TAP c m KHOA HOC TRUClNG DAl HQC TRA VINH, s 6 33, THANG 03 NAM 2019 19 I
NGHIEN Ctru QUY TRINH CHE BIEN NU6C R £ TRANH DONG CHAI THANH TRUNG
Nguyen Thi Huynh Thao^ Sdn Thi Quynh Tran^, Nguyin Dflc Toan^
RESEARCH ON THE PROCESS OF PRODUCING PASTEURIZED BEVERAGE FROM IMPERATA CYLINDRICAL BEAUV ROOT
Nguyen Thi Huynh T h a o \ Son Thi Quynh Tran^, Nguyen Due Toan^
Tom tat - Nghien ciiu quy trinh chi biin nude re tranh thanh trung nham too ra sdn phdm dat chdt lUOng tdt vd cd the keo ddi thdi gian bdo quan, Idm phong phu them mat hdng nude gidi khdt thdo duOc vd ed loi cho Stic khde. Ket qud nghien cihi cho thdy: re tranh duOc trich li d nhiet dp 100"C vdi khoi lupng 40 g trong 2 lit nude se cho dich trich ed gid tri cam quan tot nhdt vi mdu, mid vd cd dp Brix 2,05±0,04. Sdn phdm dupe phoi chi dat 9°Brix bang dudng phen vd dieu chinh vi vdi 0,03% acid citric. Thanh trung thdnh phdm chiia trong bao bi thuy tinh d nhiet dp 90°C vdi gid tri thanh triing P-value Id 5 phiit, tao ra sdn phdm it bi thay doi ve gid tri cam quan, an toan vi mat vi sinh vd sdn phdm bdo quan duoc trong thdi gian ddi
Ti( khda: ni/dc giai khdt, re cd tranh, quy trinh chi bien, thanh trung.
Abstract - The process oflmperata cylin- drical Beauv root beverage was studied for making the best quality and shelf-life of products, diversifying herbal beverage prod-
^•^Sinh vien, Khoa Nong nghiep - Thuy san, Tnfcfng Dai hoc Tra Vinh
^Khoa Nong nghiep - Thuy san, TrUcing Dai hoc Tra Vinh
Ngay nhan bai: 27/10/2018; Ngay nhan ket qua binh duyet: 23/4/2019; Ngay chap nhan dang: 06/6/2019
Email [email protected] ' Student, School of Agriculture and Aquaculture, Tra Vinh University
^School of Agncuhure and Aquaculture, Tra Vinh University
Received date 27"' October 2018 , Revised date. 23'"'' April 2019; Accepted dale 06"' June 2019
ucts and being beneficial to health. The results showed that: Imperata cylindrical Beauv roots were treated at the temperature of 100° C with 40gin 02 liter watermass that brought a good sensory and high Brix value 2,05rt0,04 for products. The products were mixed with 9°Brixby rock-sugar and 0,03%
citric acid. Pasteurization products packing in glass bottles at the temperature was 90°C and P-values was 5 minutes, respectiveU.
With the above treatment conditions, Imper- ata cylindrical Beauv roots beverage made products unchanged in flavor, yield good quality, microbiological safety and be pre- served for a long time.
Keywords: beverage, imperata cylindrical Beauv, processing, pasteurization.
I. DAT VAN DE
Co tranh (Imperata Cylindrical Beauv), thuoc hp lua Poaceae, phan bo rong rai cl cac vung nhiet ddi va can nhiet ddi d chau A, chau Phi, chau My va chau Dai Dfldng, mot s6 ndi d Nam Au. 6 chau A, cd ttanh phan bo hau het cac nfldc d Trung A, Nam A, Dong Nam A, Dong Dfldng va cac dnh phia nam Trung Qudc, ke ca dao Hai Nam, O Viet Nam, c6 tranh c6 khap ndi, tfl cac dao vung dong bang, ttung du mi^n nfli den dp cao hdn 2000 m. Cay fla sang, s6ng dai, CO the mpc tten mpi loai dat, chiu dfldc han cao, nhd c6 he thong r l dac biet phat tti^n.
