87 Khảo Sát Quá Trình Chế Biến Nước Khóm Đóng Hộp Và Sự Biến Đổi Chất Lượng Sản Phẩm Trong Thời Gian Bảo Quản Của Công Ty TNHH Nước Giải

Thc tp tt nghip kha 28 2007 Trng i hc Cn Th

KHO ST QU TRNH CH BIN NC KHM NG HP V S BIN I CHT LNG SN PHM TRONG THI GIAN BO QUN CNG TY TNHH NC GII KHT DELTA

THC TP TT NGHIP K S

Ngnh: CNG NGH THC PHM

M ngnh: 08

Cn Th, ngy thng nm 2007

Cn b hng dn Ch tch hi ng Tc gi

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang i


LI CM N

Chng em xin chn thnh cm n:

Ban gim hiu Trng i hc Cn Th, Khoa Nng nghip v Sinh Hc ng Dng, v tt c cc qu thy trong B mn Cng Ngh Thc Phm tn tnh quan tm o to v truyn t kin thc cho chng em trong sut thi gian hc ti trng.

C Trn Thanh Trc ht lng hng dn v gip cho em trong sut thi gian lm bi bo co thc tp tt nghip ny.

Ban gim c Cng Ty TNHH nc gii kht DELTA, cng tp th cn b phng QA, phng k thut, phng sn xut v RAD cng ton th cng nhn vin ca Cng Ty nhit tnh gp , hng dn, cung cp ti liu c lin quan v gip em trong sut thi gian thc tp ti cng ty.

Em xin chn thnh cm n!

Cn th, ngy 07 thng 06 nm 2007

Sinh vin

Phan Vn Lim

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang ii


TM LC NI DUNG NGHIN CU

Cng ty TNHH nc gii kht Delta vi dy chuyn cng ngh sn xut tin tin v thit b hin i nn hng v lun ti, t nhin, gi li c cc vitamin v khong cht ca nguyn liu.

Cc sn phm nc ng hp ti cng ty m cng nh l sn phm nc da ng hp c sn xut ti cng ty theo quy trnh cng ngh cao; m bo cht lng an ton v sinh thc phm.

Tm hiu cc thng s k thut mt s quy trnh cng ngh v cc thit b chnh sn xut puree.

Khi tin hnh kho st sn phm nc da ng hp trong sut qu trnh bo qun; Kt qu cho thy:

- Gi tr pH v acid ca sn phm khng thay i trong 6 tun bo qun u, tuy nhin c s tng nh cc thng s ny tun bo qun th 8.

- Gi tr Brix n nh trong sut thi gian bo qun.

- Xt v mt dinh dng, hm lng vitamin C khng c duy tr n nh v gim dn theo thi gian bo qun

- Xt v mt cm quan, sn phm sm mu hn.

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang iii


T VN

Trong thi k cng nghip ho v hin i ha hin nay, pht trin v cng nghip c nhiu chuyn bin ng k. c bit, ngnh Cng ngh thc phm gi vai tr rt quan trng. Tuy nhin, song song vi vic pht trin cng nghip, ngnh nng nghip ca nc ta cng vn gi c pht trin v l ngun cung ng nguyn liu di do cho vic sn xut thc phm quy m cng nghip, c bit l rau qu nhit i.

Rau qu l mt loi thc phm khng th thiu trong i sng hng ngy, chng cung cp nhiu loi vitamin m c th con ngi khng th t tng hp c. Trong qu trnh bo qun rau qu, tt c cc yu t mi trng bn ngoi kt hp vi nhng bin i bn trong ca rau qu, n khng cho php con ngi s dng rau qu u dng ti. Mi trng khng kh c v s vi sinh vt m iu kin tri cy li rt thch hp cho vi sinh vt pht trin gy h hng. cng l mt trong nhng nguyn nhn thc y con ngi tm mi cch gi thc phm ni chung v rau qu ni ring s dng lu di.

T lu nhn dn ta c nhng phng php ch bin cc mn n t rau qu, va l mn n dn gian va bo qun c lu di nh: rau qu phi sy kh, cc loi mt, rau mui chua trong s hp rau qu l mt loi nguyn liu chim t trng rt cao trong sn xut cng nghip. hp l loi thc n d tr cho qun i, cho nhn dn, cho khch du lch. N l loi hng ho c trao i rng ri trn th trng quc t. Cng nghip sn xut hp ng mt vai tr rt quan trng trong nn kinh t quc dn cng nh cc loi sn phm ch bin khc, n gp phn iu ho thc phm gia cc vng, tng ngun hng xut khu trong nc.

Vit Nam hin nay c rt nhiu c s sn xut cc sn phm hp khc nhau t rau, qu, tht, c, sa, Trong , hp qu cng c ch bin t nhiu ngun nguyn liu khc nhau nh: chm chm, xoi, u , khm, Cc nguyn liu ny c x l v phi ch v cc cht nh ng, axit theo nhng t l thch hp sau em thanh trng v bo qun.

hp tri cy hin l mt trong cc mt hng ch lc ca Cng ty nc gii kht Delta. Nm trong vng cung cp nguyn liu khm rt di do (Tn Lp Tin Giang, Bn Lc Long An), hp nc khm (da) hin ang c cng ty sn xut vi sn lng ln 5000 tn/nm. Chnh v th, Nghin cu tin hnh tm hiu quy trnh sn xut hp nc khm ti cng ty nc gii kht Delta; ng thi, s bin i cht lng ca sn phm trong sut thi gian bo qun cng c quan tm.

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang iv


MC LC

Chng 1 TNG QUAN V NH MY................................................................................... 1

1.1 LCH S THNH LP V PHT TRIN CNG TY ............................................... 1

1.1.1 Lch s thnh lp..................................................................................................... 1

1.1.2 V tr a l .............................................................................................................. 2

1.1.3 S mt bng nh my......................................................................................... 3

1.2 B MY QUN L V SN XUT TRONG NH MY ....................................... 3

1.2.1 S t chc nh my............................................................................................ 3

1.2.2 Chc nng ca tng b phn................................................................................... 4

1.3 VN B TR KHU VC CH BIN THC PHM ............................................ 4

1.3.1 Yu cu thit k v b tr nh xng ...................................................................... 4

1.3.2 Kt cu nh xng .................................................................................................. 4

1.3.3 Kho xng thit b .................................................................................................. 5

1.3.4 Trn nh .................................................................................................................. 5

1.3.5 Sn nh.................................................................................................................... 5

1.3.6 Tng v gc tng nh ......................................................................................... 5

1.3.7 Ca ra vo ............................................................................................................... 5

1.3.8 Ca s ..................................................................................................................... 5

1.3.9 H thng chiu sng................................................................................................ 5

1.3.10 H thng cung cp nc ......................................................................................... 5

1.4 AN TON LAO NG V PHNG CHY CHA CHY ...................................... 6

1.4.1 An ton lao ng..................................................................................................... 6

1.4.2 Phng chy cha chy ............................................................................................ 6

1.5 PHNG N X L NC THI TRONG SN XUT......................................... 8

1.6 CC SN PHM CHNH CA CNG TY................................................................. 9

Chng 2 QUY TRNH SN XUT HP KHM TI NH MY............................... 10

2.1 GII THIU NGUYN LIU ..................................................................................... 10

2.1.1 Gii thiu v khm ............................................................................................... 10

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang v


2.1.2 Thnh phn ho hc ca khm ............................................................................. 11

2.1.3 Ch tiu cht lng ca khm............................................................................... 13

2.2 CC CHT S DNG TRONG CH BIN NC DA....................................... 14

2.2.1 Nc...................................................................................................................... 14

2.2.2 ng ................................................................................................................... 15

2.2.3 Acid ascorbic (vitamin C)..................................................................................... 16

2.2.4 Acid citric (E330)- cht iu chnh pH............................................................ 23

2.2.5 Pectin..................................................................................................................... 24

2.3 QUY TRNH SN XUT NC DA TI NH MY ......................................... 25

2.4 GII THCH QUY TRNH.......................................................................................... 26

2.4.1 Phi trn................................................................................................................ 26

2.4.2 Gia nhit s b ...................................................................................................... 26

2.4.3 ng ho............................................................................................................... 27

2.4.4 Thanh trng........................................................................................................... 27

2.4.5 Lm ngui nhanh .................................................................................................. 28

2.4.6 Rt hp.................................................................................................................. 29

3.2 CH TIU CHT LNG SN PHM......................................................................... 30

3.2.1 Cc ch tiu cht lng (TCVN 1549-1994).............................................................. 30

3.2.2 Qun l k thut .......................................................................................................... 31

Chng 3 S BIN I CHT LNG SN PHM NC DA NG HP TRONG QU TRNH BO QUN........................................................................................................... 32

3.1 PHNG PHP, PHNG TIN TH NGHIM..................................................... 32

3.1.1 a im, thi gian nghin cu............................................................................. 32

3.1.2 Phng php b tr th nghim ............................................................................. 32

3.2 KT QU THO LUN............................................................................................. 32

Chng 4 KT LUN - NGH ........................................................................................... 37

4.1 KT LUN................................................................................................................... 37

4.2 NGH ...................................................................................................................... 38

TI LIU THAM KHO ............................................................................................................ 39

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang vi


DANH SCH BNG

Bng 1: Thnh phn ha hc ca khm........................................................................................ 12

