HOI NGH! KHOA HQC C O N G N G H f SINH Hp<
ANH HU'O'NG cCiA TifiN xCr LV NHIET, NONG B O MU6I VA BUONG TRONG DICH LEN MEN DfiN QUA TRiNH MU6l CHUA XOAl C A T CHU NON NGUYfiN TRAI
Trin Minh Duy, Tran Thanh TrOc, Nguyen V i n MirM Tnrdng D^i hgc Can Tha
T6M TAT
De t^i dugc thyc hi|n vcti myc tieu xac dmh mpt s^ y§u to chinh co anh hudng den qui trinh len men xoai non nguyen trdi, l^m co sft cho viec xay dvmg quy trinh ch^ biln, gop phin da dang hoa cac san ph3m muoi chua tren thj trudng. Noi dun§ nghien cihi bao gom:(i) Xdc djnh thdnh phan h6a hgc ciia nguyfin li^u; (ii) Khio sit sif tic dpng ciia qui trinh tiSn xii ly nhi^t c6 bo sung CaCl2 den vi^c cai thien clu trie cua sin phim xoii non len men; (iii) Xic dinh n^ng dg mu6i NaCl ban dSu v4 ndng dg du&ng thich hgp trong dung djch ISn men. Qua k6t qua ngbien ciiu cho thiy, trong xoai cat chu non co d$ DE thip (43,73% ± 0,02), ham lucmg dudng tfing sd va muoi NaCl trong nguy£n li^u khi thip. Vific tien xir ly nguyen lieu trudc khi len men trong dung djch CaCIi 0,5% d nhi^t d$
75 °C trong thdi gian 90 giay, sau do len men xoai non trong djch ngim co nong dg muoi NaCl 3,0% vi dudng sucrose 1,5% cho s^n phim d^t chit lu^ng tot sau 4 ngay len men. Mat so vi khuan acid lactic trong dich len men d^ cao nhit l i 17,5.10 cfii/mL, san phim cuoi cd ham lu^ng acid 1,59%, him lugng mudi 1,42% v i t y I? thay ddi dp ciing tuong ddi H/Ho Id 1,16 hay sy khic bi^tve cau true cua sin phim so vdi mau ddi chiing chi la 14%.
Tie khoa: dd ciing, dudng sucrose, len men, NaCl, vi khuin acid lactic, xoii non
Hi§n nay, xoSI cat du'ac trSng nhieu if cic finh a6ng bang song CCru Long v6i 2 dgng chinh 1^ xolii cat Hoa LOc tgp hung nhi^u d viing Tikn Giang, Can Tho va xoSi dt Chu & D6ng ThSp. & Vl§t Nam, xo&l dugc tieu thy vi xuit khau chu y^u d dang tirol vdri kh6i lu'Qng quS I6n va khdng cd cac ton thucng ben ngodi. Vi viy, 6k dam bao chat lu^ng trdi xodi khi thu ho9ch, vi^c cat tia xoai non thu'd'ng du^c tien hdnh li> 2 d4n 3 Ogt trong su6t thd'i ky phat trien, d|c bi$t ii xoai cii Chu. Lugrng xoai non tid di thuong chl^m mOt t^ ta^ng kha Icm vi cd gia tri sir dgng thap. Do dd, vi^c tan dung lugng mii non, xodi kh6ng du tieu chuin xuit khiu hay luqrng xodi thua sau tigu thg tual de c h l bi4n kh6ng nhung Idm da dgng h6a sSn phim md con gdp phin Idm tang thu nhgp cho cdc nhd vuon. Hi$n nay, dua xoai vln dang dugc sdn xuat vd tieu thy rdng rai tren thi trurimg vi dugc bdn if cdc siSu thi vd'i cdc thuang hl§u Id'n, cd nguon g6c tiJ huy§n Chg M6I, tlnh An Giang vd huy^n Lap Vd, finh Dong Thdp va rdi rac cac co so nhd khdc. Tuy nhl^n quy trinh chl biln vln dang Id bl quylt ci5a tCrng don vi san xuat, ding thol cdc sdn phim chi dugc chl biln theo huong sdn pham chua ngpt, bang cdch ngdm thim thIu bing nong d^ dud'ng rit cao 3 5 ^ 0 % , giiip dilu hda vi chua cua nguydn li^u vd kit hgp xi> t;^ cdl thien mdu sic, do gidn cda sdn phim bing hda chit. Vi§c nghiSn ci>u chl biln xodi non theo hud-ng len men lactic vSn chua cd cdng b l khoa hpc d Viet Nam. NghiSn cuu che biln xodi mull chua tren t h i giai duac tiln hdnh chu y l u d Thdi Lan (Yunchalad e( al., 2000), v6i nguySn lieu Id xodi xanh thuin thyc vd dugc len men ir nong dO muii cao, phi bien Id 10% vd thdi gian ISn men rat ddi, din hon 1 thdng; dong thd'i hdm lugng muli trong sdn pham cao, khong phil hgp thj hllu nguai Vi#t Nam. Vi Ihl, huong nghien cuu len men lactic tu nhiSn xodi cat Chu non nguyen trai duac tiln hdnh vdi cdc khdo sdt bud-c dau ve vi§c dilu khien tien trinh tien xir i^i nhiet nguy§n lieu cung nhu xdc djnh thdnli phin cCia djch ldn men thfch hgp giup tgo sdn phim c6 dgc tinh clu tnic tot, mui vi hdi hda, nham da dang hda ddng san phim cd pH thip cd trin thi tnrd'ng.
