K HOCH GING BI

K HOCH GING BI

1. Phn th tc

B mn: Dinh dng i tng hc vin: i hc (Di hn)

Tn bi ging: Gi tr dinh dng ca cc loi thc phm v phn nhm thc phm.

Tn ging vin:

Mn hc: Dinh dng

Nm hc: 2009 - 2010

Thi gian ging bi: 135 pht (3 tit)

2. Cc mc tiu hc tp:

2.1. Nm c nhng gi tr dinh dng ca cc loi thc phm v nhng bnh do thc phm gy ra.

2.2. Bit cch phn nhm thc phm, bit cch phi hp s dng v thay th thc phm trong khu phn n thng thng v khu phn n iu tr..

3. K thut tin hnh:

3.1. Loi bi ging: L thuyt

3.2. Phng php dy hc: Din ging, trnh by trc quan, m thoi, kim tra.

3.3. Hnh thc t chc dy hc: Ln lp ti ging ng.

3.4. Phng tin dy hc: Projecter, bng en, phn cc mu 4. Phn thi gian v cu trc bi ging:

4.1. T chc lp: 2 pht

4.2. Kim tra bi c: 5 pht

4.3. Gii thiu ti liu tham kho, nghin cu: 3 pht

4.4. Tin hnh ni dung bi ging: 115 pht.

Ni dung bi gingThi gianNhng PPDH vn dngPhng tinHot ng ca hc sinh

I. Gi tr dinh dng ca cc loi thc phm.

1. Tht: Gi tr dinh dng v tnh cht v sinh ca tht.

2. C: Gi tr dinh dng v tnh cht v sinh ca tht.

3. Sa: Gi tr dinh dng v tnh cht v sinh ca tht.

4. Trng: Gi tr dinh dng v tnh cht v sinh ca sa.

5. Ng cc v khoai c.

6. u v ht c du.

7. Rau qu.

II. Phn chia thc phm theo nhm.

1. Chia 2 nhm.

2. Chia 6 nhm.

3. Chia 4 nhm.15 pht

15 pht

12 pht

14 pht

12 pht

12 pht

15 pht

5 pht

5 pht

10 phtGio vin din ging, minh ho, nu vn , m thoi vi hc sinh, hi v tr li hc sinh. Projecter Bng

Phn

Nghe

Ghi chp

Tr li v hi gio vin

5. Kim tra nh gi ( Thng tin phn hi ): 3 pht

6. Tng kt bi ging: 5 pht

7. Nhn xt v rt kinh nghim: 2 phtThng qua

Ngy thng nm 2009

Ch nhim B mn

Ngi lm k hoch

PGS, TS. Nguyn Thanh Ch

GI TR DINH DNG CA CC LOI THC PHM

V PHN NHM THC PHM

I. Gi tr dinh dng ca cc loi thc phm.

1.Tht.

1.1. Gi tr dinh dng ca tht:

Tht l mt trong nhng thc phm c gi tr dinh dng cao, c nhiu acid amin cn thit, cc cht bo, cht khong, vitamin v mt s cht thm cn gi l cht chit xut. Tht cc loi ni chung ngho canxi, giu phospho, t l Ca/P thp. Tht l thc n gy toan.

Tht ca tt c cc loi ni chung u cha nhiu nc, ti 70 - 75%. Trong tht ngoi protein cn c colagen v elastin l loi protein kh hp thu, gi tr dinh dng thp v thnh phn ca n hu nh khng c tryptophan v xystin. Loi ny tp trung nhiu phn bng, th, chn gi. Colagen khi un nng chuyn thnh gelatin l cht ng keo. Cn elastin gn nh khng b tc dng ca men tiu ho, v vy n vo thi ra nguyn dng.

Trong tht c khong 1,5 - 2 % cht chit xut tan trong nc, d bay hi, c mi thm c bit, c tc dng kch thch tit dch v mnh. Cc cht chit xut gm c: creatinin, creatin, carnosin, glycogen, glucoza v acid lactic. Khi luc tht phn ln cc cht chit xut ho tan trong nc lm cho tht c mi v thm ngon.

+ Protein: chim t l trung bnh t 15 - 24%.

Tht ln m protein chim 14,5%.

Tht sn, tht ba ch protein 16,5%.

Tht ln nc protein chim 19%.

Tht b nc protein chim 21%.

Tht ch nc protein chim 24,7%.

ng ho protein ca tht l 96 - 97%. Gi tr sinh hc ca protein l 74%.

+ Lipid: dao ng nhiu t 1 - 30% tu thuc loi ng vt v bo ca n. Lipid bao gm cc acid bo no v cha no. Cc acid bo no ch yu l acid palmitic (25 - 30 %) v stearic (16 - 28 %). Cc acid bo cha no ch yu l acid oleic (35 - 43 %). Acid bo cha no c nhiu mch kp khong 2 - 7%. Ring m g c 18 % acid linoleic v m nga c 16% acid linolenic, l nhng acid bo cha no cn thit m c th khng th t tng hp c. Lp ngoi ca m ln c nhiu acid bo cha no hn lp su.

+ Glucid: Trong tht c rt t ch khong t 0 - 3%, glucid ny di dng glucoza v glycogen, ch yu gan v mt t c.

- Lng tro khong 1%.

+ Cc cht khong:

- Phospho : 116 - 117 mg%.

- Kali : 212 - 259 mg%.

- St : 1,1 - 2,3 mg% tp trung nhiu gan.

Cu, Zn, Coban, canxi trong tht thp.

