KHOA HQC C d N O NOHJ
MGHIEIV CliU XAC BWH [VHI$T OO BAO QLJAIXI THiCH HOP CHO QUA DLTA QUEEIM
Trdn Th( Ngpc Di^pS Nguyfin Tlianh Hi^n^ NguySn Duy Diic T6MTAT
Nhi^u c6ng ngh$ bao qudn ir;ii cfty sau thu ho^ch da phat tri^n nhfim k6o dii thAd gian v$n chuydn vi duy tri ch^t luong an tiroi cua quk nham nflng cao giA Iri ciia I09I ndng s.-in ndy. MOt trong nhung cong ngh$
quan trpng dupe dp dung rOng rfli tr^n th^ gidi Id bdo qudn lanh. Muc dich cCia nghidn ciru nay Id xdc djnh nhi^t do t6i im nhdm k6o ddi thdi gian vd ch^t lircTig dn luoi ciia qud diia Queen sau thu hojch. Diia Queen ducrc thu hdi khi da dat dO chin sinh ly vd dui^c bdo qudn trong nh&ng ngdn cua kho Ignh dd chinh nhi^t dO 10"C, 12^, 14"C, 16"C. Nghidm thiic ddi chting Id nhidt dO thirdng b ph6ng thi nghidm. Ch^t l u ^ g qud dupe ddnh gid dua trdn nhung phdn tich nhiing chi s6 sau ciia qud: sy hao hut khdi lupng qud. At} chdc thjt ^^
qud, mdu sdc v6 vd tbjt qud, d 1$ vd cdp dO hda ndu tdm qud, hdm lupng ch^t khd hda tan t6ng, axit tdng, vitamin C, d 1$ chdt khd hda tan t^ng so vdi axit tiSng trong djch qud vd gid tn cdm quan. K^t qud chiing minh fit ca ngbi§m thiic nhi^t dd Ignh d^u duy tri khdi luong tuoi vd mdu sdc vd qud so vdi nghidm thiic ddi chiing. Nhung hi^n tupng tdn thuong l^nh xudt hi$n a cdc nghidm thiic 10, 14,16"C u ngdy 14 vdi biiu hi^n hoa ndu a tdm qud. Nhi^t dd 12"C h^n ch^ hi^n tupng ndy cho din ngdy 21 vd ddm bdo qud trinh chin binh thudng di^n ra 2 ngay sau dd. Do vdy, 12"C dupe xem nhu nhi$t dd tdi uu dl sir dung cho nhimg nghiin ciiu ulp dieo khi kit hrrp vdi nhinig ky thudt khdc nhu xu ly ndm b^nh. bao gdi tgo dilu ki|n khi quyIn biln tao, v.v...nhdni klo ddi hon nua thdi gian bdo qudn sau thu ho?ch vd ngftn chdn hi|n tupng hda ndu tdm qua diia.
Tir khda; Bao quan, diia Queen, nhi$t d^ lanh, nhi^t d^ tliudng, tdn Uiuong lanh. hda niu tim qui.
LIWDAU
Nhifet dp anh huong rat Ion d^n chat lupng va tlioi gian bao quan qua sau thu hoach boi vi nhi^t do la yeu to quan trong tac dpng den hoat luc ciia cac enzym xiic tac cho cac chuyen hoa xay ra trong qud trinh chin qua. Nhidt d6 cao lam tang qua trinh hd hap, tang su mat nuoc lam giam khoi lupng tuoi cua qua. Nhung nhiet do qua diap se gay tac dpng ca hpc va pha vo cau tnic te bao, dan d^n hi^n tupng ton thuong lanh. Phuang phap bao quan hai cay a nhipt do lanh da va dang dupe dp dung rdng rai trdn th^
gioi. Mdi loai qua, k l ca cac gidng khac nhau, trong cimg mdt loai co mdt nhidt dp bao quan thich hpp ma tai dd cuong dp hd hap diap nhfit. Nhidt dp dd gpi la nhidt dp tdi uu. Nhidt dp tdi uu cdn thay doi tiiy theo dp chin ciia qua, thdng thudng qua cdn xanh thi nhidt dp tdi uu cao han qua chin (Wills vd cOng su, 1989). Ngoai ra, khi dupe bao quan trong dilu ki§n khi quyIn biln tao hay cd kilm soat, ngudng nhi^t dp nay cd thi thap hon. Ddi vdi diia Queen, mot bidn dp rdng v l nhidt dp bao quan lanh tir 10-20°C dupe
' Tnidng D^i hpc Quoc te, D^ii hpc Quoc gia TP. HCM
^ Trung tam Nghien cim vd Phdt triin Nong nghi?p Cong ngh? cao
^ Phan vi?n Co di?n Ndng nghi?p va Cong ngh? Sau thu hoEich
cdng bd va niu bao quan <10"C thi qua sd bi ^n thuong lanh (Bower J. H. va cdng sir, 1998; Miltrava cpng su, 1997; Add A. Kader va cOng su, 1985). Tuy nhidn, chua c6 mOt tdi Ueu nao cdng bd vl mot nhi^t dp tdi uu nhat cho qua dua Queen. Do vay muc ti^u cua thi nghidm nay nhSm thu h?p bidn dd nhidt do bao quan lanh thich hpp cho diia Queen. Tir do, nhiet dd nay sd dupe dp dimg trong nghidn cuu xac dinh chi sd thu ho^ch cua diia Queen vdi muc dich xi-at kh^u hay tdn trii qua vdi thdi gian lau nhat, cQng nhu trong thi nghi|m xu Iy nam b^nh va thi nghidm bao gdi tao dilu ki^n biln t^o cho qua diia Queen nham xdc djnh 1^ nhi?t dO tdi uu cho qua nh'mg vdn dam bao chat lupng qua dd'n tay ngudi tieu dimg.
