KHOA HOC CONG NGHE
il\iGHlEl\l CLHJ LnXIG DUIVG CdlXlG IMGHE BAD QUAIXI q U A V A I THIEU B A I V G P H U O T V G P H A P KIEIVI SOAT KHI
OUYEIXI [CA - COIVTROLLED ATMOSPHERE)
Pham Anh T u i i S Pham Thi Thanh Tliih T(:)MTAT
Muc tieu cua nghien cuu M xac dinh mgt sd dac tinh sinh Iy va su bien doi sinh hoa cua qua vai tiiidu trong mdi tiudng kiem soat khi quyen (CA), lam ca sd de xay dung quy tiinh cong nghe bao quan vai tfndu bang phuong phap dieu chinh khi quyen (CA). Noi dung nghien cuu thuoc de tai ti-ong di^m cap Bd NN&PTNT
"Nghien cihi cong ngh€ va thii't ke, che tao he thdng thiet bi dieu chinb khi (CA - Controlled Atmosphere), ling dung trong bao quan mot sd loai rau. qua, hoa tuoi" (2011 - 2013). Nguydn Ueu thi nghiem la gidng vai thi^u Thanh Ha ti-dng tai huyen Luc Ngan, tinh Bic Giang. Cac thuc nghidm don va da yeu td duoc tien hanh ti-en he thdng thiet bi thi nghiem CA da chiic nang la san pham ciia de tai, cd flie dieu khien giam sat dugc 4 tiiong so vdl dp chinh xac cao (nhifet dp ± O.S^C, dp am ± 2%, nong dp khi Oji 0,5%, ndng do khi C02± 0,5%).
Tir ket qua tdi uu hoa da xac dinh duoc che do bao quan CA thich hop vdi nhidt do 4,35 ± 0,5'*C, ndng dp khi O2 4,21 ± 0,5%. ndng do khi CO2 7,0 ± 0,5% va do am 90 ± 2%; sau 35 ngay bao quan qua vai tiiieu Luc Ngan dat yeu cau chat Iugng cam quan, dinh duong va co Itha nang duy tri chat luong thuong mai d di^u Iddn bao quan lanh 4''C dugc 3 - 5 ngay.
Tir khda: KiSm soat khi quyen, nong do khi oxy. nong do khi cacbonic toi uu hoa, vai thieu.
l.DATVANDE
Vai thieu cd tdn khoa hpc litchi sinensis, duoc trdng phd bi^n trdn the gidi la loai qua chua nhieu chat dinh dudng cd vi ngot dam, thom ngon. Huyen Luc Ngan li noi trdng vi tieu thu vai thieu ldn nhat ca nuoc vi la loai qua dac san ndi tieng. Tuy vay vai thidu la loai qua cd miia vu thu hoach ngdn va rat khd bao quan ma nguydn nhan dan den su hu hdng nhanh vdi qua vai thidu la do su bidn ddi sinh ly, sinh hda sau thu hoach cimg vdi su giy hai cua vi smh vat.
Theo Ooubert, 1986) vai thidu la loai qua hd h i p khdng dot bien va khdng cd thdi gian chin sau thu hoach. Tuy vay theo Akamme va Goo, 1973, Scott va cs, 1982 thi d giai doan phat trien cua qua, cudng dp hd hap giam nhung khi qua chin trong qua trinh tdn trii d dieu kidn thudng, cudng do hd hap tang rat manh, ddng thdi vdi su mit nudc va nau hda vo qua do cac enzym oxi hda hoat dpng manh lam phan hiiy va bien ddi cac Ihanh phan smh hda va chat lugng cam quan. Mat khac theo Scott vi cs, 1982; Jiang va Fu. 1999a. 1999b; Holcroft va Mitcham, 1996 ckc tdn thuong ca hpc, tdn thuong lanh, bi tac nhan gay benh hoac vi sinh vat tan cdng cung la nguydn nhan thuc day qua tiinh nau hda.
Theo Huang va cs, 1990 thi nguyen nhin n§u hda cung cd the do bi sdc nhiet, siu bdnh hoac sugii hda cua vd qua.
De ban chd sir nau hda vd va cuong dd hd hap ciia qua vai ciing nhu su gay hai cua vi sinh vit tiong qua trinh tdn trii, cac phuong phap dang phd bi&
hidn nay chu yeu bing bao quan lanh kdt hgp sit dung hda chat nhu xdng khi SO2. cic dung dich Topsin-M, benlat, cacbendazim, bendo kdt hgp atonic, dung dich NaHSOs 6% v i dung dich HCI 4% ...
qua dd cho thiy con nhidu rui ro tidm an giy h?u den siic khde con ngudi.