Bp phan dung la thSn r l . Re c6 ttanh dao ve (khong lay loai r l tten mat d4t) rfla sach dat
cat, tuot bo la khd va rl con, dem dung tfldi hoac dem phdi hoac say kho [1].
Tac dung dfldc li cua rl c6 ttanh nhU: giflp thanh nhiet, giai khat, ldi Heu,... [1], [2], cd hoat Hnh chong oxi hda cao [3]. Ben canh dd, rl CO ttanh con chfla cac hdp chit khoang nhU: jarosite va ferrihydrate-ferritin [4], giau hdp chit sat [5].
Vdi nhflng dac tinh dfldc li dd, rl c6 ttanh thfldng dfldc sfl dung niu cac loai nfldc mat cd bo sung them phu lieu nhfl: la dfla, mia lau, dfldng phen, nhan nhuc,... vfla cd cong dung giai khat lai giup giai nhiet cho cd the'.
Tuy nhien, san pham nUdc mat nay chi dUdc sfl dung ttong thdi gian ngan ttung binh mot den hai ngay. Vi the, viec nghien cflu xac lap che dp thanh trung nhiet, keo dai thdi gian bao quan san pham nhung khong sfl dung phu gia bao quan nham dam bao an toan sflc khoe cho ngfldi Heu dflng la can thilt.
Noi dung nghien cflu gom hai bUde: (1) nghien cflu tim ra cac ti le nguyen lieu, phu gia thich hdp mang lai tinh cam quan cao cho san pham; (2) xac dinh gia tri chit nhiet P- value cho qua ttinh tieu diet vi sinh v|t bao quan san pham.
II. TONG QUAN NGHIEN CLfU Cac nghien cflu san xuat nfldc giai khat dong chai flng dung phfldng phap xfl li nhiet ttong bao quan da dfldc tien hanh ttong va ngoai nfldc.
Nhom nghien cflu cua Le My Hdng va cong sfl [6] da thflc hien de tai "Nghien cflu quy ttinh che bien nfldc mia thanh trung", dp Brix san pham thu dfldc la 16, pH khoang 4,1-^^4,2 CO phoi che them 3% nUdc dfla ep.
Che dp thanh ttCing san pham ttong bao bi thuy Hnh dUdc dl nghi la P-value = 4,66 phut d 95''C.
Trong nghien cflu "Qua ttinh chi bien nfldc ttai cay hdn hdp (sdri, khom, chanh day)" cua Le My Hdng va cong sfl [7], san ph£m cd dp Brix 20% gia tti pH can bang
< 4,6. Che dp thanh trung dfldc xac dinh tot nhat d 90''C se lam han che mui nau chin va ton that vitamin C cung nhU mau sac san pham thap nhit. Gia tti thanh trung P - value de nghi la 34,39 phut.
Ket qua nghien cflu cua Phan Thi Thanh Que va cong sfl [8] "Anh hudng cua dieu kien che bien va bao quan den sU 6n dinh mau betacyanin ttong nUdc ep thit qua thanh long rupt do" cho thiy nUdc ep thanh long c6 bo sung 0,2% acid ascorbic, dieu chinh den 16''Brix, pH = 4,0 sau khi phoi che, gia tti thanh triing d SO^C la P-value = 5,33 phflt cho kha nang gifl mau betacyanin tot nhat sau ba tuan d 30''C ttong bao bi ngan sang (ham Ifldng con 51%) va tdi Uu nhit khi bao quan san pham d 13''C (ham Ifldng con hdn 90%).
Theo nghien cflu cua TUcker va Tone [9], doi vdi cac san pham thflc phim ed thuoc tinh acid (pH < 4,6), khi ap dung phfldng phap thanh trung bao quan thi gia tti thanh ttung li thuyit cd the dUde xac djnh can cfl theo gia tti pH can bang cua san pham theo Bang 1.