+ Vitamin: tht l ngun vitamin nhm B trong ch yu l B1 tp trung phn tht nc. Cc vitamin tan trong cht bo ch c gan, thn.

+ Cholesterol: l cht d gy va x ng mch c nhiu thn (5000 mg %); c

(2500 mg %), tim (2100 mg %), gan (320 mg %), tht (76 mg %).

1.2. Tnh cht v sinh ca tht:

Tht l ngun thc n c gi tr dinh dng cao, l thc n d ch bin di nhiu dng mn n ngon.

Tuy nhin tht c th l ngun ly cc bnh nhim khun nh: Bnh lao, than, t th, st ln sng, st nng; cc bnh k sinh trng nh: sn dy, sn ch. Tht cn c th gy ng c thc n do vi khun nhim vo tht hoc c t cha sn trong tht v ph tng nh cc (c t c da, bung trng v gan) l cht bufotonin. Cc loi nhuyn th khi cht d phn hy sinh c t mytilotoxin. Cc c t ny gy lit thn kinh trung ng. Nu ng c nng ngi bnh c th cht do lit c h hp hoc suy tun hon.

Bnh lao: kh ph bin trong ng vt, nht l loi c sng. Cc ni tng nh phi, thn thng cha nhiu vi khun lao hn c. V vy, khng s dng tht v ph tng nhng con vt mc bnh lao ton th. i vi ng vt b lao cc b phi, xng, thn th loi b cc b phn lao, cn tht ca n nu ch bin k c th dng c vi iu kin con vt khng qu gy.

Bnh than: bnh thng gp tru b, c th da, th phi v th rut. sc vt thng gp tn thng rut. Bnh ly sang ngi do tip xc nhiu hn ly qua ng n ung, nh tip xc khi git v khi ch bin tht mc bnh, phi tiu hy tht ca vt mc bnh than. Tht ca cc con vt khc ln vo u phi b i. Cng nhn tip xc phi c tim phng ngay, v nha bo than chu c nhit rt cao, sc nng kh 120 - 1400C phi sau 3 gi mi tiu dit c .

Bnh ln ng du: bnh do trc khun Erisipelothrix insidiosa gy xut huyt vim da, rut, thn v ton thn bi huyt, lch sng to. ng vt mc bnh ch yu l ln, c bit l ln con 3- 4 thng tui. D con, g,vt, b cu cng c th mc bnh ny. Bnh ly d dng sang ngi qua ng tip xc hoc n tht.

Cch ch bin thng thng khng lm cht vi khun, 1000C phi sau 2 gi vi khun mi b tiu dit.

X l: hy ton b v trit nh bnh than.

Bnh l mm long mng tru, b, d (Foot and mouth disease): bnh do virus gy ra. ng vt b bnh c cc vt lot c trng quanh vng ming, trong vm hng, li v t chi, nht l vng quanh mng. Con vt b st b n, mt kh nng lm vic. Bnh d ly lan, kh iu tr dt im. Nhng ngi tip xc vi ng vt b bnh hoc tiu th sn phm ca con vt c th b ly nhim vi cc triu chng tng t nh ng vt. Thng thng ch cn st trng vt lot, tng cng sc kho l bnh t khi.

Bnh b in: bnh b in cn c gi l bnh xp no b do t chc thn kinh c nhng khng bo c hnh thnh, to nn cc l xp lm cho cc nron thn kinh mt kh nng truyn tin. Bnh ny khng lin quan vi bnh di do virus gy ra. c nhiu cng trnh nghin cu cho rng bnh "b in" c th ly truyn qua ng tiu ho v ngun ly bnh l bt tht, bt xng ch bin t loi nhai li nh nh cu b mc bnh Scrapie. Do , t nm 1989 Chnh ph Anh cm dng bt tht, bt xng lm thc n cho b v tr thnh quy nh ca quc t.

Bnh giun sn: nhng giun sn chnh t tht ng vt truyn sang ngi l sn dy, sn nh v giun xon.

- Sn dy: sn dy k sinh b gi l T. Saginata v ln gi l T. Solium. Trng sn vo rut non sc vt, chui qua thnh rut vo mu, ri theo dng mu n cc t chc lin kt ca bp tht v cc t chc khc. khong 3 - 6 thng trng sn s bin thnh kn. Kn sn l mt bc mu trng, trong, ln nh khc nhau. Ht cha y nc, gia l u c vi ht. Kn sn ri rc trong cc bp tht, t chc lin kt.

Khi ngi n phi tht c kn sn nu cha chn th lp v ngoi ca kn b tan ra, u sn th ra bm vo nim mc rut non v ln dn, sau 2- 3 thng th pht trin thnh sn trng thnh di 6 - 7 m. T l ngi mc bnh sn do n tht ln c sn ch chim 1%, do n tht b ti c sn chim 99 %.

X l: nu s lng kn sn di 3 kn / 40cm2 tht th c th ch bin k hoc ngm nc mui 10% trong 20 ngy. Nu trn 3 kn /40cm2 tht th em hy b.

- Sn nh (Toenia echinococcus): sn nh thng gp ch, nht l ch hoang di v cc ng vt n tht. Vt ch trung gian l ng vt c sng, ln, lc , cc loi gm nhm v ngi.

K sinh trng Echinococcus sng rut non ca vt ch chnh, trng theo phn, i vo rut ca vt ch trung gian, thot v chui qua thnh rut vo mu n cc ni tng. Ti y chng chuyn thnh nang mt ti hay nhiu ti.

