C IM CA THT HEO, THT B, THT G
C IM CA THT HEO, THT B, THT GTRNG I HC BCH KHOA H CH MINHKHOA K
THUT HA HCB MN CNG NGH CH BIN THT
Tht l mt trong nhng thc phm c gi tr dinh dng cao, cung cp axit
amin cn thit, cc cht bo, cht khong, vitamin v mt s cc cht thm. Tht
cc loi ni chung ngho canxi, giu photpho.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. gan, thn, tim, no c nhiu Cholesterol v photphatit.
Thnh phn ha hc v gi tr dinh dng ca thtTht l mt trong nhng thc phm c
gi tr dinh dng cao, tht cc ng vt mu nng nh tht ln, tht b, tht gia
cm. c cha nhiu axit amin cn thit, cc cht bo, cht khong, vitamin v
mt s cc cht thm hay cn gi l cht chit xut. Tht cc loi ni chung ngho
canxi, giu photpho.2Thnh phn ha hc ca cc loi tht
Tht l mt trong nhng thc phm c gi tr dinh dng cao, tht cc ng vt
mu nng nh tht ln, tht b, tht gia cm. c cha nhiu axit amin cn thit,
cc cht bo, cht khong, vitamin v mt s cc cht thm hay cn gi l cht
chit xut. Tht cc loi ni chung ngho canxi, giu photpho.3Thnh phn ha
hc ca cc loi tht
M c c chia ra lm ba loi: m c vn ngang, m c trn v m c tim.M c vn
ngang m bo mi c ng theo mun ca con vt, chim t l ln trong c th, l m
c gi tr thc phm cao nht. M c trn v m c tim co gin khng ty , chim t
l nh. Cc loi m cTht l mt trong nhng thc phm c gi tr dinh dng cao,
tht cc ng vt mu nng nh tht ln, tht b, tht gia cm. c cha nhiu axit
amin cn thit, cc cht bo, cht khong, vitamin v mt s cc cht thm hay
cn gi l cht chit xut. Tht cc loi ni chung ngho canxi, giu
photpho.5M c vn ngang l thnh phn c dinh dng cao nht.L ni tp trung
ca cc protein hon ho, vitamin, cht khong, cht ngm raHn 85% protein
m c l protein hon thinD b phn gin di tc dng ca cc men tiu ha
(pepsin, tripsin, chimotripsin,)M c vn ngangT l cc m trong gia sc
(%)
Cu trc ca m c tht
Loi mTht bTht lnM cM mM lin ktM xng v snM mu57 623 169 1217 294
- 540 5815 466 88 187,5 8Cu to m c vn ngang
Mt ct dcb. Mt ct ngang1. Vn m2. Mng lin kt 3. Mch mu 4. Si cCu
to m c vn ngang
Hm lng m m trong c th ng vt thuc cc loi khc nhau c gii hn dao ng
t 1 40% theo khi lng sng ty theo ging, tui, mc bo v v tr tch ly m.
Thnh phn m m gm lipit (70 97%), protein (0,5 7,2%), nc (2 21%) v mt
lng nh lipoid, cht khong, sc t v vitamin.
M M
T bo m m
M LIN KT
M lin kt si xp2. Chm colagen3. Si elastinCc dy chng cu to c lin
kt cc xng vi nhau thnh khp cu to t m lin kt. Mng xng v mng sn bao
ph b mt xng v sn cng c cu to t m lin kt.Thnh phn ha hc:
nc(57,662%); protein2140%); lipid(13,3%); khong(0,40,7%). Cc dy
chng cu to c lin kt cc xng vi nhau thnh khp cu to t m lin kt. Mng
xng v mng sn bao ph b mt xng v sn cng c cu to t m lin kt.Thnh phn
ha hc trung bnh ca m lin kt gm: nc (57,662%); protein (2140%);
lipid (13,3%); khong (0,40,7%).
11M xng l mt trong cc loi m lin kt. B xng ng vt c cu to t m xng.
