'7hdjm 10 nam 2015 Nghien cilu khoa hgc
Sir BIEN DO! HAM Ll/ONG PROTEIN TONG SO VA CHJ SO PEROXIDE TRONG SffA OAU
N A N HSAU QUA TRINH XOf LY
V6 HOAT ENZYME LIPOXYGENASE BANG
N H I | T0 0 CAO
*o Nguyen Thi Kieu Diim
T6111 \irifc
Vdl muc tieu cai ihien mui v; sdn phdm sira dau nanh. dk tai tdp Irung nghien ci'ru sir bien doi hdm luang protein long so vd chi so peroxide trong dich sira cua cdc mdu khi tien hanh vo tioal enzyme lipoxygenase vdi cdc muc nhiet do 74, 76, 78 vd 80 "C d dp sudI khi quyen ung v&i thai gian ID^, 2Dj, 3Dj (ihdi gian vo hogt duac 90, 99 vd 99.9%). Ket qud phdn lich so Uqu cho thdy d nhiet dq chan 74 "C vd thai gian chdn ID^ lucrng protein long sd thu hdi cao nhat dgt muc 2,78%, va chi sd peroxide dgt muc thdp nhdt Id 0,05 7.
Tu khoa: vo hogt, lipoxygenase, d^u nanh, nhi§t dp, protein, peroxide.
Abstract
The study was aimed to investigate the effect of heat-inaclivation of lipoxygenase on total protein content and peroxide value in soymilk product for flavor improvement. The enzyme was inactivated at 74, 76. 78 and SO "C, at atmospheric pressure within three time intervals: ID^, 2D^ and SD^ (which resulted in Ihe inactivalion levels of 90, 99 and 99.9%. respectively). The results revealed that the combination treatment of 74 "C and ID^ yielded the highest total protein content oj 2.78% and the lowest peroxide value oj 0 057.
Keywords: for flavor, inactivation, lipoxygenase, soybean, temperature.
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Ddu nanh cd tdn khoa hoc id Glycine max L chiia nhieu vitamin, mudi khoang vd thdnh phdn cac acid amin kha cdn ddi (Nguyen Thanh Nguydn, 2000). Protein trong d^u nanh de hdp thu doi vdi ca the ngudi, dau nanh cdn dupc phat hi?n ed nhieu chirc nang nhu gidm riii ro bdnh tim.
ung thu, tdng tinh nang boat dpng cua than... (Singh et ai, 2008). 6 Viet Nam cac san pham chd bien tir d^u ndnh rdt phong phu nhu: chao, tdu hu, tuong va dac bidt la sCra d|iu nanh. Tuy nhidn.
vi?c su dyng ddu ndnh Iam thyc pham van cdn hgn ehd bdi mui "d^u nanh sdng" do sy hi?n di?n ciia enzyme lipoxygenase cd trong ddu nanh (Axelrod et al, 1981) lam gidm khd ndng chdp nhdn ciia ngudi tidu dung (Nichiba et ai. 1995). Cac enzyme ndy gdy phan img oxy hda acid beo chua bdo hda nhu: acid linolenic, linoleic, acid arachidonic. SO'a ddu nanh la san phdm giau dinh dudng rat phd bidn vdi ngudl tidu diing. Do do, van dd hi?n nay cdn nghidn cdu Id lam mat di miii khd chju cua d?u nanh vd tao ra san pham cd miii tham ngon, ddng thai gi& dupc gid trj dinh dudng cho san pham, d^c bi^t la giO; dupc hdm lui^ng protein vd cdc acid beo chua bdo hda nhdm gdp phdn ndng cao gid trj cua san phdm sQ^a dgu ndnh.
2. PHl/ONG TI$N VA PHUONG PHAP NGHIEN CHXi
2.1. Oja diem nghien ciru: Phdng thi nghi?m Bp mdn Cdng ngh? Thyc phdm - Khoa Ndng nghi?p vd Sinh hpe iTng dyng - Trudng Dgi hpe Cdn Tha va Khoa Kinh td Thuy san - Trudng Cao
T H 6 N G TIN KHOA HOC GiAo Dur ffl
Nghien cOu khoa hgc ^hdnt/^ 10 nam 2015
dang Kinh td - Ky thuat Can Tha.