NGUYEN LI$U vk PHt/aNG P H A P N G H I £ N CLTU NguySn lifu
Xodi non nguyen liSu. giong Cdt Chu (20 ngdy tuoi) dugc thu hdi vd tri> mlu khoang 15*20 aid tai nha vucrn ir huven Lip Vd, tinh Ding Thdp vd dugc vdn chuyin ve phdng thi nghISm trong khoang 3 gi6. 6 phdng thi nqhISm xodi dugc phan logi sa bo theo kich 00-, lo?i bd nh&ng trdi qud to hay qud nhd, lua chgn cdc qud cd khli lu-gna trono kh'odno 100 + 10 g. NguySn li^u sau khi tuyen chpn dugc rua sgch, gpt vo vd tiSn hdnh thi nghi?m. -^ y a a Bo trf thi nghiem
Phan tich cic thinh phan cabin cua nguyen li$uxoii Cit Chu non
Thi nghldm dugc tiln hdnh nglu nhien vai nguon nguySn li?u xodi non dugc «iu mua 6 hj-na th6i rtiAm t h * ^ r,K,. • y™i sau khi dugc xCr ly tiln hdnh phdn tich cdc cht tiSu thdnh phan (dd Im. hdm lugng duang khu mud vT . H H h2^i. »„nJ vitamin C vd dd ester hda cua pectin) cd trong nguySn li§u. Cdc thao tac trong qua trinh xu ly v'dThdn t t h SisitTn h i S thgt nhanh d l b^nh cdc biln d l i xdy ra Idm thay dhi thdnh phin ly hda hpc cd thi gdy dnh hu^ng ain S t Qud Shdn Uch trong qu^ trlnh th( ngtii^m. " "
Thi nghiin 1: Binh gia hi^u qui cai thifn ciu true cua xoai non »i«ng qua lie a^g ciia „hiu ah „ i .h™ ™,»
chin bong nirOccAbi sung 0.i%CaCI, " ™ e ' ^ 9 va (fto, gian XoSi non sau khi x i 1> so b6, aifyc chta trong dung dich CaOi 0,5% (w/v) ft 4 mftc nhi»l at, khjc „ ! , . „ . . „ , ^ , SO-C ling v*L 4 mOc thcri gian khSc nhau t» 60, 90, 120 vS 150 giSy. Xpii sau khi chin a„„c ISm no,?fif \ ° L ? "^
each ngim vao niroc ii. sau S6 vdt ii rio tnrftc khi x4p vio keo do tien hlinh i6n men (d diiu ki6n „S . 7 1 J ? " ^ . 29±2-C) Thinh phSn ciia dich ngim c6 dinh gSm 3,0% mu6i NaCi va 1,0% di^ftng sucrose (phi„ tram tlnh th "^^ '
.. <HOA HOC C O N G N G H E SINH HOC T O A N Q U ( 5 C 2013
t^ 1$ cOa djch ISn men: nguySn lieu Id 1:1. D^ra trSn cdc thi nghiSm tham dd, xoai non nguySn hdi muli chua cd mi^i vi ddc trung cua sdn phim len men khi pH cOa dich ISn men hg thap hon 3,0. Do dd, theo ddi qud trlnh len men xodi non den khi pH dgt y^u d u . Ghi nhdn thd'i gian len men vd do dgc cdc chi tiSu chat lugng bao gom pH vd acid djch ngdm, acid vd hdm lu^mg muli NaCl trong san phim, su thay doi dd cung cua mlu xodi muli chua (H/Ho). TrSn co sd' dd, chpn lua chl dQ chin thfch hgp giup cai thipn d$c tlnh d u tiiic dia xoai vd qud trinh ISn men d^t hiSu qud.