Bang 1: Gia tti thanh trung li thuyit cho thflc ph^m cd tinh acid (pH < 4,6)
pH p-value (phiit) d T^^f - 93,3''C va x = 8,9°C
< 3 , 9 0,1 3,9 -;- 4,1 1,0 4.1 -r 4.2 2,5 4.2 H- 4.3 5.0 4.3 ^ 4,4 10,0 4.4 -r 4,5 20,0
(Ngudn: Tucker vd Tone 2011 [9])
III. PHUONG TIEN VA PHUONG PHAP NGHIEN cOU
A. Nguyen vdt lieu nghien ciiu
Nguyen heu: re ttanh tfldi, la dfla tfldi dfldc thu hoach mpc bui d cac vung dit trdng khong c6 canh tac thuoc xa Vinh Kim, huyen Cau Ngang, tinh Tra Vinh. Nguyen lieu dfldc ngam rfla sach dat cat, khong bi am moc. Ngoai ra, nghien cflu con bo sung them nguyen Heu nhan nhuc khd (dp am leq 35%) nham tang them hUdng va mau sac cho san pham.
50
TAP CHl KHOA HQC TRUdNC DAl HOC TRA VINH. s 6 33. THANG 03 NAM 2019 N 6 N G N G H 1 $ P - THUY SAN
Phu gia: acid cittic (99,5%), dUdng phen (> 99%) xuit xfl Viet Nam.
B. Thiit bi dUng trong nghien ciiu Noi niu dien cong suit 700 w, the tich 2 lit, cd bp dieu khien kiem soat nhiet dp nSu (sai so nhiet dp ±0,2).
Data logger ghi nhan dfl lieu nhiet dp Mastech model MS6514: cd kha nang dpc va ghi vdi hai kenh dfl lieu thong qua cam bien thermocouple loai K, sai so nhiet dp do
±0,5°C. Khoang each gifla hai lan ghi nhan nhiet dp la 10 giay.
Hinh 1: He thong thilt bi thi nghiem thanh trung
(1) Data logger Mastech MS65I4 (2) Thiet bi phong doan tri^c tuyin gid tri P-value
(3) He thdng dieu khien nhiet dp (4) Noi thanh triing edng sudt 700w (5) He thdng may tinh hien thi kit qud do (6) Cam bien nhiet dp themocouple loai K
C Phuong phdp bo tri thi nghiem Thi nghiem 1: Khao sat anh hfldng cua nhiet dd ttich li va khoi lUdng rl ttanh din sfl thay doi dp Brix va gia tti cam quan cua dich ttich.
Muc dich: tim ra ti le nguyen lieu va nhiet dp ttich li thich hdp.
Cach Hen hanh: can chinh xac khoi Ifldng nguyen lieu rl ttanh theo 03 mflc ti le (30 g;
40 g; 50 g) ttong qua ttinh ttich li bo sung them CO dinh 20 g la dfla, 04 g nhan nhuc de tang them hfldng vi va mau sac cho san p h ^ . Ti le nguyen lieu dfldc nau ttong 02 lit nude 5 cac mflc nhiet dp nau (80°C; 90''C;
lOCC), qua ttinh ttich li Hen hanh ttong 02 So mlu thi nghiem: 9 mau, m6i mau Ijip lai 3 lan.
Chi Heu theo d5i: dp Brix cua dich ttich, danh gia c ^ quan (mau sac, miii) cua dich ttich.
Thi nghiem 2: Khao sat anh hfldng cua dudng phen bd sung va phan ttam acid cittic den gia tti cam quan cua san pham.
Muc dich: tim ra dp Brix thich hdp cho san p h ^ khi bo sung dudng phen va phan ttam acid cittic hieu chinh pH san pham.
Cach tien hanh: sfl dung 300 ml dich niu d thi nghiem 1. Tien hanh bo sung dfldng va acid cittic vdi cac mflc: dfldng bo sung (7''Brix; 9''Brix; IFBrix) va acid cittic (0,02%; 0,03%; 0,04%; 0,05%).
Xac dinh Ifldng dUdng bo sung:
6 a — X
100 100 -
[6]
Trong dd:
x: la lUdng dfldng bo sung (g) a: la dp Brix ban diu b: la dd Brix dieu chinh
So mlu thi nghiem: 12 mau, moi mau lap lai 3 lin. Chi Heu theo doi: pH cSn bang cua san pham va danh gia cam quan (mui, vi).