Xng gm c cht c bn c to ra lp b mt v cht xp bn trong. Cht c bn c ca
m xng gm c phn hu c thm mui khong cha trung bnh 20 25% nc, 75 80%
cht kh. M sn cu to t cht c bn c, trong c cc thnh phn t bo v cc si
colagen, elastin.M XNG, M SNTrong mu cha 16,4 18,5% protein; 79 82%
nc; 0,6 0,7% cht hu c phi protein v 0,8 1% cht khong. Mu gm c cc
thnh phn hu tnh v huyt tng lng.Sau khi phng tit bnh thng, trong sc
tht ng vt cn tn ti khong 0,5 1,2% mu theo khi lng sng. Protein ca
mu d tiu ha bi cc enzyme tiu ha.
M MUMyoglobin v Hemoglobin u l nhng sc t c kh nng vn chuyn oxi .
Hemoglobin c ch yu trong mu, tu xng, myoglobin c trong c. V oxi gn
vi myoglobin rt cht nn l sc t c li nht i vi cc c hot ng tch cc.
Myoglobin l sc t quyt nh mu sc ca tht.Myoglobin c cu to gm nhm ngoi
l nhm Heme v phn t Globin. Myoglobin l protein c cu trc bc 3. Heme
gm nguyn t Fe v vng Protoporphyrin. Nguyn t Fe c th c ho tr II hoc
ho tr III. Trng thi oxi ho ca Fe (Fe2+ hoc Fe3+) v bn cht cc phi t
ni Fe (O2, NO, CO) l nguyn nhn lm thay i mu sc ca tht.Myoglobin v
cc bin i mu sc ca tht
Myoglobin v cc bin i mu sc ca tht
Lng Myoglobin thay i tu tng loi m, tng loi, tui, gii tnh dn n mu
sc tht cng thay i theo. tui cng cao th lng Myoglobin cng nhiu nn
tht ca con vt gi c mu m hn ca con vt con. Nhng bin i ca Myoglobin
lm thay i mu sc ca tht
S bin i ca ng vt sau khi cht
Da vo nhng biu hin bn ngoi, ngi ta chia mt cch quy c nhng s bin
i tht, c sau khi git thnh 3 thi k:- T cng sau khi git- Chin ti- T
phnS bin i tip theo ca tht sau 3 thi k ny l s thi ra.
S bin i ca protein tht trong qu trnh bo qun
Gm cc qu trnh:- Phn hy glycogen thnh acid lactic.pH t im trung
ha thnh pH acid.- Phn hy glycogen thnh cc glucid c tnh kh (glyco
phn).- Phn hy acid creatinphosphoric- Phn hy ATP- Kt hp actin vi
myozyn thnh phc cht khng tan(to rn ca m c) - S pht trin t cng hon
ton xy ra vi thi gian khc nhau ph thuc vo c im ng vt va cc iu kin
xung quanh.- Vo lc ny, rn ca tht tng 25%, cn ct tng ln 2 ln.Tht nh
th s c rn ln k c sau khi nu.- Tht trng thi t cng sau khi git: tiu
ha bi pepsin km, hu nh b mt mi thm v v sn c trng thi luc.
S t cng sau khi git
T cng sau khi git ca cc bp c l kt qu ca s pht trin ca qu trnh ha
sinh phc tp do enzyme m c trng ca n khc vi cc qu trnh sng. Tht giai
on cng xc cha thch hp trong s dng ch bin, v cha cho hng thm v ngon,
kh nng hydrat ha km lm cho tht luc b cng, kh qut, nc luc canh b c,
khng c v ngt m .
19Chin ti, l nhng bin i v tnh cht ca tht gy nn bi s t phn. So vi
tht trng thi t cng th n d b tc ng bi enzyme tiu ha hn.
