KHOA HOC CONG NGHE
KET QUA KHAO SAT HIED QUA BAD QUAIV QUA DAU T A Y BAIMG COIVG IXIGHE HYDKAIV
Ta Tliu HangS Nguyen Ddc Binh MinhS Kouichi OMura^
Nguyin Ddc Hodng^ Dodn Thi Bdc\ Pham Thi Mai Anh^
TbMTAT
NghiSn cihi duoc tien hanh de khao sat hieu qua bao quan lanh bang cong nghe Hyokan den chat lunng va giam ton that sau thu hoach cua qua dau tay Moc Chau. Qua dau tay duoc thu hoach voi do chin dat 80%
phan vo qua da chuydn sang mau do. Sau khi so ch^ dau tay duoc bao quan bang hai cong tbiic: (1) Doi chiing duoc bao quan bang tu lanh Sanky nhiet do 2 - 4''C; (2) Bao quan lanh bang cong nghe Hyokan a nhiet dp -2''C, dien ap 3.500 V. Qua dau tay duae bao quan bang tu lanh thuong nhiet dp 2 - 4°C co su suy giam chat luong nhanh ban v^ chat luong cam quan, chat luong dinh duong, hao hut khoi lugng, dac biet la ty le hu hong khi so sanh voi cong thtic bao quan bang cong nghe Hyokan sau 7, 14, 21 ngay bao quan. Sau 14 ngay bao quan, qua dau tay a cong thiic Hyokan co mau sSc thay ddi cham, do ciing giam 0,2 kg/cm^;
hao hut khdi lupng la 0,22%; ham luong chat kho hoa tan giam nhe, dat 8,17''Bx; ham lupng acid tong sd tang nhe, dat 1,23%; ham lupng vitamm C giam nhe dat 13,23 mg%; ty le hu hdng la 8,33% thap hon so voi muc tieu bao quan nong san sau thu hoach,
Titithba: Bao quan lanh, edng nghe Hyokan, qua dau lay, dau lay Mpc Chau.
I.BATVANOi
Dau tay (ten khoa hpe la Fragaria) la loai thuc vat thu6c ho Hoa H6ng (Rosaceae) cho qua dupe nhieu nguoi ua chuong. O Viet Nam dau tay dupe trong a Sapa (Lao Cai), Da Lat (Lam Dong), Moe Chau (Son La)...Qua dau tay la nguon giau vitamin C, ngu6n cung cap folate va kali toL Qua co chua acid citric chu yeu va mpt sd acid malic, ham lupng cac loai acid nay khac nhau trong cac giong dau tay, ham lupng acid citric, acid malie va aeid ascorbic ciia 2 gidng dau tay
"Camarosa" va "Selva" ldn luot la 0,76%; 0,13%; 0,04%;
0,5%; 0,0%; 0,04% [5]. Dau tay co huong thom dac tnmg, vi chua thanh rat dac tnmg. Nhung lpi ich siic khoe eiia dau tay bao gom cd lpi cho mdt, nao, gnip h6 trff benh nhan huySt ap cao, viem khop, benh gut va benh tim.
Dau tay la qua cd cau tnic rat dk dap nat do tac dpng Cff hpc, CO ty Ie ho hap cao va tudi thp sau thu hpach tuong ddi ngan. Thdi han sir dung cua san pham tuffi dupe gioi han tii 1 d^n 2 ngay cr nhiet dp phong [7]. Da co nhieu phuong phap bao quan dau tay dupe ap dung. Nghien eun eiia Baka M. va cdng su (1999) da tie'n hanh khao sat anh hudng cua tia
' Vien Nghien cmi va Phat trien Viing, Bp Khoa hpc v Cong nghe
^ Cdng ty O's &Tech Co., Ltd, Nhat Ban ' Hpc vien Nong nghiep Viet Nam
UV tren qua dau tay khi chi^u anh sang tia UV bude song ngan ddi vdi su hu hdng va chat lupng bao quan ciia dau tu'ffi. Qua dau tuoi dupe chieu tia UV bude sdng ngan a miic 0,25 va 1,0 KJ/m^ va dupe bao quan a nhiet dp 4"C hoac WC. Ket qua cho thay da keo dai thffi gian bao quan them 4 - 5 ngay. Qua dupe xu li tia UV cd tdc do ho hap thap hon, do acid va ham luffng anthocyanin cao hon, be mat qua min hon so vdi khong xu li [2]. Nghi6n cuu ciia Lara va cong su (2004) da quan sat duge su thay ddi cau tnic pplyme thanh t^ bao cua qua dau b cac edng thiic xu li bang CaCl21% va duffc bao quan 10 ngay a nhiet dp 3°C.