Ngi mc bnh sn thng hao mn, gy cm nhanh.

Tht ln v tht cc ng vt c sng b nhim sn ny ch n sau khi nu chn hoc ch bin thnh sn phm th mi dng n.

- Giun xon: giun xon nh, di 2 mm, k sinh ch yu ln ri n ch, mo, chut. Kn giun thng thy cc bp tht, li, quai hm, sn, bng. Nu ngi n phi tht ln c giun xon nu cha chn, giun xon s chui vo d dy, v kn b dch v ph hy, u trng giun thot ra xung rut lm vim nim mc rut v chy mu rut. Nu i, u trng giun s chui vo mu, theo dng mu ti bp tht sau 10 - 28 ngy, c khi ch 5 - 8 ngy sau s pht bnh. Bnh nng hay nh cn ty thuc vo thi gian bnh ngn hay di. Bnh cnh lm sng ging nh bnh ng c cp tnh, bnh nhn st cao 39 - 400C, au bp tht, ming lm cho bnh nhn nhai v nut au; triu chng c hiu l au mt, mi mt, nhc mt. au cc c, bnh nhn thy kh th, kh ni, kh nut, mt cng. T l t vong cao, nu qua khi bnh nhn vn cn thy au cc bp c trong vi thng.

X l: nu tht ln c giun xon bt buc phi ct tng ming dy 8cm em nu 1000C trong 2h30' mi c th dng c. Lng ln, tit canh l loi thc n d gy bnh giun xon tuyt i khng c dng.

2. C:

2..1. Gi tr dinh dng:

- Protein: lng protein trong c ch giao ng t 16 - 19 % tu loi c.

Protein c ch yu l alumin, globulin v nucleoprotein. T chc lin kt thp v phn phi u, gn nh khng c elastin. Ni chung protein c d ng ho, hp thu hn tht.

- Lipid: lipid ca c tt hn hn ca tht. Cc acid bo cha no c hot tnh sinh hc cao chim 90% trong tng s lipid bao gm oleic, linoleic, arachidonic, klupanodonic. M c nc ngt c nhiu oleic, m c nc mn c nhiu arachidonic v klupanodonic. Nhc im ca m c l c mi kh chu, nht l c nc mn. ng thi, v m c nhiu acid bo cha no c mch kp cao nn d b oxy ho, d hng v kh bo qun.

- Glucid: glucid trong c cng nh tht hm lng rt thp hu nh khng ng k.

- Cht khong: tng lng khong trong c khong 1 - 1,7%. Nhn chung c bin c nhiu cht khong hn c nc ngt. T l Ca/P c tt hn so vi tht, tuy nhin, lng can xi trong c vn thp (t 10 - 54 mg%).

Yu t vi lng trong c cao, cao hn nhiu so vi tht, nht l c bin cha cc cht vi lng, c bit l lng it kh cao nh c thu 1,7 - 6,2 mg/ kg c, fluor cng tng i kh.

- Vitamin: gan c c nhiu vitamin A, D, vitamin nhm B gn ging tht, ring B1 (0,04 - 0,11 mg %) thp hn tht ( tht: 0,10 - 0,52 mg %). V vy, nu n c ko di n thun m cc mn n khc trong khu phn ngho B1 th c th dn ti bnh Beri - Beri.

- Cht chit xut ca c thp hn ca tht, nn tc dng kch thch tit dch tiu ho km hn tht.

2.2. Tnh cht v sinh ca c:C l loi thc n chng hng v kh bo qun v:

- Hm lng nc tng i cao (42 - 49 %).

- S c mt ca lp mng nhy l mi trng tt cho vi khun pht trin.

- Tnh a dng ca ngun v ng xm nhp.

Khi c ra khi nc thng tit ra nhiu cht nhy ng li trn vy, cht nhy c cha nhiu protein l mi trng tt cho vi khun pht trin v lm hng c. C cn sng hoc mi cht, trong tht khng c vi khun, nhng nu khng c lm sch ngay v p lnh th vi khun t mang, vy v rut s nhanh chng xm nhp vo tht c. Cc vi khun pht trin trong c nhanh hn trong tht. Cc vi khun gy thi thng l loi psychrophile pht trin rt nhanh nhit 15 - 200C.

Trong c cn c th c vi khun Clostridium botulinum gy nn ng c botulisme rt nng, t vong cao. Nu st mui trc khi p lnh c th lm mt c t do vi khun tit ra.

C c th truyn bnh sn cho ngi nu n c c sn nu cha chn. Thng gp l sn kha v sn l. Sn kha ch gp x lnh, khng c Vit Nam. Sn l mnh di 2 cm, thun v dt nh chic l, mu nh ht hng. Trng ra ngoi theo phn. Trong trng c mao u trng. Khi trng n, mao u trng bi trong nc xm nhp vo c, hn, u trng rng lng, ri phn chia thnh v u trng ti k sinh cc loi c v pht trin thnh nang trng nm bp tht v lp mng di da. Ngi hay ng vt n phi c c nang trng nu cha chn s mc bnh. nc ta trc kia mt s ni c tp tc n gi c nn b mc bnh sn l gan kh cao, nay gim. V vy, khng nn n gi c, hoc c nu cha chn.

3. Sa:

3.1. Gi tr dinh dng: Sa l loi thc phm c gi tr dinh dng cao. Protein trong sa c cc acid amin cn thit v t l cn i d tiu ho, hp thu.