S chn ti ca tht
T cng
Chn ti
C ch ca qu trnh t cng v chn ti
S phn gii protein km theo ph hy cc thnh phn cu trc hnh thi hc ca
m c. Do :+ rn ca tht gim i.+ S tch dch tht tng ln.+ Tht c mu sc
hung nu r.+Tht tr nn chua v c mi kh chu hn.Nu tht ngui khng ng quy
cch, cc enzyme c sn trong tht pht trin mnh phn hy protein thnh NH3,
H2S,Hin tng xy ra nhit 400C v thiu oxy gy ra.
S t phn Tht t phn c trng thi cm quan khng tt:+ C mi chua kh chu+
B mt ngoi i khi c mu xanh+ su trong khi tht c mi hi, mu sc i khi
hoc nu+ Khng c vi sinh vt gy thi+ Khng c hi cho sc khe ngi tiu
dung
S t phnS bin i hp cht protein ng tr quan trng nht trong s phn hy
thi ra do hot ng sng ca cc vi sinh vt phn gii protein bn ngoi xm
nhp vo cng vi cc enzyme sn c trong tht. S phn hy (thi ra)S phn hy
(thi ra)
Tht heo cung cp Viatmin B tng hp (riboflavin, niacin, thiamine)
nhiu hn cc loi tht khc, giu km, v pht pho.
THT HEOAcid
aminTryptophanThreonineIsoleucineLeucineMethionineCystineHm
lng(g)0.3381.2341.2602.1770.7120.344Acid
aminPhenylalanineTyrosineValineArginineHistidineAlanineHm
lng(g)1.0860.9361.4731.7231.0671.603Acid aminAspartic
acidA.GlutamicGlycineProlineSerineProteinHm
lng(g)2.5124.2151.4091.1581.12827.32 gBng : Thnh phn cc acid amin c
trong 100g tht ln ti.
THT HEOBng : Hm lng thnh phn bo c trong 100g tht ln ti.Tng
bo13.92
(g)Saturated5.230Monounsaturated6.190Polyunsaturated1.200Bng : Hm
lng vitamin bo c trong 100g tht ln ti.Vitamin B60.464 mgVitamin
B120.70 gCholine93.9 mgVitamin C0.6 mgVitamin D53 IU
THT HEOBng: Hm lng vi khong c trong 100g tht ln ti.Vi
khongmgCa19Fe0.87Mg28P246K423Na62Zn2.39
V tr nhng ming tht heo
Phn thtH s % tnh theo khi lng thtH s % tnh theo thnh phn ha
hckcal/kgThtMDaXngNcProtetinLipidTroVai66,922,15,410,957,812,428,80,93190Lng46,538,16,98,554,912,232,00,93480ai
lng
bng46,538,16,98,554,912,232,00,93480Ngc43,440,58,97,254,410,834,00,83600Mng
i57,525,58,09,064,215,719,01,12410Cng chn
trc4718,734,363,215,620,01,22500Cng chn
sau36,122,341,667,616,814,51,22040Bng:Ty l cac thanh phn nac, m, da
va xng tai cac vi tri
TT Gi tr pH C di lng C tht lng C mng C i 1 pHi 5,81b 0,16 6,14a
0,06 5,94b 0,10 6,10a 0,10 2 pHu 5,59b 0,06 5,76a 0,08 5,59bc 0,05
5,69ac 0,05 Bng: S thay i v gi tr pH ca tht ln King St sau git
m
- pHi: pH xc nh c thi im 45 pht sau git m- pHu: pH xc nh c thi
im 24 gi sau git m
THT BTht b cha nhiu st, protein, kali, axit amin. b sung nng lng
cho h c v tng sc do dai ca c th mt cch hiu qu. Bng: Hm lng acid
amin c trong tht b.Acid amineHm lng % trong
protidLysine8.1Methionine2.3Tryptophan1.1Phenylalanine4Threonine4Valine5.7Leucine8.4Isoleucine5.1Arginine6.6Histidine2.9