nf nghldm 2: Tic d^ng cua nSng dg mu6i NaCI vi dudng sucrose trong dich len men den hiiu qui qua trlnh mu6l chua lactic xoii non
Khdo sdt dugc thuc hi#n gilng nhu thf nghiSm 1, Trong dd, xodi non sau khi chan vd'i nghl§m thtrc tot uu h> thi nghiem 1 dugc diuIn bj cho qud trinh ISn men. Tiln hanh thi nghi#m bang vipc su dung cdc dich ngdm cd ning dd muli NaQ (2.0%. 3,0%, 4,0% vd 5,0%; phan ham tinh theo w/v) vd dirimg sucrose (vd'i ning d$ 1,0%, 1,5%. 2.0%. 2.5%; phin tram tlnh theo w/v) vd'i tJ IS cOa dich len men : nguySn lipu Id 1:1, ISn men d' nhipt dp phdng. Dua vdo cdc chi tieu hda l#, d|c bi$t Id d$c tinh d u tnic va mat s6 vi khuin add lactic sinh ra Urong irng vol h>ng nghiSm thuc khdo sat. Xac djnh nwig dO muli NaCI vd ning dd dud'ng sucrose thfch hgp cho viSc ISn men lactic xodi non.
Cdc phuong phdp phan tich
Cdc chl SSu dugc phdn tich theo d c phuang phdp ting hpp trong Bang 1.
Bing 1. Phvcmg phip va thiet bi sir d^ing d4 phdn tfch cic chi tieu Chl tifiu Phuong phip
pH djch I6n men SLP dyng miy do pH Hana 212 (NMKL 179-2005) DO Im (%) Sly d nhi§t 30105 °C din khfii lugng khdng doi (AOAC 934.06)
Him lugng mufii (%) DCing phu-ong phip Mohr (AOAC 971.27). Si> dyng AgNOj chuSn (0,1 N) dfi phan ung het viri mufii cd trcKig dung djch trung tinh vbi dilt chi Vn\ KzCrO*
Him lugng add (%) DOng dung djch ki^m chuin NaOH 0,1 N dfi tmng hda hfit acid trong th^rc phim vdi phenollalein lam chi thj mdu (AOAC 942.15)
Him lugng dufrng hda tan (%) DOng phuvng phip phin tfch Lane - Eynon, dga vio tlnh chit khO oxy cua nhdm aldehyde hay cetone h/do cd hong phin ti> glucid dfi djnh lugng (Ranganna, 1986)
Him lugng vitamin C (mg%) Phuong phdp Muri (AOAC 967.21)
Od ci>ng (gt) SO dyng miy do d u ln:ic Rheotex, the hien d li/c d t . DOng mdy do Rheotex. Cat miu thinh cic khfii chO nhdt cd kich thudc 20 mm x 10 mm x 8 mm. Do igc d t mSu d phin sd ngang (chifiu cao 10 mm), d djnh dudmg dic£)a dao d t vao th|t qua Id 4 mm (Yunchalad etaf.. 2010).
DO ester hda ci^a pectin, DE (%) Phuong phdp chuin dd acid - baz (Food Chemical Codex.FCC, 1981; trich d§n boi Singthong et al., 2005)
M$t sfi VI khuin lactic (cfu/mL) SCr dgng ky thudt d y ling, dfim khufin Igc trgn mdi tardng th^ch MRS sau khi d vi hifiu khi d nhi^t dp 30 ± 1 °C trong 24 gid (Trin Linh Thudc, 2007).