2.2. Nguyen lieu: Ddu nanh (giong MTD 760-4-M) mua d tai Bd mdn Di truyen gidng ndng nghiep - Khoa Ndng nghidp va Sinh hoc LTng dyng - Trudng Dai hoc Cdn Tho, sau dd tdn triJ d nhiet dp 20 "C sir dung cho toan bp cac thi nghidm dd cd sy ddng deu trong sudt qud trinh phdn tich.
2.3. Phuong phap phan tich
Chi s6peroxide: phdn tich dya trdn nguydn Iy trong mdi trudng acid, peroxide giai phong iod tir mudi kali iodua d nhiet dp ndng hodc lanh. Chudn dp iod giai phdng ra thd ty do bang dung dieh Natri thiosulfate (Pham Vdn 86 va Biii Nhu Thudn, 1995).
Hdm luang protein tdng sd: dupc phdn tich bdng phuang phap Kjeldahl (Le Thanh Mai et al. 2009).
Trong edng nghd thyc phdm sir dung gia tri D thay cho hdng sd tdc dp vd hoat k (D la thdi gian edn thidt d nhiet dp T tucmg ung de Iam thay ddi hoat tinh cua enzyme 10 Idn)
Ai\'~'n
Thi nghiem dugc bd tri ngau nhien vdi 3 lan lap lai. Ket qua dugc phan tich thdng ke bang phan mem Statgraphics 4i} va SAS 9.0.
2.4. Bo tri thi nghiem
Thi nghiem: xac dinh ham lugng protein tdng sd va chi sd peroxide cua siia dau nanh sau qua trinh vd hoat hoat tinh enzyme lipoxygenase d c^c mirc dp 90, 99 vk 99,9% (Ihig vdi gia tri lD^2D^v4 3D^).
D^u nanh logi sgch tap chat, ngam tir 8-9 gid, riia sach. Can 300g dau nanh cho vao tiii vSi, ch4n trong be dieu nhi?t vdi 4 mirc nhi?t dp (74,76, 78 va 80 °C) img vdi 3 mirc thdi gian vd ho^t enzyme lipoxygenase (ID^ 2D^ v4 3D^). Tijn hanh nghijn dju vdi nudc theo ti 1^ (1:4) trong 1 phot. Lgc dung djeh nghien thu dich trich dau nanh.
K§t qud: phan tich chi sd peroxide va protein tdng sd thu hdi trong djeh d^u n^nh.
3. Ktl QUA - THAO LU^N
3.1. Him Iv^ng protein thng s6 thu hoi dugc irng vdi cic mii'c dp vo ho^t enzyme lipoxygenase 90,99 v4 99,9%
De tii tidn hinh phan tich ham lugng protein tong sd cua djeh siJa dju ninh sau qua trinh vd hojt ho?t tinh enzyme lipoxygenase d cic mire dO 90, 99 va 99,9% img vdi cdc mirc nhift dp 74, 76,78 vd 80 °C do d nhi?t dd dudi 74 °C hojt tinh enzyme cdn rdt manh (ket qui cy th^ khdng dugc trinh biy d day). Htai lugng protein tong s6 thu hoi eua cic man xii 1^ d cic che dg da chpn, Q THdNG TIN KHOA HQC GlAo Dyc
^hdtt^ 10 ndm 2015 Nghien cOu khoa hgc
dupc phan tich va thd hien d Bang 1.
Bang 1. Gia tri truag binh cua ham lirong protein tong so thu hoi (%) theo nhiet do chan va thdi gian xu* ly nhiet vd hoat enzyme lipoxygenase
Nhiet dp chdn CC)
Thdi gian xii ly nhiet theo gia tri D (phut)
ID 2D 3D Tmng binh
nghiem thirc 74
76 78 80
2,780 2,665 2,455 2,195
2,650 2,585 2,405 2,115
2,530 2,555 2,340 2,100
2,653- 2,602- 2,400' 2,107' Tmng binh
nghiem thirc 2,524* 2,439= 2,359^
Ghi chti: Cdc sd mgng cha sd mU khac nhau cung mQt cdt (hodc hdng) sai khde cd y nghia thing ke (P<0,05) theo phep thie LSD.
