Tgp chi Kboa bgc Truang Dgi bgc Cdn Tha Phdn B: Nong nghiip, Thuysdnvd Cong nghf Sinh hgc: 33(2014): 110-115^
Tap chi Khoa hoc Tri/dng Dal hoc Can Thtf website: sj.ctu.edu.vn
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NGHIEN CUtJ CHE BIEN S I - R 6 BlTdl CO C 6 N Nguyen Cong Ha\ Dang Thj My Tien' va Le Nguyen Doan Duy' ' Khoa Ndng nghiep di Sinh hgc Ifng dung, Trudng Dgi hgc Cdn Tha Thong tin chung:
Ngdy nhgn: 04/06/2014 Ngdy chdp nhgn: 28/08/2014 Title:
Study on alcoholic pomelo syrup processing Ttr khda:
Vi ddng, enzyme p-glucosidase, len men, si-rd budi, cdm quan Keywords:
Bitter taste, P-glucosidase.
fermentation, pomelo syrup, sensory
ABSTRACT
Diversification of pomelo product to enhance the economic value of this fruit using enzyme ^-glucosidase for bitter taste control from the fruit
was done. In addition, the experiments that find out the suitable recipe for processing such as bBrix degree, pectin and citric acid concentrations were also investigated. The results showed that when
^-glucosidase was used at 1.4% for 40 minutes, the bitter taste oflhe product could be controlled well Pomelo syrup product had good sensory evaluation when il was adjusted at 55°Bx, 2% pectin and 0.5%
citric acid. The pasteurization regime at 85°Cfor 5 minutes could store the product well for 4 weeks at room temperature. The results indicated that P-glucosidase could be used to control bitter taste well during pomelo syrup processing.
Vdi muc tiiu da dgng hda cdc sdn phdm lir qud budi de ndng cao gid tri kinh te ciia chiing, nghien cicu che biin sdn phdm si-rd budi cd cdn da dugc thtec hien. Trong dd, khdo sdt dnh hudng cua ndng dg enzym P-glucosidase vd thdi gian thiy phdn din hieu sudt khir ddng ciia dich buoi sau khi len men cUng nhu khdo sdt tim ra cdng thuc phdi chi (dg brix, pectin, acid citric) ket hgp voi che dg thanh triing 85''C trong 5 phat den gid tri cdm quan vf vd khd ndng giii mdu sdc ciia si-rd budi theo thdi gian tdn trir da dugc thuc hiin. Ket qud nghien cuu cho thdy khi sir dung 1,4% enzyme /i-glucosidase kit hgp vdi thai gian thuy phdn 40 phiit cho hieu gud khir vi ddng la cao nhdt. Sdn phdm si-rd budi kid bd sung dudng a 55''Bx cimg vdi ndng do pectin 2% tgo cho sdn phdm trgng thdi tdt nhdt. Ddng that, khi bd sung acid citric o ndng dg 0,5% se tgo vi hdi hda cho sdn phdm vd mdu sac ciia si-rd budi dugc duy tri trong sudt 4 tudn bdo qudn a nhiet dg phdng. Kit qud da chi ra rdng cd thi sir dung enzyme p-glucosidase de kiim sodt vi ddng trong chi biin chi phdm si-rd budi len men.
I GIOI THIEU
Ddng bing sdng Cuu Long dugc thien nliiln uu dai vdi nhilu logi trii cdy nhiet ddi rat ed gid ttj.
Trong do, budi la logi ttdi cay dugc ua chudng va ttong phd bien d Ddng bing sdng Cuu Long ndi rieng va ca nudc ndi cfaung. Ciing vdi sy tien b^
ciia khoa hgc ky thudt, ky thugt trdng va chdm sdc
cdy budi dugc nang cao ldm cho sdn lugng budi hdng nam khdng ngimg tang la dau hi?u ddng mimg cho nfaa vudn. Tuy nfailn, san lugng budi tang cao ddn den sy ton dgng vd hu hdng vdo miia thu hoach vd klian hiim sdn pham ldc nghjcfa miia.
