> Nghien cu'u - Ky thuat
Xac djnli Icha nang ciiju dung sy thuy phan ciia tinh hot cii mai (Rhizoma Dioscoreae persimilis) in-vitro bm he enzym amylase
Nguyen Thj Thu 'I'lia^t, Ld Thj Loan Chi, Tr^n Hihi Dung
Khoa Du(/c, Tnr&ng BH Y - Du(xc HueD^t van de
Theo t l chirc Y t l t h i gidi (WHO), b$nh ddi thdo du-d-ng gia tdng ngdy cdng nhanh trfin todn the gidi vdi ly l§ m i c phdi d cdc nu-dc phdt I r i l n Id 42% vd cao han d cdc nu-d-c dang phdt t h i n nhu- Vipt Nam. Do v§y, ddy thyc s y dang Id m^t v i n d l thdeh thirc Idn d l i vd-i e$ng d i n g vd xd hpi'''. D 6 I vdi ngu-d-i b$nh ddi thdo du-dng, tinh bOt ddng vai trd quan trpng trong vi^c cung e l p ndng lu-png. c h i l m khodng 40 - 60% l i n g ndng lu-ang cung cap hang ngayf^ Tuy nhidn, mpt c h i dp dn vdi lu-png tinh bpt hpp ly d l vira d i l u hda lu-png du-dng h u y l t vd vira cung d p du-pc ndng lu-png, Ihoa man du-pc s y them an cho ngu-di bpnh ddi thdo du-dng Ipi la van de ddng quan tdm. Mpt trong nhu-ng loai thyc pham ed khd nang dd la cdc thyc pham ed chira tinh bpt de khang (RS) cd khd ndng khang lai s y thuy phdn cua hp amylase du-d-ng tieu hod ldm hgn e h l s y giai phdng ndng lu-png dang glucose, mpt y l u to nguy ca eao cua ngu-di bpnh ddi thdo du-dng, giup cdi thipn lu-png du-dng h u y l t quy dinh d ngu-d-i ddi thao du-dng vd tpo d i l u kipn k i l m sodt edn ngng t i t han d ngu-d-i bdo phi. Do dd vi$c nghien ciru cdc lopi thyc pham cd chira tinh bpt de khdng eao dang n h | n 6u/<yc su- quan tdm r I t Idn ciia epng dong vi ede Ipi ich ve sd-e khde va cdc tinh c h i t chirc ndng md tinh bOt d l khdng mang Igi'^'^'.
Cii mdi (Rhizoma Dioscoreae persimilis) id mOt du-pc li$u du-pc su- dyng tir rat s d m d l chij-a cdc bpnh do ty vj suy nhu-pc. B§n cgnh dd, theo dan gian, cii mdi edn cd mpt tdc dyng rat ddng chii y id d i l u tr[ ddi thdo du-dng. Tinh bdt id thanh phan chinh ciia cu mai, e h i l m ty 1$
khodng 63.3% vd hau nhu- khdng ed cdc nhdm chat cd hogt linh sinh hpc'^'. Vi v | y , nhdm nghidn ciru thyc hipn de tai "Xac djnh dgc tinh
chju d y n g s y thuy phdn cua tinh bOt cu mdi (Rhizoma Dioscorea persimilis) trong in-vitm bai h$ enzym amylase" nhdm tgo c a s d cho s y irng dyng eua tinh bOt ndy trong cdng tdc h6 trp dilu trj b§nh ddi thdo du'd'ng.
D o i t u ' o ' n g v^ p h u ' a n g p h a p n g h i e n c i r u
D o i tu-pfng n g h i e n cu-u
Cu mdi du-p'c thu hdi d Huypn L# Thuy, Tinh Qudng Binh, rira sach, gpt vd, phai khfl, c I t thdnh Idt ddy khoang 0,3em, xay thdnh bOt mjn, r l i bdo quan trong binh nhya kin d nai khd thodng mdt. M l u chirng la bdt my (Cdng ty TNHH Dgi Phong) chira protein (9.0g), chat beo (0,8g), linh bpt (73,6g), natri (23mg).
Phu'O'ng phap n g h i e n c u u ^^^
Xdc djnh thanh phan dinh dipong cu mai - Xac djnh hdm lu-png protein bdng phi/ang phdp Kjeldahl.
- Xdc djnh hdm lu-p-ng glucid bdng phuwng phdp Bertran.
- Xdc djnh hdm lu-p-ng tinh bpt b I n g phirang phdp hda tan.