L VAT LfU VA PHUDNG HUP NGHBI CUU l.V^tU^u
Dira Queen Alexandra (Ananas comosus (L) Merrill hay cdn gpi la Ananas comosus var comosus- Hp Bromeliaceae) dat dd chin sinh 1^, dupe thu hoach vdo 124 -130 ngay sau khi xii ly^ ra hoa trong miia khd t ^ cdc vudn diia 2 nam tudi ciia mdt ^^
ndng dan - xa Phudc I4p vk ciia Ndng trudng dife Tan Lap - xa Tan Lap I cua huy^n Tan Lap - tinh TM
Giang. -^
2. Phuong p h ^ nghidn cihi "^
- Cho diia vao kho lanh a nhiing ngdn nhiet w khac nhau: 10°C, 12''C, 14'*C, WC vdi am dO duy tri 52 N 6 N G NGHllP VA PHAT TRIEN N 6 N G T H O N - K^ 1 - THANG 10/2012
KHOA HQC C 6 N G NGHt 8M59t; m chiing 14 qua d?t a nhiit dg thuong
(NDT) voi nhiet do thip nhit 22-25''C/cao nhSt 30- 33°C, voi fal do 55-60%.
- Phan tich dinh k^ nhiing chi tiiu sinh ly hoi, hinh t h a va cam quan 7 ngdy/ldn, gom 7, 14, 21 va 23 ngay (2 ngay sau khi My ra khoi kho l?nh vi theo doi o NETD. Nhu v4y, m6i loai qua c6 5 nghidm thiic nhiet do voi so luwig 10 qua/nghiem thiic/d(rt phSn tich, thvrc hi6n 3 lan l$p.
- Xic djnh nhiet dO tOi ira giiip bio quin trii cSy ISu nhat nhung khOng i n h hu4ng nhiiu 6in gii trj cam quan v i chat luong trii cay.
Nhung chi tiiu phin tich:
KhOi luong tuoi cua q u i (g) duoc x i c djnh bing cin OHAUS, CS 5000,5000 ± 2 g.
Chi sO miu sdc cua thit v i vo q u i dupe dinh gii qua cic chi sO L, a*, b* ciia miy so miu Minotal CR-20O (Nhit). L: dp sing (0 -100); a': xanh li cay den do (-60 den 4*0); b ' : xanh da troi d^n ving (-60
iimm).
Cuong do ho hap q u i (mgCOj/kg/gio): Qua dupe dst trong binh ciia he thOng do cuong dO hO hap trong 24 g i o v i do cuong d6 ho hap bing phuong phip dong khOng khi hin tue a luu luong va nhiet dp xac dinh, sii dung thi^t bi phan tich COj tu dpng Gas DataCO2 (Anh).
- DO chdc thit qua (kg/cm^ dupe dp bdng thiit bi dp dp ciing Penetrometer Fr327 0 0 .
- Ham lupng chat kho hoa tan tOng cua dich lui (%) duoc t h i hien qua dp brix va duoc do bing diiic xa k i (Digital refractometer) ATAGO (Nhat), hang do 0^2%.
Ham lupng axit tong eua dich qua (96) duoc h i hiOn qua ham lupng axit hiiu co toan phdn va
dupe x i c dinh bing phuong phip chudn dp dung dich NaOH 0,1N, chi thj miu phenplphtalein 1%.
Him lupng vitamin C ciia dich qua (mg%) dupe xic djnh bing phuong phip chuan d6 v « dung dich 2,6 diclophenol -indpphenol 0,001%.