Vi vdy, can pfadi cd bi|n pfaip bao qudn hay che biin budi pfau hgp vd tiij ttuong tiiu tiiu dn dinh 6k giiip nhd vudn yin tam trdng trgt. Ben canh dd, gid
Tgp chi Khoa hgc Tnrdng Dgi hgc Can Tha Phdn B: Nong nghiep. Thdy sdn vd Cong nghi Sinh hgc: 33 (2014). 110-115 tri kinfa ti eua qud budi cfaua that sy dugc phat fauy.
Trin thi ttudng hiln nay ciia nudc ta, budi chti ylu dugc sii dung dk an tuoi vd cfae biln eic sdn phim cd gid tri kinh ti thip nhu: nem budi, cfae budi, cde logi nudc udng tii budi, mdt sd it dugc xuit khdu ra tfai trudng ngoii nuoc. Mat khdc, budi la loai trdi cay dugc rat nhiiu ngudi ua thich bdi rapt sd lgi ich nfau: lira gidm cfaolesterol ttong mdu, cfadng cao huylt dp, ngin ngira ung thu. Ngoai tep budi ngudi ta cdn sii dung la budi, hoa budi, ciii budi, hat budi tfaira chi li vd xanfa ttong cfae bien tfayc pham hay chua benh. Tuy nhien, trong qua ttinh chl biln cac sdn phdra tir budi nhu nudc ep budi, rugu vang budi, tinh ddu budi, nhi sin xuit thudng phii ddi mat vdi nhilu van de giy ra bdi vj ddng hiln cd ttong budi, dilu nay lam giim gid tri cdm quan ciia sin pham. Trong qud, naringin (4',5,7- rihydroxyfiavanone-7-rfaamnoglycoside) nhu li mdt glycoside flavonoid, la thdnh phfra dang chinfa ciia radt sd loai ttdi cay fag cam quyt (Kimball, 1991). Cdc fagp chdt giy dang nhit hiln diln ttong cdc loai nudc hg cam quyt li naringin, liraonin, va neohesperidin (Marwaha e( a/., 1994).
Viec khu ddng cua nudc ttdi cdy hg citrus la mdt qua ttinh quan ttgng dugc sii dung de kilm soit chit lugng va ndng cao gii tri thuong mgi.
Hiu hit cic phuong phip cdng nghiep de khii dang cdc logi nudc ep niy li su dyng cdng nghe ttao ddi ion (Kimball, 1987), phuong phip hda hgc (Kefford, 1959), enzyme naringmase, p- glucosidase (Purl et ai, 2000), ttich ly (Griffitii, 1969) va hip thu (Caldini et al, 1994). Trong sd dd ngogi trir phuong phdp enzyrae, nfaung pfauong pfaip cdn la tin tai nhung hgn che, chinh vi vdy, nghiin ciiu ehi biin si-rd budi ed edn tii qud ttinh len raen cd stt dyng enzyme p-giucosidase dl xii ly chit ding dd dugc thyc hiln.
2 PHU'ONG PHAP NGHIEN ClTU 2.1 Phuong pfaip chudn bi man Len men dich budi vd xir ly vi ddng bdng enzyme p-glucosidase
Budi sau khi dugc xir ly (ggt vd, loai hgt) sl dugc n ^ i i n , loc di thu dugc dich qui. Dich qud se dugc phdi cfai vdi dudng den 12°Bx vd dilu cfainh din pH 4,2. Sau do tiin hanli thanh trung bdng NaHSOs vdi ham lugng 122mg/lit ttong 60 phiit di tiiu diet vi sinh \%X cd ttong djch qua. Khi thanh triing xong, bd sung nam men Sacharomyces cerevisie vao vdi ti 11 0,04% (nam men phai dugc hogt hda trudc 30 phiit ttong nudc ira), khuiy diu vd rdt vao binli lln raen, tiln faanh lln men d nhilt
do phdng ttong 24 gid. Sau khi len men, tien hdnh lgc, thanh trung d nfailt dp 85''C thdi gian 15 phut nhara tiiu diet cdc te bdo ndm men cdn sdt lai ttong dich lln men dl ttanh hiln tugng nira men se tilp tuc len men khi bd sung dudng vao sin phim. Dich budi sau lln raen se tiln hanh khii vj ding bdng enzyrae p-glueosidase cd hogt tinh 6 UT/lmg, enzyme sii dung dugc pha vdi ti ll lOOrag/lml.