Cdng nghe bao quan rau, hoa, qua tuoi bjng kiem soit khi quy^n (CA) la mgt phuong phap vit IJ an toin, da va dang duoc ung dung pho bidn ff cac nud'c tidn tidn. Trong pham vi bai bao nay gidi thi^u ket qua budc dau vd thuc nghidm khao sat vi toi iru hda che dp bao quan qua vai thieu Luc Ngan d quy md phdng thi nghidm.
1. NGUYEN UEU VA PHUDNG PHAP NGHIBU CUU 2.1. Nguydn lidu
Gidng vai thidu Thanh H i dugc trdng tai huy$n Luc Ngan tinh Bic Giang. Thdi diem thu hii 80 - 85 ngay sau ngiy diu qua, mau sic vo qua da chuydn ti vang sing sang dd 1/3 didn tich qua.
Vi?n Co dign Ndng nghiep va CNSTH
-^ NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 8/2014
KHOA HOC C O N G NGHl
22. Fhiiong p h ^ nghidn cuu 2J.1. Thidt bi sir dtmg
Hd thdng gdm 9 budng CA (hinh 1) dung tich 90 lit/budng cd thd didu khidn giam sat bing hd PLC kdt ndi may tinh trung tam, cap nhat, luu trir va m an sd lidu thi nghidm vdi 4 thdng sd chinh cd dd chinh xac cao (nhidt dp ± 0,5"C, dp im ± 2%, ndng dg khi O2
± 0,5%, ndng dp khi CO; ± 0,5%,) v i hien thi giim sat canh bao ndng dd khi C2H4 vugt q u i gidi han. Ngoii ra hd thdng cd 01 budng ddi chiing khdng dieu chinh khi cd thd didu khien giim s i t 2 thdng sd (nhidt dp, ddam).
Hinh 1. Hd thdng thidt bi Ihi nghidm CA Vdi thidt kd niy hd thdng cd the thuc hidn ddng thdi 9 thi nghi§m phii hgp vdi, kd hoach thuc nghidm da ydu td (nhidt dd, ndng do khi O2 v i ndng ddkhiCOa).
2.2.2. Phuong phip nghien ciiu thuc nghiem a. Thuc nghiem don ydu td anh hudng ciia ndng dg khi O2 v i ndng dp khi CO2 den chat lugng v i thdi gian bao quan: Tidn hanh 02 nhdm thi nghidm gdm:
(i) 04 tiii nghidm cd ky hidu (Vn, V12, V13, V,,) khao sit inh hudng cua ndng do O2 thap trong mien bien tiiidn 2 -5- 8% vdi budc nhay 2%; (ii) 04 tiii nghidm cd ky hi^u (V2i,V22,V23. V24) khao sat anh hirdng cua ndng do CO2 cao trong midn bien thidn 3 ^ 9% vdi budc nhay 2%. Chuan bi 8 miu nguydn Udu vai thidu (5 kg/miu) dugc sa chd v i xii ly trudc bao quan theo quy tiinh {Tuan P. A, 2013). Ddng thdi tidn hanh 01 thi nghidm ddi chiing khdng didu chinh khi ff)C) d cung chd dg bao quan (4 ± 0,5"C, dp am 90 ± 2%).
Thdi gian khao sit li 24 ngiy vdi chu ky lay miu phin tich chit Iugng 6 ngay/lan vdi cic chi tidu chat lugng Ii ham Iuong dudng tdng sd (%), him lugng axit hiiu co tdng sd (%) v i chat Iugng cam quan (didm).
b. Thuc nghidm da ydu td anh hudng cua (nhidt do, ndng do khi O2, ndng dg khi CO2) ddn ch^t lugng
qua vai thieu: tuong ung 3 ydu td thuc nghidm vdi nuen bidn thidn Ii kdt qua tir nghien cuu tdng quan v i thuc nghidm dan ydu td voi ky hidu: Xj- nhiet dO, Xa - ndng do khi Oj, X3 - ndng dO khi CO2. Md hinh ihuc nghidm (2^ cd lap lai tai tim gdm 9 thi nghidm TT^„. TN12. TN13. TNi^. TN15, TNie. TT^,7. TNia. TN^^.