- Xdc djnh hdm lu-png x a theo phuxyng phap thuy phdn trong mdi tru-d-ng acid baza
- Xdc djnh hdm lu-p-ng nu-dc bang phu-ang phdp s l y .
- Xdc djnh hdm lu-png khodng tong bang phu-ang phdp tro hda.
Khdo sdt mOv d^ bf thOy phan cua tinh b^t cu mdi so v6fi tinh b6t my dieifi tdc dyng cua h$ enzym amylase ^"""^
M l u d y p c ij vdi hon h p p enzym a-amylase vd amyloglucosidase (AMG) d 37''C trong 16 gid. Trong s u i t qud trinh ti, p h I n tinh bpt d l tiSu se bj thuy phdn hodn todn thdnh glusoce. Qiia trinh thuy phdn du-p-e k i t thuc trong ethanol. Ly
TAP CHi DlfaC H O C - 04/2012 r s 6 d^t? N A M K1\
• N g h i e n CLPU - Ky t h u a t
tam logi djch, diing ethanol de ru-a edn. Gom toan bp phan djch long thu du-pc, xdc djnh hdm lu-png glucose gidi phdng bang kit thu- glucose peroxidase, tir dd tinh du-ac hdm lu-png tinh bOt tieu hda trong mau.
P h I n can du-pc hda tan trong dung djch KOH 2M trong nu-dc da. Diing enzym AMG trong d§m acetat pH 3,8 de thuy phan phan tinh bpt cdn Igi.
Hdm lu-png tinh bdt de khdng trong m l u thCr du-ac xdc djnh bdi lu-png glucose tgo thdnh bang kit thir glucose peroxidase.
Ngodi ra. phan glucose t y do todn phan cd s i n trong mau bpt (bao gom glucose t y do va glucose du-ac tao thanh tir saccharose) du-pc xdc dinh theo nguyen tdc dung enzym invertase, id enzym chuyen biet cho s y thiiy phdn saccharose thdnh glucose vd fructose. Phan glucose t y do todn phan du-pc xac d|nh bdi kit thir glucose peroxidase.
Cac gia trj ham lu-png glucose du-ac xdc djnh dya tren du-dng t u y I n tinh du-pe xay dyng t h i hien s y phu thupc cua nong dp glucose chuan vdo dd hap thu tu-ang irng tgi bu-dc sdng 546 nm. Danh gia s y khdc bipt giO-a cdc phan dogn tinh bpt tieu hda va linh bdt d l khdng ciia cii mdi thu du-pc vdi tinh bpt my nhu- la m l u so sdnh b I n g test student v d i mu-c y nghTa 0,01.
Ket qua va banluan
K i t qua xdc djnh ham lu-png ede thdnh p h I n dinh du-dng tren nguyen lieu bdt cu mai khd du-pc thyc hien tren 6 Idn do de lay gid trj trung binh du-pc the hien trong bang 1.
Bang 1 : Cac thanh phan dinh dirang chu y4u trong cu mdi
Cac thanh phan dinh dv&ng Ham luo-ng protein
Ham lu-o-ng glucid Ham lu-o-ng tinh bgt
Ham lu-png xo- Ham lu-png nu-dc Ham luang khodng tong
Ham Iwp-ng (%) 5,3 0,5 61,8 2,1 10,1 2,0 K i t qua phan tich cho thay ham lu-ang ede thdnh phan dinh du-dng cua cu mdi thu hogch tai Quang Binh tu-ang du-ang v d i cdc thanh p h I n dinh du-d-ng cCia cu mai da du-ac cdng bo trong mdt so tai lieu tham khdo va thda man tieu chuan c h i t lu-png theo DDVN III (hdm luvng nu-de khdng qua 12% va hdm lu-p-ng khodng long khong qud 2%) '^'^"l Thdnh phan chu yeu
Id tinh bpt chiem ham tu-png Idn (61,8%), so vdi mpt so thyc p h I m cung cap tinh bdt chu yeu hipn nay nhu- gao (65 - 82%), ngd (63 - 75%), liia mi (55 - 75%), khoai tay (8 - 13%), khoai lang (15 - 31%) '^' thi hdm lu-png tinh bpt trong eCi mdi id kha cao. Qua dd ed the khang djnh ddy Id nguon cung cap tinh b^t d l y t i l m ndng.