Phuang phap xu ly bdng canxium tuy lam cham qua trinh chin a miic do khdng dang k^ nhung nd cai ti^n kha nang chdng lai cac loai nam mdc gay hai ma khong anh hudng vk be ngoai ciia qua [6].
Ngay nay, xu hudng phat trien ciia xa hoi hien dai nhu cau ddi hdi cua con nguoi ngay cang cao, ngoai ydu cau ve chat lupng dmh dudng, cam quan can dam bao vd an toan thuc pham va than thien mdi trudng, do vay viec dd xuat nghien ciiu iing dung nhung phuong phap bao quan bdng nguyen ly vat ly an toan la thuc su can thiet. Cdng nghe Hyokan la mdt cdng nghd mdi ciia Nhat Ban, hpat ddng vdi nguyen li ca ban la su kdt hop giua trudng hnh didn (50- 60 Hz) va ddng dien ap cao (tdi da 7.000 V) de tao ra ddng ion on dinh quanh hai cue ben trong ciia tu lanh. Khi khdng khi lanh thdi vao, va dap tao ra NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 12/2019 91
KHOA HOC CdNG NGHE cac ddng ion lam cho nude (nude tu do va nude lien
kel) cd trong te bao thuc pham khdng ddng bang ngay ca khi cr didu kien nhiet dp am. Chinh didu dd ma cdng nghd Hyokan cd the giii dupe chat Iupng thuc pham sau mdt thdi gian dai, dupe ung dung trong cac kho bao quan cac loai ndng, thiiy hai san, thuc pham khac nhau; dac biet iing dung cho cae contamer lanh van chuyen cung ting thuc pham cd ehiie nang bao quan va duy tri dp tuffi cua thuc pham [81. Vdi nhijng hidu qua eiia cdng ngh§ Hyokan, da thuc hien thu nghiem "Kit qud khao sat biiu qua bdo qudn qud dau tay bing cdng ngbi Hyokan ".
2 . DO! TUONG VA PHUDNG PHAP NGHEU CUU 2.1. Doi tupng nghidn ciiu
Ddi tupng nghifin ciiu la da.u tay Mdc Ch^u, tai ban Ang, xa Ddng Sang, thi tran Mpc Chau, iinh Son La. Dau tay duoe thu hai vao liic som, qua dau cdn nguydn cudng. Sau do dau tay dupe bd vao hop nhua, dupe giii trong thiing cartpn va van chuyen ve phdng thi nghidm cua Vien Nghien cmi va Phat tridn Viing de tien hanh xtr li.
2.2. Phuong phdp nghidn cuu 2.2.1. Bd ti-i till nghiim
Qua dau tay dupe chpn dimg cho thi nghiem phai ddng deu, dp chin dat 80% vd qua chuyen sang mau do, qua tuoi, nguydn ven, khdng bi dap nat, hu hong. Qua dau dugc rua sach, lau khd, sau dd duffc hoc trong mang xdp hoi PE (3 mm) va cho vao hdp nhua cd day nap. Tien hanh bao quan dau tay d' 2 cdng thiic (CT) nhu sau:
+ Cdng thiic ddi chiing: bao quan bang tii lanh thudng, nhiet dd 2 - 4°C.
+ Cdng thiic Hyokan: bao quan bang cong nghd Hyokan ed nhiet dp -2''C, dien ap 3.500 V.
Mdi cdng thiic thi nghiem lam 100 qua/cdng thiic, lam lap lai 3 lan. Tdng sd la 25 irCau. Thdi gian phan tich chat lupng qua dau tay dupe tien hanh dinh kjf 1 tuan/lan, thuc hien hao quan sau 28 ngay, phan tich cac chi tieu nhu su thay ddi mau sac, hao hut khdi lupng, dp ciing, ham lugng chat khd hda tan, ham lupng acid tdng sd, ham lupng vitamin C, danh gia chat lupng cam quan va vi sinh vat tdng sd.
2.2.2. Pbuong pbap phan ticb cdcehitiiu - Xac dinh chi sd mau sac (L, a) bang may do mau sac cam tay NR3000. Do tai 3 vi tri khac nhau
trdn qua dau tay, gia tn mau sdc dupe danh gia theo heth6ngCIE(L,a,b).
- Xac dinh ty le hao hut khdi lupng bang phuong phap can, su dung can phan ky thuat dien tii SPS202F, cd sai sd ± 0,01 g. Ty le hao hut khdi lugng dupe tinh theo cdng thiic:
X=^^^LZ^100(%) M,
Trong dd: X (%): hao hut khdi lupng tu nhidn d mdi lan phan tich; M, (g): khdi lugng qua trude khi bao quan; M2 (g): khdi lupng qua b cac lan phan tich.