Phuo'ng phdp thu th|p vd xi> ly so lifu
Thi nghISm dugc l$p lgi 3 lan. riSng thi nghldm xdc dinh thdnh phin nguySn IISu dugc tiln hdnh 10 lln. Dd 16n ciia mlu thi nghi$m Id 500g/mlu. S l liSu phdn tich tir cic thf nghiSm dugc linh todn thing kS bing chuong hlnh Statgraphics Cenhution 16.1, phdn tfch ANOVA vdi phSp thi> LSD d l so sdnh trung binh d c nghiSm thi>c.
K ^ QUA Vk T H A O LUAN
Xdc djnh thdnh phin hda hgc cua nguySn li^u xodi non
Thdnh phin nguySn liSu Id mOt trong nhO-ng y l u t l quan trpng quylt dinh din chit lugng sdn phim chl biln tij rau qua (Lu ef al., 2002). Chfnh vl vdy. viSc phdn tfch thdnh phin hda hgc nguySn liSu ban diu Id tiln d l cho vifc nghiSn ci>u d c tiln trlnh xi> l<^ vd che bien san pham h> xodi non dat hiSu qua. Kit qud phdn tich vd do dgc dugc t h i hiSn trong Bdng 2.
Bing 2. Thinh phin hda hoc trong 100 g phin i n dirge cua xoai Kit qua ting hgp d Bdng 2 cho thiy xodi non
" ° " hlu nhu khdng cd sg hi§n dISn cua ducrng trong nguySn liSu ban diu trong khi dd hdm lugng acid lgi rit cao (5.31%) ~ day Id khd khan diu tiSn cho qud trinh ISn men lactic. VI vdy, wSc bo sung mgt ty IS dudng thich hgp d l thuc dly qud trlnh ISn men lactic Kr xodi non Id d n thilt. Hdm lugng dudYig ^fch hgp cho muoi chua vao khoang 1 + 3%, (Trin Minh Tdm. 2002;
lUlcCreight et al., 1978). Tuy nhiSn, d l dam bdo ngdn d n d c vi khuin ISn men thoi hogt dOng, viSc si> dgng hdm lugng mull NaCI trong djch ISn men I6n ho'n 2,0% Id didu d n dugc quan tam (Tran Minh Tdm. 2002) do hdm lugng muoi nguySn liSu rat thdp (0,24%). Ben canh do, frong xodi Cdt Chu non d dd DE thip (43,73% ± 0,02) vd thu$c nhdm rau qud d dd methoxyl hda thip. Vi vdy, viSc bo sung ion Ca^* trong qud trinh c h l biln dugc nghT den nhu gidl phdp hiiu hieu trong viSc cdi thiSn dg cirng chac cua d n phim. Do xodi nguySn qud cd kich cd' Idn, qud trlnh chin nguydn lieu d n duac thgc hiSn nham gia tang hieu qud ngim Ca^* vdo t l bdo.
Thdnh p h i n DOlm Acid tfing sfi Vitamin C Mufii NaCI Dudng hda tan DO ester hda cda pectin. DE
Don v[
% %
mg%
% %
%
Gidtn 90,08 ±1,12
5,31 ±0,44 19.68 ±4,55 0,24 i 0,03 Vfit 43.73 ± 0.02
HOl NGHI KHOA H O C C O N G T l G n r g l R f f f l ^ ..__
Anh hifdng nhi#t do vd thd'i gian c h i n co bo sung 0,5% CaClj trong nip^c chan den d u tnic san p h i m xodi non muoi chua nguyen trdi
Qud trinh chin dnh hud'ng d i n t l bdo nguyen liSu. Idm thay dli tlnh chit keo cua protein hong chit nguySn ^ " ^ ^ thdnh t l bdo cua te bdo nguySn liSu, ldm m i l tfnh chit bdn Ihim cOa ttidnh t l bdo. DiSu ndy dSn den sg "^^ , J ^ " - ^A thdnh phin dich trong t l bdo ra mdi trufirng ISn men, day Id Itidnh phin dinh dirong gidp cho vi khuin lacfic stf ag g thgc hiSn qud Wnh ISn men (Fellow, 2002). Theo dd, qud hinh ttiam thau Ca^ vdo trong nguySn H#u nhanh " ^ j " . ^ " g qud trinh chin khi chin vdi thd'i gian vd nhiSt dd Uifch hgp. TrSn eg sd dd, thf nghiSm dugc tiln hdnh nham knao sai anh hudng cfia nhiSt dd vd thcri gian chin d b l sung 0,5% CaCb (tin chit lugng cua sdn phim sau d n g .