Cac him muc tidu cua md hinh thuc nghiem Yi - him lugng dudng tdng sd (%), Ya - him lugng axit hiiu ca tdng sd (%), Y3 - chat Iugng cam quan (diem). Chuan bi miu nguydn lidu vai thidu, dugc sii dung quy trinh sa chd va xii Iy nguyen lieu ciia Tuan P. A , 2013 viA khdi lupng 5 kg/miu. Danh gia chat lirgng bing mdt lan sau 35 ngay bao quan CA.
2.2.3. Phuong phip phan ti'ch dinh gii chit luong san pham
a. Phuong phip lay m i u q u i tuoi theo TCVN 5120 - 90.
b. Dinh gii chat lugng cam quan bing lip hgi ddng cham didm vdi 4 chi tieu dugc lua chgn la: miu sic, miii, vi va trang thii, dinh g i i ridng re theo thang 5 didm, diem cao nhat l i 5, diem thap nhat li 1.
Tuong ling hd sd quan trgng d i dugc hgi ddng xac dinh: Man sic (1,2), miii (0,8), vi (0,8), tiang thai (1,2). Mirc xdp loai theo tdng diem: tdt (18,2 - 20), k h i (15,2 -18,1), tinng binh (11,2 -15,1), kem (7,2 - 11,1); hdng < 7,1. Xac dinh him lugng dudng TS theo TCVN 4594-88. Xic dinh h i m lugng axit huu c a TS tiieo TCVN 5483-91.
2.2.4. Phinmg phip xu Iy sd liiu
Su dung phan mem Design - Expertversion 7.1 dd xir ly sd lieu thuc nghiem da yeu td v i tdi uu md hinh thuc nghiem theo thuit toan him mong dgi.
3.KFrQUliVAT11A0UMN
3.1. Anh hudng cua ndng dg khi O2 th^p ddn ch^t lugng q u i vai thidu
3.1.1.. Bien ddi ve ham luong dudng tdng sd Quan sit tai hinh 2 cho thay him lugng dudng tdng sd trong nguyen heu ban dau li 15,8% cd xu hudng ting d- tat ca cic thi nghidm trong qui trinh bao quin, dac biet manh nhat la thi nghidm DC, didn bien nay la do him luong nudc ban dau tiong nguyen Ueu cao, su mat nudc tiong qui trinh hd hap din ddn him lugng dudng tdng sd ting, tuy vay vdi cic thi nghidm ndng do khi O^ thap cd bidn ddng it hon so vdi thi nghidm ddi chiing (DC). Cu th^ voi ndng dp khi O2 tir 2 ddn 4%, him Iuong dudng tdng sd tang
KHOA HOC CdNG NGHE
Idn khoang 17,1 -17,3% sau 24 ngay bao quin, trong khi vdi miu DC tang den 18,5%. Didu nay chiing td trong mdi tnrdng khi O2 thap cd kha nang han chd cudng dd hd hap nen giam miic mat nuoc cua q u i vai.
quan giam it ti-ong 12 ngiy dau bao quin, tuy nhidnj V,3 bat diu giim manh ban tir ngay thii 12 den ngiy;
24, trong khi cic thi nghiem V„, V12 vin duy tii kha dn dinh 17,8 -18,2 diem sau 24 ngiy bao quan. So v^
miu DC tir ngiy bao quan tiiii 12 den ngay thii 24, ' didm cam quan giim vdi tdc do nhanh hon ca tu 173 diem xudng 13,5 diem. Qua do chung ta tiiay tac dgng cua ndng dp khi O2 thap l i kha rd ret den chat lupng cam quan, do lic chd dugc cudng dp hd hap, han chd dugc su mat nuoc va hoat tinh cua enzim la nguydn nhin din den su nau hda vd qua.