Bng 2: Tp cht cho php trong nc dng lm thc ung ........................................................ 14

Bng 3: Mt s thng s ca vitamin C........................................................................................ 18

Bng 4: Liu lng vitamin C cn dng cho cc i tng ......................................................... 20

Bng 5: Lng kim loi ti thiu c th c trong sn phm......................................................... 31

Bng 6: Ch tiu v vi sinh vt...................................................................................................... 31

Bng 7: S bin i cc ch cht lng nc da trong qu trnh bo qun ................................ 33

Bng 8: Cch nh gi cm quan................................................................................................... ix

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang vii


DANH SCH HNH

Hnh 1: Mt tin nh my ............................................................................................................... 2

Hnh 2: S mt bng ca nh my ............................................................................................. 3

Hnh 3: S t chc v qun l ti nh my................................................................................ 3

Hnh 4: S cng ngh x l nc thi ti nh my sn xut ..................................................... 8

Hnh 5: Khm nhm Queen.......................................................................................................... 11

Hnh 6: Cng thc cu to ca saccharose ................................................................................... 15

Hnh 7: Cu to ca acid ascorbic................................................................................................. 17

Hnh 8: S phn ng ha nu do enzyme ................................................................................ 21

Hnh 9: Hm lng ca vitamin C trong thc phm .................................................................... 22

Hnh 10: Cu to ca acid citric.................................................................................................... 23

Hnh 11: Cu to ca pectin.......................................................................................................... 24

Hnh 12: S quy trnh sn xut nc da ................................................................................ 25

Hnh 13: Bn trn 1000 lt v Tank cha tun hon 8000 lt ....................................................... 26

Hnh 14: Thit b gia nhit ............................................................................................................ 26

Hnh 15: Thit b ng ha ........................................................................................................... 27

Hnh 16: Thit b thanh trng........................................................................................................ 27

Hnh 17: Thit b lm lnh............................................................................................................ 28

Hnh 19: Tank tit trng 12000 lt v bng chuyn ...................................................................... 29

Hnh 20: S bin i pH theo thi gian bo qun ........................................................................ 34

Hnh 21: S bin i % Acid theo thi gian bo qun ................................................................. 34

Hnh 22: S bin i vitamin C theo thi gian bo qun ............................................................. 35

Hnh 23: S bin i L theo thi gian bo qun........................................................................... 36

Hnh 24: Thit b o Brix........................................................................................................... x

Hnh 25: Thit b o pH.................................................................................................................. x

Hnh 26: Cn in t v thit b ly tm......................................................................................... xii

Hnh 27: Khu vc chun ......................................................................................................... xiii

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang viii


CHNG 1 TNG QUAN V NH MY

1.1 LCH S THNH LP V PHT TRIN CNG TY

1.1.1 Lch s thnh lp

Cng ty trch nhim hu hn (TNHH) nc gii kht Delta c ng k kinh doanh ti S k hoch v u t Long An vo ngy 22/02/2002, di hnh thc Cng ty TNHH vi 100% vn trong nc. Tr s chnh ca cng ty t ti phng 6, th x Tn An, tnh Long An; vn phng i din ca nh my t ti 62-64 L Th Ring, Qun 1, thnh ph H Ch Minh.

Trc 2002, cng ty mang tn Cng ty nc tri cy Delta (Vit nam) vi 100% vn nc ngoi, cng sut thit k l 4 triu lt nc tri cy ung lin v 3000 tn nc da c c trong mt nm.

Ngy 09/09/1999, tp on Daso mua li vn php nh ca nh u t nc ngoi v dng sn xut ti u t thm trang thit b nhm m rng mt hng, a cng sut thit k ca nh my ln 30 triu lt nc gii kht mt nm. Ngoi cng sut 3000 tn nc tri cy c c, Delta cn lp t thm dy chuyn ch bin v ng gi sa bt vi cng sut l 25000 tn/nm. Tng vn u t (bao gm c vn u t nc ngoi v vn u t trong nc b sung cho n ngy ra sn phm 19/5/2001) ca Delta l gn 11 triu USD.

Lot sn phm ang sn xut hin nay ca Delta l sa u nnh, nc cam ti, nc khm c ch ch bin bng cng ngh tin tin v thit b hin i nn duy tr c hng v ti, t nhin ca hoa qu, ng thi gi li c cc vitamin v khong cht ca hoa qu rt c li cho sc khe.

Cc sn phm ca Cng ty Delta s gp phn vo th trng trong v ngoi nc xut khu, phc v tha mn nhu cu ca ngi tiu dng v loi nc gii kht va thm ngon, b dng.

Ngay t u, nh my nc tri cy Delta (VN) c cng ty G.E.A ca Ty c thit k v lp t ton b thit b. Thi gian qua, Delta c m rng theo tht k v lp t ca cng ty Tetra Pak (Thy in). y l hai trong nhng cng ty ng u th gii v cng ngh v thit b ch bin thc phm.

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang 1


Nh my c lp t t ng ho hon ton, cc chng trnh ch bin c ci t sn trn PLC/PC bi cc chuyn gia gii ca Tetra Pak v G.E.A gm cc dy chuyn thit b ng b.

Hnh 1: Mt tin nh my

1.1.2 V tr a l

Nh my nm trong khu t c th x Tn An tnh Long An quy hoch v pht trin cng nghip.

a im ny cch Thnh Ph H Ch Minh khong 60km, gn cc ngun cung cp nguyn liu v cc iu kin giao thng thun li cho vic vn chuyn nguyn liu v phn phi sn phm.

Cc iu kin mi trng vt l nh ch kh hu khng c nhng t bin nh hng n hot ng ca nh my. nh hng ca l lt vng BSCL cng khng ln i vi khu vc ny.

Cht lng mi trng khng kh ti khu vc nh my hin nay cha c vn nhim t bit. nhim khng kh hin nay l do mt giao thng cao, dn c tp trung ng.

Lc lng lao ng ti a phng rt di do va gip cng ty d dng tm ngun dn cng phc v cho nh my, mt khc li gii quyt cho a phng mt s cng n vic lm ng k. Nn kinh t ca a phng cn mc thp v ch yu phc v vo nng nghip. Vic xy dng nh my s thc y ng k vic pht trin kinh t ca th x Tn An ni ring v ca tnh Long An ni chung.



1.1.3 S mt bng nh my

Hnh 2: S mt bng ca nh my

1.2 B MY QUN L V SN XUT TRONG NH MY

1.2.1 S t chc nh my

Tng Gim c

Gim c

Ph gim c sn xut Ph gim c KT

Phng QA Phng SX P. Bo Tr Kho KHVT P. T chc hnh chnh nhn s

P. K ton - ti v

Hnh 3: S t chc v qun l ti nh my



1.2.2 Chc nng ca tng b phn

Gim c: Trc tip lnh o cng ty, chu trch nhim trc Tng gim c v tt c hot ng ca cng ty.

Ph gim c sn xut: Ph t ca gim c v trc tip ch o sn xut ca cng ty.

Ph gim c k thut: Ph t ca gim c v trc tip ch o k thut ca cng ty.

Phng QA,RD: Th nghim kim kim tra cht lng v thc nghin cu cho ra sn phm mi, kim tra nguyn liu trc khi nhp kho v kim tra cht lng sn phm trc khi a ra th trng v nghin cu pht trin cc sn phm mi ca cng ty.

Phng sn xut: iu hnh sn xut cc sn phm ca cng ty.

Phng bo tr: Sa cha vn hnh, lp rp cc thit b sn xut ca cng ty.

Kho k hoch - vt t: Lu v cung cp vt liu cho sn xut.

Phng t chc hnh chnh, nhn s: Tham mu cng tc, tuyn dng nhn s v b tr vic lm cho nhn s.

Phng k ton ti v: Thc hin cng tc k ton thng k, thng tin kinh t, hoch ton kinh doanh.

Nhn xt: Nh s b tr c cu t chc sn xut nh trn, cng ty i vo hot ng vi dy chuyn t hiu qu.

1.3 VN B TR KHU VC CH BIN THC PHM

1.3.1 Yu cu thit k v b tr nh xng

Khu vc sn xut, ch bit thc phm phi c thit k theo quy tc mt chiu t nguyn liu u vo n sn phm cui cng trnh ly nhim.

S cch bit gia khu sn xut v khng sn xut, gia cc khu tip nhn nguyn liu, s ch, ch bin, kho hng, khu v sinh, khu nh n trnh nhim, nhim cho. Kho cha ng v bo qun thc phm ca c s sn xut, kinh doanh thc phm phi c thit k ph hp vi yu cu ca tng loi thc phm v trnh s xm nhp ca ng vt mang mm bnh gy hi.

1.3.2 Kt cu nh xng

Nh xng ca cng ty c thit k theo ng tiu chun nhm m bo p ng cc iu kin v sinh v an ton trong sn xut.



1.3.3 Kho xng thit b

Kho xng c b tr ph hp v thun li trong qu trnh sn xut, ch bin thc phm d dng p dng cc bin php x l v sinh.

1.3.4 Trn nh

Sng mu, lm bng cc vt liu khng thm nc, khng rn nt, trnh nc ng v cc cht bn bm vo.

1.3.5 Sn nh

Sng mu, lm bng cc vt liu d lau chi, c ra, khng gy nhim cho thc phm, thot nc tt.