Ton thupng lanh: Cip dp tOn thuong lanh cua qui (tit 04) dupe dinh gii nhu sau: 9: khong co vit hOa niu b tim qua; 1: vit hOa nau <1 cm^ va co miu nh?t; 2: vit hoa niu tir 1-2 cm^ va c6 mau niu nhat; 3: vit hOa niu tii 2-3 cm'; 4: vit niu djm hoa den >3 cm'Ti li qua bj tdn thuong lanh (%) . 100 x s i qua bj ton thuong lanh /tong so qui thi nghiOm.
Diim cim quan (huong vi, thu nim): theo thang diem tit 1 (cue ky do) din 9 (cue ky ngon), ngirPng chdp nhjn li 5 diim.
S i liiu dupe xii ly thong k i bing phdn mim Excel/Tool/Data analysis.
•.KETQIIAVATUAOLIUN
1. NhUng thay d i i v i euOng dO ho hdp v i khOi lupng tuoi ciia qua diia Queen khi bao quan a nhiing nhiit do khic nhau
Cuong dp ho hap cua qui diia Queen ban ddu rdt cap 802,56 mgCOj/kg/gio d i giim manh khi bao quan a nhiOt dO lanh, giam din khoang 50 ldn trong khi chi so nay o NDT chi giim 1,2 ldn sau 1 tudn vi 2,3 lin sau 2 tudn bao quin. Cuong dO hO hap giim ti le thujn voi nhiit dp: nhiet dO cing Ihdp thi cuong dO ho hap cang giim tuy su sai biit khong Ion chi khoing 2 - 6 mgCOa/kg/gio. Kliong co su sai biet c6 y nghla ve chi so nay trong suit thoi gian bio quin nhung giim nhe doi vol nghiOm thiic 14V va 16"C o ngiy 21. Tuy nhien, sau khi d i q u i o nhiet dO phong thi nghiem 2 ngiy, cuong dO ho hap ciia tat c i nghiem dnic ting vpt lOn khping >300 mgCO,/kg/giO ( B i n g l ) .
Bing 1. Anh hu6ng ciia Nghidm thiic
10°C 12°C W C le-'C DC
nhiit do din cuOng dO hO hdp (mgCO, Ag/giO) eua qud diia Queen Thdi gian bio quin (ngiy)
Ban ddu
802,56 ±12,3
7 ngiy 12,46 ±0,4 14,57 ±0,3 15,06 ±0,2 18,95 ±0,7 668,21 ±1,7
14 ngiy 12,39 ±2,1 14,71 ±1,6 15,21 ±1,3 19,03 ±0,9 354,74 ±0,6
21 ngiy 12,47 ±0,4 14,65 ±0,5 15,32 ±1,1 18,89 ±0,5
Sau 2 ngiy 6 NDT 325,85 ± 5,3 346,84 ±9,2 314,53 ±10,1 355,17 ±12,4
Khi qua diia Queen hd hap, nudc trong dich qua 5 bi ueu hao, ddng thdi cac thanh phan ch^t khd
ciing bi giam dan do cac chat nay da dupe su dung trong qua trinh sinh Iy, sinh hda ciJa qua. Vi vay khdi lupng tuoi cua qua ciing giam din theo thdi gian bao I 6 N G NGHIEP V A PHAT TRIEN NONG THON - KY 1 - THANG 10/2012 53
K H O A HQC C 6 N 0 H O H j
quan. Tuy nhiOn, nhiit dO cing thdp s6 lim cho q u i cing it ho hdp, cO nghia li q u i eing it hao hut khii lupng. Do viy, trong tudn ddu qui d i hao hyt 2,45%, 2,26%, 2,44%, 3,15% v i 8,74% so vdi khOi lupng ban ddu theo thir tu nghiim thiic 10 , 12, 14, 16°C v i NDT. Khoi lupng tuoi ciia q u i a lit c i nghiim diiic 0 hidn thli hai d i giim khoing 1,5 ldn so vOi tudn lj"uOc do. Chi so niy cing hao hgt (V tudn liip llieo, d^c biit l i qui o 16"C da hao hut 5,47%. Sau hai ngiy * NDT, chi so niy giim manh tirong ling vOi cuOng dO hO hdp gia ting tro lai (Hinh 1).
TN21 Sa hao fcul Irong t'ong luci cua dua Oueea
« 7 N | i a » N - ^ 2 : S i 23N 1
L 455
y u u u
tioC lioC M M OC Hinh 1. Anh huOng eua nhiit dO din su hao hyt khOi
lupng cua diia Queen
Qua phin tich cuong dO hO hap, khOi luong, 12°C li miic nhiit dO kim h i m hO hap cua qua nhung vin dam bao nhirng ho?t dpng biin duOng; nhiing host dpng niy diin ra vOi thoi gian liu hon a 14°C v i
le-c.