3.1.2. Bien ddi ham luong axit huu cu tdng so Quan sat tai hinh 3 cho thay, ham lugng axit hiiu ca tdng sd tiong nguyen lieu ban dau la 0,38% co xu hudng giam d tat ca cac thi nghiem theo thoi gian bao quan, tuy vay miic giam la khdng ldn ddi voi cac thi nghiem cd nong dd khi O2 thap (0,3 - 0,32%) so vol DC miic giam Ion nhat (0,24%). Dieu nay co the ly giai song song vdi qua trinh hd hap la su mat nudc da din den ham lupng duong tdng sd tang va !iam luong axit cung bl anh huong tang, tuy vay thuc te ham luang axit hiru co tdng sd giam chung to qua trinh bidn ddi smh hda didn ra kha manh din den su tieu hao axit hiiu ca tdng sd oing nhu mdt phan la dudng tdng sd cung bi mat ti'ong qua trinh chuyen hda tao ra cac hgp chat hiiu co mdi. trong. dd cd nhiing chat thom dd bay hoi. iyj QAHT AV AUD T3)l .S nab 9 .", . . £ 0 3 ,> ,
' » ^ — • : t ! " = ^ - - r ^ - -^.•,
^ys\y> •,v.\',^'>\ ^uwV"^TT-rw4i>
0 b 12 18 24 Anh VZ
—•—DC - • - - V I I V12 VI3
^4t~V14 Ngay
•' -Wh
Hmh 3 3.1.3. Bidn ddi chit luong cim quan Quan sat tai hinh 4 cho thay, chat lupng cam quan cd xu hudng giam d tat ca cac thi nghiem, trong dd Vii, Vi2va Vi3 vdi ndng dd khi 0^ tir 2 ddn 6% cam
ijjidb nj ) ^rl • o
" - < ; ; • ——' — _ _ .
" ——.^ -»
V^ ^
»
- » — D C - • - V 1 1 V12
— V13 V14
12 18 24
Hmh 4
Ket qua thuc nghidm niy budc dau cho thay hieu ung tich cue trong mdi trudng cd ndng dp khi 0;; thap den su bien ddi chit lugng qua vai thieu Luc Ngan trong qua trinh bao quan, thong qua su bien ddi cac chi tieu sinh hda va chat lugng cam quan.
Qtia do cd the gidi han mien bien thidn ciia ndng dO khi 0^ thlip trong khoang 2% < N^j < 6% la cd kha ning duy tri chit Iugng va keo dii thdi gian bao quan qua vai thidu, H-:;
^^ 3.2. Anh hudng ciia ndng dp khi CO2 cao d&
chat lugng qua vai thidu
3.2.1. Bien ddi ham luang duong tdng sd J ,r!i Quan sat tai hinh 5 cho thay, ham luong duong
tdng sd tang din theo thdi gian bao quan, tdc dd ting giim khi ndng dp khi CO2 tang, dieu niy chung to ndng dd khi CO2 cao cd kha ning uc che qui trinh hd hap din den Iam cham qua trinh chuyen hda va str mat nudc. Cu the ham luong dudng tdng sd ban dau la 15,8%, sau thai gian bao quan 24 ngiy ting ldn 17,9%, 17,3%, 17,0% va 16,8%. Tuy nhien vai tiii nghiem V21 him lugng dudng da tien den miic khi cao (17,9%) cd the du doin kha nang suy giam c h ^ luong sd sam hon so vdi cac thi nghidm cdn lai. t
30 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 8/20U^
KHOA HQC C 6 N G NGHE
-oc
-V21 V22 - V 2 3 V24 ngSy
HinhS
3.2.2. Bidn ddi ham luong axit hiru catdngsd Quan sat tai hinh 6 cho thay ham lugng axit huu , ca tdng sd cd xu hudng giam dan theo thdi gian bao
quin b tit ca cic thi nghidm vdi ndng do khi COg cung nhu thi nghidm DC, ndng dd khi CO2 cang cao thi him Iugng axit hiiu ca tdng sd giam cang it va ngupc I^i. Cu tiid sau 24 ngay bao quan, ham lupng axit hiru co tdng sd ban dau tir 0,38%, giam dan xudng 0,27%, 0,29%, 0,31% v i 0,33% tirong irng cic tiii nghidm V2,, V22, V23, V24. Trong khi vai miu DC thi miic giam hiirt Iugng axit hiiu ca tdng sd xudng thap nh^t li 0,24%. Kdt qua dd cho thiy kha nang kim ham su chuydn hda m ^ h nhat la thi nghidm V24 tuang ling ndng dO khi CO2 cao nhat li 9%. Di^u nay cd the luin giai vdi ndng dd khi CO2 cao ciing cd kha ning kim him qui trinh bidn ddi sinh hda nhu ddi vdi mdi tiifdng cd ndng do khi O2 thap.