Sau do tiln hinh khio sit d 5 ndng dO (0,8 - 1,6%) vai 3 raiic dp thdi gian (20 - 60 phiit).
Chudn bi si-rd budi
Djch budi sau khi lln men, kfaii dang se dugc bd sung dudng sucrose de dat dugc do khd vdi 3 miic do 50, 55 va dO^'Bx kit hgp vdi ndng do pectui d 3 miic dp 0,1; 0,2; 0,3%. Tiln hanh do dd nhdt cac miu cung nhu cho danh gid cira quan vl raiu sac vd vi ciia san pham.
2.2 Pfauong phdp phan tfch Hdm lugng naringin
Ham lugng naringin dugc xdc dinh theo phuong phap eiia Davis (1947).
Xdc dfnh hieu sudt cua qud trinh thiiy phdn chdt ddng
Hieu suit ciia qua trinli thuy phan dugc xdc djnfa dya tren ty 11 % cua lugng naringin dugc thiiy phdn va lugng naringin ttudc qud ttinh thiiy phdn.
Cdng thiic tinh hieu suit dugc the hiln d phuang trinh 1.
H ( % ) = ^ X 1 0 0 (1) H: Hieu sudt qud tr'mh thuy phdn chdt ddng (%) N: Lugng naringin dugc thdy phdn (ppm) No: Lugng naringin ban ddu (trudc khi thdy phdn) (ppm) _
Xdc dinh do nhdt
Do nhdt dugc xac djnh bang raiy do nhdt kl DV-E Viscometer, spindle 60RPM, UK.
2.3 Pfainmg phap danh gia cam quan San phdm si-rd dugc danh gii ciin quan vl vi va radu sdc theo phuong phip cho diera vdi thang diim 5 tuong ling vdi miic dp chdp nhin ve vj hodc mau sdc tdt nhit. Hdi ddng danh gid cam quan gdm 10 ngudi dugc huin luyln ve phuong pfadp ddnh gia cim quan cho diim.
2.4 Pfaan tt'cfa si lieu
Thi n^iem dugc bd tti ngau nhiin vdi 3 lan lap lai, kit qua dugc phin tich thdng kl, kilm dinh LSD vi ve dd thi bing chuong ttinh Statgj^phics version 15.0.
Tgp chi Khoa hgc Trudng Dgi hgc Cdn Tha Pbdn B: Nong nghiip, Thuy sdn vd Cdng nghf Sinh hgc: 33 (2014): 110-115^
3 KET QUA VA THAO LUAN 3.1 Khao sdt anh budng cua nong dg va thdi gian thuy phan chat dang naringin ciia dich budi sau khi len men bang enzyme p-glncosidase
Naringin tdn tgi trong vd, ciii v i cd thit qud gay nen vj dang nhilu hay it tiiy thugc vao him lugng Naringin cd ttong qui. Tuy vj ding cua naruigra khdng giy hgi cho siic khde ngudi tiiu diing nhung nd lira giim gid ttj cdm quan cho sin pham, gidm
Bang 1: Hieu suat thuy pbdn (%) chat dang naringin bang enzyme p-glucosidase ciia dich budi sau khi len men
khd nang chap nhgn sdn phim. San phdm siro ehiia ham lugng dudng tuong ddi cao (> 50%) nhung vi ding chu ylu do naringin vdn tdn tai. Ndng do naringin do dugc ttong dich budi Id 74,74 ppm giy nen vi ding khdng dugc chip nhgn eho sdn phdm.
Cfainfa vi tfai vile xu ly cfadt ding de tang gid hi cam quan cho sdn phdm la cin thiet. Kit qui cQa viec khii ddng dich budi len men bing ensyme p- glucosidase dugc thi hiln d Bdng I.