Thi nghiem 3: Khao sat che dp thanh trung san pham
Muc dich: xac dinh gia tti chet nhiet cho qua ttinh thanh ttung nUdc rl ttanh dong chai.
Cach Hen hanh: dich phoi chi dUdc rot chai (200 ml) a 60°C, Hln hanh thanh ttung d 03 mflc nhiet d6 (85°C; 90''C; 95<'C) vdi gia tti thanh ttung (P-value): 03 phut; 04 phiit; 05 phut.
Cong thiic xac dinh gia tti thanh trung:
'-f
Jo10- dt [10]
P : gia tri thanh trung (phiit) t : thdi gian xit li nhi6t (phiit) T : nhi6t dp t^m san pham (°C) Tref ; nhiet do tham chieu (°C) 51
TAP CHl KHOA HOC T R U O N G D/)1 HQC TRA VINft S 6 33. T H A N G 03 NAM 2019 N O N G N G H I E P - THUY SAN
z : khoang tang nhiSt dp ("C) Chi tieu theo doi: danh gia an toan vi sinh vat. Ghi nhan sfl thay doi gia tri dp sang L*
ciaa san pham d cac nhiet dp xfl li.
D. PhUdng phdp phdn tich
Bang 2: Phfldng phap phan tich
STT 1 2
3
C a c chi tieu phan pH
£)o do Brix
EM sing (gia ti\ L«)
Tong so VI sioh v;it hieu khi (MNP/ml), nam men nam moc
tich
(CFU/ml), Ecoh (MNP/ml)
PhiTcAig p h a p p h S n tich p H Hana ffl 99161 Khijc xa ke Atago Thilt bi do mau cam tay RGB-1002
Tieu chuan ISO 4884: 2005
Danh gia chit Ifldng cam quan theo thang di^m Hedonic ve thi hilu ngfldi Heu dving [11], Ngfldi tham gia danh gia, cd chuyen mon v l linh vflc danh gia cam quan, dd tudi tfl 18 - 25 vdi s6 Ifldng la 80 ngfldi.
Bang 3: Thang diem danh gia cam quan theo mflc dp yen thich
T h a n g d i ^ Miic d 8 ySu thich Cue kl khong thich RAI khong thich
Khong thich TUOng d&i khong thich Kh6ng thich, khong ghet
TUOng doi thich Thich R i t thich Cilc ki thich
E. Phuong phdp xvt li so lieu
Thiet ke thi nghiem bang phan mem chuyen dung JMP 9.0.2 (SAS Instittite Inc.,
2011; USA) va Microsoft Excel 2010. Cac gia tti p < 0,05 dfldc coi la cd y nghia thong ke.
rV. K ^ T QUA VA THAO LUAN A. Kit qud khdo sdt khoi lUdng ri tranh trich li d cdc nhiet do
Ket qua nghien ciJu anh hfldng cua nhiet dp ttich li va kh6i r l ttanh din sfl thay ddi dp Brix dich ttich dfldc the hien d Bang 4.
Bang 4: Ket qua thong ke anh hUdng cua nhiet dp ttich U va ti le re ttanh - Ifldng nUdc den sU thay d6i dp Brix cua dich ttich
Nhiet d o -fi K , ^ Xraahlmtdc (g/llt) Do Brix 30/2
40/2 50/2
0,859 ± 0,043 1,00^ ± 0,043 1,45'' ± 0,041 30/2
40/2 50/2
1,00^ ± 0,042 1,75'^ ± 0,043 1,85'^ ± 0,046 30/2
40/2 50/2
1.20= ± 0,043 2,05^ ± 0,047 2.25° ± 0,043
(Ghi chu: Cdc chQ cdi khdc nhau tren cung mot cot the hiin sU khdc biet giiia cdc nghiem thiic d
inticy nghia p < 0,05)
K i t qua d Bang 4 cho thay: khi tang khoi lUdng nguyen lieu, ham lUdng cac chat hoa tan se tang ttong qua ttinh ttich li bieu thi qua mflc tang gia tti dp Brix. 6 cung nhiet dp ttich li, mflc dp thay doi dp Brix khi sfl dung kh6i Ifldng r l ttanh ttich li 40 g va 50 g la khong nhieu.