- Ty le hu hdng (%): F = Hn xlOO/H
Trong do: F (%) ty le hu hdng; Hn sd qua bi hu hdng dcac lan phan tich (n = 1,2, 3,...); Hsd qua liic dau trong mau thi nghiem.
Qua hu hdng la qua xuat hien nhiing ddm den, xuat hien nam moc, qua hi iing, dap nat.
- Ham lugng chat khd tdng sd dupe xae dinh bang chiet quang ke dien hi Atago.
- Xac dinh dp ciing qua bang may do TigerDirect HTGY3, donvi do kg/cml
- Xae dinh ham luong acid tdng sd bang phuong phap theo TCVN 5483^91 0 5 0 750 - 19811).
- Xac dinh ham lupng vitamm C theo phuong phap chuan dp bang idt 0,01N.
- Danh gia chat lupng earn quan dua vao phuong phap cho diem theo TCVN 3215-79 vdi thang diem hj 0 - 5 ddi vdi 4 chi tidu: hinh fhiic ben ngoai qua, vj, trang thai bdn trong qua va miu.
+ Ma hda mau: Lay 3 sd nglu nhien trong bang sd tu nhien,
+ Chuan hi mlu: M&u dupe xep vao dia theo thii tu dupe ma hda va mdi ngudi trong hpi ddng nhan duffC m d t dia.
+ Cach thiic tap huan hpi ddng: Hdi ddng 10 ngudi, nguffi kiem tra phai cd kha nang danh gia khach quan cd kha nang phan biet cam giac tdt, cd kien thiic chuydn mdn tdt va kien thiic phan tich cam quan; ngudi kiem tra khdng d- trang thai qua no hoac qua ddi, khdng dupe diing do an thiic udng cd chat gia vi kich thich manh hay mdt chat nao dd cd luu vi lau.
+ Thli tu danh gia cac chi tieu theo doi: Mau sac ben ngoai qua => vi => trang thai ben trong qua ->
mill.
92 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 12/2019
KHOA HOC CONO NGHE
Bang 1. Mite dd quan trpng cua tijmg chl tigu d^inh STT
1 2 3 4
T6nchiti6u Mau sdc b^n ngoai qua Vi
Trang thai ben trong qua IMui
He s6 trong luong
1,2 1 0,95 0,85 - Vi sinh vat hieu khi tdng sd bang phucmg phap dd dia theo TCVN 4884:2005
2.2.3. Pbuong phdp xii ly so hiu
Sd lieu dupe xu ly thdng kd bang phan mem Irristat 4.0 va phan mem Microsoft Excel 2007.
3 . KET QUA NGHBU GtiU VA THAU LUAN
3.1. K^t qua d^nh gi^ su bi^n d6i m^u s^c qua dau tay trong qu^ trinh bao quan bang cdng nghd Hyokan
Mau sdc la mdt trong nhtrng tieu chi hang dau anh hudng ddn quyet dinh mua cua ngudi tieu dimg.
Dau tay mau do sang, be ngoai hap din se thu hiit khach hang. Pelargonidm-3-glucpside, pelargpnidin- 3-rutinoside va cyanidm-3-glucoside la thanh phan chinh ciia anthocyanin trong dau tay quyet dinh mau do tuoi cua qua [4]. Danh gia su bidn ddi mau sac cua qua dau tay tren ba tieu chi: dd sang (chi sd L), mau do ciia dau (chi sd a), mau vang (chi sd b). Ket qua dupe the hidn ff bang 2.
BSng 2. K^t qu^ danh gid su bidn ddi m^u sac qua dSu tay trong Chi hdu
Chi sd L
Chi sd a
Chi sd b
Cdng thuc Ddi chiing Hyokan LSD„„, Ddi chiing Hyokan LSDaa, Ddi chiing Hyokan LSDnas
Ongay 34,69 34,69 25,47 25,47 53,58 53,58
7 ngay 33,98"
34,68"
0,95 24,52'' 28,11"
0,76 50,23»
53,05"
1,61
qua trinh bao quan bang cong ngh$ Hyokar 14 ngay
33,17' 34,64' 2,81 23,93' 26,90' 2,03 44.93' 50,98' 4,72
21 ngay 32,85' 34,56' 1,18 23,16' 25,83' 1,67 43,59' 49,22' 1,21
28 ngay 34,54
25,27
48,12 Ghicbii: Trong ciing mpt cot, cac cdng tbiic co cbi sd mu kbac nbau tbi khacnhau coy nghia dmiic dp tin cay 95%.