* 0 Ngiiy
Hinh 6 3.2.3.. Bidn ddi chit Iuong cam quan Quan sit tai hinh 7 cho thay chat lupng cam rjuan cua qua vai thidu suy giam theo thdi gian bio r|uan b t^t ca cac thi nghiem, tuy viy miic suy giim la khac nhau. Cu the cac thi nghidm V21, V„ V23 tuong img ndng dO CO2 3 ddn 7% cho chit lugng cam quan :ao hon so vdi V24 (9%) va miu DC sau 24 ngay bao iuan. Didu nay chiing to tic dpng cua ndng dp khi
CO2 trong khoang 3 den 7% cd kha ning lic che q u i trinh hd hap, giam su mat nudc v i boat tinh cua enzun do do cai thidn duac chat Iugng cam quan, mit khic vdi ndng do khi CO2 cao hon (9%) cd the din ddn su rdi Ioai sinh Iy din ddn su bien ddi chat lugng cam quan theo chieu hudng khdng mong mudn.
S. 18 I 17
^ V ~
Hinh7
Ket qua thuc nghidm niy cho thay trong mdi trudng cd ndng do khi CO2 cao ciing cd tic ddng dang kd den su bien ddi chat lugng cua qui vai thidu Luc Ngan tiong qua trinh bio quan, thdng qua cic chi tidu sinh hda vi chat lupng cam quan. Qua dd cd th^ gidi han midn bien thien cua ndng dp khi CO2 cao tiong khoang 3% < Nco2 < 7% la cd k h i nang duy tii chit lupng vi keo dai thdi gian bao quan qua vai thidu.
3.3. Kdt qua thgc nghiOm da ydu td (nhi^t dO, ndng dp khi Dg, ndng dO khi CO2) ddn chit Iugng q u i vai thidu Luc N g ^
Kdt qua tdng hop sd lidu thuc nghiem da ydu td dugc thdng kd tai bang 1.
TT T N l l TN12 TN13 TN14 TN15 TN16 TN17 TN18 TN19
X, 4,5 6,0 3,0 6,0 6,0 3,0 3,0 6.0 3,0
X2 3,5 5,0 5,0 2,0 2,0 2,0 2,0 5,0 5.0
X, 5,0 3.0 7,0 7,0 3,0 3,0 7,0 7,0 3,0
Y, 17,4 18,2 16,7 17.3 17,7 16,4 16,1 17,8 17,1
Y, 0,29 0,22 0,33 0,30 0,27 0,35 0,36 0,25 0,31
Y, 17.5 16.8 17,8 17,7 17,3 18,1 18,3 17,2 17,7 Xir ly sd lieu bang phin mem Design - Kxpert 7.1, quy trinh xii ly dugc thuc hidn qua cic budc
KHOA HOC C O N G NGHi
kidm tra sir cd nghia ciia cac h e sd hdi quy va su tuong thich cua md hinh thuc nghidm, cd dang phuang trinh hdi quy b i c n h a t Kdt qua d i xac dinh duoc cic phuang trinh hdi quy, tuang iing cac bidn tiiucY,(l),Y2(2),Y3(3).
3.3.1. Khao sit anh huong cua cic yeu td thuc nghiem ddn cic him muc tieu
a. Him Iuong dudng tdng sd
Yi - 14,79514 + 0,47083Xi -H 0,2875X2 - 0,060417X3 - 0,016667XiX2 - 0,00416667X1X3 - 0,00416667X2X3 (1)
Phuang trinh hdi quy (1) thdng qua c i c hd sd bdi quy va mdi quan hd giiia cac ydu td thuc nghiem den ham lugng dudng tdng sd cho thay su anh hudng nhieu nhat l i ydu td nhidt do, tiep theo Ii ndng dp khi O2 va cudi cimg la ndng do khi CO2. Khi nhidt dp va ndng dp khi ©2 ting thi ham lugng dudng tdng sd ting v i ngugc lai, mat khac khi ndng do khi CO2 tang thi ham luong dudng tdng sd cd xu hudng gia ting chim va ngupc lai. Quy luat nay la phu hgp vdi q u i trinh sinh Iy v i su bidn ddi sinh hda cua rau qua sau thu hoach ndi chung, ddi vdl qua vai thidu li loai it cd su bidu hien cua qua trinh chin sau thu hoach, tuy vay su gia tang cua h i m lupng dudng tdng sd cdn do su mat nudc lam hao hut khdi lugng tdng, chii khdng hoin toan li do su chuyen hda.