2. Nhimg thay d i i sinh hOa ciia q u i diia Queen khi bao quin 6 nhiing nhiit dO khic nhau
Him lupng chdt khO hOa tan ting (thi hiin qua dp brix) cua qua diia Queen cua hai nghiim thitc 10 va 12°C ting ti l i thuan voi nhiit dO trong suit thoi gian bao quan. 10°C ehi giiip qua tSng thim 0,4% so
vdi ban ddu trong khi nghiim thiic 12"C e6 dO bri d^t 15,0% sau 2 ngiy Idy ra khoi kho lanh, nghk I ngpt nhu qud chin tu nhiin v i d i m bio mOt su chi binh thirOng diin ra. Nghiim thiie 14 v i 16°C cOn giiip q u i ting dO brix Uieo thOi gian din tudn thir nhung sang tudn thii 3 thi dO brix b i t ddu giim. \ du do brix ciia nghiim thiic 16°C li 15,4%, 14,991 it 14,5% tlieo thli tu 0 14, 21 v i 23 ngiy, chung to qm da Sli dyng chdt khO hOa tan d i thi,rc hiin qui trinl ho hdp vi giii phOng ning lupng. NOi cich khic, qui da vio gi.il do?n lio suy v i cOng cO t h i li thoi difc nhirng ndm g i y binh nhu ndm men, Penkilim funiculosum, Fusarium moniliforme, Phytophthon cinnamomi hay Aspergillus Savus c6 diiu kiin sinh sin v i phit triin nhO thiie i n chinh li him lugng ehdt kho hOa tan ting ciia qui. Tuong tu, NDT lam q u i chin nhanh v6i dO ngpt 15,4% trong tudn dau tiin, nhung cung lim q u i sOm vio giai doan lao sup vi do brix chi cOn 14,3% o n g i y 14 (H2.I).
Ngupe 1^, h i m lupng axit ting cua qua diia Queen giam ddn theo UiOi gian v i giim d li nghidi vOi nhiit dO: nhiit dO cing cao thi him lupng axit cang giim nhiiu: 1,3 ldn so voi ban dau, die biet nghiim thiic 12^C lim ham lupng niy giim 1,4 lii sau khi liy khoi kho lanh va d i 2 ngiy o NDT (H2.?).
Do viy, chi sO TSS/TA flii hiin dO ngpt cda qua cung biin fliiin Uieo ti l i thuin voi nhiit dp vi M gian b i o quin. Ban ddu chi s i nay voi gia tri dii khoang 18,38 nhung sau 3 tudn d i ting lin 19,5,63A 49,8 v i 53,5 Uieo fliii tu nhiit dO iai6°C. R6 ring, nghiim thiic 12"C c6 tisO nay cao nhat, ehiingtS qua ngpt nhdt (H2.3).
Tuong tv chi s6 axit, h i m luyng vitamin C ciing glim m ^ h Uieo thOi gian v i d l i thuan vol nhiit do.
Sau 7 ngay thi nghiim, ham lupng niy da giam 43,1%, 61,1%, 86,8%, 107,0% v i 134,2% ttieo thii tij 10- 16°C v i NDT. Sau 2 ngiy Idy ra khoi kho lanh, vitamin C c i a nghiim ttnic 10,14,16°C ehi con ¥ 5- 6%mg nhung duy nhdt c6 nghiim Uuic 12»C vSn giii dupe vitamin C b miic eao hon: 8,93%iiig (H2.4).
Qua phin tich nhOng ehi sO sinh hoa, cr di^
kiin 12°C giiip giu dupe ehdt lupng dich qui cao hon nhOng nghiim thiic khic theo thoi gian bio quan.
NONG NGHllP VA PHAT TRIEN N 6 N G T H 6 N - K * 1 - THANG 10/2012
KHOA Hpc CONG NOHt
I "
L
H2.4
Hinh 2. Anh hu6ng cua nhi§t dO d^n nhiing chi tieu sinh hda cua diia Queen: Ham lu^ng ch^t khd hda tan t^ng (H2.1), ham lupng axit t^ng (H2^), chi sd TSS/TA (H2.3) va ham lugng vitamin C (H2.4) 3. Nhbng thay ddi hinh thai va cam quan ciia qua
diia Queen khi bao quan a nhOng nhi^t dO kliac nhau Bi^u dd or hinh 3 cho thay dp ch^c ciia qua da giam dan flieo thoi gian va ti le thuan vdi nhidt dd bdi vi nhung enzym xenluloza, pectinaza ... da phan hiiy nhiing thanh phan cua vach te bao lam cau tnic t^
bao trd n6n long leo. Nhiet dp cang thap se cang kim ham hoat tinh nhimg enzym tren. Dp chac thjt qua khi bao quan nhidt dp 10 va 12°C hau nhu khdng fliay ddi sau mpt tuan bao quan. Tuy nhidn, chi sd nay da giam cdn 3,42, 3,13 va 2,87 kg/cm^d nhidt dp
TN2 IDS chac Ifidqu^ dua Queen
14"C, WC va NDT theo tiiu hi. Trong nhung tuan ti^p theo, dp chac thit qua b nghidm thuc 10 va 12°C cung giam, cdn 2,45, 2,47 kg/cm^.