20 40 60 Trung binh
Nong do enzYme p^glucosidase (%) 0,8
40 46,85 44,2 43,68"
1 48,39 53,12 45,52 49,01°'
1,2 56,76 61,71 46,67 55,05=
1,4 74,28 79,28 65,15 72,90"
1,6 62,48 70,48 61,23
Trung binh
56,382"
62,288' 52,554' 64,73' Ghi chii: cdc irung binh nghiem ihuc di kem vdi cdc chir giong nhau khong cd su khdc biii iren cimg mgl cgl hogc mgl hdng vdi muc y nghta 5%
K i t qua d Bdng 1 cfao t h i y v i l e sir dyng c h l pham p-glucosidase dl khii vi ding mang lai hiiu suit tuang ddi cao. Kit qud thdng ke cho thdy, trong cimg kfaoing tfadi gian thiiy phan ndng do enzyme cdng cao thi co chdt bj thiiy phin nhilu lam tang hi?u sudt kliCr dang, cu till la hieu sudt khii ding tang khi ndng dd enzyme tang tir 0,8 -^
1,4%. Nhung klii tdng ndng do enzyrae lln tdi 1,6% till hieu suit thiiy phdn lai gidm xudng ro ret Liic nay, hdm lugng narragin edn lgi ttong djch qud rit it tiic la ndng dp co chit cdn it rai bd sung ndng dg en2yrae khdng tuang img ldm giim failu qui tiiiiy pfadn cua enzyrae. Theo Nguyin Diic Lugng (2003), khi tang lugng enzyrae sir dung ttong qud ttinh xir ly rau qud den mgt gid ttj xac djnfa thi tic do phan ling tdng. Nhung khi^tdc*dd pfadn"iing dat cyc dgi, cho dii ed tang hira lugng enzyme thi tie do phdn ling hoin toan khdng cd khi ndng tdng theo do bd sung ndng do enzyme cao sl gay ra sy mdt can bdng giiia enzyrae - co chdt ldm cho tie dd phin ling giam.
Ddi vdi pfadn lii^ enzyrae ttong dilu kien ed djnh ndng do enzyme, nfailt dd, pH hieu suit thiiy phdn ctia enzyme cung bi chi phdi bdi thdi gian thiiy phdn, tfadi gian cang lau thi sy tilp xiic giira enzyme vd eo chdt cdng nhieu lam ting hiiu suit thuy phin, cu tfae khi thdi gian tfaiiy pfain tang ttr 20 -^ 40 phiit thi hieu sudt thiiy phan tang lln rd ret.
Tuy nhiin, khi keo dii thdi gian din 60 phiit tiii hieu suit thuy phdn lgi gidm xudng rd r§t, din thdi diera niy thi co chit cdn rdt it faoac khdng cdn thi thdi gian thiiy phan khdng edn y nghTa. Vi vdy, d
ndng dd enzyrae 1,4% vdi thdi gian thiiy phdn 40 pfaiit cfao hieu sudt khii ding tuong ddi cao dugc chgn de dp dung trong qud ttinh che bien sdn phdm.
3.2 Anh hirdng ciia do Brix vd ndng dp pectin din trang tfadi ciia sin pfaim
Ket qua sy kfaac nhau vi do nfadt giiia cdc miu dugc phdi che vdi dd Brix va ndng do pectin khac nhau dugc the failn d Bing 2 va diem ddnh gia cam quan giiia cic miu d Bang 3. Tir bing sd lilu cfao thdy do nhdt tdng ti ll thudn theo ndng dd pectin va do Brix.