b . Ham Iuong axit hihi CO tdng sd
Y2 0,44465 0,02625Xi 0.00875X2 0,00145833X3 0,00166667X,X2 + 0,00125X^X3 + 0,00416667X2X3 (2)
P h u o n g t r i n h h d i q u y (2) t h d n g q u a c a c h e sd h d i q u y v a m d i q u a n h e giira c a c y e n td t h u c n g h i e m d d n h a m l u g n g axit hiiu c o t d n g s d c i i n g c h o t h i y a n h h u d n g n h i e u n h a t la ydu td n h i e t d p , tiep t h e o la n d n g d o k h i O2 va cudi c i i n g la n d n g d p k h i C O j . Q u y l u i t b i e n t h i e n c u a h a m I u g n g axit hiru c a t o n g s d n g u g c vdl s u b i e n tiiien c u a h a m l u g n g d u d n g t o n g sd, k h i n h i e t d o v i n d n g d o k h i O2 t a n g t h i h a m l u p n g axit hiru c o t d n g sd g i a m v a n g u g c lai, m a t k h a c k h i n d n g dd k h i CO2 t a n g t h i c d x u h u d n g t a n g c h i m c u a h a m l u p n g axit hiru c a t d n g s d . Didu n a y la phil h g p vdi q u a t r i n h s i n h ly v a s i n h h d a c u a q u a vai thidu n h u d d i v d i c h i tieu h a m l u g n g d u d n g t d n g sd thi s u m a t n u d c c u n g l a m b i d n d g n g t a n g c u a h a m l u g n g axit hiru c o .
c. Chit Iuong cim quan
Y3 = 19,20625 - 0,32639Xi - 0,1125X2 - 0,010417X3 0,005555556X,X2 + 0,020833XiX3 - 0,00416667X2X, (3)
Phuong tiinh hdi quy (3) thdng qua cac hd so hdi quy v i mdi quan he giua cac ydu td thuc nghidm den ham chat lupng cam quan cung cho thiy anh hudng nhidu nhat Ii nhiet dp, tidp ttieo la ndng do khi O2 va ndng do khi CO2. Ch^t lirgng cam quan U kha tuong ddng vdi quy luit bidn thidn cua axit hiru ca tdng sd, dieu n i y cd mdi quan hd mat thiet ddn cic chi tieu chat lugng vd mui, vi cua qua vai thi^u.
Mat khac nhidt dp va ndng do khi O2 tang lim giam chat lupng cam quan do qua trinh hd hap manh hon, gia ting tdc dd m i t nuoc gay bidn ddi trang thii va gia ting kha su niu hda vd qua.
Kdt qua khao s i t da yeu td ddi vdi q u i vai t h i ^ Luc Ngan cho thay miic dp anh hirdng Idn nhat la ydu td nhidt do, tiep theo la ndng dp khi O2 v i it nhat la ndng dp khi COg. Do viy trong md hinh tdi uu hoa dupc lua chgn uu tidn theo miic hd sd quan trong (HSQT) tuong iing cac ydu td nhidt dd, ndng dd khi O2 va ndng dd khi CO2 la 5, 5, 4 (theo thang di^m 5/5) la mdt trong nhung didu kidn rang huge cd i nghia trong viec x i c dinh chd do bao quan qua vai tiiieu phil hgp vdi phuang phap didu chinh khi ( C ^ . 3.3.2. Tdi uu hoa md hinh bio quin qui vii thiSii Luc Ngan
Ket qua nghien ciiu khao sat don ydu td vi da ydu td ket hop sd lieu tdng quan va sd hdu phin tich miu tiong qua tiinh thuc nghidm cho thay didu kidn ring budc thoa man su mong mudn dat dugc tuong ling cac ydu td thirc nghidm v i cac ham muc tidu: Xr nhidt dp (3 - &'0, HSQT 5, mong mudn Max; X^- ndng do khi O2 (2 - 5%), HSQT 5, mong mudn Max;
X3- ndng dp khi CO2 (3 - 7%), HSQT 4, mong mudn Max; Yi- ham lugng dudng tdng sd (16,1 - 18,2%) HSQT 4, mong mudn Min; Y2-ham Iugng axit hiiu Cff tdng sd (0,22 - 0,36%), HSQT 4, mong mudn Max; Yj- chit luong cam quan (16,8 - 18,3 didm), HSQT 5, mong mudn Max.