Ve gia tr; cam quan, trong tudn dau hdn, di^m cam quan cua tat ca cac nghiem thuc da cao hon so vdi ban dau vdi gia tri trong khoang 6,2-6,9 (qua dupe danh gia la ngon). Trong tuan thir 2 nghiem thiic 12"C cd chat lupng thu n^m cao nhat (7,9 diem) so vdi nhung nghidm thuc khac. Sau 2 ngay de d NDT, chat lupng thii nem cua qua vol nghidm thiic 12°C van cao: 7,4 di^m (Hinh 4, 5,6).
I
CoC ^oC
Hinh 3. Anh huong ciia nhiit dO d i n dO chdc thjt qud diia Queen
HuJi 4. Anh huong eiia nhiit dO din gii tti cam quan eiia qui diia Queen
NONG NGHIEP VA PHAT TRIEN NONG THdN - KV* 1 - THANG 10/2012 55
KHOA H Q C C O N O N G H I
Phdn vo qua ban ddu vdn cin xanh, chi img ving mOt hing mdt duOi ciing n i n chi s i a v i b rdt Uidp:
0,34 va 12,68 ttieo Uiii ttt. Sau 1 tudn bio quin Ijnh, vo qua vin xanh nin chi s i a chi ting hon ban ddu khoang 3,7%, 14,8%, 35,2%, 42,6% v i chi sO b tang 0,55%, 1,50%, 2,37%, 4,18% Uieo ttui tu nghiim Uuic lO-ie-C. Tuy nhiin 6 NDT, vo q u i da chuyin sang mau ving voi gii tri a 4,05 v i gii tri b 16,25. Xu huong gia ting hai chi sO niy li li Uiudn vOi nhiit dO van tiip tue o hai tuin Uip Uieo. Vo q u i s i c6 miu vang nhu NDT o tudn Uiii nhdt li nghiim Uliic 16"C ngiy 21 vi nghiim thiic 12"C sau 2 ngiy o NDT, t h i hiin qua chi s i a khoang 4 v i b khoing 16. Trong hai tudn ddu, chi so L tang ddn v i ting ti li thu0n viri nhiit do, ngoai tni nghiim Uuic dOi chiing. dt tudn tiip theo v i hai ngiy Idy ra khOi kho lanh, chi so niy
Bing 2. Miu sdc q u i diia Queen
da giim vOi g i i tri khoing 31-33, trong dO gii lij can nhdt 33,64 l i cua nghiim Uuic 12°C (Bing 2).
Phdn thjt q u i ban ddu cO miu ving sing vOi chi sO L v i b rdt cao: 71,37 v i 28,83 Uieo Uiit tu. Chi sd 1, gidm nhp theo thOd gian it tdt cd nghiim ttuic. Chi si b tang ddn d i n hidn fliii 2 v i ti l i U i u ^ v6i nhiit i^:
tang 0,7%, 2,6%, 2,8%, 3,5% v i 13,6% so vOi ban dSu Uieo Uiii tu nhiit dO 10-16°C v i NE)T. Tuy nhiin sang ludn Uiit 3, qui ludt niy chi cOn diing vdi nghiim thiic 12 v i 14"C vi nghiim Uitic 10°C da lim qui bi tdn thuong linh vOi nhiing vit ndu den 6 tim qua va le-C lim q u i lao suy s6m va phin huy nhanh carotenoid, mOt hpp chdt quyit dinh miu ving cua ttijt qui. Sau khi d i 0 NDT, chi s i niy giira o tdt ci cic nghiim thiic (Bing 2, hinh 5,6).