Bang 2 cho thay cac ehi sd mau sac L, a, b ciia qua dau tay b ckc cdng thiic ddu cd xu hudng giam dan, giam nhanh hon b cdng thuc ddi chiing sau 21 ngay bao quan. Cu the: Sau 14 ngay bao quan ehi sd L da cd xu hudng giam tuy nhidn vin khdng cd su khac nhau cr hai cdng thuc. Den ngay thii 21, b cdng thiic ddi chting ehi sd L ciia dau tay cd su giam nhanh hon so vdi cdng thiic dau duoe bao quan bang cdng nghd Hyokan va su thay doi nay la khac nhau cd y nghia khi so sanh hai edng thiic a miic y nghia p= 0,05.
Vd hai chi sd a va b ciia qua dau tay, cdng thuc
khac bidt vdi cdng thiic Hyokan d- mpi thdi diem thdng ke.
cac chi so b edng thiic Hyokan thay ddi cham hon do cd su tac dpng cua dien trudng lam cac phan tii bdn trong qua dao ddng Hen tuc va khdng lien ket vdi nhau, lam ban che cac qua trinh hd hap cflng nhu su bien ddi cac sac td ciia qua. Didu nay cho thay edng nghe Hyokan cd tac dung duy tri mau sic qua tdt hon bao quan trong tii Ianh thudng.
3.2. K^t qua ddnh gid su bidn doi dp ciing ciia qua dau tay trong qud trinh bao quan b ^ cdng nghd Hyokan
ddi ehiing cd xu hudng giam nhanh hon va ed su
Bang 3. K^t qua danh gid su bi^n ddi dd ciing cua qua dau tay (kg/cm^ trong qua trinh bao quan bang chi tieu
Do cimg thit qua (kg/cm^
Cdng thiic Ddi chiing Hyokan LSDoK
Ongay 1,37 1,37
7 ngay 1,03' 1,27' 0,13
14 ngay 0,93' 1,17"
0,21
21 ngay 0,77' 1,13' 0,21
28 ngay 1,07 Ghi chu: Trong cdng mdt cdt, cac cdng thdc cd chi sd mu khac nhau thi khac nhau cdy nghia d-muc do tin cay 95%.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 12/2019 93
KHOA HQC CdNG N G H £
Mdt hong nhung chi tidu quan trpng trong vigc danh gia chat lupng ciia qua dau tay la dd eiing ciia thit qua. Trong qua trinh bao quan dau tay bi mem di do cd su mat nude lam cho hen ket giua cae pbln tii thit qua bi long leo, cau tnic qua khdng giu nguyen dupe trang thai ban diu. Ket qua theo doi su bien ddi dp Cling cua qua hong sudt qua hinh bao quan duuc thd hidn dbang 3.
Bang 3 cho thay, sau 21 ngay bao quan, do ciing cua qua dau tay d' hai cdng thiic deu giam, giam nhanh nhat la cdng thiie ddi chting, giam ttr 1,37
vat tdt hon, ban chd qua hinh hd hap va trao ddi chat, do do eau tnic qua dupe duy tri. Cdng Ihtic dot chting didn ra boat ddng hd hap nhieu hon aen st;
chuydn hda pectin xay ra nhanh hon, qua dau tay co dp Cling mem hon.
3.3. Kdt qua dlnh gid su hao hut khdi luong ciia qua dau tay trong qud hinh bdo quan bang cdng nghd Hyokan
Hao hut khdi lupng ta nhien la hao hut khdng the tranh khdi cua bat cti loai rau, cii, qua ndo sau thu hoach. Sir mat nude la nguyen nhan chinh din kg/cm^ xudng 0,77 kg/cm^ cdng thiic bao quan den khdi lupng qua bi hao hut, lam qua khd, lam bang Hyokan giam cham hon, giam ta 1,37 kg/cm^
giam xudng cdn 1,13 k g / e m l Dp cting giam do trong qua trinh bao quan, hpp chat propeetm giam, iam chuyen hda pectin din ddn kha nang lien ket giira cac te bao va md ydu di, ben eanh ydu td thtiy phan ndi tai ctia protopectin thi vi sinh vat gay thdi hdng qua ciing gdp phan pha vu cau tnic qua. Viec ket hop xu ly bang nhiet dp va dien trudng hong cdng nghe Hyokan cd tac dung lie che su phat trien ciia vi sinh
Bang 4. Ket qua ddnh gid su hao hut khdi lupng ciia qua ddu tdy (%) trong qud trinh bdo qukn bdng cdng nghd Hyokan
giam chat lugng cam quan cua qua. Ngodi ra, con do qua trinh hd hap lam heu hao cac chat du tru trong qua. cac kdt qua nghien ciiu ctia cac tac gia trong va ngoai nude deu cho thay nhiet do thap lam giam cudng dp hd hap ciia qua. Tuy nhien, nhidt dp thap lai lam gia tang cudng dp thoat hoi nude. Ket qua danh gia six hao htit khdi lugng qua dupe thd hien d bang 4.