Kdt qua phan tich LSD cho thdy: gia tri tmng binh ham lugng protein tdng sd thu hdi dugc khi xir ly man dau nanh d cac miic nhiet dp 74, 76, 78 va 80 °C ling vdi d cic miic thcri gian khac nhau cd su khic biet d mirc y nghTa 5% (p<0,05). Dau ninh chin d nhiet dp 74 °C cd ham lugng protein tdng sd thu hdi cao nhit (2,780%), d nhiet dp chin 80 °C ham lugng protein tdng sd li thip nhat (2,107%). Ham lupng protein tdng sd thu hdi ung vdi cac mire do chin ID^ la cao nhat vi him lugng protein tdng sd thu hdi ung vdi cic mirc dp chan 3 D.^ li thip nhit.
Nhi?t dp cao, thdi gian dai lam bien tinh protein va lam cho protein giam tinh tan trong dich siia (Nguyen Thanh Nguyen, 2000). Vi vay, khi tang nhiet do vi thdi gian xir ly ham lugng protein thu hdi giim (Hinh I). Khi kdt hgp ap suit vdi nhi$t dp cao dd vd hoat en2yme hay ire ehe vi sinh vat sS it thay ddi chit lugng ciia thirc phim (Hendrickx va Knorr, 2001; Barbosa-Canova a a/., 2005).
Hinh 1. HJm lirgmg protein djeh siia thu hoi theo nhift d? ('C) vi thdi gian (x D^ phiit) xu ly Phuang trinh h6i quy da thirc bjc hai (polynomia) dugc sir dyng dS md hinh hda inh hudng T H 6 N G T I N KHOA HQC GlAo DUC
Nghien c(hj l<hoa hgc CThdnq 10 ndnt 2015
cua nhiet dp chdn va thdi gian xu Iy ddn ham Iuong protein tdng sd thu hoi trong dich SO'a dau nanh dupc trinh bay d Hinh 2.
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Hinh 2. Do thi mat dap ung va Contour bidu dien anh hudng cua nhiet do va thdi gian vo hoat enzyme lipoxygenase den ham luytig protein thu hoi (%) trong dich sira dau nanh
Kdt qua phdn tich hdi quy khdng tuydn tinh (Proc nlin, SAS) cho thdy sy thay ddi ham luprng protein thu hdi phu thudc vao nhiet dp, thdi gian xir ly nhiet va tudn theo md hinh sau:
Zp„= a„ + a,X + a,Y + a3X^ (1) Trong dd Zp_^: ham luong protein tdng so (%) X: nhiet dp chdn ("C)
Y: thdi gian xu Iy d cac gia tri D, (phut) a^,, ii|, dj, a,: cac he sd cua md hinh
Tir he sd eua md hinh tuong quan dupc trinh bay d Bang 2 cd thd tinh duoc ham lupng protein thu hdi dya vdo nhiet dp vd thdi gian xu ly vd ho?t enzyme lipoxygenase.
Bang 2, Gia tri cua cac he so ciia md hinh tuong quan gitra nhiet do va thdi gian xu ly nhiet anh hirdng den ham lirang protein thu hoi trong dich sua dau nanh
He sd Gia tri d^ -79.7813 ±15.9825 a, 2.2340 ±0,4154 a, -0.0825 ±0.0132 aj -0,0151 ±0.0027
Corrected R^ = 0,949 SD = 0,0529
Chdt lupng ciia md hinh tuong quan (1) dupc thd hi?n bdi dd thj bieu dien mdi tuong quan ciia nhi?t do va thdi gian. giita ham lugng protein dy doan va hdm Iuong protein thu hdi trong djeh SO'a ddu nanh ciia dd tai dupe md ta d Hinh 3, 4. 5, 6 va 7.