KhongCaMgFeKNaPHm lng25,5211,531351183THT BBng: Hm lng khong mg
trong 100g thtBng: Hm lng vitamin trong 100g tht bLoi
vitaminThiaminRiboflavinNiacinB6B12Hm lng
(mg)0,050,096,70,561,1
THT BBng : Hm lng thnh phn bo c trong 100g tht ln ti.Tng bo13.92
(g)Saturated5.230Monounsaturated6.190Polyunsaturated1.200Bng : Hm
lng vitamin bo c trong 100g tht ln ti.Vitamin B60.464 mgVitamin
B120.70 gCholine93.9 mgVitamin C0.6 mgVitamin D53 IU
V tr nhng ming tht b
tt c cc loi b, pH c thn gim nhanh t 1 n 12 gi sau git tht v tip
tc gim ti thi im 48 gi. pH n nh trong khong thi gian t 48 gi n 8
ngy sau git tht
Mu sc
Mu ca tht lin quan mt thit vi hm lng myoglobin O2 v cc dng chuyn
ho ca myoglobin. Hm lng myoglobin trong tht b l 3-6mg/g v ln hn
trong tht heo v tht g nn mu ca tht b m hni vi tt c loi b, cc gi tr
mu sc (L*, a*, b*) c xu hng tng t thi im 12 gi n 48 gi v n nh n 8
ngy37
THT GTht gia cm thuc loi tht trng c nhiu protein, lipid, khong v
vitamin hn so vi tht . Bng: Hm lng vi khong c trong 100g tht ln
ti.Acid amineHm lng % trong
protidLysine8.1Methionine3.1Tryptophan1.3Phenylalanine3.8Threonine4.7Valine-Leucine-Isoleucine-Arginine6.9Histidine2.3
KhongKPCaMgFeNaMnZnCuHm lng24521414271,07710,0181,020,05THT
GBng: Thnh phn khong trong 100g tht (n v: mg)Bng: Thnh phn vitamin
trong 100g tht (n v: mg)VitaminB1 (mg)B2 (mg)B6
(mg)Folate(mcg)B12(mcg)A(UI)E (mg)K(mcg)D(UI)Hm
lng0,0660,1190,5640,32930,270,35V tr nhng ming tht g
Dinh dng c g (khng da, xng)Chn g i g (khng da)i gCnh g Cnh g
(khng da)Tht g (khng xng, khng da)Tht g Nng lng
(Calo)114161119221222126119215Protein
(g)21,219,319,717,318,32221,418,7Cht bo bo ha
(g)0,62,414,34,50,90,84,3Cht bo cha bo ha
(g)0,83,41,26,36,40,80,96,2Cholesterol (mg)6481838477577075Natri
(mg)11683867673817775St (mg)0,41110,90,90,90,9THT GBng: Thnh phn
dinh dng trong 100g tht g nguyn liu
Nhn chung hm lng cht dinh dng trong cc b phn khc nhau khng thay
i nhiu. Phn m tp trung st phn da bn ngoi nn vic loi b da lm hm lng
bo gim r rt. Cng v l do ny m tht g s khng mm mi c nh tht heo v tht
b.
41Hnh: Thay i pH ca tht theo thi gian
Nhng bin i sau khi git tht
pH gim nhanh sau 2 gi git m do vi sinh vt pht trin.
MuCc si c co rt chm ch yu s dng qu trnh oxy ha axit bo v cha mt
lng ty th v mc myoglobin cao. Hai yu t ny l l do khin si co rt chm
c mu . Si co rt nhanh ch yu s dng qu trnh oxy ha glucose thnh
pyruvate sn xut ATP, cha t ty th v myoglobin hn si co git chm v do
, cc si ny c mu trng. Hm lng myoglobin khong 0,1 mg/g kh nh so vi
tht heo khong 1-3 mg/g v tht b 3-6mg/g. C tht g c cu to ch yu t cc
si co rt nhanh do tht c mu trng.
Nhng bin i sau khi git tht