Bing 2: D$ nfadt (cP) eiia eac miu vdi ti II phii chi pectin vd d§ Brix khic nhau NOng d$
pectin (%) 0,1 0,2 0,3 Trunji binli
So Brix 50 55 23,08 30,00 35,75 43,12 49.15 53,18 35,99' 42,1'
60 48,80 60,93 70,93 60,22"
Trnng binh 33,96' 46,60' 57,76' Qua kit qud thdng ke cfao tfaiy diim cira quan tang khi dg Brix tdng lln, tuy nhiin d do Brix Id 50 thi dugc ddnfa gii thdp, d 55''Bx v i dO^Bx dugc ddnh gid eao hon. Cy thi la 3 raiu 60°Bx, 0,3%
pectin; 60°Bx, 0,2% pectin va 55°Bx, 0,2% pectin diu cd diem danfa ^ d cim quan eao, ttong dd mau cd 55°Bx, 0,2% pectin lgi ed diira cao nhdt, ddy li miu cd ti Ie phdi chi dudng ft hon nen raang lai gid tri kinfa te cao hem. Do dd, ndng dd 55'Bx se dugc chgn lim co sd cfao cic thi n ^ i | m sau. Ddi vdi ndng dg pectin thi d cung ndng dg dudng 55''Bx,
Tgp chi Khoa hgc TruangDgi hoc Cdn Tba Phdn B: Ndng nghiip, Thiiy sdn vd Cdng nghi Sinh hgc: 33 (2014): 110-115 gid trj c i m q u a n eua cdc mdu cd su khdc biet rd ret,
ttong dd d 0 , 2 % cd diira c i r a quan cao n h i t Tdm Igi d n d n g d o pectin 0 , 2 % v i n d n g do d u d n g 55°Bx cho diem edm quan v i trang thdi cao nhat v i cd ^ d ttj dO n h d t thiefa h g p kfadng q u i lodng ciing kfadng qud s e t
B a n g 3 : Danfa gid c a m q u a n giiia cdc m a u cd n d n g dg pectin vd dp B r i x k h a c n h a u Mau
55''Brix + 0, 50''Brix + 0, 55°Brix + 0, 60°Brix + 0, 50°Brix + 0, 50''Brix + 0, 60°Brix + 0, 60°Brix + 0, 55''Brix + 0,
, 1 % pectin , 2 % pectin , 3 % pectin , 1 % pectin , 1 % pectin , 3 % pectin , 3 % pectin , 2 % pectin , 2 % pectin
B i l m c a m q u a n t r u n g binfa 2,58'' 2,66'*
2,75'^
2,75"^
3,00*^=
3 , 5 0 ^ 3,58=
3,66^
3,75"
Ghi chu: cdc trung binh nghiim ihuc di kem v&i cdc chir gidng nhau khong co su khdc biit trin cimg mgl egt vdi mucy nghTa 5%
Ddc tinh ciia gel pectin ragnfa hay y l u phy thugc vdo miic do este hda. Pectin cd do metfaoxyl hda cao d u g c d u a vdo ttong thi nghiem nay la mdt ttong nhiing polysaccharides tao gel quan ttgng nhdt ttong thyc p h i r a . Pectin metlioxyl cao s l tao gel khi cd su h i l n d i l n ciia cac loai d u d n g hodc cdc hgp chdt hoa tan (nhu dudng, polyol, hogc rugu raonofaydric) va tai p H dii t h i p (3,0 - 4,5) (Oakenfiill v i Scott, 1984). Trong phdn t u pectin cd mang d i l n tich am n i n chiing cd kha ndng d i y lan nhau cd khd ndng lam gian ragch v i l i m t i n g dd nhdt eiia dung dich. D u d n g cd k h i n i n g faiit dm, vi v i y nd lira giam raiic do faydrat fada ciia p h i n h i pectin ttong dung d j c h . I o n H + tir acid ttong djch q u i trung fada cdc gdc C O O ' , ldra gidm do ticli d i l n cua cdc phdn hi. Vi vay, cdc phan tii cd the tiln lgi gdn nhau d l tgo t h i n h liln k i t ndi phan t u vd tao dg nfadt cho d u n g djcfa (Cliinachoti, 1995). Vai ttd ciia d u d n g ttong v i l e tao d d n g Id khii n u d c , gidm solvat hda cua cdc phdn tii pectin, phu thugc vao sd lugng vd c h i t l u g n g pectin rad diing lugng d u d n g khdc nhau. L u g n g d u d n g phdi ldn hon 5 0 % thi mdi cd khd n i n g tgo do nlidt cho d u n g djch. N l u hara lugng d u d n g cao qud cd t h i gdy k i t tmh dudng"
ttin be m a t hat keo hay ttong h e keo (Al-Ruqaie et ai, 1997). Djch budi sau khi l l n raen cd p H 3,94 vd d u g c phdi c h l t h i m sucrose dd tgo d i l u
k i l n thiefa hgp cfao pectin cd dp metfaoxyl hda cao tao gel.