TH6NG TIN KHOA HOC GlAo DITr
"Jhduif 10 natn 2015 Nghien citu khoa hgc
J, Protein du doan
Hinh 3 . Moi quan h? gifra h a m lirgng protein t h u c nghiem va protein d u d o a n
Hinh 4. D9 sai biel giira ham lirong protein tinh to&a so voi thirc t£ theo nhiet d9 chan ("C)
Hinh 5. Do sai biet giira ham lirang protein tinh toan $0 v6i thtrc te theo Ib61 gian chan (x D.^ phiit)
r 4 2 9
Protein dy doan
Hinh 6. D9 sai bift giira ham Iir9'ng protein tinh toin so voi thyc te theo gia tri protein tinh toan
1 9 2 *• 7 9
Protein thyc nghidm
Hinh 7. D$ sai bift giiS^ hdm Itrong protein tinh toan so voi thyc te theo gii trj protein thyc te
3.2. Sy thay doi chi so peroxide ung voi kha nang vd hoat hoait tinh ciia enz>'me lipoxygenase d cac muc 90, 99 va 99,9%
Bang 3. Gia tri trung binh cua chi so peroxide theo nhiet do chan va thdi gian xu H nhi^t de vd hoat hoat tinh ciia enzyme lipoxygenase
Nhi?t do chan CO
74 76 78 80
ID 0,057 0,113 0,123 0,103
Thdi gian xii ly nhiet theo gia tri D (phiit) 2D
0,073 0,096 0,085 0,093
3D 0,084 0,106 0,109 0,086
Trung binh nghiem thiic
0,071=
0,105"
0,106"
0,094'
^ THONG TIN KHOA HOC GIAO DUC
Nghien cdu khoa hoc <7fidii9 10 naiH 201S
Tnuig binh
nghiem thiic 0,099* 0,087" 0,096*
Ghi chii: Cac sd mang cha sd mii khac nhau ciing mdt cdt (hodc hdng) sgi lihdc co y nghia thdng ke (P<0.05) theo phep thu LSD
Kit qua phan tich thdng ke Bang 3 cho thay chi sd peroxide d cac nhiet do xCt ly 74, 76, 78, 80 °C ling vdi cac miic thdi gian thdi gian vd boat enzyme lipoxygenase 10^ 2D^ va 3D^ c6 su khac biet nhau d miie y nghia 5% (p<0,05). 6 nhiet dp 74 °C chi sd peroxide la thap nhit. Gia tri trung binh cua chi sd peroxide ling vdi miic thdi gian vd hoat ID.^ enzyme lipoxygenase la cao nhjt (0,099), thdi gian vd boat 2D^ enzyme lipoxygenase cho chi sd peroxide trung binh thap nhat (0,087) (Hinh 8).
Khi xii ly nhiet de vd boat 90% boat tinh enzyme lipoxygenase thi ham luong enzyme cdn lai ket hop vdi oxy tiep tue oxy hda de tao ra peroxide. Khi xir ly nhiet vd hoat 99% boat tinh enzyme bam lugfng enzyme cdn lai it tuy nhien do thdi gian xii ly dai da tae ddng thiic day qua trinh tu oxy hda nen ham luong peroxide tang len.
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Hinh 8. Chi so peroxide trong djeh sua theo nhi^t dp ("C) va tbM gian (x D.^ phut) xir ly Phuong trinh hdi quy da thiic bac hai (polynomia) duac su dung de md hinh hda sy anh hudng ciia nhiet dp chan va thdi gian xu ly den su bien ddi chi sd peroxide trong dich sira duoc trinh bay d Hinh 9.
H k i e t do ( C l
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Qhdngi 10 niin 2015 Nghien cHu khoa hoc
Hin^ 9. Do thi mat dap irng va Contour bieu dien anh h u d n g ciia nhiet do chan va thai gian vo hoat enzyme lipoxygenase den chi so peroxide trong dich sira 4 a u nanh
Kdt qua phan lich hdi quy khdng tuydn tinh (Proc nlin, SAS) cho thay su thay ddi chi sd peroxide phu thudc vao nhiet dp, thdi gian xii ly nhiet va man theo phuong trinh hdi quy sau:
Z ^ , = b , + b , X + b , Y + b3X= + b , Y = + b ^ Y (2) Trong dd Z : Chi sd peroxide
X: Nhiet dp chjn ("C)
Y: Thdi gian xu ly d cac gia tri D (phiit) b(j, b,. b j , b j , b j , bji cac he sd ciia md hinh
Tu cac he sd cua md hinh tuong quan d Bang 4 cd the tinh dupc chi sd peroxide sinh ra dua vao nhiet dp va thdi gian xii ly nhiet vd boat enzyme lipoxygenase.