Hlnh 1. Anh huong cua nhift dO vd thd') gian chin dan chit lugrng xoai non muoi chua (a): pH d a djch ldn men (b): Hdm lugng i acid d(ch, %w/v (c): Hdm lugng add trong sin pham sdn pham (%w/w) (d): Ham lugng muoi NaCI tnmg sin phim {%w/w) (e): Bo cdng | tuong doi cila sin phfim (H/H>, vdi H i i dO ci>ng cCia mlu khao sdt va Hg l i dg cung cGa nguyfin liOu xodi ban diu)
Kit qud khdo sdt cho thiy, d su gidm din pH cOa dich ISn men cung nhu sg gia tang ham lugng add b^ng djch ISn men theo thdi gian muli dua d tat cd d c mau khdo sdt (Hinh l a vd lb). Sau 4 ngdy ISn men d nhi|t dd phdng, gid hi pH cua t i t d nghiem thiic diu thap. Xodi dugc chin d cCing mOt nhiet a$ nhung th&i gian chan d n g kSo ddi thi pH thu dugc d n g thip, ham lugng acid trong djch ISn men cdng cao Dieu ndy c6 Uie gldi thich Id do qua trinh xO ly nhiSt ldm tilu digt mOt s l vi sinh vdt trfin b l mdt sdn phim, dong thdi thay dli d u hijc nguySn ligu giup gia tang t i c dg thim thIu, cdc thdnh phin dinh dudng d l hda tan vdo djch ISn men, do dd tao dieu kiSn Uiudn Igi cho qud trinh ISn men (McFeeters et aL, 1985). BSn canh dd. su gia tdng nhiSt dd vd thdi gian chin cdn thCic day sg tham thIu cua muoi trong djch ngdm vdo trong nguySn li#u, ham lugng muli ngim vdo hong san phim cdng nhilu (Hlnh Id).
Xdt ve sg thay dll ddc tinh d u trCic xodi non mull chua. khdo sdt cho thiy, qua trinh ISn men lam cho mieng xodi mit dO gi6n. Uil hiSn d gid tn Igc cat cao hon klii so sdnh vdi mdu xodi nguydn ligu, ndi cdch khdc ty IS dd ciing tuong dli H/Ho d a sdn phim gia tang (ldn hgn 1). O l thj d Hlnh 1e cho thiy. d cung mdt nhiSt dg «ln xi> ly, thdi gian gia nhi^
ngln (60 gidy), gid trj HMo thu dugc Idn khi so vcri mlu chan d d c miic thdi gian cao hun; tuy vgy, khong d su khdc bISt ldn v l dd ciing tuomg dli a cung mOt nhiSt dg khdo sdt khi ttidi gian chin tdng tir 90 din 150 giay Khi xSt d d n g met mdc thdi gian, gid tn H/Ho giam din (tiln v l 1) theo nhiet dg tien xii iji tang din. Mac dii vgy. d$c tinh d u tnJc d a xodi mull chua hKmg iing vdi d c mlu dugc tiln xd i'jf a nhiet dO 75 vd 80-c vd thdi gian tu 90 din 150 gidy duoc duy tri tot nhlt vd khdng d sg khdc bi#t.