3 3 Anfa h i r d n g cua n d n g dg acid citric phoi c h l d e n vi va m a u s a c ciia si rd b u d i t r o n g q u d t r i n h t d n trir
A n h h u d o g ciia ndng dp acid cittic phdi c h l d i n vi ciia sdn phdm
Vj eua siro Id sy k i t hgp hdi hda giOa vi nggt ciia d u d n g va vj chua ciia acid. CJ ndng dd d u d n g cd dinfa da kfaao sdt vd dugc chgn d thi nghi$m tten la 55°Bx thi vdi ti l l phdi che ndng do acid khdc nhau, k i t qua danfa gid cam quan v l vj vd mdu sac d u g c tfal h i l n ttong Bang 4 vd Hinfa I.
Bang 4 : 8 i e m d a n h gia cam q u a n ve v | giua c i c mau cd ti Ie phoi cfae acid citric kfaac nhau N d n g d o acid
citric ( % ) 0,2 0,3 0,4 0,5 0,6 0,7
Diem c a m q u a n t r u n g b i n h 2,37*=
3.00*^
3,12'' 4,12=
3,50'"' 3,12"
Ghi chu: cdc trung binh nghiem thuc di kem vdi cdc chU giong nhau khdng co sir khdc biii iren ci»ng mgl cgl vdi muc y nghTa 5%
K i t qua thdng k l cho thdy vdi ndng dg acid pfadi che tdng tir 0,2 -^ 0 , 5 % thi diera cam quan t n m g binh v l vj se tang d i n . Miic do c h i p nfain vj ciia s i n pfaim cao nfaat d ndng do 0 , 5 % va kfai vugt qua gidi hgn nay thi diera c i m quan gidm ddn.
D i l u n i y cho t h i y q u i rd rang, sdn pham si-rd edn pfadi cd vj cfaua nggt hai hda, s i n phira nggt nhung kfadng q u i cfaua mdi d u g c efaip nfadn cao.
Anh hudng cOa ti li phdi che acid citric den mdu sdc cHo si-rd trong qud trinh tdn trir
Trong sdn pfadm si-rd mau sac Id y l u td quan ttgng d e danh g i i c h i t lugng v i gid tti t h u a n g mgi ciia san phara. S y dn djnh mdu cua si-rd chju t i c ddng d nfaiiu mat, nd cd the bj anh h u d n g bdi cfainfa bdn tfaan nguyen lieu, eac t i c nfain vdt \y nliu dnfa sang, n h i l t dp va hda hgc nhu pH, cdc chdt tao phiic. Cac yeu td nay anii hudng d i n s u dn djnh m i u , vi v i y can chu ddng ttong v i l e lya chpn n g u y i n lilu, ttinh cac t i c hai ciia cdc tac n h i n b i n ngodi d l giii mau sac ciia si-rd tdt nhdt.