Trong khi hdm lu-png glucid, Id nguIn tgo ra lu-png glucose giai phdng nhanh h l u nhu- khdng ddng k l (0,5%), ndn cd t h i bj mat trong qua trinh che bien Gid trj glucid t h I p ed ^ nghTa quan trong trong vipc giup k i l m sodt t i l du-dng huyet, trdnh ldm tdng du-dng h u y l t dpt ngpt trong bu-a an, dieu nay dac bidt r I t cd Ipi d l i v d i c h i dp an ddnh cho benh nhan ddi thdo du-dng.
D l xdc djnh hdm lu-png cdc logi tinh bdt tieu hda (DS) vd linh bpt d l khdng (RS) du-di s y thuy phan cua he amylase du-dng tidu hda, d l thj du-dng t u y I n linh the hien s y phu thupc dp h i p thy vdi ede dung djch glucose chuIn cd cac nong dp khdc nhau v d i dung d[ch thuoc thu- GOP d bu-dc sdng 546 nm du-ac xdy dyng (r = 0,999) theo hinh 1.
0.3 3-0-25
^ 0.2
•<w"0 15 .•i- o., 23 0 05
y - 0 . 0 4 6 X - I - 0 . 0 0 2 R ^ = 0 . 9 9 9
IVong do (mmol/])
Hinh 1 : Dd thi biSu diSn si/ phu thudc giCra nong dp va dp hap thu cua glucose chuan trong dung djch glucose peroxidase tai 546 nmHam lu-ang glucose t y do, tinh bpt lieu hda vd ham lu-png tinh bpt de khdng trong 2 mdu tinh bpt eu mdi va tinh bdt my du-ac xdc djnh bdng each su- dyng he enzym amylase theo nghipm phdp do glucose trong in-vitro. Thi nghipm du-pc tien hanh 6 Ian lap Igi vd k i t qua trung binh thu du-pe the hien qua bdng 2.
Bdng 2: Hdm luung glucose ti/ do, tinh bpt tieu hda va tinh bdt dd khdng
Hdm luxyng phan Tinh bpt Tinh do%n dinh duvmg cu mai bdt my Glucose ty do (%) 0,6 1,6 P < 0,01 Tinh bpt tieu hoa (%) 15,9 81,8 P < 0,oT
Tinh bgt d l khang ~ ~ ^ ^
(A)
TAP CHI D i r a C H Q C - 04/2012 (SO 432 NAM 52)
• Nghien CLFU - Ky thuat
K i t qud khdo sdt cho t h I y hdm lu-png glucose s i n ed trong cdc m l u tinh b^t r I t nhd va h l u nhu- khdng ddng k l . Tuy nhiSn, hdm lu-png tinh bOt d l khdng cua tinh bOt oil mdi id 72,9% vd tinh b^t tidu hda Id 15.9%. Trong khi d- linh bpt my, hdm lu-p-ng tinh bpt d l khdng id 7.0% vd tinh b i t d l tidu Id 81,8%. Qua dd cho t h I y hdm lu-png tinh bdt d l khdng trong m l u tinh bpt eu mdi cao han so vdi m l u tinh b^t my vd ngu-pc Igi hdm lu-png linh bOt d l ti6u trong m l u tinh bdt my cao han so vdi mau tinh bOt cu mdi vdi mii-c y nghTa 0,01. Chinh d^c tfnh u-u d i l m da ldm cho linh bOt cii mdi ed khd ndng hgn e h l s y thuy phdn ciia h§ enzym amylase, ldm gidm lu-png glucose gidi phdng nhanh sau bu-a dn, d i n d i n hgn c h i vi§c tdng du-d-ng h u y l t dpt ngpt. Ben egnh khd ndng d l khdng cua tinh bpt cu mdi khdng nhu-ng giiip du-dng h u y l t ludn du-pe duy tri d khodng gid trj cho phdp, md p h I n linh bOl de khdng cdn giup c a the ludn duy tri mdt mu-c ndng lu-png thich hpp, lam trdnh linh trgng ddi nhanh sau bu-a dn. Bdi do khi di vdo he tieu hda, mOt p h I n ndng lu-png du-pc tgo ra d rudt non tir lu-png nhd tinh bpt de khang bj thuy phan tao thanh glucose, phan ndng lu-png chij yeu cdn Igi du-pc tgo ra d rupt gia qua cdc qua trinh len men cua he vl k h u I n du-d-ng rupt, tao ra ede acid beo mgch ngdn. Trong khi glucose Id nguon nang lu-png c I n thiet cho cac hogt dOng cua nao thi cac acid beo lai rat can cho hogt ddng ciia cac md va ca. Dieu nay that s y quan trpng doi vdi b§nh nhdn ddi thdo du-d-ng vd cd ngu-di beo phi can c h i dp an kieng.