Ket qua chay sd heu bing pham mem Design - Expert 7.1 da dua ra dugc 10 phuong i n cd muc tidu chung thda man su mong mudn dat dugc tir 61,12%
den 61,19%. Phuong i n dugc lua chgn vdi muc tidu chung dat 61,19%, vdi che dp tdi uu cua c i c ydu ti thuc nghiem: nhiet do bao quan 4,35''C, ndng dd khi O2 4,21%, ndng dp khi CO2 7%. Tuong iing cac him muc tieu dat dugc: h i m lugng dudng tdng sd 17,07%, him Iuong axit htm co tdng sd 0,3%, chat lugng cam quan 17,65 diem.
32 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 8/20U
KHO* HOC CdNG NGH|
HinhS
Vdi muc tidu chung ciia md hinh tdi uu dat 61,19% mong mudn, khi dd cic muc tidu cu thd la nhidt do, ndng do khi O2, ndng do khi CO2, ham Iugng dudng tdng sd, h i m lupng axit huu ca tdng sd vi chit Iugng cam quan lan lugt dat dugc miic mong mudn Ii 45,09%, 73,5%, 100%, 53,52%, 59,45%, 56,66%
dupc bidu didn tai hinh 8.
Tir kdt qua tdi uu hda bao quin qua vai thidu Luc Ngan b quy md phdng thi nghidm, budc ddu cd thd dua ra chd dO bio quan CA thich hgp trong didu kidn ling dimg vdi nhidt dg 4,35 ± 0,5"C, ndng dg khi O2 4,21 ± 0,5%, ndng do khi CO2 7,0 ± 0,5% v i dg am 90 ± 2% tuong ling, cic chi tidu dat dugc Ii dip iing ydu ciu chit Iugng cim quan, dinh dudng v i thirong mai.
So vdi kdt qui nghidn ciiu ciia Jiang vi Fu, 1999, Dharini Sivakumar, 2007tiii trong mdi tnrdng CA 3 - 5% CO2, 3 - 5% O2, nhidt dO +1°C, RH 90% cd thd kiem soit tdt miu niu v i giu dugc chit lugng tdt ddn 30 ngiy. Tuy nhidn d nhidt dO bao quan cing thap thi kha ning duy tri chat Iugng sau bao quan se giam nhanh hon. Kdt qua nghidn ciiu nay cho thay diem khic bidt vdi nhiOt dd bao quan tuong iing ndng do khi CO2 cao hon (4,35''C vi 7%) vin cd kha ning cai thiOn dugc chit lugng va keo dii thdi gian bao quan han ddi vdi qua vii thidu Luc Ngan. Trong khi so vdi cic kdt qua nghidn cihi khic trong nudc bang phuong phip bio quin I^inh kdt hgp xii Iy vdi hda chit nhir xdng khi SO2, Topsin M.benlat, Cacbendazim (Htiitg C. V., 200^, hendo kdt hgp atonic (Hoan N. C. 2002), dung dich NaHSOg 6% v i dung dich HCI 4% (Binh N. H, 2006) tiiy d i duy tii dugc chit lugng cim quan 20 - 30 ngay vdi chi phi bio quan thlp, nhung ban chd Idn nhit l i dd Iai du lugng hda chit cd nguy ca anh hudng ddn sue khoe con ngudi. Mit khac vdi cic chi tidu chit Iugng dat dugc tir kdt qui tdi uu hda, qua khio nghidm danh gii miu sau bio quin CA cd thd duy tri chat Iugng
thuang mai or didu kien bao quan lanh 4 ^ trong khoang 3 - 5 ngay.
4. KETUIAN
Cong nghd bao quan qua vai thieu Uic Ngan bing phuong phap kiem soat khi quyen (CA) la co hidu ling tich cue trong vide kdo dii thdi gian bao quan va duy tri chit tugng dinh duang, cam quan va ATIP. Chd dd c6ng nghd bao quan qua vai thidu Luc Ngan bing CA thich hgp b nhiet dfi 4,35 ± 0,5"C, ndng dp khi O2 4,21 ± 0,5%, ndng dd khi CO2 7,0 ± 0,5% v i dd am 90 ± 2%. Sau 35 ngiy hao quan cic chi tidu chat lugng dat ydu cau ve cam quan, dinh duong va cd kha nang duy tii chat Iugng thuong mai a didu kidn bao quan lanh 4''C trong khoang 3 - 5 ngiy.
TAI l i u THAM KHAO
1. Binh N. H. (2006). Kdt qua nghidn a i u ciy i n qua vung duydn hai midn Trung 2(X)2-2005.
Chuong trinh KHCN Ndng nghidp duydn hai mien Trung. N h i xuit ban Ndng nghidp H i NOi, 2006, ti".