- Protein: protein ca sa bao gm: casein, lactoalbumin v lactoglobulin. Sa b, sa tru, sa d thuc loi sa casein v lng casein chim trn 75% tng s protein. Sa m thuc loi sa albumin, phn ln protein trong sa m l albumin. Sa m l thc n hon ho nht cho tr em. Casein l mt loi phospho protein c cc acid amin cn thit, trong sa ti casein di dng mui can xi (caseinat canxi) d ho tan. Khi gp acid yu casein s kt ta do s tch cc lin kt ca casein v canxi. Lactoalbumin khc vi casein l khng cha photpho nhng c nhiu lu hunh lm cho sa c mi kh chu. V vy, sa ch c php tit trng nhit thp ko di (phng php Tindal) 55 - 650C trong 30 pht, phi tit trng 2 - 3 ln, mi ln cch nhau 12 gi.

+ Lipid sa c gi tr sinh hc cao, v:

- trng thi nh tng v c phn tn cao, do vy d tiu ho, hp thu.

- C nhiu acid bo cha no cn thit.

- C nhiu photphatit l mt phospho lipid quan trng.

- C tan chy thp v d ng ho. Tuy nhin so vi du thc vt, lng acid bo cha no cn thit cn thp hn nhiu.

+ Glucid: glucid sa l lactoza, thuc loi ng kp, khi thy phn cho hai phn t ng n l galactoza v glucoza. Lactoza trong sa m (7 %) cao hn trong sa b (4,8 %), nhng khng ngt v ngt ca lactoza km sacaroza 6 ln.

+ Cht khong: sa c nhiu Ca, K, v vy sa l thc n gy kim. ng ho canxi ca sa cao hn cc thc n khc, v n di dng lin kt vi casein. V vy, sa l ngun canxi tt.

Trong 100g sa b ti c :

Canxi: 120 mg. Kali: 157,8 mg.

Phospho : 95 mg. Natri: 45,3 mg.

Magi : 14 mg. St: 0,1 mg.

Clo: 106 mg. Lu hunh: 34 mg.

m bo cho c th mi ngy 500 mg canxi cn khong gn 500 ml sa. Lng st trong sa thp, do khng th coi sa l ngun st c gi tr, nn cn phi n thm cc thc n giu st khc. Tuy nhin st trong sa d ng ho.

+ Vitamin: sa l ngun cung cp vitamin A, B1, B2, cn cc vitamin khc khng ng k. Vitamin D trong sa rt thp, v th sa b khng tho mn nhu cu cho tr em cng nh ngi ln. Ngi ta phi tng cng thm vitamin ny vo sa hoc tm nng tia t ngoi ly thm vitamin ny.

Vitamin C trong sa cng thp v thay i nhiu theo iu kin ly sa, bo qun v vn chuyn. Bo qun ko di, x l nhit ko di lm cho sa trn thc t khng cn vitamin C.

3.2. Tnh cht v sinh ca sa:+ Sa ti c cht lng tt phi c mu trng ng, hi vng, mi thm c hiu ca sa. Khi sa b kt ta th chc chn sa b nhim khun.

- T trng ca sa dao ng t 1,029 - 1,034, nu sa b pha long th t trng thp i v nu b ly mt b i th t trng s tng ln.

- chua ca sa phn nh ti ca sa, bnh thng t 18 - 20 thorner. Nu tng qu 22 thorner km theo c hin tng kt ta casein th chc chn sa b nhim khun.

Nu vt sa theo ng quy trnh v sinh th sa mi vt ra l v khun. Thi gian sa v khun s c ko di nu bo qun sa nhit thp. Nu khng sa s nhim khun rt nhanh, do sa l mi trng nui dng tt i vi vi trng.

+ Vi khun thng c trong sa l vi khun lactic nh Streptococus lactic phn ho sa sinh ra acid lactic. Ngoi ra, cn c loi vi khun gy thi phn hy protein lm hng sa nh: B. proteus, B. fubtilis, B. fluorescens. Sa cn c th nhim cc vi khun gy bnh nh t, l, thng hn, ph thng hn, lao, st ln sng v c bit l nhim t cu khun gy ng c thc n. V vy, sa vt ra nht thit phi c tit khun trc khi s dng.

4. Trng:

4.1. Gi tr dinh dng :

Trng l loi thc n c gi tr dinh dng cao, nht l v cht lng ca protein. Ngoi ra trong trng cn c lipid, glucid, vitamin, khong, men v hormon. Trong trng gia cm lng chim khong 32 - 36 %, lng trng 52 - 56 %, cc lp v 12 %. Lng l thnh phn quan trng nht ca trng trong tp trung ch yu cc cht dinh dng.

+ Protein:

Trng g ton phn c 12,7%.

Trng vt ton phn c 11,4%.

Trng vt ln c 12,0%.

Protein lng trng thuc loi protein phc tp gn ging nh protein ca sa. Protein lng trng thuc loi protein n gin, ch yu l albumin. Protein trng ni chung c thnh phn acid amin tt nht v ton din nht so vi cc acid amin ca cc loi thc phm khc; ng thi l ngun cung cp cc acid amin hay thiu ht trong ba n hng ngy ca nhn dn ta nh metionin, tryptophan, xystin. + Lipid: lipid tp trung lng , thuc loi glucolipid. Trng l ngun lexitin qy, lng c 8,8%. Trng l thc n ng vt duy nht c t l lexitin cao hn hn cholesterol (6/1).

Lng c 1,6% l cholesterol, khong 84% cholesterol trong lng di dng t do v ch 16% di dng este. V phng din sinh hc dng t do c ng c gi tr hn.