1.3.6 Tng v gc tng nh

Tng phng, gc nh trn, snh mu, khng gy nhim cho thc phm, d lau chi kh trng.

1.3.7 Ca ra vo

Ca c thit k vi b mt nhn, khng thm nc, dng ca t ng m nhm trnh ngi cng nhn dng tay bn m ca, hay bi bn ca tip xc vi tay cng nhn v nhim vo thc phm.

1.3.8 Ca s

D lau chi, thit k sao cho hn ch ti a vic bm bi. Ca s c tc dng bo v, trnh xm nhp ca cn trng.

1.3.9 H thng chiu sng

Ngun sng c che chn an ton trnh b v v bo m trong trng hp cc mnh v khng ri vo thc phm.

1.3.10 H thng cung cp nc

Nc s dng cho ch bin thc phm t nh my l ngun nc ly t ging khoang em x l m bo theo tiu chun nc sch, khng cha cc cht nhim khc, m bo tiu chun v sinh an ton nc theo quy nh ca B Y t.



1.4 AN TON LAO NG V PHNG CHY CHA CHY

1.4.1 An ton lao ng

Ton th cn b cng nhn vin trong cng ty u chp hnh v an ton lao ng v an ton v sinh thc phm.

Tham gia y cc chng trnh hun luyn o to v h thng qun l thch hp (IMS) ISO 9001-2000 + HACCP + cGMP quy nh quy trnh cng ngh qui phm k thut, tiu chun cht lng v an ton lao ng, an ton v sinh thc phm v cc bin php phng nga thin tai. Mi ngi u c hun luyn phng chng chy n, tai nn ngh nghip ph hp i vi nhim v c giao.

Thc hin ng cc thao tc quy trnh s dng vn hnh thit b trong dy chuyn sn xut.

Bo qun gi gn v s dng cc phng tin phng h ca cng ty trang b nh: qun o bo h lao ng, nn giy, dp, gng tay, khu trang, t c nhn.

Thng xuyn kim tra v thc hin ch bo tr, bo dng, sa cha my mc thit b theo ng k hoch v quy nh ca cng ty.

i vi chng trnh HACCP (Hazard analysis critial control points- phn tch mi nguy v xc nh im kim sot ti hn), phi thng xuyn kim tra v sinh cng nghip v sinh c nhn, v sinh an ton thc phm, phng nga ly nhim cho, cn trng xm nhp, kim tra cc mi nguy (ri ro) ng k, cc CCP ca qu trnh HACCP .

Khi lm vic nu thy hin tng my mc thit b c nguy c gy ra tai nn, khng m bo v sinh an ton thc phm, h hng, chy, n hoc gy ra bnh ngh nghip phi bo co ngay vi ngi qun l trc tip, ngi ph trch c bin php ngn chn kip thi.

Khi lm vic pht hin c nguy c xy ra tai nn lao ng e da n tnh mng, sc kho ca mnh hoc ngi khc th c quyn t chi hoc ri khi v tr cho n khi c khc phc.

Khi mt mi, c au bnh, c php ngh xin ngh khm cha bnh bo m an ton cho ngi v my mc thit b.

1.4.2 Phng chy cha chy

(i) i vi kho v khu vc sn xut

Tuyt i cm la, cm ht thuc trong kho v trong khu vc sn xut, tun th theo bng ch dn.



Khng cu, mc s dng in tu tin, ht gi lm vic phi kim tra v tt n, qut v cc thit b s dng in khc trc khi ra v. Khng ai c li ng, ngh ngi trong kho v ni lm vic (tr trng hp c bit c cho php).

Khng dng dy ng, giy bc thay th cu ch. Khng dng dy in cm trc tip vo in.

Sp xp vt t, hng ho phi theo tng l, loi sn phm (s kho). Phi c ballet k hng ho, khong cch gia cc l hng l 1m, li i sut trong 1-2m, cch tng 0,5 m. Khng cht hng ho, bt li ra vo cc ca kho, ca thot him, dng c phng chy cha chy.

Khi giao nhn hng ho, xe khng c bt li ra vo ca kho.

Cm ho cht d chy, ho cht c hi trong kho, xung quanh pha ngoi kho (ho cht c hi phi c nhn bit v cch li), thng xuyn v sinh nh xng trong v ngoi kho lun sch s, hn ch cn trng gy hi xm nhp. Kt hp vi i phng chy cha chy, i HACCP thng xuyn kim tra, phng nga s suy gim cht lng, an ton hng ho v an ton v sinh thc phm.

(ii) i vi cn b cng nhn vin

Phi tuyt i chp hnh cc quy nh v an ton phng chy cha chy, khng c s dng cc trang thit b phng chy cha chy vo mc ch khc.

(iii) V dng c phng tin phng chy cha chy

Phi c ngi thng xuyn kim tra hiu qu v cht lng cc dng c, phng tin phng chy cha chy theo nh k, nu pht hin khng m bo phi xut thay th hoc trang b ngay.

Phi lp th kho, giao cho ngi c trch nhim c ch nh kim tra v theo di v s lng, dng c, phng tin phng chy cha chy. Giao cho i trng phng chy cha chy cng bo v, kim tra nh k hng tun cc dng c phng tin phng chy cha chy.

Ring cc thit b cha chy dng nc, phi kim tra thay th cc loi van, ng v chun b sn sng cc dy chuyn dn nc cha chy ti cc t cha. Chun b my pht trong t th sn sng cha chy.

Kim tra cc im xung yu nh: kho bn du th, du t l hi, hng ho kho thanh phm. tuyt i khng c cc hng ho c bit ny gn cc loi ho cht in, nhit d gy chy.



Kim tra cc dy chuyn bng ti dn in trong kho v khu vc sn xut phi bo m ng quy cch, tuyt i an ton, dy dn phi chuyn ra ngoi kho.

1.5 PHNG N X L NC THI TRONG SN XUT

B lng 2

B gom nc thi

B u ha + tuyn ni

B lng 1

Sn phi bn

H ga

Ngn cha bn

Cng

B kh trng

B lc

B sinh hc

Cn kh

Nc thi

B nn bn

Bn kh

Hnh 4: S cng ngh x l nc thi ti nh my sn xut

Nc thi sn xut c tp trung cng vi nc thi sau b t hoi v cc loi nc sinh hot khc vo h thng x l nc thi chung.



Nc thi t cc phn xng ca nh my s t chy theo trng lc trong h thng cng c tp trung v h thu gom sau khi c loi rc, tp cht v c K n, nc thi c bm vo b iu ho iu ho nng lu lng v x l mt phn cht nhim bn hu c. Mt lng kh c cung cp cho b iu ho vi tc dng trn iu nc thi v trnh hin tng ln men ym kh xy ra y. Kim c thm vo b vi tc dng nng pH ca nc thi ln gi tr 6,5 7,0 l gi tr pH thch hp cho qu trnh x l sinh hc tip theo.

Nc t b iu ho tip tc c bm sang b lng 1 vi lu lng c nh lng cc cht l lng c trong nc thi. Nc sau khi lng chy theo trng lc theo b sinh hc hiu kh phn hu cc cht hu c ho tan trong nc thi nh cc vi sinh vt hiu kh sau nc thi c a qua b lng 2.

Ti b lng hai bn hot tnh c tch ra khi hn hp nc. Nc sau lng c a qua b lc v b kh trng tip tc x l t cc tiu chun thi ra ngun tip nhn.

Bn y b lng hai c dn vo ngn thu bn. Ti y chng s c bm tun hon v b sinh hc m bo mt vi sinh vt khng i phn bn d s c nh k bm qua b nn bn v sn phi bn kh nc cn vi bn cn b lng mt. Bn sau khi x l c th s dng lm phn bn.

1.6 CC SN PHM CHNH CA CNG TY

Hin nay, cng ty ang sn xut cc sn phm chnh l: Pure chanh dy, nc chanh dy c c, pure s ri, pure mng cu, hp nha am, hp da khoanh, nc da v hp coctalk.

Trong thi im kho st ti nh my, cc mt hng ang hot ng mnh l sn phm pure chanh dy v cc nc tri cy t dng c c hay pure, trong nhm ny c nc da ng hp.



CHNG 2 QUY TRNH SN XUT HP KHM TI NH

MY

2.1 GII THIU NGUYN LIU

2.1.1 Gii thiu v khm

Khm (cn gi l Da) c tn khoa hc l Ananas Comosus Merr hay Ananas Sativus Sehult.

Khm l mt loi c sn nhit i, tuy ng hng th mi v sn lng tri cy n qu nhng v cht lng hng v li ng u v c mnh danh l vua hoa qu. Vi mi qu thm, hp dn, ngt cao (16 20oBx hoc cao hn) chua va phi, m qu li p, mu sc bn ngoi p. c bit trong khm c enzyme bromelin, gip tiu ho tt protein nn ngi ta thng dng khm trn vi cc mn khai v. Khm dng n sng, xo nu, lm hp. Gn y qu khm cn l nguyn liu s dng cho chit tch bromelin dng trong ngnh cng nghip v lm thuc cha bnh.