Tuy nhiSn d nhiSt dd 80 "C vdi thdi gian chin 150 gidy cd hdm lugng mu6, cao gdy vi man cho sdn phim. Dga frSn d c kit qud ttiu nhdn v l su thay dli tmh chat hda ly cua xodi sau qud trinh len men (Hlnh 1) vd kit qud ddnh aid d m quan (sl Sgu khflng dugc t h i hiSn). dilu ki§n t i n xd ly xgdi non W ^ " / " - ™ , nh'^^^^^^ , ^ ^^^^ ^ 75^C vd^ hdTgTangia nhigt 90 gidy id thdng s l thfch hgp dugc lua chgn cho khdo sdt xdc djnh ttidnh phin djch ISn men tilp thg™
Anh hifdng cua n i n g do difdng sucrose va m u l i NaCI trong djch ngdm d i n c h i t lifgng sdn phim xodi non nguydn trdi m u l i chua
.-HOA HOC C O N G N G H E SINH HOC T O A N Q U 6 C 2013
Hlnh 2: Anh hudng ciJa nong dd NaCI vd ning d$ sucrose dfin chit lugng xoai non mull chua (a) Hdm lugng acid trong djch lin men (%. w/v) (b) Hdm lugng acid hong sdn phim (%w/w) (c) Him lugng mudi NaCI trong sin phim (%.w/w) (d) Dg cdng tuong dfii H/Ho cita sdn phim (vdi H Id dO ciing cda mlu khio sat vd Hg l i dd ciing ciia nguyen iigu xoii ban dfiu)
B i n g 3. Anh h u d n g c&a n i n g d $ m u l i E^chlgnmei
Nfing d$
m u & ( % )
3,0
4.0
5,0
Nfing dd dudng {%) 1.0 1.5 2,0 1.0 1.5 2.0 1.0 1,5 2,0 1,0 1,5 2,0
N g d y l
1,52 2,31 1,98 1.60 2.53 2.69 2.30 2.36 2.08 2,41 2.30 2,46 1,53 1,69 2,13 2.34
NaCI v i d u ^ n g sucrose O&n sw Mdt sd lactK (kig chi/mL) N g i y 2 3,15 3.88 3.37 3.55 4.06 4.17 3,92 3.88 3,99 4.02 3.95 3,93 3,51 3,45 3.67 3,62
Ngdy 3 6,09 6.88 6,32 6.37 6.74 6.97 6.56 6.13 6,64 6,84 6,83 6,77 6,32 6,69 6,50 6,12
thay doi m f t s l
Ngay 4
6,52 7,06 6.90 6,93 7.01 7.24 7.08 6.77 6.99 7.02 7.16 7.06 6,73 6,86 6,96 6.82
lactic theo ttidi
N g i y 5
5.94 6,62 6.11 6,34 6.73 6,94 6.82 6,04 6.54 6,65 6,75 6,85 5,90 6,16 6,26 6,46
gian l i n m e n
Ngay 6 4.74 5.97 4.03 4,75 5.76 5.87 4.99 4.39 5.67 5,16 4.96 5,55 4,86 4,95 4,11 5,50
Qua bilu do Hlnh 2 cho Uily dng vdi sg thay d l i ning dd acid trong dich ldn men tti) hdm lugng add tong san phim cGng ttiay dli theo d c ning dd muli ngdm khdc nhau. Ldn men xodi trong dung d j d 2.0% muli NaCl tgo nong dO acid djch thip trong khi hdm lugng acid trong san phim lgi cao. Dilu ndy Id do khi nong d$ muli thip kha nang ISn men y l u vd khfing tgo dirge dp suit thim thIu cao nen ham lugng acid ttong san phim cdn nhilu. Ngugc lgi. d ndng dd muli bong djch ISn men cao (5% NaCI) d o ning dg acid bong djch cao nhung hdm lugng acid trong d n pham thip. NguySn nhdn Id do ning dd muoi cao t^o dp suit tham thau ldn nSn uc chl vi sinh vgt trong dd d vi khuin lactic, ldm ch$m sg phdt ttien vi khuin lactic vd chfnh vl vgy ham lugng acid lade hinh thdnh ttong sdn phim ttilp (Buescher e( al., 1979).
Lugng muoi ngim vdo trong sdn phim dugc cho Id d dnh hudng den d u tnic sdn phim (McFeeters ef al., 1989).
Chfnh vi vgy, viSc do dgc d u tnic san pham cung dugc ttigc hign ngay sau qud trinh ISn men. Sau thdi gian ISn men phij hgp, d u tnic d a sin phim tiiu dugc ung vdi d c nong dd muli, dudng len men khdc nhau Id khdc bigt d •) nghia.
Clu tn^c d a d n phim d j u dnh hudng bdi hdm lugng I m trong san phim. Ding thdi, d u tnic cung chju tdc dfing d a ning dfi muli trong sdn phim. LSn men trong dung d j d d ning dfl muoi 2,0% vd 3.0% muli d o d u ttdc san phim t i t hon vd d sg khdc biSt y nghTa so vdi d c mdu ISn men d ning dg muli cao (4,0% vd 5,0% muoi) Id do hdm lugng muli ttting d n phim anh hudng den d u tnic d a d n pham. Khi lugng muli ttilm Uilu vdo d n phim nhieu se gdy tin ttiucmg nhilu den t l bdo d a xodi. ddn din d u ttiic dai hon. LSn men d ning dg mull 3.0% d o d i t lugng ISn men t i t vd d u tnJc tot.