+ Glucid: glucid trong trng rt thp ch t 0,4 g% (trng g) - 0,9 g (trng vt), phn ln nm trong thnh phn cc protein v glucolipid phc tp. Mt lng nh glucoza dng t do

+ Cht khong: 96 % cht khong tp trung v cng, phn cn li 4% phn phi u gia lng v lng trng ca trng.

+ Vitamin: lng trng cha nhiu vitamin A v caroten, ngoi ra trng c cc vitamin khc nh D, E, K, B, v C.

+ ng ho: lng v lng trng c ng ho khng ging nhau.

Lng trng c nh tng v phn tn cao nn n chn v n sng u hp thu nh nhau, lng trng trng sng c cha antitrypsin khi un nng ti 800C, men ny mi b ph hy, do vy khng nn n lng trng sng. Ngoi ra cn c cht avidin lm mt hot tnh biotin lng trng sng v nh vy c tc dng c i vi c th. Khi un si 800C biotin cng c gii phng ra khi phc hp biotin - avidin.

4.2. Tnh cht v sinh:Trn b mt v trng, ty theo iu kin bo qun c th c cc vi khun t, nc, khng kh. Nhng vi khun hay gp l B. proteus vulgaris, B. coli comnunis, B. subtilis...

Trng cc loi gia cm nh vt, ngan, ngng, do sng v trng di nc bn t ng m t, nn c th b nhim salmonella, shigella.

Cch bo qun trng: do qu trnh phn gii men, trng trong khng kh mt dn nc, gii phng kh CO2, pH tng v trng lng gim dn. Nhit xung quanh cao, cc men t dung gii hot ng mnh cui cng a ti phn gii cc protein ca trng v to thnh cc sn phm thoi ho mi rt thi (H 2S, metan, indon, scaton...). Qu trnh t dung gii do men thng phi hp vi qu trnh thi do vi khun.

Cch bo qun trng tt nht l bo qun lnh. Trc khi bo qun lnh, trng phi c ra sch, lau kh.

5. Ng cc v khoai c:

5.1. Ng cc:Ng cc l ngun cung cp nng lng chnh cho khu phn hng ngy ca nhn dn ta, ng thi ng cc cng l ngun cung cp protein thc vt v vitamin nhm B.

5.1.1. Go:

Go l lng thc chnh trong ba n hng ngy ca nhn dn ta. Gi tr dinh dng ca ht go ph thuc vo ging, t ai, kh hu, xay xt, bo qun v ch bin.

+ Protein: protein go thp hn m v ng (7 - 7,5%) nhng gi tr sinh hc tt hn, go gi cng trng, th lng protein cng gim. So vi protein ca trng th protein go thiu lysin, v vy khi n nn phi hp vi thc n ng vt v u .

+ Lipid: lipid go thp (1 - 1,5%) nm ci v mm.

+ Glucid: l thnh phn dinh dng chnh ca ht go, glucid chim 70 - 80% tp trung li go. Go gi cng trng th t l glucid cng cao. Glucid go ch yu l tinh bt (polysaccarit), cn mt t ng n, ng kp nm ci v mm.

- Cht khong: go c t canxi, nhiu photpho nn go l thc n gy toan (29,6/ 102,4 : Ca/P).

- Vitamin: go l ngun vitamin nhm B1. Lng B1 trong ht go nguyn, hoc xt va phi cho chuyn ho glucid trong go. Tuy nhin, hm lng B1 cng nh cc vitamin khc ph thuc rt nhiu vo xay xt, v phn ln chng nm v ngoi ca ht go.

Ht go nguyn c:

Vitamin B1: 0,38 mg %. Niaxin : 4,1 mg %.

Vitamin B2: 0,1 mg %. Biotin : 0,012 mg %.

VitaminB6 : 1,0 mg %. Acid pantotenic : 1,7 mg %.

Ht go xay xt trng:

Vitamin B1: 0,08 mg %. Niaxin : 1,9 mg %.

Vitamin B2: 0,04 mg %. Biotin : 0,004 mg %.

Vitamin B6 : 0,30 mg %. Acid pantotenic : 0,66 mg %.

Cc thnh phn dinh dng nh protein, lipid v vitamin nhm B tp trung phn ln mm v ci. V vy, cn ch :

. Khng xt go qu trng.

. Khng vo go qu k.

. Nu cm khng cho qu nhiu nc hoc cht nc cm s lm hao ph nhiu cht dinh dng.

. Bo qun go ni kh ro, thong mt, trnh nh sng trc tip, chng m mc, su, mt, khng nn bo qun go qu ba thng.

5.1.2. Ng :

+ Protein: 8,5 - 10%, protein ca ng hu nh khng c tryptophan v lysin. Ng phi hp vi u hoc cc thc n ng vt th gi tr sinh hc ca protein ng s tng ln nhiu.

+ Lipid: 4 - 5% phn ln tp trung mm. Trong cht bo ca ng c 50% l acid linoleic, 31% l acid oleic, 13% acid panmitic v 3% l stearic.

+ Glucid: khong t 60 - 68%. ng gi glucid dng tinh bt cn ng non glucid ch yu dng ng n v kp, do vy, n ng non thy v ngt .

+ Cht khong: ng ngho canxi, giu phospho, ging nh go, ng l thc n gy toan.

+ Vitamin: vitamin ca ng tp trung lp ngoi v mm. Ng cng c nhiu vitamin B1(0,27 mg%), B2: 0,11 mg%, PP : 2 mg%. Ng vng c hm lng bta - caroten (tin vitamin A) cao: 0,39 mg% .