Khm c ngun gc ng Bc chu M La Tinh (Braxin, Guana, Venezuela). Hin nay khm c trng tt c cc nc nhit i, tp trung nhiu Hawai, Thi Lan, Braxin, Mexico. Vit Nam, khm c trng nhiu Long An, Kin Giang, Tin Giang, Minh Hi, Cn Th, Sc Trng, Vnh Ph, H Bc, Thanh Ho, Ngh An.

Khm c khong 60 70 ging, Hume v Miller (Nguyn Bo V, 2004) tm chia khm thnh 3 nhm l: Hong Hu (Queen), Cayenne v Ty Ban Nha (Spanish).

- Nhm Hong Hu (Queen): Qu tng i nh, mt li, chu vn chuyn, tht qu vng m, giu hng thm, v chua ngt m (hnh 5) Loi ny c cht lng cao nht, trn th gii dng n ti. Khm hoa, khm ty, khm Victoria thuc loi nhm ny. Loi ny c trng nhiu nht trong 3 nhm Vit Nam. Hin nay, cc vng nguyn liu trng khm ch yu ng bng sng Cu Long nh Bn Lc (Long An), Tn Lp (Tin Giang), V Thanh (Hu Giang) v G Quao (Kin Giang) u trng ch yu khm Hong Hu.

- Nhm Cayenne: Qu ln nht c khi n 3 kg, mt phng v nng, tht qu km vng v nhiu nc, t ngt, km thm hn khm Queen. Khm c Bnh, Thm ty thuc loi ny. Do c tnh mt nng, ph hp vi ch bin cng nghip (d dng loi mt ng lot vi hiu sut thu hi cao) nn loi Cayenne c trng hu ht cc vng ln trn th gii (Thi Lan, Hawai. Philippin) trong khi rt t thy Vit Nam.



- Nhm Ty Ban Nha (Spanish): tri ln hn khm Queen, mt su, tht qu vng

nht, c ch trng, v chua, t thm nhng nhiu nc hn khm hoa. Khm ta, khm mt, khm thm thuc loi ny. Khm thuc nhm Ty Ban Nha c cht lng km nht (Bartholomew et al. 2003). Vit Nam, khm nhm ny c trng lu i v tp trung khu vc Liu Sn (Tam Dng tnh Vnh Ph).

Hnh 5: Khm nhm Queen

Ngun: www.caribfruits.cirad.fr/ fiches_fruits/ananas (hnh bn phi)

2.1.2 Thnh phn ho hc ca khm

Thnh phn ho hc ca khm thay i theo ging, a im v iu kin trng, thi gian thu hi trong nm v chn (Teisson et al., 1982).

Cc thnh phn c bn ca khm:

- Protein: y l cht to thnh s sng, rt quan trng i vi khu phn ca con ngi. Trong hu ht cc loi khm c cha khong 1% cht m v thng tn ti dng protein chc nng. Tuy nhin, do protein trong khm c hm lng kh thp nn khm khng phi l ngun cung cp protein quan trng cho khu phn n ca con ngi.

- Lipid: y l thnh phn c vai tr cung cp nng lng, cu thnh cc t chc, thc y vic hp thu cc vitamin tan trong cht bo. Khm cha rt t cht bo (0,11%) v hin din di dng lin kt vi lp cutin bo v b mt v mng t bo. Do lipid chim t l rt t trong khm nn c xem l yu t quan trng phng chng bnh tim (Bartholomew et al. 2003)



Bng 1: Thnh phn ha hc ca khm

Thnh phn n v Cht dinh dng/100g tri cy (phn n c) Nng lng cal 47 Nc g 87 Gluxit tng s k c celulose g 11,6 Protein g 0,7 Lipid g 0,3 Tro g 0,4 Canxi (Ca) mg 17 Photpho (P) mg 12 St (Fe) mg 0,5 Vitamin A ( caroten) g 35 Vitamin B1 (Riboflavin) mg 0,06 Vitamin C (Acid ascorbic) mg 22

Ngun: Hunh Th Dung; Nguyn Th Kim Thoa, 2003

- ng: Gp phn cung cp nng lng cho c th, ngoi ra ng cn to v ngt lm tng thm tnh cm quan cho khm. ng trong khm nhiu nht l glucose, fructose v saccharose. Trong , saccharose chim khong 2/3 tng hm lng ng trong qu. Qu c a thch v mt cm quan l do s hin din ca ng to c v ngt. ng d ha tan trong nc, nht l nc nng. Trong mi trng nc (axit), saccharose c th thy phn thnh hn hp ng glucose v fructose.

C12H22O11 + H2O C6H12O6 + C6H12O6 Saccharose glucose fructose

- Mui khong: ngoi cc hp cht hu c, trong qu cn cha c mui khong. Hm lng mui khong xc nh bng lng tro. tro ca qu trong khong 0,25 1%. Trong khm c nhiu loi mui khong khc nhau:

+ Kali: hnh thnh c h thng m trong c th gip cho c th n nh c sinh l trc nhng thay i ca mi trng, c tc dng gy hng phn h thn kinh trung ng v chng t qu (do K+ l cht dn truyn thn kinh n c), bi xut Na+ ra khi c th v vy m c tc dng chng tng huyt p.

+ Natri: tham gia vo qu trnh chuyn ha nc, ngoi ra cn c vai tr duy tr tnh n nh p lc thm thu ca nguyn sinh cht v dch sinh hc ca c th.



+ St: tham gia vo qu trnh to mu, ngoi ra cn gi vai tr quan trng trong cc qu trnh oxi ha v kch thch chuyn ha bn trong t bo. St cn l thnh phn cn thit ca cc nhn t bo v tham gia vo thnh phn ca enzyme oxy ha.

+ Canxi: c nhiu vai tr quan trng trong c th. Trong c th canxi tp trung nhiu xng, rng v n gi vai tr ch yu trong xy dng v duy tr m xng v c trong s hnh thnh rng. Ngoi ra canxi cn tham gia vo vic tn tr v s dng nng lng t bo tim (Hunh Th Dung; Nguyn Th Kim Thoa, 2003).

+ Vitamin: Vitamin l yu t dinh dng rt cn cho c th ngi v vitamin l thnh phn tham gia vo cu to ca cc enzyme chuyn ha trong c th ngi, thc vt c kh nng tng hp vitamin. Vitamin c bn c chia lm 2 nhm: vitamin tan trong cht bo (A, D, E, K) v vitamin tan trong nc (B, C, H, PP).

2.1.3 Ch tiu cht lng ca khm

nh gi cht lng ca khm thng quan tm n cc c trng lm cho khm hp dn ngi tiu dng (Singleton, 1955; Paul, 1993). Tiu chun cht lng khm c th da vo hnh dng bn ngoi (kch thc, hnh dng), mu sc (v qu v tht qu), v (ng, acid), hng thm, dn.

Mu sc ca v qu l tiu chun ph bin nht ngi tiu dng nh gi chn sinh l v d on cht lng ca khm (Dull, 1971). Mt s ngi tiu dng th quan tm n gi tr thc phm v hm lng vitamin.

Mt cch xc nh chnh xc cht lng ca khm l da vo t l gia hm lng TSS (tng cht kh ha tan, trong khm ng chim t l ch yu trong TSS) v hm lng acid trong khm.

Trong khm, s thay i hm lng ca TSS v acid l do s kt hp ca nhng yu t nh ging cy, ma v, chn lc thu hoch, v tr trng v iu kin pht trin ca qu.

Sideris v Krauss (1934) ch ra t l tham kho cho ngt ca khm TSS/acid l 19, s cho hng v ngt t chua.

Soler (1992) a ra t l l TSS/ acid thay i t 20 40 s cho v ngt. V theo Smiths (1988) th a ra t l l TSS : acid thay i t 8 23. Hin nay, tiu chun xc nh cht lng khm da trn t l TSS/ acid c cng nhn l ch tiu ng tin cy nh gi cht lng (hng v) ca khm.



Tuy nhin, khm s dng cho ch bin cc sn phm t khm ti nh my thng c nh gi da trn s thay i Brix. Khm c Brix cao (1820oBx) thng c s dng ph bin. Mc d vy, vic la chn chn thch hp v ng lot thng kh p dng do khm chn rt nhanh sau khi thu hoch, ng thi thng chn thm trong qu trnh chuyn ch n nh my. Chnh v l do ny, ngun nguyn liu u vo thng c phi trn to ra dch qu c Brix theo yu cu.

2.2 CC CHT S DNG TRONG CH BIN NC DA

2.2.1 Nc

Nc l thnh phn quan trng c mt hu ht trong cc loi nc gii kht, v th cht lng nc nh hng rt ln n cht lng sn phm. Tuy nhin, nc trong t nhin khng dng tinh khit m thng c ln tp cht, vi sinh vt Do khi s dng ngun nc ny phi tin hnh kh trng, lc khng nh hng n mi, v, mu sc v hnh thi sn phm, cht lng H2O s dng trong nc lm thc ung c th hin bng 2.

Bng 2: Tp cht cho php trong nc dng lm thc ung Ch tiu Tiu chun Ch tiu vt l Mi v,Mu sc trong Ch tiu ho hc pH

Khng 100 ml 6,0-7,8

CaO 50-100 mg/lit Fe2O3 0,3 mg/lit BO43- 1,2-2,5 mg/lit SO42- 0,5 mg/lit NH4+ 0,1-0,3 mg/lit NO2- Khng NO3- Khng Pb Khng

Cu As Zn F MgO MnO

2 mg/lit 0,06 mg/lit 5 mg/lit 5 mg/lit 50 mg/lit 0,2 mg/lit



Ch tiu vi sinh vt Tng s vi sinh vt hiu kh Ch s Coli (s Coli/1lit nc) Chun s Coli (s ml nc c 1 Coli)


Vi s c mt ca ion H+ hoc mt s enzyme c hiu, dung dch saccharose s phn gii to thnh hp cht gm D glucose v D fructose, hp cht ny gi l ng nghch chuyn.