Nhu viy, nghiim thiic 12^C bio dim miu sdc vo vi thjt q u i ving dep hon nhirng nghiim thiic khic.
bdo quin Or nhting nhijt dp khdc nhau ThOi
gian (ngiy) Ban ddu
7 ngiy
14 ngay
21 ngay
23 ngiy Nghiim
Uuic
10"C 12°C 14"C 16"C DC 10°C 12°C 14°C 16°C DC 10°C 12''C 14°C 16°C DC 10°C 12°C 14°C 16-C DC
Nhiing chi tiiu miu s, VOqui
L 35,58 ±0,2 36,52 ±0,1 36,54 ± 0.3 37,15 ±0,2 37,57 ±0,1 39,63 ± 0,3 39,87 ± 0,4 35.25 ±0,1 35,89 ±0,1 35,56 ± 0,3 33,89 ± 0,2 33,25 ±0,1 34,18 ±0,2 32,56 ± 0,2 32,77 ±0,1 32,57 ±0,1
-
33,64 ± 0,2 31,85±0,1 31,49±0,1
a 0,34 ± 0.02
1,26 ±0,01 1,38 ±0,03 1,26 ±0,01 1.28 ±0,01 4.27 ± 0,03 1,28 ±0,01 1,49 ±0,01 2,45 ± 0,02 3,24 ±0,01 5,73 ± 0,05 3,14 ±0,02 3,18±0,01 3,23 ±0,01 4,28 ± 0,02 3,36 ± 0,02
-
3,75 ± 0,03 4,18 ±0,02 5,23 ±0,01
b 12,68*0,05 12.75 ±0,03 12.87 ±0,04 12,98 ±0,01 13,21 ±0,05 16,25 ±0.04 13,27 ±0,01 14,25 ±0,05 14,68 ±0,06 14,77 ±0,01 19,18 ±0,03 13,59 ±0,01 15,44 ±0.02 15,88 ±0,05 16.03 ±0.03 13,64 ±0,01
-
16,44 ±0,03 16,75 ±0,01 17,03 ±0,03
ic ciia q u i diia Queen Thit q u i L
71,37 ±0,3 68,54 ±0,1 69,14 ±0,05 68,45 ± 0,03 68,69 ±0,1 69,52 ± 0,03 68,42 ± 0,02 67,52 ±0,01 66,41 ±0,02 66,45 ± 0,03 66,24 ± 0,04 57,36 ±0,01 66,52 ±0,03 64,05 ± 0,02 62,46 ±0,01 47,25 ±0,1
-
56,63 ± 0,05 60,24 ±0,06 59,32 ±0,07
a 0,34 ±0,01 0,39 ±0,02 0,52 ±0,03 0,62 ±0,02 0,87 ±0,01 1,47 ±0,03 0,41 ±0,01 1,58 ±0,02 1,74 ±0,01 2,25 ± 0,03 3,76 ±0,01 1,19±0,02 2,26 ± 0,02 2,74 ± 0,03 3,22 ±0,01 1,43 ±0,01 3,35 ±0,02 3,67 ±0,03 3,71 ±0,01
b 28,83 ±0,02 28,95 ±0,01 29,14±0,02 29,24 ±0,02 29,43 ±0,01 30,25 ±0,03 29,02 ±0,01 29,58 ±0,02 29,65 ±0,01 29,85*0,01 32,76 ±0,03 29,06 ±l),0<
30,28 J i P 30,25 ±0J)i 31,04±0,OI 29,41 ±0,03 30,43 ±0,lK 30,67 ±0,03 31,65 ±0,01
-
trpng khi phdn thit hOa n i u lan ddn din viing A Trpng hidn ddu tiin khong eO ddu hiiu bj tin fliume lanh. Trong tudn thii 2 cO su xudt hiin vung hda nSn noi t i m qua vOd cdp dO tdn fliuong 1-2, nghia la tam q u i vira mdi hOa ndu vdi vimg hOa niu <2 cml Ti'?
t i n Uiuong ti l i nghjch vOri nhiit dO: 10°C c6 ti li Q"*
N 6 N G NGHlfP VA PHAT T R I I N N 6 N G T H 6 N - KY 1 - T H A N G 1 0 / » 1 J 4. Hiin tupng t6n thuong l^nh ciia q u i diia
Queen khi bio quin it nhflng nhiit dO khic nhau Triiu chiing ton thuong lanh eua qua diia Id su hoa niu h-ong tam qui, phdn thjt o gdn loi. Miic dO ton thuong (dupe ehia thanh 5 miic: 0 - 4) cdng trdm
56
KHOA HPC C6HO NGHt
bj t6n ttiuong cao nhdt 22,23% vi 16°C Uidp nhdt 5,56%. Sang tadn Uiir 3, ti li qua bj tdn fliuong liuih cua 10°C lin din 36,11% vOi cdp dO tin Uiuong 3,31, nhung nghiim thiic 12°C cO ti li qui bj tin thuong lanh flidp nhdt 13,89% voi cdp dO t^n thuong 2,6. Sau 2 ngiy di o NDT, dOi vdi nhOng qui da bj tin Uiuong, diiu kiin NDT da lim qua bj sic nhiit, vit ton ttiuong trd nin trdm ti-png hon, djc biit li nghiim thitc 10°C: thim den vi lan r^ng >3 cm'hxing khi nhang nghiim thiic khie cO cap dO tin fliuong chi tang hon 9-14% so vdi ngiy 21 (Hinh 4, 5, 6). Nhu vay, niu bio quin qua d nhiit dO <10°C, qui s6 bj tin ttiuong lanh; cap dO ton thuong cang trdm ti-png dOi vol qui bao quin d NDT sau khi Idy ra khOi kho liuih.