Ng v bnh pellagr: bnh pellagr hay gp nhng vng n ng l chnh. l do lng vitamin PP trong ng thp v ng ngho tryptophan. phng bnh cn n ng phi hp vi u, lc v cc thc n ng vt khc...

1.5.1.3. Bt m :

Gi tr dinh dng ca bt m ty thuc vo cch ch bin. Bt m sn xut t ht ton phn c gi tr dinh dng ging nh nguyn liu. Cn loi bt m trng mt i lp v alron v mm nn nhiu cht dinh dng quan trng cng mt theo .

+ Protein: bt m ngoi albumin, globulim cn c prolamin v glutelin do vy bt m c th dng lm bnh. Yu t hn ch ca protein bt m l lysin.

+ Cc cht dinh dng khc nh: lipid, glucid, vitamin v cht khong trong bt m cng tng t nh go.

+ V phng din v sinh: cn ch bt m d ht m v mc. Khi bt mc th khng c dng ch bin ra cc thnh phm khc cho ngi n nh bnh m, cc loi bnh khc v m si...

5.2. Khoai c:

c im chung ca khoai c l ngho protein nhng c nhiu glucid, vitamin v cc cht khong qu.

5.2.1. Khoai lang:

+ Protein: protein khoai lang thp (khoai ti: 0,8%, khoai kh: 2,2%). Gi tr sinh hc ca protein khoai lang hn ng v sn, nhng km go v khoai ty.

+ Lipid: lipid trong khoai lang rt thp ch c 0,2%.

+ Glucid: 28,5%.

+ Vitamin: khoai lang c nhiu vitamin C (23 mg%). Ring khoai ngh c nhiu caroten.

+ Cht khong: can xi v pcpho u thp, t l Ca/P tng i hp l: 34/49.

+ V phng din v sinh: khoai lang kh bo qun, khng gi c lu. Mun gi lu phi em thi mng v phi kh.

5.2.2. Sn:

Sn ti c gi tr dinh dng thp.

+ Protein: km c v s lng v cht lng. Protein sn ngho lysin, tryptophan v cc acid amin cha lu hunh khc.

+ Cc cht dinh dng khc: glucid 36,4%, nng lng 156 kcal/100g. Lipid, cc vitamin v cht khong u ngho. T l Ca/P ging nh khoai lang.

+ V mt v sinh: sn ti c th gy ng c thc n v trong sn ti, nht l v tm c cha xyanogen rt c. V vy, khi n sn ti phi bc v, ngm nc v luc k, hoc n sn kh l an ton. Tuy nhin, sn nc ta cha t cht c hn cc nc khc trong khu vc ng Nam .

1.5.2.3. Khoai ty:

+ So vi khoai lang, khoai ty c nhiu protein hn (2%). Protein khoai ty c nhiu lysin nn phi hp tt vi ng cc. Gi tr sinh hc ca protein khoai ty ln ti 75%. Khoai ty l thc n gy toan, canxi: 10 mg%, phospho: 50 mg%, kali: 553,9 mg%.

+ Vitamin: vitamin C trong khoai ty tng i cao 10 mg%, vitamin B cao hn khoai lang, gn ging go. Nng lng khoai ty thp (94 kcal/100g).

+ V phng din v sinh: trong khoai ty, nht l khoai ty mc mm v lp v ngoi c cha nhiu cht c solanin, khi khoai mc mm c th cha 50 - 100 mg% cht solanin. Do vy, cch phng tt nht l khng n khoai mc mm.

6. u v ht c du:

6.1. u :Ht u kh ni chung cung cp nng lng gn bng ng cc.

+ Protein: cao t 17 - 25%, ring u nnh (u tng) ln ti 34%. Protein ca u tng ngho cc cht acid amin cha lu hunh nh metionin, xystin nhng giu lysin nn phi hp vi ng cc c bit l ng rt tt. Gi tr sinh hc protein ca u : 40 - 50%, ring ca u tng l 75%.

+ Lipid: 1 - 3%, ring u tng ln ti 18%.

+ Vitamin: u l ngun kh tt v vitamin nhm B, lng B1: 0,5 - 0,7 mg%,

B2: 0,2 - 0,3 mg%, PP: 1,8 - 2,4%, vitamin C thp: 3 - 4 mg%.

+ Cht khong: u giu canxi, phospho v st, canxi: 56 - 165 mg%, phospho: 318 - 400 mg%, st: 6 - 11 mg%.

Mt s ch phm ca u thng dng:

- Gi u xanh: ngho nng lng, nhng nhiu vitamin nhm B, B1: 0,2mg%; B2: 0,13 mg%; C:10 mg%.

- Sa u nnh: gi tr dinh dng ca sa u nnh ph thuc t l u nnh nhiu hay t, thng c cc t l u nnh 100g/l, 150g/l - 200g/l. Ni chung sa u nnh c th dng thay sa b nui tr em khi khng c sa b v sa m.

- u ph: trong qu trnh sn xut u ph protein u tng c thy phn thnh dng d hp thu.

Protein khong: 10 - 12%, lipid: 4 - 5%. u ph l mn n tt cho ngi cao huyt p, bo ph v i tho ng. Hng thng mi ngi bnh thng cng nn n t 2 - 3 kg u ph.