Saccharose d ha tan trong nc, nhit tng ha tan tng. nhit thng c th ha tan gia nc v ng l 1:2. Saccharose khng ha tan trong cc dung mi khng phn cc.

Vi hm lng nc kh thp nn saccharose t b tn cng bi cc vi sinh vt. Tuy nhin, trong qu trnh bo qun cn phi ch gi saccharose ni kh ro, thong mt, trnh m t gy ng cc ng lm kh khn trong cc cng on ch bin sau ny nht l cng on ha tan ng.

Saccharose tan chy v phn ly 1860C to caramel, khi chy to CO2 v nc.

Saccharose l cht dinh dng rt d tiu ha v cung cp ngun nng lng rt nhanh chng cho c th, to ra s gia tng hm lng glucose trong mu khi n vo c th. N lm cho thc phm ngon hn. Trong cc sn phm c hm lng ng cao th n ngoi tc dng to ngt cn l cht bo qun sn phm rt tt trong iu kin nhit bnh thng.

Hm lng ng trong nc gii kht chim trn 10% trong lng. ng l mt l thnh phn chnh quan trng nh hng ti cc ch s cht lng v dinh dng ca nc gii kht pha ch. Ngoi ra ng cn iu chnh hi ho gia v chua, ngt v mi thm ca nc gii kht.

2.2.3 Acid ascorbic (vitamin C)

Vitamin l hp cht hu c rt quan trng cho cc qu trnh sinh trng ca c th. Mi loi vitamin c tnh cht v vai tr c trng. Vitamin c chia lm 2 nhm: vitamin tan trong du (gm vitamin A, D, E, K) v vitamin tan trong nc (gm vitamin nhm B, C ).

Trong vitamin C l mt hp cht khng th thiu i vi c th. N m nhim vai tr sinh l ht sc quan trng, tham gia vo nhiu phn ng sinh ha ca c th. N l mt thnh phn quan trng trong ngnh dc phm, s xut hin ca vitamin C gip nhn loi thot c nhiu bnh him ngho.



(i) Cng thc cu to

O = C O = C

HO - C O = C

HO - C O = C

H - C H - C

HO - C - H HO - C - H

CH OH CH OH

Acid L - ascorbic Acid L - dehydroascorbic2

O

2

O- 2H+2H

(Dng kh) (Dng oxy ha)

Hnh 7: Cu to ca acid ascorbic

(ii) Cc dng tn ti trong t nhin

Vitamin C tn ti trong t nhin di ba dng ph bin l acid ascorbic, acid dehydroascorbic v ascorbigen. Dng ascorbigen ca vitamin C l dng lin kt vi polypeptit. Trong thc vt ascorbigen chim ti 70% tng hm lng vitamin C. Ascorbigen bn i vi cc cht oxy ha nhng hot tnh ch bng mt na ca vitamin C t do. Ngoi dng lin kt vi polypeptit i khi cn gp ascorbigen vi cc dng lin kt khc nh lin kt vi Fe v axit nucleic, lin kt vi polyphenol.

Vitamin C thng tn ti dng L trong cc sn phm thin nhin. Cho n nay, c 14 ng phn v ng ng ca vitamin C c hot tnh chng bnh hoi huyt v 15 cht ng phn khng c hot tnh c pht hin. Cc cht ny phn bit nhau bi s lng nguyn t cacbon, s sp xp ca cc nhm nguyn t cc nguyn t cacbon bt i v dng kh hoc dng oxy ha (Kristiina Hyyssnen, Jukka T.Salen and Markku T.Parviainen, 2004)

T cng thc cu to cho thy vitamin C l mt dn xut ca ng.

(iii) Tnh cht ca vitamin C

Tnh cht vt l ca vitamin C



Bng 3: Mt s thng s ca vitamin C

Cng thc phn t C6H8O6

Tn ha hc 2-oxo-L-threo-hexono-1,4-lactone-2,3-enediol hay

(R)-3,4-dihydroxy-5-((S)-1,2-dihydroxyethyl)furan-2(5H)-one

CAS 50-81-7

Khi lng phn t 176,12g/mol

Nhit nng chy 190 1920C Hng s phn ly pK1=4,2 ; pK2=11,6

Kh nng ha tan Tan trong nc, methanol, ethanol

Khng tan trong ether, benzen, toluen.

Quang ph hp th max =245nm v pH < 1,5 max =265nm v pH > 6,8

Hiu in th chun 0,166V pH=4, t0=350C

n v quc t 1 UI = 0,05mg acid ascorbic, l hm lng trung bnh ca 0,1ml nc p h citron.

Kh nng trin quang 240 (trong nc), 480 (trong methanol)

Ngun: www.chemistry-software.com

Vitamin C l mt hp cht d tan trong nc, kh tan trong ru methanol, ethanol, khng tan trong benzen, toluen, ester, cloroform, l mt cht kh oxy ha rt mnh, c tnh ny s dng rt nhiu trong k ngh ch bin thc phm.

Vitamin C khng c mi, c v chua ca acid, tn ti di dng tinh th mu trng, dng kh vitamin C tng i bn nhng khi ha tan trong nc d b ph hy bi s oxy ha, nht l tip xc vi khng kh v nhit . S oxy ha vitamin C din ra cng nhanh nu c s hin din ca vi ion kim loi nh st, ng hay mi trng kim. nhit thp vitamin C kh bn nu c s hin din ca nhng hp cht chng oxy ha hoc nhng cht kh oxy.

Tnh kh ca vitamin C ph thuc vo s c mt ca nhm dienol trong phn t ca n. Chnh v vy m dung dch Feling, bc Nitrat hoc mt s hp cht c mu, c bit l cht 2,6-diclophenolindophenol b kh bi axit ascorbic ngay nhit thng.



Tnh cht chng oxy ha ca axit ascorbic c p dng nhiu trong qu trnh ch bin v bo qun thc phm. Da vo tnh cht chng oxy ha ca axit ascorbic, ngi ta thng thm n vo dch qu ngn cn qu trnh sm mu ca qu. Cng c th tnh axit ca qu l mt yu t bo v vitamin C.

(iv) Vai tr ca vitamin C

T lu, vitamin C c xem nh thnh phn ch c c tnh cha bnh Scorbut. Tuy nhin, khi khoa hc ngy cng pht trin, cc nghin cu khng nh vai tr rt quan trng ca vitamin C trong s pht trin ca rau qu v i vi sc khe ca con ngi.

- i vi c th ngi

Vitamin C c xem nh thnh phn ch c c tnh cha bnh Scorbut (xut huyt di da). Tuy nhin, khi khoa hc ngy cng pht trin, cc nghin cu khng nh vai tr rt quan trng ca vitamin C i vi sc khe ca con ngi.

Vitamin C cn ng mt vai tr rt quan trng trong vic ngn chn qu trnh sn xut cc gc t do, bo v cc acid bo khng no ca mng t bo, ng thi tc ng trc tip trong t bo v gin tip bng cch ti to vitamin E, cht chng oxi ha chnh ca mng t bo.

Vitamin C kch thch qu trnh tng hp v duy tr cht to keo, kt qu l tng cng sc khng v s khe mnh ca cc m: da, sn, dy chng, thnh mch mu (nht l mao mch), rng xng (khng c vitamin C gy xng lu lnh).

Vitamin C cn tham d vo qu trnh tng hp mt vi cht vn chuyn trung gian thn kinh nh noradrenalin, duy tr kh nng tnh to, ch v tp trung.

Vitamin C cn to iu kin cho c th d hp thu st v tng o thi cc cht kim loi c nh ch v cc cht nhim khc. Tuy nhin, lng tha vitamin C trong c th s lm gim kh nng hp thu ng.

Vitamin C tham d vo mi trng oxi ha ca acid bo cung cp nng lng cn thit cho hot ng ca c.

Cc nghin cu v vitamin C cng xc nhn vai tr l cht xc tc cho qu trnh tng hp cc catecholamin, hormon thng thn - cc hormon ng vai tr quan trng trong vic iu chnh ri lon thn kinh (stress); ng thi vitamin C cn tham gia vo c ch min dch, chng li nhim trng vi khun v virus. Chnh v th vic tng cng vitamin C trong c th gip cng c sc lc v chng vi mt mi.



Nghin cu v y hc cn chng thc vitamin C c kh nng gim tun hon ca histamin, mt cht trung gian gy d ng v mt vi tai bin khi c thai.