Chi tieu Hao hut khdi
lupng
(%)
Cdng thiic Ddi chiing Hyokan
LSDoos
Ongay 0 0
7 ngay 0,04"
0,02' 0,02
14 ngay 1,33' 0,22' 0,57
21 ngay 2,09' 0,47"
0,69
28 ngay 0,60 sd'mu kbic nbau thi kbic nbau cd y ngbia &muc
Ty le hu hdng ciia dau tdy trong qua trinh bao quan la mdt trong cac chi heu quan trpng de xac dinh hieu qua cua qua hinh bao quan sau thu hoaeh.
Mdt hong nhung nguydn nhan gay thdi mem, hu hdng qua la benh mdc xam Botrytis cinerea va Rhizopus sp. [3], su lay nhidm nam tir cae qua hi benh sang qua khdng hi benh hong qua trinh thu hoach cung nhu bao quan lam cho ly le hu hdng qua nhieu hon, giam gia tri cua qua. De ban che ty le hu hdng phai khdng che su phat hidn ctia vi sinh vat. Vi vay da hen hanh theo doi ty le thdi hdng trgn qua dau tay. Kdt qua dupe hidn d' bang 5.
Bang 5 cho thay ty le thdi hdng cua dau tay cr hai cdng thtic cd xu hudng tang dan theo thdi gian bao quan. Ty le thdi hdng gitia cae cdng thtic cd su khac nhau ro ret sau 7 ngay, 14 ngay va 21 ngay bao quan. Sau 7 ngay bao quan, qua dau tdy duoe bao quan a tu lanh thudng cd ty le thdi hdng la 22,22%
trong khi dau tay duoe bao quan bang cdng nghe NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 12/2019 Ghi cbu: Trong cung mot cpt, cac edng thue ed chi
dp tin cay 95%.
Su hao htit khdi lupng: Trong thdi gian bao quan, khdi lupng dau tay cua 2 cdng thtic cd xu hudng giam din, giam nhanh hon b cdng tlitic ddi chting, ty le hao hut khoi lupng dat 2,09% sau 21 ngly bao quan, hong khi dd su hao htit khdi lupng ctia dau tay b cdng thtie Hyokan rat nhd, chi dat 0,47%. Va sti khac nhau nay cua 2 cdng thtic la cd y nghia thdng ke a miic dd tin cay 95% sau thdi diem 14 ngay va 21 ngay bao quan. Su hao htit nay cd thd giai thich do xay ra qua trinh hd hap sit dung cff chat va mat nude a qua. Cdng nghd Hyokan cd kha nang ban chd qua hinh hd hap xay ra ben hong qua cung nhu uc che sir phdt tridn cua vi sinh vat nen su hao htjt khdi luong didn ra cham, tdn that sau thu hoach khi bao quan qua dau tay tdt hon ta lanh thudng.
3.4. Kdt qud ddnh gid ty Id hu hong ciia qua ddu tay trong qud trinh bdo quan bdng cdng ngh^
Hyokan 94
KHOA HOC CONG NGH|
Hyokan ehua xuat hidn hien tugng thdi hdng. Sau 14 ngay bdo quan thi ty le hu hdng ddu tay ff tii lanh thudng va ta lanh vdi cdng nghd Hyokan tuong iing Id 41,67% va 8,33% (< 10%). Tuy vay, ty Id thdi hdng cua dau tay bao quan bing cdng nghd Hyokan cung
gia tang den ngay 21 la 13,89% va ngay 28 la 36,11%.
Dieu nay eho thay cdng nghd Hyokan cd kha nang bao quan dau tay hong 14 ngay vdi ly Id hu hdng thap 8,33% va tdt hon so vdi dau tay duoc bao quan a ta lanh thdng thudng.