124-131
2. Himg C. V. (2006). Nghidn ciiu cdng nghd bao gdi didu bidn khi (Modified Atmosphere Packaging - MAP) nhim ning cao gii tri mdt sd l o ^ rau qui xuit khiu va tidu dung trong nird'c. KC06- 25NN.
3. Hoan N. C. (2002). Nghidn cim ning cao cdng nghd v i chuydn giao cdng nghd bao quan cam, vii cho ho ndng din v i co sd san xuat kinh doanh.
Bio cio kdt qua nghidn ctiu khoa hpc nim 2001.
Vidn Cfing nghd Sau tiiu hoach, ti". 11-12, 4. Tuan P. A (2013). Nghidn ciiu cfing nghd v i thidt ke, chd tao hd thdng thidt hi didu chinh khi (CA -Controlled Atmosphere), iing dung trong bao quan mdt sd loai rau, qua, hoa tuoi. Bio cao tdng kdt KHKT de tii d p Bg NN&PTNT.
5. Dharini Sivakumar, Lise Korsten, Karin Zeeman (2007). Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, 2002, South Africa. Postharvest Management on QuaUty Retention of Litchi dunng Storage. Fresh Produce © 2007 Global Science Books.
6. Jiang, Y. M. and Fu, J. R. (1999a).
Biochemical and physiological changes involved m browning of litchi frnit caused by water loss...
Joumal of Horticultural Science and Biotechnology, 7(l):4a46.
33
KHOA HOC C O N G NGHfi
7. Jiang, Y. M. and Fu, J. R (1999b). 10. Huang, S., Hart, H., Lee, H. and Wicker, L Postharvest browning of Utirhi by water loss and its (1990). Enzymatic and colour changes during prevention by controlled atmosphere storage at high postharvest storage of Utchi fruits. Joumal of Food relative humidity. Lebensmittel Wissenschaft Und Science, 55(6):1762-1763.
Technology, 32:278-283. ll.Joubert, A J. (1986). Litchi. In: S. P.
8. Akamine, E. K and Goo, T. (1973). MonseUse (ed). Handbook of fiiiit set &
Respiration and ethylene production during development CRC press, Boca Ralx)n, Horida, ontogeny of fmit. Joumal of the American Society for pp,233-246.
Horticultimal Science, 98:381-383. 12. Scott, K J., Brown, B. I., ChapUn, G. R, 9. Holcroft, D.. M., Miti:ham, E. (1996). Wilcox, M. E., Bam, J. M. (1982). The contixil of Postharvest physiology and handing of Utchi {Litchi rotting and browmng of Utchi fruit by hot benomyl chinensis Sonn). Postharvest Biol. Technol., and plastic film. Sci. Hort. 16: 253-262.
9(3):265-281.
RESEARCH ON THE APPUCATION OF LYCHEE PRESERVATION TECHNOLOGY BY CONTROLLED ATMOSPHERE
Pham Anh Tuan, Pham Thi Thanh Tmh Sumniaiy
The objective of this study was to determine some charactenstic physiological and biochemical changes of lychee fruits in controlled atmosphere (CA) environment, as a basis for building the process of lychee preservation technology by CA. The research content of subject "Research on technoloy and design manufacturing CA equipment systems to apply for vegetabales, 6-uits and Howers storage at Ministry level (2011 -2013)". Experiments have been on Thanh Ha lychee which were grown in Luc Ngan, Bic Giang provrne. The experimental single and multi-element have been done on laboratory CA equipment system which is the product of the subject. The CA equipment system can be control four parameters with high accuracy (as temperature ± CS^C, relative humidity ± 2%, O^ concentration ± 0.5%, CO2 concentration ± 0.5%). From the optimization results have determined control atmosphere of 4.21 ± 0.5% Oj + 7.0 ± 0.5% COj, at 4.35 ± 0.5''C, with 90 ± 2% relative humidity. After 35 days store in the CA the quality of Luc Ngan lychee achived the requirement of sensory quality, nutrition quality, and the capable of maintaining commercial quality in cold storage conditions 4''C for 3-5 days.
Keywords; Controlled atmosphere, oxygen concentration, carbon dioxide concentration, optimization, lychee.
Ngudi phan bidn: TS. Hoing Thi Ld Hing Ngiy nhin bai: 05/5/2014
Ngay thdng qua phan bidn: 05/6/2014 Ngiy duydt dang: 12/6/2014