Vitamin C hot ng trong kh nng phng nga ung th theo 3 c ch: (a) c ch qu trnh to thnh nitrosamin (cht gy ung th) trong d dy v trung ha mt s cht c; (b) c ch qu trnh sn xut mt s gc t do, m cc gc ny s ph hy gen v (c) Kch thch h thng min dch

Vitamin C gi vai tr ngn nga cc bnh v tim mch (hip ng vi vitamin E v -caroten) thng qua nhiu tc dng: (a) Ti s dng vitamin E, bo v m lu thng khi b oxi ha (khi b oxi ha, m s lng ng trn thnh ng mch), (b) Gim tnh c ca thuc l, gim m trong mu v (c) To iu kin loi tr cholesterol cho mt, gp phn gim huyt p ng mch

Khi c th b thiu vitamin C s xut hin cc triu chng bnh l nh chy mu li, rng, cc l chn lng hoc cc ni quan. Do , cn thit phi b sung lng vitamin C cn thit cho c th, nhu cu v vitamin C thay i ph thuc vo nhiu yu t: tui, iu kin lao ng, ngh nghip, kh hu, .Ngi bnh thng cn khong 80100 (mg) vitamin C trong 24 gi (Ngun : Jean Paul Curtay Josette Lyon, 1996)

Bng 4: Liu lng vitamin C cn dng cho cc i tng i tng n v (mg/ngy) Tr s sinh 35 Tr em t 1-3 tui 35 Tr em t 4 -13 tui 40 60 Tr em t 13 tui tr ln v ngi ln 60 100 Ph n mang thai 70 100 Ph n cho con b 80 100 Ngun : Jean Paul Curtay Josette Lyon, 1996

- Vai tr ca vitamin C i vi s pht trin ca rau qu

- Vitamin C hay cc vitamin v khong cht ni chung u c ng gp quan trng vo s tng trng v pht trin ca rau qu. Trong rau qu hm lng vitamin C kh nhiu c bit l trong cc loi rau qu c tnh acid, vitamin C l thnh phn dinh dng ch yu, hm lng vitamin C cao nht c th t 130 170 mg%. Vitamin C bn cht l mt acid hu c, n s cng vi cc acid hu c khc lm nguyn liu cung cp cho qu trnh h hp ca t bo (nht l i vi rau qu). Mt



khc cc acid hu c ny cn tc dng vi ru sinh ra trong rau qu to thnh cc ester lm cho rau qu c mi thm c bit, c bit l khi rau qu chn.

- Trong thc phm

- Acid ascorbic c s dng rng ri trong cng nghip thc phm, khng nhng bi gi tr dinh dng m cn do nhiu chc nng khc nhau i vi thc phm.

- Vi vai tr l cht chng oxy ho, acid ascorbic c th ci thin mu sc v v ngon ca nhiu loi thc phm. Bi vic loi b oxy t mi trng xung quanh, acid ascorbic dng kh tr thnh dng b oxy ho, acid dehydroascorbic. Phn ng oxy ho ny kh oxy c sn trong mi trng lm cho acid ascorbic l mt cht chng oxy ho hiu qu.

- Trong sn xut nc gii kht

+Vic thm acid ascorbic ph bin trong sn xut nc gii kht, c bit l cc sn phm nc tri cy. Acid ascorbic khng nhng phc hi li nhng gi tr dinh dng b mt i trong qu trnh ch bin m cn to v ngon v cm quan cho thc phm.

+ Trong sn xut acid ascorbic c th c thm vo trong sut qu trnh trnh phn ng ho nu c enzym ca tri cy.

+ Phn ng ho nu din ra khi c enzym polyphenoloxydase, xy ra t nhin trong m tri cy xc tc s oxy ho cc hp cht phenol, cng c sn trong tri cy, hnh thnh hp cht quinones. Cc quinones sau c th trng hp to thnh melanins to ra cc hp cht mu nu (hnh 8).

Phenol Quinone Melanins Polyphenolase

(mu nu) Oxygen

Hnh 8: S phn ng ha nu do enzyme

+ Acid ascorbic c th c ch phn ng ho nu bi vic chuyn cc hp cht quinones thnh cc hp cht phenols ban u. Khi c s hin din ca oxy hoc ion kim loi, cc phenols c th d dng bin i thnh quinones. Trong mi trng c mt vitamin C, hp cht ny s ngn cn tin trnh ha nu theo s sau:



Phenol + O2 quinones + H2O quinones + acid ascobic Phenol + Acid dehydroascobic Acid ascorbic + O2 Acid dehydroascobic + H2O Nh vy, vitamin C va c tc dng ngn cn hin tng ha nu, va loi tr oxy khi mi trng phn ng. + Acid ascorbic c th c ch phn ng ho nu bi vic to lin kt chelate vi ion kim trung tm ca enzym phenolase, do c ch hot ng ca enzyme ny. Bn cnh , do enzym polyphenoloxydase hot ng ti u trong khong pH = 6,0 7,0 vic kt hp acid ascorbic v acid citric hoc acid malic i khi c s dng gim hot tnh ca enzym bi vic h thp pH ca nc p. Nhng ch li khc ca vic thm acid ascorbic: +Acid ascorbic thng c thm trong qu trnh phi trn phc hi nhng tn tht c th xy ra trong sut qu trnh ch bin. + Acid ascorbic c thm vo nc qu trnh bin i mi v do oxy ho. + Vic thm acid ascorbic vo nc gii kht ng hp lm gim oxy trong khong khng ca hp trnh s oxy ho sn phm sau ny. Thng thng 3,3 mg acid ascorbic s loi c oxy trong 1 cm3 khong khng.

- Hm lng vitamin C trong thc phm Vitamin C hin din trong hu ht thc phm, trong thc phm c ngun gc t thc vt c xem l ngun chnh cung cp vitamin C cho con ngi (hnh 9). Hm lng vitamin C trong cy n qu ph thuc vo nhiu yu t nh loi, t trng, kh hu, ma v, chiu sng, chn, bo qun sau thu hochBnh thng lng vitamin C gim dn t pha v ngoi vo bn trong rut ca qu.

Hnh 9: Hm lng ca vitamin C trong thc phm

Ngun: http://www.supplementnews.org/vitamin-c/



Cc loi rau qu nh cam, chanh, du, c chua, rau, hnh,v.v. cha rt nhiu vitamin C, cn trong cc loi ht ng cc hoc trong trng, tht hu nh khng c vitamin C.

2.2.4 Acid citric (E330)- cht iu chnh pH

(i) Ngun gc

Acid citric l hp cht c tm thy trong mi vt cht sng. N hin din ch yu thc vt, trong nhiu m ng vt v l mt thnh phn trong con ng chuyn ha ca t bo trong c th. N c tm thy trong nhiu tri cy h citrus (nhm cy c mi), qu kiwi, du, s ri v nhiu loi tri cy khc

Hnh 10: Cu to ca acid citric

(ii) Chc nng

Acid citric l hp cht hu c khng mu, kt tinh thuc h acid cacboxylic. N c nhiu tc dng v c s d c ch khc nhau:

Acid lm tng cngcht oxy ha.

Acid citric c s mi. ng thi, cn cy v sn phm ch

Acid citric c th lmkh nng to chelate ca enzym.

Ngnh Cng ngh thc phng nh mt cht ph gia vi nhiu m hot ng ca cht chng oxy ha nhng bn thn n khng l

dng nh l ch yu nh l cht iu chnh acid v iu chnh s dng lm gim phn ng ha nu do enzym trong cc loi tri bin t tri cy.

hn ch phn ng ha nu do lm gim pH mi trng v n c vi kim loi trung tm ca enzym phenolalase nn c ch hot ng

m-Khoa Nng nghip v Sinh hc ng dng Trang 23


To mi trng acid ngn cn s pht trin ca vi khun, nm men, nm mc, tuy nhin n khng s dng trc tip nh cht chng khun m ch c kh nng chng mt s nm mc v vi khun.

2.2.5 Pectin

Pectin l hp cht cao phn t mch thng cu to t s kt hp ca cc acid galacturonic qua cc lin kt -1,4-glucoside. Khi lng phn t ca pectin t 80.000 200.000. Pectin khng ha tan trong ru v dung mi hu c khc. Pectin ha tan trong nc amoniac, dung dch kim, cacbonat natri v trong glycerin nng. ha tan ca pectin trong nc tng ln khi mc ester ha trong phn t pectin tng v khi khi lng phn t pectin gim. Pectinic acid l thnh phn ch yu trong pectin. Cc pectin t nhin nh v trong thnh t bo c th lin kt vi cc cu trc polysaccaride v cc protein to thnh cc protopectin khng tan. C th phn hy lm cho pectin tan trong nc bng cch un nng pectin trong mi trng acid.

Pectin l polysacaride c nhiu rau qu, c hoc thn cy. Trong thc vt pectin tn ti hai dng ch yu l: protopectin khng tan, tn ti ch yu thnh t bo c l di dng kt hp vi polysacaride araban, dng ha tan ca pectin tn ti ch yu dch bo.

Trong thc vt petin tn ti di 3 dng:

- Pectin ha tan.

- Pectinic acid.

- Protopectin.

Hnh 11: Cu to ca pectin

Ngun: Nguyn c Lng, 2004

Trong ch bin nc qu, pectin c b sung vo vi mc ch lm n nh trng thi keo ca nc qu trong thi gian bo qun v phn phi gip sn phm khng b kt ta phn lp.