Ton fliuong lanh li mOt hiin hipng phd biin cua diia, cO 16 vi cdu tinic ti bip die fliO cda nO: cd nhiiu xo, it tinh bit vi him lupng djch qui chiim din >80%.
Nhiit do qui ttidp: <12»C dOi vdi diia Queen da lim phi vd nhang fliinh phdn eiia ti bio, lam ti bio sdm vio giai doan lao suy, nhiing enzym phin hOy ting ho^t tinh, trong dd ed enzym phenoperoxldaza - mpt enzym sin sinh phenol lim vimg tim qui hoa niu.
Hon niia, nhiit dO qui cao hoic qui thdp cting lim cho qui phin huy vitamin C, mOt vitamin ddng vai trO kim ham hogt tinh enzym phenoperoxldaza. Dd li lj> do tai sao nhiit dO cao hon 16°C vi 14°C eung lam qui diia Queen cung bj niu den 0 vimg tim qua.
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Hinh 4. Anh budng ciia nhiit do din ti 10 (H4.
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Qua phin tich nhimg chi tiiu sinh ly, sinh hda, hinh thii vi cim quan ciia qui diia Queen bao quin d nhOng nhiit dO khac nhau, cd flii kit luin 12°C li nhiit do tOi uu nhdt vi thdi gian bao quin diia Queen dam bao chdt lupng d nhiit dO nay li 14 ngiy. Khi dd qua se cd him lupng chdt khd hOa tan tong cao nhdt, ddng thdi him lupng axit ting cflng khi thdp, nghia li ti sO TSSAA - flii hiin dO ngpt cua qui - cO gia trj cao nhdt Hon nfla, vitamin C cung it bi phin huy vi duy tri d mOt him lupng cao. Chinh yiu tO nay lim qua it bj tin thuong Ignh hon nhflng nghiim fluic nhiit do khic. Hon nOa, chi so L (chi dO sdng) va b (ttii hiin miu vang) cd gid trj cao nhdt ciia ca phdn fllit vi phdn vo cua qua trong flldi gian bio quan lanh vi ngay ca di d nhiit dO fliudng 2 ngiy sau dO. Tuy nhiin hiin hipng hda nau tim qua bdt ddu xudt hiin d hidn fliii 3 mic du 12°C vin dim bio mOt qui trinh chin binh fliuong diin ra d nhiit dO fliudng sau khi
N 6 N G NGHlfP VA PHAT TRIEN N 6 N G T H 6 N - K^' 1 - THANG 10/2012
1) vi cip do t6n thuong 1 ^ (H4.2) ciia diia Queen Idy qui da bio quin 21 ngiy khdi ngan lanh nay. Vi vay, nhiit dO 12"C li nhiit dp toi uu dupe sir dung di fliuc hiin cic thi nghiim tiip theo bang cich kit hpp nhiit do 12"C vdi nhirng ky ttiuSt khic nhu xu ly ndm binh, bao gdi nhdm kio dii thdi gian bio quan vi ngin chan hiin tupng hOa niu tim qua ctia diia Queen.
TAI LtU IHAM KHAO
1. Biii Trang Viit (2000). Sinh 1^ ttiirc vat dai cuong. Phdn II: Phit triin. Nhi xuat bin Dai hpe QuOc giaTp. Hi Chi Minh, 333 ti-.
2. Nguyin van Ki (2000). Cay diia. Trudng D?i hpc NOng Lim Tp. Ho Chi Minh.
3. Mai Trdn Ngpc Tiing (2001). Giio tiinh lao
suy fliuc vdt Trudng Dji hpc Quoc gia Tp. H6 Chi
Minh.
KHOA HQC C O N O NOHJ
4. Nguyin Manh Chinh, Nguyin Ding Nghia (2006). Ciy diia (khdm, ±am). N h i xudt bin NOng nghiip.
5. Add A. Kader, Robert F. Kasmire, F. Gordon Motchell, Michael S. Reid, Noel, F. Sommer, James F. Thompson (1985). Postharvest Technology of horticultural crops. Division of Agriculture and Natural Resources, USA.
