Bảo quản thịt bò

  • View
    215

  • Download
    6

Embed Size (px)

DESCRIPTION

CN Sau thu hoch

Transcript

TRNG I HC BCH KHOA TP. HCM KHOA K THUT HA HC B MN CNG NGH THC PHM

TIU LUN CNG NGH SAU THU HOCH

BO QUN THT B

GVHD:

Ths TRN TH THU TR

Nhm sinh vin thc hin: TH THY TRM V TNG LC NGUYN NGC QUANG Lp: HC09KTTP 60902880 60901468 60902105

TP. H CH MINH, 12/2011

MC LC I. NGUYN LIU THT B 1.1. CU TRC THT B ...................................................................................................... 4 1.1.1. Cu trc m c ............................................................................................................ 4 1.1.2. Cu trc ca m m..................................................................................................... 4 1.1.3. Cu trc m lin kt .................................................................................................... 5 1.2. TNH CHT VT L- HA L C BN CA THT B ........................................ 5 1.2.1. Khi lng ring ......................................................................................................... 5 1.2.2. Nhit dung ring .......................................................................................................... 5 1.2.3. Tnh dn nhit .............................................................................................................. 6 1.2.4. Ph ................................................................................................................................. 6 1.3. MT S TNH CHT CM QUAN CA THT B .................................................. 7 1.3.1. Mu sc tht b ............................................................................................................ 7 1.3.2. Mi v ca tht b ........................................................................................................ 7 1.3.3. mm ca tht .......................................................................................................... 8 1.4. THNH PHN HA HC CA THT B .................................................................. 8 II. NHNG BIN I CA THT B SAU KHI GIT M 2.1. GII THIU CHUNG ...................................................................................................... 9 2.2. QU TRNH CO CNG .................................................................................................. 9 2.2.1. nh ngha ................................................................................................................... 9 2.2.2. Cch thc nh gi ...................................................................................................... 9 2.2.3. Din bin ................................................................................................................... 10 2.2.3.1. Thy phn glycogen ............................................................................................. 10 2.2.3.2. Thy phn ATP, cretinphosphat .......................................................................... 10 2.2.3.3. To actomyosin .................................................................................................... 10 2.2.4. S tc ng ............................................................................................................. 11 2.2.4.1. mm ................................................................................................................ 11 2.2.4.2. pH......................................................................................................................... 11 2.2.4.3. S tng nhit khi tht ..................................................................................... 12 2.2.5. Cc yu t nh hng qu trnh co cng ................................................................... 12 2.2.5.1. Cc yu t v bn thn nguyn liu ..................................................................... 12 2.2.5.2. V trng thi khi cht ........................................................................................... 13 2.2.5.3. Cc yu t bn ngoi khc nh nhit , m .................................................. 13 2.3. QU TRNH T CHN ................................................................................................. 15 2.3.1. nh ngha ................................................................................................................. 15 2.3.2. Cch thc nh gi .................................................................................................... 15 2.3.3. Din bin ca qu trnh t phn ................................................................................ 15 2.3.4. S tc ng ca qu trnh t chn .............................................................................. 16 2.3.5. Cc yu t nh hng n qu trnh t chn .............................................................. 17 2.4. QU TRNH THI RA .............................................................................................. 19 2.4.1. nh ngha ................................................................................................................. 19 2.4.2. Cch thc nh gi .................................................................................................... 19 2

2.4.3. Din bin qu trnh phn hy ................................................................................... 19 2.4.4. S tc ng ca qu trnh thi ra ............................................................................. 20 2.4.5. Cc yu t nh hng ................................................................................................ 21 III. BO QUN THT B 3.1. CC LU ..................................................................................................................... 22 3.2. BO QUN THT BNG PHNG PHP GIM NHIT .............................. 22 3.3. CHIU X ....................................................................................................................... 30 3.4. SY ................................................................................................................................... 36 3.5. BAO GI THT .............................................................................................................. 38 3.6. HA CHT BO QUN ............................................................................................... 40 3.7. CC PHNG PHP SINH HC............................................................................... 45 3.8. KT LUN ...................................................................................................................... 47 TI LIU THAM KHO ............................................................................................................ 48

3

I.