2.3 QUY TRNH SN XUT NC DA TI NH MY

Hnh 12: S quy trnh sn xut nc da

Dung dch c c

Bn phi trn

Gia nhit s b(65-70oC)

ng ho

Thnh trng 97oC,30s

Lm ngui nhanh 40oC

Lm lnh 16-20oC

Tank tr tit trng(12000

lit, 24h)

Rt hp 1 lit

Bo qun

Hng

ng

Nc

Acid ascorbic

Pectin ADM

Tank trn tun hon



2.4 GII THCH QUY TRNH

2.4.1 Phi trn

Hnh 13: Bn trn 1000 lt v Tank cha tun hon 8000 lt

Dung dch nc da c c v cc ph gia c bm vo thng phi trn. Thng phi trn dng hnh tr c cnh khuy trn u dung dch. My c ch to ton b bng thp khng r. Th tch thng trn l 1000 lt v c lu thng tun hon cng vi bn 8000 lt. Hot ng theo nguyn tc ly dung dch t y ca bn 8000 lt chuyn n bn trn 1000 lt v dung dch c phi trn c bm n ming ca bn 8000 lt s tun hon nh th nhm mc dch lm cho dung dch sau khi phi trn c ng u. Cc ch tiu v ha l ty theo yu cu trong n t hng ca khch hng m phi ch cc cht theo thnh phn v hm lng yu cu

2.4.2 Gia nhit s b

Hnh 14: Thit b gia nhit



Gia nhit s b khong 65700C trong thit b dng ng lng ng. Cng on gia nhit ny nhm mc ch lm gim nht ca dung dch gip cho qu trnh ng ho d thc hin hn

2.4.3 ng ho

Hnh 15: Thit b ng ha

Qu trnh ng ho c mc ch lm gim kch thc ca cc ht phn tn trong dung dch dung dch ng nht hn.

Nguyn tc hot ng: dung dch c bm vo thit b ng ho, c nn p sut cao khong 120180kg/cm2 qua mt khe hp c kch thc 0,0010,005mm. p sut pha bn kia ca khe h ch khong 23kg/cm2. Do s thay i p sut rt ln v t ngt, sn phm c tc di chuyn rt ln (150200m/s) v sau khi qua khe, sn phm p vo mt tm kim loi lm v cc ht tht qu. Vi kch thc ht rt mn khong 0,001mm, nc qu dng huyn ph vi th, tht qu l lng v phn tn u trong dung dch.

2.4.4 Thanh trng

Hnh 16: Thit b thanh trng

Dung dch nc da cha nhiu acid citric, acid malic v cc acid hu c khc nn c pH rt thp, khong pH 3,54. pH thp nh vy th vi khun a nhit khng nhng



khng pht trin c m kh nng chu nhit cn b gim, nn d dng b tiu dit khi gia nhit. Do ch cn thanh trng nhit 970C cho sn phm ny.

Trong trng hp sn xut nc da ngi ta bm dung dch nc da vo thit b trao i nhit vi hi nc dng ng lng ng nng nhit ca dung dch ln khong 970C trong thi gian 30 giy tiu dit cc vi sinh vt.

2.4.5 Lm ngui nhanh

Hnh 17: Thit b lm lnh

Sau khi thanh trng dung dch c lm ngui nhanh xung cn 40500C cng bng cch trao i nhit vi nc lnh cng mt thit b dng ng lng ng. Lm ngui nhanh nhm mc ch trnh to nhit thch hp cho s pht trin tr li ca vi sinh vt. Sau khi c lm ngui xong sn phm c lm lnh xung cn 160C nhm mc ch gi c gi tr cm quan ca sn phm.



2.4.6 Rt hp

Hnh 19: Tank tit trng 12000 lt v bng chuyn

Sau khi dung dch c lm lnh xong th c a qua tank tr 12000 lt. Tank c cu to c bit l tank tit trng c kh nng bo qun sn phm khng b h hng trong thi gian 24h. Khi tank tr d tr lng dung dch cn thit th bt u cho qu trnh rt hp. Khng kh c lc sch m bo tit trng c bm vo tank tr to p sut. Dung dch trong tank tr c chuyn n my rt hp nh p lc khng kh.

Vt liu lm hp l mng phc hp gm 5 lp, ngoi cng l PE chng m, lp k trong l celllophane d in, lp giy tng cng cho bao b, lp PE ni kt gia lp giy v lp nhm trong cng, lp nhm ngn m, gi mi, ngn sng. Tng hp cc thnh phn ny gip m bo s cch m v gi hng rt tt, ng thi trnh c s tc ng ca nh sng hn ch c s phn hy ca cc thnh phn dinh dng nh vitamin, protein c trong nc qu. Lp giy phc hp cng c tit trng bng tia cc tm trc khi c a vo my ct, nh dng hp, c rt dung dch v ghp m. Ton b qu trnh ny c thc hin trong phng v trng. Trc khi cho dy chuyn vo hot ng v sau mi m ngi ta phi bt n cc tm v trng cho phng trong vng 15 pht. Chnh v vy m sn phm c bo m an ton tuyt i.



3.2 CH TIU CHT LNG SN PHM

V mt cm quan, nc da c mu sc, hng v t nhin ca dch qu nn c sc hp dn i vi ngi s dng, nht l trong thi k hin nay khi con ngi c xu hng tm cch gn gi vi thin nhin.

V mt dinh dng nc gii kht t dch qu cung cp nng lng cho c th ch yu bi lng ng v cc vitamin m n hm cha.

Nc gii kht t dch qu t nhiu u c cha pectin. Tuy hu nh khng c c th phn gii v hp th song pectin c tc dng hp th nc gip cho sn phm c gi lu trong c th, lm tng tnh gii kht ca sn phm.

Sn phm c hm lng cht kh trong khong 1213%, pH t 34, cc ch tiu v sinh t tiu chun TCVN5042-90 quy nh cho nc gii kht. Sn phm bo qun c 6 thng trong iu kin bnh thng.

3.2.1 Cc ch tiu cht lng (TCVN 1549-1994)

Ch tiu cm quan

Sn phm phi c hng v mu sc c trng ca nc da, cho php c s lng nh tht qu y bao b, nhng khi lc nh hoc khuy trn phi phn tn u.

Bao b v nhn

- Khi lng tnh: khi lng tnh ca mi n v bao gi phi ph hp vi khi lng tnh ghi trn nhn. Cho php c s sai lch 5%. Khi lng tnh trung bnh cc hp khng c nh hn khi lng tnh ghi trn nhn.

- Ni dung ghi trn nhn: cho php tha thun trong hp ng gia nh sn xut v bn nhn hng, nhng phi bao gm nhng im.

- Tn sn phm

- Tn c quan qun l sn xut.

- Khi lng tnh.

- Thnh phn theo th t cc ph gia s dng.

Ch tiu ha l

- y ca hp: mc ti thiu ca nc da phi chim t nht l 90% dung tch.



- Hm lng cht kh ha tan: hm lng cht kh ha tan ca nc da khng c

nh hn 12%.

- Hm lng ng thm vo khng qu 25g/kg.

Ch tiu vi sinh

- Cn ch bin hp v sinh theo tiu chun hin hnh.

- Khng cha vi sinh vt gy thi hng c th pht trin trong iu kin pht trin thng thng.

- Khng cha cc cht c ngun gc vi sinh vt c th gy hi cho con ngi.

Bng 5: Lng kim loi ti thiu c th c trong sn phm Tn kim loi Hm lng ti a (mg/kg) Asen (As) 0,1 Ch(Pb) 0,5 ng (Cu) 10 Km (Zn) 5 Thic (Sn) 40 Cadimi (Cd) 1 Thy ngn (Hg) 0,005

Bng 6: Ch tiu v vi sinh vt

3.2.2 Qun l k thut

Vi sinh vt Mc cho php trong 1ml Tng s vi sinh vt hiu kh 102

Coliforms 0 E .coli 0 S. aureus 0 Treptococci faecal 0 Paeruginosa 0 Tng s bo t nm men nm mc 10 Cl. perfringens 0

Bn thnh phm trc khi phi trn c kim tra kh, acid, pH.

Sn phm c kim tra dung tch, kn, pH, cm quan v cc ch tiu vi sinh. Chu trnh kim tra vi mi bn phi trn, khi bt u chit rt s kim tra 56 hp u tin. Tip c 15 pht kim tra mt ln ly mu v kim tra 2 hp. Cui cng c nhp kho lu mt s hp li kim tra n khi ht hn s dng.



CHNG 3 S BIN I CHT LNG SN PHM NC DA NG HP TRONG QU TRNH BO QUN

3.1 PHNG PHP, PHNG TIN TH NGHIM

3.1.1 a im, thi gian nghin cu

- Th nghim c tin hnh ti Cng Ty TNHH nc gii kht DELTA.

- Thi gian t ngy 05/02/2007 n ngy 12/05/2007.

3.1.2 Phng php b tr th nghim

Kho st s bin i cht lng ca sn phm nc da ng hp trong qu trnh bo qun

(i) Mc ch th nghim

Theo di s thay i cc ch tiu v cht lng nh Brix, pH, acid, vitamin C, mu sc,theo tng thi gian bo qun nhit thng.

(ii) B tr th nghim

Tin hnh ly mu nc da ngu nhin trong kho thnh phm ca nh my.

Phn tch cc ch tiu c bn bao gm Brix, pH, acid, vitamin C, mu sc qua cc thi gian bo qun l 0, 2, 4, 6, 8 tun.

(iii) Kt qu th nghim

nh gi c cht lng sn phm v s bin i cht lng nhng thi gian bo qun kho st.