Bang 4. Gia trj ciia cac he so bieu thi mdi tuong quan giira nhiet dp va thdi gian %v ly nhiet anh hirdng den chi so peroxide trong dich sua dau nanh
H ^ g sd Gia tri
-17,4470 ±2,8661 0,4467 ± 0,0744 0,2219 ±0,0831 - 0,0028 ± 0,0005
0,0108 ±0,0041 -0,0035 ±0,0011 Corrected R- = 0,733
SD = 0,0095
Chat lugng ciia md hinh tuong quan (2) dupc the hien bdi dd thi bieu dien mdi tuong quan ciia nhiet dp va thdi gian, giiia chi sd peroxide dy doan va chi sd peroxide hien dien trong dich sua dau nanh duoc trinh bay d Hinh 10,11,12,13 va 14.
p . c: Q Q9 -
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C h i so p e r o x i d e d u d o a n
Hinh 10. Moi quan be giiia chi so peroxide thin; nghiem va peroxide d u doan
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Nghien cUjfu Idioa hoc <7hdiig^ 10 nam 2015
Hinh 11. BQ sai biet gi&a chi so peroxide tinh toSn so v&i thyc ti theo nhi^t S^ chan (°C)
Hinh 12. D§ sai bi^t gifla chi so peroxide tinh toan so voi thyc te theo thiri gian chan (x D^ phiit)
Chi SO peroxide thyc nghiem Hinh 14. f>o sai bi£t giira chi so peroxide tinh toan so voi thyc t^ theo gi^ tri peroxide thyc te Chi SO peroxide du doan
Hinh 13. Do sai biet giua chi s6 peroxide tinh toan so voi thyc te theo gia trj peroxide tinh toan
5. K E T LUAN VA KIEN NGHI
d nhiet dp 74 "C va thai gian ID^ ham lugng protein tong so eon lai trong dich sua la cao nhat va chi so peroxide la thap nhat. Ngoai ra a nhiet do nay qua trinh ehe bien it xay ra su oxy hoa lipid nen loai bo dugc miii dau nanh song, gop phan nang cao chat luffng ctia san pham.
TAI LIEU THAM KHAO
Nguyin Thanh Nguyen, 2000, Ky thugt che bien vd sir diflig dgu nanh, Dai hoc Can Tho.
Le Thanh Mai, Nguyen Thj HiSn, Ph^m Thu Thiiy, Nguyen Thanh Hing, Le Thi Lan Chi, 2009, Cac phmmg phap phdn tich nganh cong nghe len men, NXB Khoa hoc va Ky thuat.
Pham Van So, Bill Nhu Thuan, 1995, Kiem nghiem Lumig thirc, Thirc phdm, Dai hpe Bach Khoa Ha Npi.
Axeirod B.C., Cheesbrough, T.M., Laasko, S.L.,1981, Lipoxygenase from soybean, Methods in Enzymology. V71. p.441 -451.
Barbosa-Canova G.V, Tapia M.S., Cano M.P., 2005, Novel Food Processing Technologies, CRC Press. Boca Raton, FL.
HendrickxM.E.G.,KnorrD,200I,Ultra High Pressure Treatments of Foods, Kluwer Academic/
Plenum. New York. NY.
Nishiba Y., Furuta S., Hajika M., Igita K., Suda i, 1995, Hexanal accumulation and DETBA value in homogenate of soybean seeds lacking two or three lipoxygenase isozymes,. Journal of Agricultural and Food Chemistry. V.43. p.738-741.
Singh P., Kumar R., Sabapalhy S.N., Bawa A.S., 2008, Functional and edible uses of soy protein products comprehensive. Food Science and Food Safety. V.7. p. 14-28.
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