Sfl khac biet dp Brix do dac ro ret nhat khi Hen hanh ttich li d cac nhiet do 80''C, 90''C, 100°C. Dieu nay cho thiy nhiet dp ciing la ylu to anh hfldng quan ttpng den kha nang khulch tan cac chat tan ttong qua ttinh ttich li. D l dang nhan thiy khi ttich li d cac nhiet dp khac nhau 80°C, 90''C va 100°C ttong cung mdt khoi Ifldng 30 g hoac 40 g hoac 50 g, dp Brix dich ttich tang din. Ket qua danh 52
TAP CHi KHOA HOC TRUCING DAI HOC TRA VINH. 36 33. THANG 03 NAM 2019 NONG NGHIEP - THU f SAN
gia cam quan mau sac va mui dich ttich dUdc the hien qua dd thi thong ke d Hinh 2.
Khoi liTtfiig r« tranli, nhiet So trii:h li Hinh 2: Anh hUdng cua nhiet dp trich li va khoi lUdng re tranh den gia tti cam quan mau va mui cua dich ttich
Ghi chii: Cdc cha cdi khdc nhau the hien sU khdc biet giiia cdc nghiem thiic 3 miic y nghia p < 0,05
Tinh chit cam quan la mdt trong cac tinh chat quan ttpng doi vdi san pham noi chung va nfldc giai khat noi rieng [12]. K i t qua danh gia cam quan dich trich cho thiy khi trich li nguyen lieu d nhiet dp 80°C va lOO^C sfl khac biet vl mau sac va mui san pham the hien ro nhit. Kit qua cam quan cua dich trich d lOO^C ve mau mui cd diem cam quan cao nhit. Khi ttich li d lOO^C, gia tri dp Brix 6 40 g (2,05±0,047) nho hdn 50 g (2,25±0,043) (Bang 3), tuy nhien diem cam quan vl dp dam mau cua san pham khong qua khac biet.
Kit qua cam quan mui san pham sau khi nau 40 g d lOO^C cho diem cam quan yeu thich cao nhit. Tinh thi hieu ttong qua ttinh sfl dung san pham truyen thong cung phan anh ro tren kit qua lUa chpn diem cam quan mui, dich trich 40 g d 100°C dUdc yen thfeh hdn 50 g d lOO^C, lUdng nguyen lieu sut dung trong qua trinh trich li la yeu to quan ttpng quylt dinh sU chip nhan cua san pham vdi ngUcii tieu dung.
B. Anh hudng cua nong dp dudng, acid citric phoi chi din chat lUOng sdn phdm
Ket qua pH cua san pham sau khi phii che vdi cac mflc ndng dd acid cittic (0,02%, 0,03%, 0,04%, 0,05%) va dp Brix hidu chinh bang dfldng phen (T^Brix, 9'*Brix, ll^Brix) the hien d Bang 5.
Bang 5: Gia tti pH can bang cua san pham sau phoi che
Do Brix iioas, do add dtric Gia tri pH can bfing
7''Brix
9''Brix
i l ' ' B r i x 0,02%
0,03%
0.04%
0.05%
0,02%
0,03%
0,04%
0,05%
0,02%
0,03%
0,04%
0.05%
4,355" ± 0,013 4,090= ± 0.015 3.1\5f ± 0 , 0 1 3
3,4859 ± 0,010 4,355" ± 0 , 0 1 1 4,090'^ ± 0.014 3.785'' ± 0,013 3,680/ ± 0.012 4.230'' ± 0.014 4.060'^ ± 0,010 B.QOS'' ± 0.013 3.755= ± 0,013
(Ghi chii: Cdc chU cdi khdc nhau tren ciing mpt cot the hien sU khdc biet giSa cdc nghiem thiic 6
miic y nghia p < 0,05)
O cung gia tti 7°Brix hoac 9°Brix hoac U^Brix, pH can bang cua san pham giam khi tang ndng dp acid citric. 0 cung nong dp acid citric, gia tri pH thay doi theo chieu hfldng tang khi tang ndng dp dfldng. Cac mlu san pham khi phdi chi cd gia tti pH thap (<
4,6), kha nang khang nhiet cua vi sinh vat kem nen de dang bi tieu diet khi thanh trung [13].