- Tng: l thc n c dng thay nc chm. Trong qu trnh ln men, protein thc vt (t nguyn liu u tng v go hoc ng) chuyn thnh acid amin v pepton. Nu lm ng quy trnh k thut, v sinh m bo th tng l mt mn n tt. Song trong qu trnh ln men rt c th b nhim mc Aspergillus flavus t khng kh. y l loi mc c kh nng sinh c t aflatoxin gy ung th mnh gan v mt s ph tng khc.

6. 2. Ht c du: nc ta ht c du c dng nhiu l lc ht, vng. Ngoi lng protein v lipid cao ht vng cn c nhiu cht khong, ch yu l st, vitamin ch yu l vitamin PP.

6.2.1. Lc:

+ Protein: 27,5%, gi tr sinh hc km v thiu nhiu acid amin cn thit.

So vi ng cc, protein lc km go, nhng tt hn ng.

Nn phi hp lc vi ng cc, th gi tr sinh hc ca protein phi hp s tt ln rt nhiu, v ng cc ngho lysin v lc ngho metionin. Lc phi hp rt tt vi ng v lc c nhiu vitamin PP (15,7 mg%) v tryptophan l hai yu t hn ch ca ng.

+ Du lc (lipid): 44,5% c 80% l acid bo cha no (oleic v linoleic) v 10% l acid bo no (palmitic) ngoi ra l cc acid bo khc.

- V phng din v sinh: nu bo qun khng tt lc c th b m v mc. Khi lc b nhim mc rt d c c t aflatoxin gy ung th gan. Bo qun lc tt nht l c v, trnh nh sng trc tip.

6.2.2. Vng:

Vng l mt loi thc n c gi tr.

+ Protein: 20%, protein ca vng ngho lysin, nhng giu metionin. Nu phi hp vi ng cc th s c khu phn c hn hp protein rt tt.

+ Lipid: 46,4%, y l lipid qy.

+ Vitamin: vng c nhiu vitamin nhm B.

+ Khong: vng c nhiu canxi (1200 mg%) ngang vi sa, nhng hp thu km, v vng c nhiu acid oxalic cn tr hp thu canxi ca c th.

7. Rau qu:

Rau qu c vai tr quan trng trong dinh dng. V lng protid, lipid, glucid, rau qu km xa cc thc phm ng vt v ng cc. Nhng gi tr chnh ca rau qu l cung cp cho c th nhiu cht c hot tnh sinh hc, c bit l cc cht khong kim, vitamin, pectin v acid hu c, ngoi ra rau qu cn c cc loi ng tan trong nc, tinh bt v xelluloza.

Mt c tnh quan trng l rau qu gy cho ta cm gic thm n v kch thch tit dch tiu ho. Rau phi hp vi cc thc n nhiu protein, lipid, glucid s lm tng kch thch tit dch v. Ch n rau kt hp vi protein, lng dch d dy tit tng 2 ln so vi n protein n thun. Ba n c rau to iu kin thun li cho s tiu ho hp thu cc cht dinh dng khc.

Trong rau cn c cc men, men trong c hnh ging pepxin ca dch v, men trong bp ci v x lch ging trypxin ca tuyn ty.

7.1. Rau:

Lng nc trong rau rt cao 70 - 95%. V vy, rau rt kh bo qun, nht l v ma h, rau d b hng.

+ Protein: trung bnh t 0,5 - 1,5%. Ring rau ngt v gi c t l protein kh cao 5,3 - 5,5%. Protein ca rau c nhiu lyzin v methionin, nn phi hp tt vi ng cc.

+ Lipid: trong rau hm lng lipid hu nh khng ng k.

+ Glucid: thp, t 3 - 4% bao gm ng n, ng kp, tinh bt, xelluloza v pectin. Xelluloza ca rau thuc loi mn d chuyn sang dng ho tan trong rut. Trong rau xelluloza di dng lin kt vi cc cht pectin to thnh phc hp pectin - xelluloza kch thch mnh nhu ng rut v tit dch rut. Ngi ta cho rng xelluloza ca rau c kh nng o thi cholesterol ra khi c th. Lng xelluloza trong rau khong 0,3 - 3,5 % ty loi rau.

+ Vitamin: rau l ngun vitamin C v bta- caroten cho khu phn n hng ngy.

Rau c nhiu vitamin C: rau ngt (185 mg%), cn ty (150 mg%), rau mi (140 mg%), mng ti (72 mg%), ci sen (51 mg%), c chua (40 mg%), ci bp (30 mg%), ci cc (27 mg%), ci soong (25 mg%), rau mung (23 mg%)...

Bta - caroten c nhiu trong cc rau, c c mu vng, , da cam hoc mu xanh m: rau ngt (6650 mg%), t (5790 mg%), c rt (5040 mg%), cn ty (5000 mg%), hnh l (1370 mg%), c chua (1115 mg%)...

+ Cht khong: rau l ngun cung cp cc cht khong kim nh: K (200 500 mg%), Na (5 - 60 mg%), Mg (20 - 160 mg%), Zn (0,5 - 1 mg%).

7.2. Qu:V thnh phn dinh dng so vi rau, qu c nhiu glucid hn v phn ln di dng c ng n, ng kp nh fructoza, glucoza, sacaroza. Qu cng l ngun cung cp vitamin C nh rau, nhng u vit hn do trong qu khng c men phn gii vitamin C v n qu khng phi qua nu nng, do vy hm lng cc vitamin khng b tn tht nh rau.

Qu cng l ngun cc cht khong kim, ch yu l kali, lng Ca/P t nhng t l hp l. Qu cn cha mt s acid hu c nh acid xitric, malic, tactric, benzoic. pH qu vo khong 2,5 - 5,2 v rau t 5,3 - 5,9.

