s can thip nh: to git, bay hi, va chm, tch t, ph v, chuyn i nhit v khi lng ca nhng git sng, lng ph nng lng v khng th s dng tt c cc nhit i qua bung sy.4. ng dng ng gi vi bao cho sn phm bt chanh dy chui Nguyn liu nhn: Bt chanh dy chui. Chanh dy chui l mt loi tri cy nhit i vi tim nng l mt ph gia thin nhin c kh nng chng oxy ha thay th cho cc ph gia tng hp, l do l trong bn thn ca chanh dy chui c cha hm lng nhng hp cht phenolic kh cao, acid ascorbic ( vitamin C) , l nhng cht c kh nng chng oxy ha c ng dng rt nhiu trong thc phm v dc phm. Tuy vy cho nhng hp cht ny c bo qun tt v n nh, hot ng mt cch ti u trong iu kin thch hp cng nh hn ch nhng nhc im gy cn ch cho vic s dng ngi ta nghin cu cng ngh mng vi bao ng gi bt chanh dy chui, c th l nghin cu vi ng gi bt chanh dy chui. Bng 1:Cc gi tr ch tiu kh nng chng oxy ha ca bt tri chanh dy mui:DPPH6630.2 91 Mtrolox/100g

ABTS18764.3 270.4 Mtrolox/100g

FRAP1703.6 938.2 mgAA/100g

ORAC8105.4 424.2 mol TEAC/100g

Tng s phenol8862.2 451.4 gallic ac. mg/100g

(Phng php DPPH (Scavenging ability towards DPPH radicals) kh nng kh gc t do DPPH, Phng php TEAC (Trolox equivalent antioxidant capacity) xc nh hot tnh chng oxi ha so vi kh nng chng oxi ha ca Trolox, Phng php FRAP (ferric reducing-antioxidant power) lc chng oxi ha bng phng php kh st, Phng php ORAC (oxygen radical absorbance capacity) xc nh kh nng hp th gc t do cha oxy hot ng).Vi cht bao gi c s dng l MD ( Maltosedextrin) tng ng vi ch s DE l 10 v MS (modified starch), trong nghin cu ny da vo so snh kh nng hot tnh oxy ha ca bt chanh dy mui vi cc phng php xc nh v kt qu nh nu bng 1, nghin cu phi trn 2 vt liu bao gi trn vi mt s t l t a ra kt qu so snh vi bng 1 chn c t l ti u cho vt cht mng bao m bo tt nht hot tnh chng oxy ha ca sn phm ny. Cc t l c kho st: (MD:MS) = (0:1), (1:0), ( : ), ( : ), ( : ).Phng php bao gi: Sy phun bt chanh dy chui Bng 2: Kt qu th nghim t c t l ti u cho tnh cht chng oxi ha ca bt chanh dy mun c vi bao theo thi gian bo qun.T l ( MD:MS)Phenol v AOA02 46

0:1PHENOLS1335.0 42.5746.4 20.5800.1 21.5562.2 24.3

: 794.2 9.9691.1 52.8651.1 41.5552.4 16.8

0:1 DPPH1229.2 185.31073.1 139.4932.5 109.4732.1 48.1

: 1637.3 206.31502.4 148.31325.5 148.3865.9 55.8

0:1ABTS15301.4 888.315027.4 1969.1 14335.6 1671.113384.9 845.5

: 10548.2 219.09789.6 273.29645.2 191.59025.6 718.7

0:1FRAP1591.6 12.61541.1 26.7904.0 31.8879.8 75.9

: 1682.0 43.8887.7 9.5866.2 50.0852.4 21.9

Qua kho st vi bao bt chanh dy chui cc t l nu trn th kt qu thu c hot tnh chng oxi ha ca sn phm ny tng ng vi cc t l ( 0:1) v t l (1/4 :3/4) l cho kt qu tt nht nh lit k bng 2, vi t l ny cho thy vai tr vt liu bao gi ch o l MS, cho sn phm c tnh n nh cao. Trong nghin cu ny th ht bt chanh dy chui c vi bao c kch thc t 10m 23m, vi kch thc ny cho php sn phm cui cng c ha tan tt.

H2: nh chp vin bao nang cho 2 mu tng ng vi 5 t l kho st.Tuy nhin cng theo nghin cu ny th trong cc ch tiu trn th ch tiu ABTS l ch tiu o lng tt hn cc ch tiu DPPH, FRAP nh gi kh nng chng oxy ha ca bt chanh dy chui v ch s ABTS tng quan nhiu n hp cht penolic tt hn so vi 2 pp DPPH v FRAP. Ch tiu ABTS trong bng 2 gn vi ch tiu ABTS trong bng 1 cho ta thy c hiu qu ca vi bao m bo tt tnh cht chng oxy ha ca bt chanh dy chui, cng trn bng 2 ta thy nhng ch s chng oxy ha trong qu trnh bo qun gim rt chm v c bo qun tt.V mc tiu ca nghin cu l m bo cho hot tnh chng oxy ha, cng nh bo qun tui th ca sn phm ca bt chanh dy chui, gip cho bt chanh dy chui c s dng nh mt loi ph gia bo qun chng oxy ha bng phng php bao vi nang s dng sy phun ( sy phun ng nghip dng c th ln n quy m cng nghip, chi ph thp) vi mt s hp cht vi bao c s dng rng ri trong cng nghip thc phm. TI LIU THAM KHO[1] Maritza Gil1*, Ana Restrepo1, Leonidas Milln1, Luz Alzate1, Benjamn Rojano2, Microencapsulation of Banana Passion Fruit (Passiflora tripartita Var. Mollissima): A New Alternative as a Natural Additive as Antioxidant Food and Nutrition Sciences, 2014, 5, 671-682.[2] Adem Gharsallaoui *, Gaelle Roudaut, Odile Chambin, Andree Voilley, Remi Saurel, Applications of spray-drying in microencapsulation of foodingredients: An overview, Food Research International 40 (2007) 11071121.

Microencapsulation of antioxidants in food 1

Microencapsulation of antioxidant in food 6