Vi$c kilm b^ mgt s l lactic theo tiing ngdy ISn men la-mfit thdng so quan ttgng d l ddnh gid chlnh xdc higu qud qud ttinh ISn men. Mgt s l lactic d n g cao chiing Id qua ttinh ISn man d n g hiSu qud. Kgt qud bdng 3 d o ttiay sau 4 ngdy ISn men d ning dfi 3,0% NaCI vd 1,5% sucrose cho mat s l lactic cao nhlt (7,24 logdu/mL). Qua khao sdt d o ttily, miu ISn men vdi djch ngdm d nong dfi NaCl 3,0% vd sucnase 1,5% ttii hi^u qud ISn men cao nhlt do mdt s l lade sinh ra cao nhlt, hdm lugng acid vd lugng muli ngim vdo trong d n phim dgt gid tri tot va d u true t i t vd dgc bifit vdi t& hgp ning dfi muli dudng ndy cho kit qud ddnh gid d m quan tot hon so vdi d c nghiem thiic d n lgi (so lifiu khdng dugc t h i hifin).
VI vfiy. ddy Id t l hgp ning dfi muli vd dudng t l i uu su dgng d o qud trinh ISn men.
K^TLUAN
HQI NGHI KHOA HOC CUNO NGHE SINH HQC
' ^ ! L ? ' ' l r * " ^ ' ^ * ° " " ^ . ' I T * * " " ' * " • * * " * " " * "« ™ °C irong thfti gian 90 giay c6 bS sung 0,5% CaClj vao
" ^ * 4 n giup nang cao cliat t ^ n g (ate tfnh ciu tnic. c i m quan cao) cOa S ^ phim x o " CH Chu non ngus-Sn tra, i - S . ^ H " " ^ ' ' ^ i ' ^ " ^ " 1 " ? " ' 9 " " " 9 " I " * "=« "*n9 i « mu6i NaCI 3 0 % kit h<,p vfti 1,5% ' » « = ^ T ^ f ^ ° . f ' ? T ^ ^ "V?^:^^- * ''*"9 ao muii nay, qua Mnh muii chua x o i nm. kit thSc ft nga, i i n men Ihu^ 4 dat mat so lactic cao nhat 17,5.10= cfuftnL va co <Jw: miii v| dac tnmg cua san phim muii chua v i d w c ngu*l
tieu dung u a t t i i d . '^
TkA L I E U THAIM K H A O
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EFFECT OF MILD HEAT PRETREATMENT, SODIUM CHLORIDE & SUCROSE CONCENTRATION IN BRINE SOLUTION ON PREMATURE GREEN MANGO FERMENTED PROCESSING
Tran Minh Duy, Tran Thanh True, Nguyen Van Muoi C a n Tho UniversHy
This research aimed to determine major elements affecting on premature green mango lactic fermented processing- by product source to produce hictic fennented product, to utilize fermented product on market The research conducted witti two experiments (i) hivcstigate effection of mild heat pretreatment combmed wiUi the addition of CaClj on texture charactraistic of product, and (ii) Determine suitable sodium chloride and sucrose concentration in mitial brine solution of fermented processmg. Results of research shows ttiat, DE degree in premature mango was about (43,73% ± 0.02). total sugar and sodium chlonde concentration in material was rattier low. TTie best quaUty of fermented green mango was obtained by applying the mUd heat pretreatment at IS'C for 90 s in the solution of 0.5% CaClj before brining m ttie solution of 3.0% sodium chloride and 1.5% sucrose during 4 days Uctic acid bacteria density in final brine sohitira obtained the highest density was 17.5x10* cfii/mL, lactic acid concentration m '* — was 1.59%. and NaCl reached to 1.42%. TTie relative hardness H/H„ of product was 1.16 or ttie difference of texture between product and the control only 14%.
Keywords: fermentation, green mango, hardness, lactic acid bacteria, sucrose, NaCl
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