Bang 5. Kdt qua danh gid t^ Id hu hong cua qua ddu tay (%) trong qud trinh bao quan bang cong nghd Hyokan Chi tieu
Ty le thdi hdng
(%)
Cdng thiic Ddi chiing Hyokan
LSD„„s
Ongay 0 0
7 ngay 22,22' 0' 15,4
14 ngay 41,67'
8,33' 26,67
21 ngay 91,67' 13,89' 7,7
28 ngay 36,11 Gbichu- Trong Cling mdt cdt, cac cdng thuc cd cbi sd mil khac nhau thi khac nbau coy nghia a muc dp tin cay 95%.
ngudi heu dimg ehap nhan. Kdt qud danh gia ham lugng chat khd hda tan (TSS), ham lupng acid tong sd, ham lupng vitamin C cua 2 cdng thtic bao quan duoc thd hien d bang 6.
3.5. K^t qud danh gid hdm lupng TSS, acid tong sd, vitamin C ciia qua ddu tay trong qud trinh bao quan bing cdng ngh^ Hyokan
Chat lupng hda sinh cua qua la mdt ydu td hang dau dd danh gia gia hi cua san pham duoc
Bang 6. Kdt qua danh gid hdm lupng TSS, acid tdng sd, vitamin C cua qua ddu tdy trong qud trinh bdo qudn bang cdng nghe Hyokan
Chi tieu Ham lupng chat khd hda tan ("Bx) Ham lugng acid tdng sd
(%)
Ham luong VitaminC (mg/g)
Cdng thiic Ddi chiing Hyokan
LSD„.5 Ddi chiing
Hyokan Ddi chiing
Hyokan LSD„„,,
0 ngay 9,83 9,83 1,20 1,20 14,20 14,20
7 ngay 8,53' 8,93' 0,21 1,18' 1,25"
0,03 12,51' 13,81"
14 ngay 7,63' 8,17"
0,26 1,12' 1,23"
0,04 11,96' 13,73'
21 ngay 6,13'
7,9"
0,24 1,01' 1,18"
0,07 10,84' 13,44'
28 ngay 7,87
1,10
13,33 Ghi chii: Trong cung mpt cpt, cac cdng thuc cd chi sd mii khdc nhau tbi khac nhau cd y ngbia a miic dp tin cay 95%.
Ham lugng chat khd boa tan (TSS) cua qua ddu tay cd thanh phan chu ydu la dudng. Ham luong chat khd hda tan cd xu hudng giam dan a cac cdng thuc.
Sau 21 ngay bao quan, cdng thtic Hyokan giam ta 9,83''Bx xudng 7,9''Bx, cdng thtic ddi ehiing giam nhanh hon, giam ta 9,83°Bx xudng 6,13°Bx. Ket qua xu ly thdng ke cho thay, ham lupng TSS ciia hai cdng thtic nay 11 khac nhau dang ke b mpi thdi diem so sanh Vffi miic y nghia p=0,05.
Ham lupng acid tdng sd: Ham luong acid tong sd ctia qua dau tay duge bao quan b cdng thuc ddi chting cd xu hudng giam xudng theo thdi gian bao quan, giam ta 1,2% xudng 1,01%, a cdng thtic Hyokan, ham lupng acid tong sd ctia dau tdy lai ed xu hudng tang len sau 7 ngay bao quan va giam eham cr cac ngdy bao quan tiep theo. Ket qua xii ly thdng ke cho NONG NGHIEP VA PHAT TRIEN NONG THON
thay ff mpi thdi diem thdng ke, su khdc nhau cua hai cdng thiic nay Id cd y nghia a mtic dd tin cay 95%.
Ham lupng vitamin C: Trpng qud hinh bap quan, hdm lugng vitamin C d 2 cdng thtic bdo quan cd xu hudng giam xudng. O cdng thtic Hyokan hdm lupng vitamin C giam tii' 14,20 mg% xudng 13,44 mg% sau 21 ngay bao quan. Trong khi do cdng thtic ddi chiing, ham lupng vitamin C ctia qua dau tdy gidm xudng mtic tiiap hon, dat 10,68 mg%. SIJ khdc nhau Cila hai cdng thiic ndy la cd y nghia a thdi diem 21 ngay bao qudn.
Ket qua nay phii hpp vdi nghien ciiu Fernando Ayala-Zavalaa, SA (2004) [6] TSS, acid, vitamin C hong ddu tay dupe luu tini d' O^C, 5°C, lO^C ddu cd xu hudng giam la do cac boat ddng hd hap cao ciia qua. Dau tdy khi duoe luu trti p CC kha ndng hd
-KY 2-THANG 12/2019 95
KHOA HOC CdNG NGHE hap thap hon nen ed the giup bao tdn cac
carbohydarte hong md tdt hon.