Ket qua danh gia cam quan anh hfldng cua ndng dp dfldng va acid citric den miii, vi san pham the hien d Hinh 3.
Ket qua cam quan xfl li 6 Hinh 3, diem cam quan cao nhat khi sfl dung ndng d6 acid citric 0,03% tUdng flng vdi 9''Brix va I P B r i x . Trong d6, san pham dilu chinh 9''Brix mflc dp yeu thich mui, vi cfla san 53
TAP CHI KHOA HOC TRUONG D^l HpC TRA VINH. SO 33, THANG 03 NAM 2019 N 6 N G NGHlfiP - THUY SAN
• Mau @ Vt
Hinh 3: Anh hfldng cua dp Brix va nong dp acid cittic den mui, vi san pham phoi che Ghi chii: Cdc chit cdi khdc nhau the hien sU khdc biet giiia cdc nghiem thiic 3 miic y nghia p< 0,05
pham sau khi phoi e h l c6 diem trung binh cam quan cao. Cac san pham nfldc giai khat ddng chai cd gia tti dd Brix dUdc dieu chinh phu thuoc dac tinh, tinh chat cam quan yeu thich cua san pham nhU nUdc mia ddng chai 16°Brix theo nghien ciJu cua Le My Hong &
cong sU [6] va Phan Thi Thanh Q u i & cong sfl [8] hay san pham nfldc ttai cay hon hdp la 20''Brix cua Le My Hong & cong sfl [7], San pham nfldc r l tranh e h l biln theo phfldng phap ttuyin thdng, thfldng khdng sfl dung dfldng hay sfi dung rit it dudng phen.
Vi vay, k i t qua cho die'm cua cac thanh vien cam quan cung phan anh dUdc thdi quen yeu thich khi sfl dung san pham nfldc r l tranh.
Dieu chinh Ifldng dfldng d 9*'Brix va ndng dp acid cittic 0,03% dam bao san ph&n sau phoi che hai hoa ve mui, vi, khong qua ngpt hay qua chua.
C. Khdo sdt che dp thanh triing bdo qudn sdn phdm nude re tranh ddng chai
Dien biln thay doi nhiet dp tam cua san pham va ddng hpc thuoc tinh cua thflc pham, tac ddng cua qua trinh nhiet doi vdi thuoc Hnh cua thUc pham dUdc quan tam cd the dfldc tinh toan thong qua he thdng thanh trung [10]. Thay ddi nhiet dp san pham va moi trUdng theo thdi gian cua qua ttinh thanh
ttiing dfldc ghi lai bang cam biln nhiet dp c6 kit noi vdi he thong may tinh. Dfl lieu ghi nhan dUdc tinh toan gia tri P-value da bd tti de xac dinh thdi diem dflng x^ li nhiet, qua ttinh lam ngupi san pham d cac mflc P-value la nhfl nhau (tien hanh lam ngupi tfl nhien).
Ket qua dfl lieu thi nghiem dfldc tinh toan va bieu diln dfldi dang do thi Hinh 4, Hinh 5, Hinh 6.
Dieu kien thanh trung d quy md thiet bi nho, thdi gian nang nhiet la khong dang ke', CO the' xem dien biln toan bp qua ttinh gia nhiet la thdi gian gifl nhiet. Gia tri chit nhiet vi sinh vat phu thuoc vao sfl thay doi nhiet dp tam cua san pham tfldng flng vdi gia tri nhiet dp Hiam chieu Tref = 93,3''C, z = 8,9°C [9].