Tgp cbi Khoa hgc Trudng Dgi hgc Cdn Tha Phdn B: Nong nghiip, Thiy sdn vd Cdng nghi Sinb hgc: 33 (2014): 110-1 IS
0,4 0,5 N6ngd6 acid citric (%)
Hinfa 1: Dd thi bieu hifn diem cam quan mau sac si-rd theo tfadi gian tdn trir khi xir ly d cae nong do acid citric kfadc nfaau
Trong qud trinli bdo qudn si-rd, mau sac dugc quan sat qua cae tuan vi so sinh giiia cdc ndng dp kfadc nfaau. Sau khi chl biln, mau sic ciia si-rd it cd sy khdc bilt d cac ndng dp acid khdc nhau. Mdu cd ndng dg acid 0,5% duge danfa gia cao hon va cd sy khac bill so vdi cac raiu cdn Igi. Sau 2 tuan bao quan, mdu sdc cua si-rd khdng cd sy khdc bilt ldn, khi bao quan den tuan thii 3 ttd di thi gid tri cam quan vl mau giara xudng va khoing each chenh lech gid tri ngiy cdng Idn. Kit qui d Hinh 1 da cho thay, ddi vdi mau cd ndng dp acid 0,5% van dugc ddnh gid cao hon va cd diera cam quan cao hon cac mdu cdn lai trong suit qui ttinh tdn tru. Nfau vay, d raau sir dung 0,5% acid cittic dugc ddnh gia cao vl vj Cling nhu vl raau sdc.
4 KET LUAN
Sau klii len men, tien hdnfa khii vi ddng bdng en^me P-glucosidase d ndng do 1,4% trong 40 phiit se cho hieu qua khir dang cao. Tiln hanh phdi che nong do dudng 55''Bx ket hgp vdi ndng dg pectin 0,2% cho kit qud diim cam quan cao nhit vl ttang thii eiia san phdm. Si-rd budi cd cdn dugc phdi chl 0,5% acid cittic cho diira cam quan vi vj cao nhat vi giii dugc mdu sac eua si-rd d trang thai tot nhdt it nhit 4 tudn khi bio quan 6 nhilt dg phong.
TAI LI j:U THAM K H A O 1. Al-Ruqaie, I.M., Al-Ruqaie, Kasapis,
S.R.A, 1997. Structural properties of pectin- gelatin gels. Part II: effect of sucrose/glucose syrup. Carbohydrates Polymers, 34, 309-321.
^. Caldini, C , Bonomi, F., Pifferi, P.O., Lanzarini, G and Galente, Y.M, 1994.
Kinetic and iraraobilization studies on fungal glycosidase for ai'oraa enhancement in wine. Enzyme Microbiol. Technol. 16:
286-91.
3. Chinachoti, P, 1995. Carbohydrates:
functionality in foods. Am TCliii Nutr, ..-v^—
922s- 929s. " " ^ "" ''-'- '"^^ ^' 4. Davis, D.W, 1947. Determination of
flavonones in cittusjuice. Anal. Chera.l9:
46-48.
5. David, O andAlan, S, 1984. Hydrophobic Interaction ra the Gelation of High Metfaoxyl Pectins. Joumal of Food Science, V49, Issue 4,1093-1098.
6. Griffitii, F.P,1969. Process for reactivating polyaraides resins used in debittering citrus juice. US Patent 3,463,763.
Tgp chi Kboa hpc TrudngDgi hgc Cdn Tha Pbdn B: Ndng nghiep. Thiy sdn vd Cong nghi Sinh bgc: 33 (2014): 110-115 7. Kefford, J.F,1959. The cheraical constiments
of cittus fruits. Adv Food Res;9:285.
8. Kimball, D.A, 1987. Debittering of cittus juices using supercritical carbon dioxide. J.
Food Sci. 52:481-482.
9. Kimball, D.A, 1991. Citrus Processmg:
Quality Conttol Tecfanology. New York:
Van Nostrand Reinfaold.
10. Marwafaa, S.S., M. Puri, M. Bfaular and R.M. Kotiiari, 1994. Optimization of parameters for tfae hydrolysis of limonin for debittering of kinnow mandarin juice by Rhodococcus fascians. Enz Mlcrob Technol 16:723-7255.
11. Nguyin Diic Lugng, Cao Cudng, 2003. Thi nghiem Cdng nghe sinh hgc tap 1 :Thi n ^ l m Hda Sinh hpc. NXB Dai fagc Qudc gia Thanh phd Hd Chi Minli.
12. Puri, M. and U.C. Banerjee, 2000.
Production, purification and characterization of the debittering enzyme naringinase. Biotechnol. Adv. 18: 207-217.