3.6. K^t qua ddnh gid ch^t lupng cam quan qua ddu tdy trong qud trinh bao quan bang cdng nghd Hyokan
Phan ldn ngudi tidu dimg khi dua ra quydt dinh mua hay khdng mua san pham hudc tidn ddu can cii
Bang 7. Khdo sdt hidu qua a i a di^u ]a$n bdo quan bang cdng ngh§ Hyokan d^n ch^t lupng cdm quan qua ddu vao thudc hnh cam quan cua san pham, vdi loai qua dimg an taoi thi dieu ndy rat quan hgng. Trong qua trinh bao quan, chat lupng cdm quan ciia dau tSy hi thay ddi nhieu. Da tien hanh ddnh gid cam q " ^ ^ ngdy thti 21 vdi hdi ddng gdm 10 ngudi diing phuong phdp cho diem theo Tieu chuan TCVN 321&-97, ket qua thd bien dbdng 7.
Cdng thiic Djtutuoi Hyokan Ddi chiing He sd trpng lugng
Mau sac ben ngoai qua
4,7 4,4 3,3 1,2
Trang thai ben trong
qua 4,7 4,3 3,1 0,95
iVIiii 4,8 4,3 3,2 0,85
Vi 4,8 4,3 3,2 1
Diem trung binh cd h^ sd trong luong
18,99 17,32 12,64
Xdp loai Tdt Kha Trung bmh Bang 7 eho thay, sau 21 ngdy bao quan cd 2 cdng
thtic thi nghiem cd chat lupng cdm quan giam dan ve cdc chi tidu nhu hinh thtic ben ngoai, hang thdi ben trong, miii va vi. CS cdng thiic ddi chting eac chi tidu theo doi ehat lupng cam quan giam nhanh, do taoi giam, mau sdc vd qua thay ddi nhieu, qua mdm hon, mill va vi da cd su thay ddi, chat luong cam quan chi d- muc trung binh. Chat lupng cam quan ciia ddu tay bao quan bang cdng nghe Hyokan ed dp tupi, vi nggt gidm nhe, qua mem hon, chat luong cam quan vdn dat loai kha.
3.7. Kdt qua ddnh gid chi tidu vi sinh vdt ciia qua ddu tay hong qud trinh bao quan bang cdng nghd Hyokan
Ddu tdy la loai qua rat mim cam vdi su gay hai cua vi sinh vdt, dac biet la vi khuan va nam sau thu hoach do ddu tdy cd bd mat vd mdng. Cac vi smh vat nay chu yeu ta nhung qud bi bdnh bi tdn thuong do va dap hong qud hinh thu hoach va van chuyen va bao qudn. Vi vay, trudc khi dua vao bao quan can chpn lira ddu tdy Idnh lan, khong dap ndt, mdu sac dep, thom, ngon. Bdng 8 Id ket qud vi sinh vdt tong sd da theo doi dupe khi bao quan dau tdy bang cdng nghe Hyokan va d ta lanh thdng thudng.
Nhu vay, hieu qua cua cdng nghe Hyokan Id cd tac dung duy tri chit lupng dau tay khd tdt. Kdt qua nay hodn toan phii hgp vdi kdt qua phdn tieh cac ehi tieu mau sdc vd qua, chat lugng hda ly d' tren.
Bkig 8. Chi tidu vi sinh vdt hidu khi tdng sd ciia qud ddu tdy (CFU/g) trong qud trinh bao quan bing cdng nghg Hyokan
Cdng thiic Ddi chiing Hyokan
Trudc bao quan 3,3x10' 3,3x10'
Sau 7 ngay 9,4x10' 4,3x10'
Sau 14 ngay 1,1x10' 4,5x10'
Sau 21 ngay 2,5x10' 4,9x10'
Sau 28 ngay 7,5x10' Bang 8 cho thay, sd lupng vi sinh vat hieu khi
tdng sd hong qua dau tay ciia hai cdng thiic cd xu hudng tdng dan theo thdi gian bao quan. Sd luong vi sinh vat trong dau tay a cdng thiie ddi ehiing cd xu hudng tang nhanh hon edng thtic Hyokan, tuy nhien sd Iupng vi sinh vat vdn b ngudng cho phep theo heu ehuan nganh ve tieu chuan rau qua (lOTCN 846:
2006). Didu nay cho thay cdng nghe Hyokan cd khd nang lic che su phdt tnen cua vi sinh vdt tdt hon so vdi ta lanh thudng (Cdng thiic ddi chiing).
4. KET LUPI
Bao qudn ddu tay Mdc Chdu bang cdng nghe Hyokan - cdng nghe dien trudng cua Nhat Ban d nhiet dd -2''C, dien ap 3.500 V eho chat lupng tdt hon so vdi bap qudn d nhiet do thuong d- nhiet dp 2 - 4''C.