Ket qua d cac Hinh 4, 5, 6 cho thay gia tti thanh ttiing P-value cang Idn thi thdi gian xfl li nhiet cua san pham cang dai. Thy nhien, d cung gia trj thanh trung la 5 phut, thdi gian gia nhiet san pham d cac nhiet dp cung khac nhau: p85 thdi gian gia nhiet 68 phut, Pgo thdi gian gia nhiet 36 phut, P95 thdi gian gia nhiet 18 phut. Gia tri chet nhiet cua san pham phu thuoc vao ban chat cua san pham va vi sinh vat muc tieu trong qua ttinh thanh ttung [14]. Viec xfl li thanh trung d cac nhiet dp khac nhau 85°C, 90'*C, 95''C hoan toan dam bao dfldc kha nang tieu diet vi sinh vat bao quan cho san pham, nlu xfl li dung gia tti chet nhiet an toan. Tuy nhien, thdi gian xfl li nhiet cd anh hudng den sU thay doi chit lUdng, cu the la mau sac (bie'u thi thdng qua gia tri dp sang L*) cua san pham. Ket qua dp sang san pham do dat dUdc the hien d Bang 6 so vdi m l u ddi chflng khi khong cd xfl li nhiet.
K i t qua the' hien d Bang 6 cho thiy gia tri thanh trung P-value cang Idn thi gia tti L* san pham cang giam. Ci cac nhiet dp tang d i n tfl 85''C den 95''C, gia tti L* giam dan.
Tuy nhien, nhiet dp 90''C cho sif khac biet khdng Idn v l mau sac cho thay khi xfl li d 90"C thi san pham c6 dd on dinh tot vl mau sac. Cac sac to ttong san pham c6 kha nang bi tdn that bdi nhiet dp va pH thip [13]. Tuy nhien, sfl thay ddi theo hfldng giam dp sang cua san pham c6 nguyen nhan chinh la do tac dong cua yeu to nhiet dp va thdi gian gifl
TAP CHi KHOA HOC TRUCJNG DAI HOC TRA VINH, s 6 33. THANG 03 NAM 2019 NONCi NUHiJ?*-• inilYsAN
Moiliuniig lOD
9 0
? 5 0 S. | 4 0
1 1 1
l ™ _ c
\
•a
0 20 40 60 !D n « BUM (pfcvt)
Hinh 4: Bieu dien tliay doi nhiet do m6i tniang, nhiet dp tani san phS'm va gia tri chet nhiet vi sinh vat 6 nhiet do 85°C
100 w 80 70
^ 6 0
iso
| «
30
^ -> ^ MDifnnng P-value = 2
. . ^
/ - ^
^
— • — • P-value = 3
•^ — P-value = 5
^
.. • I \
I
0A06 ~ 0JI04 -S
04102 K
20 30 Tfcoi gim (pfanj)
Hinh 5: Bieu diln thay d6i nhiet do moi trubng, nhiet do tam san pham va gia tri ch6t nhiet vi sinh vSt d nhiet do 90°C
TAP CHf KHOA H p c T R U O N G DAI HOC TRA VINH. s 6 33. THANG 03 NAM 2019 N O N G N G H I $ P - THUY SAN
^— ^— MoitnaoBg - - - P-value=2
^ ^ ^ ^ — San pham
— • — - p . T a l u e = 3
* 5 0
- ' • " p-value = 4 — ^ P-value = S
''/^ "V
1 A' /I
'1 1 1 ' 1 \
1 1
0 10 20 30
ll
Thori gun (phnt)
Hinh 6: Bieu diln thay ddi nhiet dp mdi trUbng, nhiet dp tam san pham va gia tti chet nhiet vi sinh vat d nhiet do 90''C
Bang 6: Gia tti dp sang L* cua san pham sau khi thanh trung
chet nhiet F (phut) L* (d8 sang) Mau doi cbthig Mau doi cbiiiig 6,89 ± 0.029"
6.58 ± 0,021°
5.43 ± 0.020'' 3.97 ± 0,022"
3.35 ± 0 . 0 2 1 ' ' 5,88 ± 0 , 0 2 1 ' ' 5,65 ± 0,024=
5,34 ± 0,022'"' 5.19 ± 0 . 0 2 1 ' 5,37 ± 0,021'' 5,32 ± 0.021=
4,50 ± 0 . 0 2 4 ' ' ' 3,26 ± 0.023''
(Ghi chu: Cdc chU cdi khdc nhau tren ciing m^t^
cpt the hien sU khdc biet giiia cdc nghiem thiic d tnvtc y nghia p < 0,05)
nhiet lam cho dudng chuyen hda lam sam mau san ph&i.