Ket fuan
Cac thanh p h I n dinh du-d-ng cua cu mdi trong tgi tfnh Qudng Binh cung nhu- cdc phdn dogn dinh du-dng cua logi linh bOt ndy da du-pc xac djnh khd d l y dii. Ddng quan tdm n h l t Id ham lu-png tinh bdt c h i l m 61,8%, trong dd tinh bpt de khdng e h i l m 72,9%, da h i trp r I t ddng k l trong s y chju d y n g thuy phdn bdi enzym amylase so vdi tinh b | t my. K i t qua nghiSn eCru da t h i hipn du-pe khd ndng de khdng r I t cao cua tinh bOt eu mdi vdi enzym amylase du-dng lieu hda. Dieu dd gdp p h I n gidi thich vl sao kinh nghipm dan gian da sir dyng du-pe li§u ndy trong d i l u trj ddi thdo du-d-ng, dong thi^i cung chirng minh du-pe djnh h y d n g diing dan cua nhdm nghien ciru dang t h y c hi^n nhu-ng nghifin cu-u sdu han ve cdc dac d i l m ly hda vd c l u trCic
ciia tinh bpt cu mdi n h i m tgo c a s d ly lu|in cho vi$c ii-ng dyng logi tinh bOt ndy trong cdng tdc c h i b i l n thyc p h I m chO-c ndng h i trp d i l u trj b$nh ddi thdo du-d-ng,
Summary
Nutritious compositions of Dioscorea persimilis tuber harvested from Quang Binh Province of Vietnam were investiaged and evaluated the hydrolysis-resistance in-vitro of the obtained starch against the intestine amylase enzymes. Noted that the starch amount accounted for about 61.8% of the absolutely dried tubers, including 72.9% of resistant starch (considerably stable against the enzymic hydrolysis by amylase). High resistance of this starch to enzymic hydrolysis suggested theoretical basis for applying the research to processing functional foods for diabetes-treating use.
Tai lieu tham khao 1. Tg van Binh, B0nh ddi thdo du-dng - TSng glucose mdu, NXB Y hoc, Hd N^i (2006)
2. 06 T i t Lpi, NhOng cdy thulc vS vj thulc Vi$t Nam, NXB Yhpc. HS NOi, (2004), tr 848.
3 Cyc quan ly chdit lirpng ve sinh an toan thi/c phIm, T§p hpp phi/ang phdp thir ve chat lirpng ve sinh an todn thyc phIm, Tieu chuIn Vi#t Nam so 3705(1990), tr. 156-158.
4 Bui Thj NhiF Thu§n, Kilm nghiem lirang thirc thyc phIm, NXB Khoa hoc Ky thudt Hd N0i, Ha N$i, (1975) tr 42-264.
5. L§ van Hodng. Truong Thj Minh Hgnh, Tinti bOt khai thdc va i>ng dung, NXB Dd Ning. Oa Ning, (2007), tr. 5-40.
6. Nguyen Phu-ang, L§ Thj Ciic, Hodng Oinh Hoa, NghiSn cipu ttnh chit hda ly cua tinh b0l m$t s i gilng khoai mdn - sp (Colocasia esculenta (L.) Shott) phi biln vd cd gia trj d miln bIc Vi$t Nam, Tap chi Khoa hpc C6ng ngh4. Ndng nghi$p vd phdt thin ndng than, (2008)(10).tr.44-48.
7 Steyn N.P., Mann J., Bennett P.H.. Temple N, Zimmet P., Zimmet J., Lindstrom J. and Louheranta A.
Diet, nutrition and ttie prevention of type 2 diabetes.
Puttie Health Nutrition, (2004). 7 (1), p. 147 -165.
8. Giacco R.. Riccardi G., Metabolic effects of resistant starch in patients with type 2 diabetes, Diabetes Nutrition Metabolism. (1998), 34 (5), p. 330- 335.
9. Higgins A., Resistant starch: metabolic effects and potential health benefits. Journal of AOAC lntemationaH2004). 87(3). p. 761- 768
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30 TAP CHI DlTQC HQC - 04/2012 (S6 432 NAM 52)