6. Bower J. H., Jobling J. J., Patterson B. D. and Ryan D. J. (1998). A mefliod for measuring the respiration rate and respiratory quotient of detached plant tissues. In: Postharvest Biology and Techology 13. Elsevier. 263-270.
7. D. P. Barfliolomew, R. E. PauU and K. G.
Rohrbach (2003). The Pineapple Botany, Production and Uses. ABI Publishing, UK-
8. Kays S. J. (1991). Postharvest physiology of perishable plant products. An avi book. PubUshed by Van Nostrand Reinhold, NewYork. 415 pp.
9. lindy Coates et al., Postharvest diseases of horticulral produce. Volume 2: Tropical fruit Department of Primary Industries. Queenland.
10. Meidner H. (1984). Class experiment in Plant Physiology. George Allen and Unwin Ltd. New York. 57 pp.
11. Miti-a S. K. (1997). Postharvest Physmht and Storage of Tropical and Subtropical Fruits. CA International. UK. 423 pp.
12. Noodefln L D., and Leopold A. C. (1988 Senescence and Aging bi Plants. Academic Presi New York. 526 pp.
13. Polderdijk J. J., Kho R. M. and Krulf A P. H (2001). Firmness of mangoes {Mangifera indical.
measured acoustically, mechanically and manuallj Horticultiiral Abstiacts 2001. Vol. 71 No. 7, CAI International. 1131.
14. Py C , Lacoeuilhe J. J, Teison C. (1987). TTii Pineapple - cultivation and uses. G. P. Maisonneuw Et Larose. France.
15. Seymour G. and Taylor J., E. (1993) Biochemistry of hvit ripening. Chapman and Hall London. 69-143.
16. Shewfelt R L. and Prussia a E. (1992) Postharvest handling. Academic Pres, Inc. USA
Ldi cim on: Cdng trinh duoc Hi tro'boi So Khoi hoc vi Cdng nghi Thinh phi Hd Chi Minh vdidiH
"Nghiin ciru xic dinh chi sd thu ho^ vicdngsghi xirly, bio quin thich hgp cho diia vi du dtl'alu, 2005 - 2007 Cic thi nghiim dugc tiin hinh cd si dung ti-ang thiit bj cua Phin viin Ccr di(n Nint nghiip vi CXngnghi Sau thu hoach.
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Hinh S.DliaQueenbio quin 6 nhiit dO thudng sau 7 ngdy vd sau 14 ngiy
58
N 6 N G NGHlfP VA PHAT TRIEN N 6 N G T H 6 N - KY 1 - THANG 10/2012KHOA HOC C O N O NGHt
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Hinh 6. Dira Queen sau 14 ngdy bio q u ^ b nhi^t dO 10°C, 12*'C, WC, WC
STUDY ON DETERMINING THE OPTIMAL STORAGE TEMPERATURE FOR QUEEN PINEAPPLE FRUrr
Tran TTii Ngoc Diep, Nguyen Thanh Hien, Nguyen Duy Due Summary
The extension of fruit shelf hfe is an important goal to be attained to miprove the value of this horticulture crop. Many postharvest technologies have been developed to extend the marketing distances and maintain the fresh quality of these commodities after harvest One of the most pivotal techniques applied world-wide IS cold storage. The objective of this study was to determine the optimal temperature for extend the shelf life and quaLty of Queen pmeapple. The Queen pineapple at maUmty stage were stored at lO'C, 12°C, 14°C, 16''C, and ambient temperature in the laboratory. Fruit qualities were evaluated by the fruit weight loss, flesh firmness, flesh and peel color development, internal browning, total titratable acidity, total soluble sobds, total vitamin C content, total soluble solid and acidity content ratios and sensory attributes. The results showed that all the cold temperature treatments were sigmficantly effective on the retention of peel color and the weight loss. However, the internal browning symptom appeared on the core of the fruits which were preserved at WC, WC, le'C at day 14. The temperature 12°C restricted this symptom until the day 21 and ensured a natural ripening process to reach the best fresh quahty during 2 days at the ambient temperatures since getting the fruits of the expenmental refrigerator compartment Therefore, this temperature was optimal to be used for our further research by combining viith other storage techniques like fungicide freatment, modified atmosphere packaging to extend more storage days as well as preventing internal browning of this fruit after harvest
Key words: Storage, cold temperature, ambient temperature. Queen pineapple, chilling injury, internal browning.
Ngu6i p h ^ bi#n: TS. Hodng TTii U H ^ NgAy nh$n bM: 15/8/2012
Ng4y th6ng qua phin bi$n: 26/9/2012 Ngiy duy^t dSng: 3/10/2012
I 6 N G NGHIDP V A PHAT TRIEN N O N G THON - KY 1 • THANG 10/2012