NGUYN LIU THT B

1.1. CU TRC THT B Tht c cu trc rt phc tp nhng v c bn thnh phn tht b c th bao gm cc m: m c, m m, m lin kt, mu, m thn kinh. Trong m c, m m v m lin kt theo th t l nhng thnh phn c gi tr dinh dng cao nht v c nghin cu nhiu nht. T l thnh phn ca cc m trong cc loi tht khc nhau

1.1.1. Cu trc m c M c l mt b phn quan trng ca tht b n chim khong 57- 62% khi lng ca tht v chim khong 35% trng lng ca con vt. M c ca cc loi ng vt khng ch khc nhau v ging loi, gii tnh, tui m cn ph thuc nhiu vo ch chm sc v trng thi ca ng vt sau trc khi git m. M c thng c mu thm hoc nht, m c ca cc ng vt c, trng thnh v lao ng nhiu c mu thm hn so vi nhng loi ng vt ci, cn non hoc ch nui ly tht. M c l cu trc c gi tr dinh dng cao nht ca tht, hm lng cc cht trong m c tht b dao ng nh sau: Nc: 72- 75%, protein: 18.522%, lipid v lipoid: 2- 3, cht ngm ra: 2- 2.8%, 0.3-0.8% glycogen, khong: 1- 1.4%, ch yu gm Fe, cc hp cht P, Ca, Mg, Zn,..v vitamin: thiamin, vitamin B6, vitamin E, vitamin A,.. 1.1.2. Cu trc ca m m M m c to thnh t cc m lin kt hnh li xp mm ha v cc t bo cht bo. Trong tht b hm lng m m dao ng trong khong kh rng t 2- 40% v t l nghch vi hm lng nc trong cu trc c tht. Lng cht bo vi mt t l nht nh s lm tng gi tr cm quan v gi tr dinh dng ca tht. Lng m m, v tri tch ly, thnh phn ,mu sc, mi v v cc tnh cht khc ca m m ph thuc nhiu vo ging loi, tui, gii tnh, mc bo ca vt nui v iu kin nui dng.

4

Thnh phn ha hc ca m m ch yu l lipid v cc dn xut(chim 70- 90%). Ngoi ra cn c cha protein(chim 0.5- 7.2%), nc(chim 2- 21%), sc t, enzyme v cc vitamin tan trong du. 1.1.3. Cu trc m lin kt Trong c th, m lin kt c phn b rng ri, c tc dng lin kt cc b phn li vi nhau, tham gia vo qu trnh trao i cht v thc hin nhim v bo v c th. M lin kt c cu thnh t ba phn: cht nn, cu trc hnh si v dch m. M lin kt c hnh thnh trn c s t cc si colagen v si eslatin, trong si colagen l cu trc quan trng nht. Hm lng m lin kt ph thuc vo ging loi, mc bo, tui, gii tnh, b phn c quan nhng thng khng vt qu 12% khi lng ca sc tht. Thnh phn ha hc trung bnh ca m lin kt c th hin nh sau: Nc: 62- 74%, protein: 21- 35%, lipid v lipoid: 1- 3.3% v cc thnh phn khc. Tm ti, m lin kt v m m tuy c gi tr dinh dng v hm lng trong tht b thp hn so vi m c nhng cng c s dng nhiu trong cc sn xut cc sn phm nh: xc xch, pate, ch, nem chua, vy kt hp s dng m c, m m v m lin kt lm tng khi lng sn phm, to ra gi tr cm quan tt cho sn phm, tng tnh to nh, to gel ph hp vi yu cu mt s sn phm, tn dng c nhiu sn phm khc nhau ca tht do hiu qu s dng v gi tr kinh t s tng ln. 1.2. TNH CHT VT L- HA L C BN CA THT B Tnh cht vt l ca tht b khc nhau theo tng ging loi, tui, gii tnh, ch chm sc, ch dinh dng. Tnh cht vt l ca tht cng l mt trong nhng tiu chun nh gi cht lng ca tht, nghin cu r v tnh cht vt l-ha l ca tht gip ta c nhng c s b ch trong vic tnh ton cc qu trnh bo qun nh nhit, lnh,....Mt s tnh cht vt l quan trng c xt nh sau: 1.2.1. Khi lng ring Khi lng ring ca tht b thay i theo rt nhiu yu t nh ging loi, gii tnh, tui,...nhng quan trng nht l hm lng cht bo trong tht v v tr ca sc tht. Khi lng ring trung bnh 150C ca tht b kh m l 1.02- 1.07kg/l, ca cht bo l 0.950.97kg/l v ca xng l 1.13- 1.3kg/l. 1.2.2. Nhit dung ring Nhit dung ring ca tht khc nhau theo t chc hc v thnh phn ha hc ca n.

5

Nhit dung ring ca mt s loi sc tht ca tht b.

Mt lu khi tnh nhit dung ring ca cc loi thc phm l phi tnh nhit dung ring ca n trn