Dau tdy bao quan bdng cdng nghe Hyokan sau 14 ngay vin giu dupe mlu sac ben ngoai, do cung gidm cham; cac bien ddi ham luong TSS, hdm luong acid vd vitamin C xu hudng giam cham, hao hut tir nhien gidm 0,22%, ty le hu hdng Id 8,33%. Didu nay da lam 96 N O N G NGHIEP VA PHAT TRIEN N O N G THON - KY 2 - THANG 12/2019
KHOA HOC CONG NGHE rd tdc diing cua dien trudng ket hpp vdi nhidt dp lanh
lam lie che hoat dpng ctia vi sinh vat, Idm chdm cac qua trinh bidn ddi hda, ly, sinh hgc ben hong qua ddu tay. Dd ban chd nhting tdn that vl hao htit ve chat lupng, hieu qud ve bao quan sau thu hoach, tieu thli ddu tdy trong khoang 14 ngay khi bao quan bang cdng nghd Hyokan la phii hgp vdi mtjc tidu sau thu hoach ndng sdn hien nay.
TAl UEU THAM KHAO
to High - CO2 During Stprage at 0 "C on Biology andlnfectivity of Botiytis cinerea in RedChicory, J.
Phytopathology, 151, pp. 201 - 207.
4. Han, Y. Selby, T. L. Schultze, K K Nelson, E. E. Linton, R H (2004). Decpntamination of shawberries usmg batch and continuous chlorine dioxide gas heatments, 67 (11), pp. 2450 - 2455.
5. Hancock, J. F. (2000). shawberry industry, Strawberries CABI.
6. Lara, I. Garcisa, P. Vendrell, M (2004).
Modifications in cell wall composition after cold storage of calcium-heated shawbeny (Fragaria a ananassa Duch.) fruit, Postharvest Biology and Technology, 34 (3), pp.331-339.
7. Fernando Ayala-Zavalaa, S. A. (2004). Effect of storage temperatures on antioxidant capacity and aroma compounds in shawberry fruit, Lebensm- Wiss,u-Technpl.37.
8. http://www.pstec.co.jp/vn/hyokan/.
1. Ld Huong Lan (2012). Nghign ciiu su dung bao hi va phuong phdp lam lanh de bdo quan vd van chuyen vai thidu di tieu thu. Ludn van tdt nghiep thac Sl ndng nghidp nganh cdng nghe sau thu hoach. Dai hpc Ndng nghiep Ha Ndi.
2. Baka, M. Mercier, J. Corcuff, R. Castaigne, F.
Aral, J. (1999). Photochemical Treatment to Improve Storability of Fresh Shawberries, Joinnal of Food Science, 64 (6), pp.1068-1072.
3. Bertolini, P. Baraldi, E. Man, M. Trufelli, B.
Lazzarin, R. (2003). Effects of Long Term Exposure
RESULTS OF SURVEYING EFFICIENCY STORAGE STRAWBERRIES BY HYOKAN TECHNOLOGY TalTiu Hang, Nguyen Dac Binh Minh, Kouichi OMura,
Nguyen Dac Hoang, Doan Thi Bac, Pham Thi Mai Anh Summary
The study was conducted to investigate the efficiency of the cryo-storage conditions of Hyokan technology on the quality and reduction of post-harvest losses of Moc Chau strawberries. Strawbemes are harvested with 80% of their pods npening to red. After processing, strawbemes are preserved by two formulas: (1) Control is preserved by Sanky fridge at 2 - 4''C; (2) Refrigeration by Hyokan technology at -2''C, voltage of 3,500 V. Strawberries stored in a refrigerator typically 2 - 4°C have a faster detenoration in quality than the organoleptic quality, nutritional quality, weight loss as well as damage rate when compared to the processing. Preserved by Hyokan technology after 7, 14, and 21 days of storage. After 14 days of storage, the strawbemes m the Hyokan formula changed color slowly, hardness decreased by 0.2 kg/cm^ volume loss reached 0.22%; The content of dissolved dry matter decreased slightly, reaching S.iyBx; total acid content slightly increased, reaching 1.23%; content of vitamin C slightly decreased to 13.23 mg%; the failure rate is 8.3396 lower than the target of preserving agricultural products after harvest.
Keywords: Cold storage, Hyokan technology, strawbeiry hvil, Moc Chau strawberry.
Ngirdi phan bidn: PGS.TS. Pham Anh Tudn Ngdy nhdn bdi: 28/10/2019
Ngdy thdng qua phan bidn: 29/11/2019 Ngdy duyet ddng: 6/12/2019
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 12/2019 97