7.3. Tnh cht v sinh ca rau qu:

Rau c th nhim cc vi khun gy bnh v trng giun sn, do ti rau bng phn ti hoc nc bn. c bit l cc loi rau n sng l mn n c nhiu ngi a thch nhng rt nguy him do khng qua un nu. Nhng phng php ra rau thng thng khng th dit c cc loi vi khun.

Hin nay, mc nhim ho cht bo v thc vt trong rau qu kh cao, gy nn ng c cp v mn cho ngi tiu dng.

hn ch bt s nguy him ca ho cht c trong rau, qu trc khi n ta phi ra sch v ngm trong nc sch ti thiu t 10 - 15 pht. i vi qu phi gt v trc khi n. i vi rau sng cn ch ra tng tu l di vi nc chy hn ch bt trng giun, sn bm trn l rau.

Nh vy, mi loi thc phm u c gi tr dinh dng khc nhau. Chng u c u v nhc im ring i vi sc kho con ngi. Cch n ung tt nht l nn phi hp cc loi thc phm vi nhau trong khu phn, chng s b sung nhng u im cho nhau c mt khu phn hon ho hn.

II. Phn chia thc phm theo nhm.

dinh dng hp l v cn i cn phi bit phi hp cc loi thc phm. V vy, ngi ta c gng sp xp thc phm theo nhm da theo s ging nhau v thnh phn ho hc v vai tr dinh dng. Ty theo tc gi ngi ta chia thc phm ra 2 nhm, 4 nhm v 6, 7, 9, hoc 12 nhm.

Sau y l mt vi cch phn nhm:

1. Chia thc phm ra 2 nhm:

+ Nhm bo v: cc thc phm cha nhiu m c gi tr sinh hc cao, canxi v vitamin nht l vitamin: A, C, B1, B2, PP. Thuc loi nhm ny c tht, c, trng, sa, ng cc ton phn, mt s loi rau qu.

+ Nhm cung cp nng lng: gm tt c cc thc phm khc nh bt trng, cht bo, ng v ngt, khoai c v phn ln cc loi rau ngho vitamin.

2. Chia thc phm ra 6 nhm:

Cch chia thc phm ra 6 nhm chi tit hn, cho php la chn thc phm mt cch hp l hn. Trong cch chia ny cng c cc cch chia khc nhau:

Cch chia ACch chia B

Nhm I - Tht, c, trng

- u kh Nhm I - Tht, c, trng

- V cc ch phm

Nhm II - Sa

- Pho mtNhm II : - Sa

- Pho mt

Nhm III : - B

- Cc cht bo khc Nhm III : - Cc cht bo b

- Cht bo ng, thc vt

Nhm IV - Bnh m

- Ng cc Nhm IV - Ng cc

( k c ch phm )

Nhm V - Qu Nhm V - Rau qu

Nhm VI - Rau ti -Cc thc n ngt:

ng, scla, ko. Nhm VI - ng v ngt

3. Chia thc phm ra 4 nhm:

+ y l cch chia c dng ph bin hin nay v cng c coi l hp l nht.

Nhm cung cp cht bt:

- Ng cc

- Khoai c... Nhm cung cp cht m:

- Tht, c, trng, sa

- u ...

Nhm cung cp cht bo:

- M, b

- Du... Nhm cung cp vitamin, cht khong, cht x: - Rau

- Qu...

+ Khu phn n cn i v hp l cn phi c mt c 4 nhm thc phm.

+ Cc thc phm trong cng mt nhm c th thay th cho nhau, v c gi tr dinh dng gn ging nhau.

+ Nu khu phn c nhiu thc phm cung cp cht m, nhng thiu thc phm cung cp nng lng th cht m s b tiu ph cho nng lng. Ngc li khu phn ch yu cung cp nng lng m khng cht m th s nh hng xu ti sc kho. Khu phn cng khng th thiu nhm thc phm cung cp cht bo, vitamin v cht khong, v chng c nhiu vai tr sinh hc quan trng trong c th.

Tm li, mi nhm thc phm c nhng chc nng, vai tr dinh dng nht nh i vi c th. Ch c th phi hp cc nhm thc phm mt cch hp l mi pht huy c hiu qu dinh dng tt nht ca thc phm cho sc kho con ngi.

Cu hi n tp:

Cu 1: Gi tr dinh dng v tnh cht v sinh ca tht, c, sa, trng.

Cu 2: Gi tr dinh dng v tnh cht v sinh ca ng cc v khoai c.

Cu 3: Gi tr dinh dng v tnh cht v sinh ca u v ht c du.

Cu 4: Gi tr dinh dng v tnh cht v sinh ca rau, qu.

Cu 5: Phn chia thc phm theo nhm.

Ti liu tham kho.

1. B mn Dinh dng - HVQY (2008).

Dinh dng lm sng.

NXB Qun i Nhn dn, tr: 39 - 55.2. Dinh dng v ATTP

NXB Y hc, 1996, tr; 69 - 85.

3. Hong Tch Mch, H Huy Khi.

V sinh dinh dng v v sinh thc phm.

NXB Y hc, 1977, tr: 153 - 213.

4. Vin Dinh dng.

Bng thnh phn thc phm Vit Nam

NXB Y hc, 2000.

5. Susan G.Dudek.

Nutrition Handbook

for nursing Practise

lippincott - Pulishers, New York, p: 5 - 226.

6. World health organnization.

The health aspects of food and nutrition.

Manila - 1979, p: 5- 41, 253 - 297.