Viec Ifla chpn nhiet dp thanh trung va gia tti P-value thich hdp de bao quan dfldc san ph£m, dat yeu cau cam quan con dfla vao viec theo doi bien doi vi sinh vat ttong thdi gian bao quan. Kit qua kiem tta vi sinh sau 15 ngay bao quan san pham khi xfl H d nhiet dp 90''C vdi gia tti thanh triing P = 5 phut, nhiet dd tham chieu 93,3''C, z = 8,9 °C dzX kit qua an toan vl mat vi sinh theo tieu chuMi Viet Nam ve nude giai khat khong con (TCVN 5042:1994) [15]. Gia tti thanh tiling P-value nay phu hdp vdi de xuat khi san pham cd tinh acid cao nam ttong khoang pH tfl 4,0 - 4,2 [9], [14] va ciing phu hdp vdi kit qua nghien cflu cua cac tac gia ttong nfldc [6]-[8].
V. KET LUAN
Thong so ttong giai doan ttich li d nhiet dp lOO^C vdi khoi Ifldng r l ttanh 40 g dich ttich cho chat Ifldng cam quan tdt ve mau sac va mui. Nghiem thflc phoi che 9''Brix bang dudng phen va 0,03% acid cittic ttong 300 ml dich ttich thu dUdc san pham cd pH 56
TAP CHJ K H O A H O C T R U O N G DAI HOC TRA VINH. SO 33. THANG 03 NAM 2019 N O N G N G H I $ P - THUY SAN
can bang nho hdn 4,6 la gia tti pH dam bao dilu kien ap dung phUdng phap thanh ttung cho bao quan san pham. Mflc do an toan ve mat vi sinh cua san pham dUdc khao sat vdi gia tti thanh trung la P90 = 5 phut (nhiet do tham chilu T^e/ = 93,3''C, z = 8,9''C), dong thdi chi dp xut li nhiet nay cung duy tti dUdc chat lUdng mau sac cua san pham tdt nhat sau 15 ngay bao quan khi chfla ttong bao bi thuy tinh. Thdi gian bao quan san pham cd cai thien so vdi phfldng phap chi bien truyen thong, dong thdi giai phap thanh trung bao quan san pham cho phep flng dung ddn gian vdi quy md san xuat nho.
TAX LifiU THAM KHAO
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[5] V Fuente, L Rufo, B H Juarez, N Menendez, M Garcia-Hcrnadez, E Salas-Colera, et al. Formation of biominerai iron oxides compounds in a Fe hyper- accumulator plant: Imperata cylindrica (L.) P. Beauv.
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[7] Le My Hong, Nguyen Thi Minh Duyen, Vo Ngoc Thuy, Nguyen Thai Hi^u Hanh. Qua trinh ch^ biln nilcte trai cay hSn hdp {sd ri, khom, chanh day) Tap chi Khoa hoc, TrUdng Dai hoc Cdn Thd.
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[8] Phan Thi Thanh Que. Nguyen Thj Thu Thuy, T^ng Thi Anh Ngoc, Le Duy Nghia. Anh huSng cua dieu kien che bien va bao quan din siJ ^n dinh mau betacyanin trong ni/dc ep thit qui thanh long ru6t do Tap chi Khoa hoc, TrUdng Dai hoc Can Thd.
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Gary S Tbcker, Susan Feathers Tone. Essentials of thermal processing. BlackwellPudhshing Ltdl; 2011, Li Nguyen B'mh, Nguyin Nhat Minh Phifdng. Cdc qud trinh nhiit 36 cao trong che bien thUc phdm. TP.
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2000'.
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