3.2 KT QU THO LUN

Trong bt k sn phm no cng vy, cht lng lun l tiu ch m c nh sn xut ln ngi s dng u t ln hng u. i vi sn phm thc phm tiu ch ny li ng vai tr quan trng hn na, v n trc tip nh hng n sc khe ca ngi tiu dng v quyt nh s sng cn ca nh sn xut. Tuy nhin trong tin trnh sn xut lun xy ra cc bin i lm tn tht hoc thay i tnh cht mt s hp phn trong nguyn liu ban u, s gim cht lng xy ra nhiu mt bao gm mi, v, mu sc, cng nh cc cht dinh dng nhy cm khc... i vi dng sn phm c c im d bin i v cht lng nh sn phm nc da ng hp th vn theo di cht lng sn phm l v



cng quan trng. C nh vy mi c c s ci thin qui trnh sn xut, nng cao cht lng sn phm, trnh c nhng bin i khng mong mun trong qu trnh bo qun.

Th nghim kho st s bin i cht lng ca sn phm nc da ng hp trong qu trnh bo qun c thc hin bng cch ly mu nc da mt cch ngu nhin trong kho thnh phm ca cng Ty TNHH nc gii kht DELTA. Sau em phn tch cc ch tiu c bn theo tng thi gian bo qun l 0, 2, 4, 6, 8 tun. Cc ch tiu c phn tch bao gm Brix, pH, acid, vitamin C, mu sc. Kt qu thng k c trnh by bng 7 v th biu din s tng tc ny c th hin hnh 20, 21, 22, 23.

Bng 7: S bin i cc ch cht lng nc da trong qu trnh bo qun

Thi gian pH Brix Acid (%) VitaminC (mg%) mu L

0

2

4

6

8

3,76b

3,75b

3,75b

3,75b

3,74a

12,2a

12,17a

12,13a

12,17a

12,17a

0,426a

0,423a

0,426a

0,432a

0,488b

21,35e

6,67d

2,15c

1,23b

0,53a

33,42e

32,23d

30,83c

30,05b

29,04a

Cc ch ci khc nhau biu th s khc bit c ngha trong cng mt ct tin cy 95%



3.76

3.75 3.75 3.75

3.74

3.73

3.74

3.74

3.75

3.75

3.76

3.76

3.77

Thi gian

pH

02469

Hnh 20: S bin i pH theo thi gian bo qun

0.43 0.42 0.430.43

0.49

0.38

0.40

0.42

0.44

0.46

0.48

0.50

Thi gian bo qun

% A

cid

0 tun2 tun

4 tun6 tun

8 tun Hnh 21: S bin i % acid theo thi gian bo qun

T kt qu phn tch v th hnh 21, 22 cho thy gi tr pH v t l acid c trong sn phm n nh theo thi gian, khng c s khc bit ngha v mt thng k n tun bo



qun th 6. iu ny chng t sn phm c x l nhit t yu cu v do khng c s bin i cht lng xy ra trong 6 tun u. tun bo qun th 8, kt qu o c v phn tch cho thy, c s gim ca pH v tng acid mc khc bit c ngha so vi cc thi im trc. pH gim nh n gi tr 3,74 cng vi s gia tng hm lng acid t 0,432% tun th 6 ln n 0,488% tun th 8. iu ny c th l do s bt u xut hin vi sinh vt sinh acid, gy h hng.

Thng k s thay i Brix ca sn phm trong qu trnh bo qun nhn thy, hu nh khng c s thay i v gi tr ny sau 8 tun bo qun nhit thng. iu ny mt ln na gp phn khng nh s n nh v cht lng sn phm trong khong thi gian kho st. Gi tr Brix o c l 12,2oBx.

Tuy nhin, kh nng duy tr vitamin C trong sn phm cha cao. Kt qu thu c bng 7 v th hnh 23 cho thy, c s suy gim hm lng vitamin C rt r rt theo thi gian bo qun.

21.35

6.67

2.151.23 0.53

0.00

5.00

10.00

15.00

20.00

25.00

Thi gian bo qun

% m

g

0 tun

2 tun

4 tun

6 tun

8 tun Hnh 22: S bin i vitamin C theo thi gian bo qun

Hm lng vitamin C gim nhanh theo thi gian bo qun do y l hp cht khng bn, d b phn hy di tc dng ca nh sng, nhit , khng kh Sau hai tun bo qun hm lng vitamin C gim rt nhanh, sau gim chm li cc tun tip theo. Sau 8 tun bo qun hm lng vitamin C cn li l 0,53%mg.



Nh vy, quy trnh sn xut nc khm ng hp ti nh my Delta c kim sot cht ch vi dy chuyn hin i v k thut cao nn cho sn phm c cht lng n nh v mt dinh dng. Tuy nhin, vic duy tr hm lng vitamin C cha c m bo tt. Thm vo , xt v gi tr cm quan, mu sc sn phm cng c s thay i (hnh 24)

Kt qu thng k bng 7 cho thy, gi tr L (biu th sng ti ca sn phm) gim dn theo thi gian bo qun, iu ny cho thy mu sc nc da sm dn v bt u c s bin i ngay t tun th hai tr ln. Hin tng sm mu ny c l l do s hot ng ca cc enzyme gy ha nu, ch yu trong khm l peroxidase. Di tc ng ca nhit di 100oC, peroxidase khng b phn hy do vn cn hot tnh vo phn ng, tng sm mu ca sn phm.

33.42

32.23

30.83

30.05

29.04

26.00

27.00

28.00

29.00

30.00

31.00

32.00

33.00

34.00

Thi gian bo qun

L

0 tun

2 tun

4 tun

6 tun

8 tun Hnh 23: S bin i L theo thi gian bo qun

Tm li, nc khm ng hp l sn phm c gi tr pH thp v qua thanh trng nn c kh nng bo qun iu kin nhit thng. Tuy nhin, trong iu kin bo qun ny, vn c mt s bin i khng mong mun xy ra nh s suy gim vitamin C v thay i mu sn phm do phn ng ha nu. c th ci thin tt cht lng sn phm v duy tr hm lng vitamin C mc cao nh ngay sau ch bin, cn kt hp cc phng php bo qun khc.



CHNG 4 KT LUN - NGH

4.1 KT LUN

Cng ty nc gii kht DELTA vi quy trnh ch bin hin i v vic qun l theo tiu chun ISO cng nh p dng cht ch HACCP cho cc qu trnh ch bin. Trong thi gian thc tp ti Cng ty TNHH nc gii kht DELTA, em c c hi hc hi v cng ngh ln k thut sn xut nc da ng hp v tip cn h thng dy chuyn sn xut hin i ca cng ty. Ngy nay, cc loi nc ung tri cy ni ring v cc sn phm ng hp khc ni chung ng vai tr kh quan trng, gip a dng ho cc sn phm thc phm cho mi ngi. p dng khoa hc k thut hin i vo sn xut, Cng ty TNHH nc gii kht DELTA p ng mt phn nhu cu trong nc v xut khu.

Sn phm ca cng ty rt a dng v chng loi, cht lng n nh v c trng, c xut sang nhiu nc. Ni chung, nhng thay i cht lng ny yu cu trong qu trnh ch bin phi c thit lp v kim sot trnh s gim cht lng qu mc khng cn thit. V vy vic nh hng ca cc ch x l t khu nguyn liu cho n nhit , thi gian thanh trng v iu kin bo qun chng c nh hng rt ln n s bin i cht lng sn phm nc da do cn c quan tm v t ln hng u.

Vic nghin cu kho st s bin i cht lng sn phm nc da ng hp trong qu trnh bo qun thu c mt s kt qu nh sau:

- Gi tr pH v acid ca sn phm khng thay i trong 6 tun bo qun u, tuy nhin c s tng nh cc thng s ny tun bo qun th 8.

- Gi tr Brix n nh trong sut thi gian bo qun.

- Xt v mt dinh dng, hm lng vitamin C khng c duy tr n nh v gim dn theo thi gian bo qun

- Xt v mt cm quan, sn phm sm mu hn.



4.2 NGH

ngy cng pht trin cc mt hng hn cng ty cn m rng thm din tch phc v cho sn xut v nh kho c c sc cha cc sn phm hn na.

Tng cng vic qung b trn th trng bng cc thng tin i chng trn mng, qung co cc sn phm ca cng ty c tip cn mt cch ton din trong nc v trn th gii.

C chnh sch thu ht ngun nhn lc, nhn cng lm cc sn phm c tung ra th trng p ng vi nhu cu ngi tiu dng. Nn tng cng vic gim st ti mi b phn sn xut trong vic kim tra cc loi my mc, thng xuyn tu b, sa cha nhm trnh tnh trng lng ph khi ng gi thnh phm khng t yu cu.

Vic bo qun sn phm nc da ng hp nn c thc hin nhit lnh nhm gim thiu s mt mt vitamin C v cc gi tr dinh dng khc, tng gi tr cm quan ca sn phm.



TI LIU THAM KHO Ting Vit

Bnh, Trn Quang v H Vn Thit. 2000. Bo qun rau qu ti v bn ch phm. Nh xut bn nng nghip.

Lng, 2004, Nguyn c. Cng Ngh Enzyme, nh xut bn i hc quc gia Thnh Ph H Ch Minh.

Nhng, L Vn 1977. Ha Hc Trong Cng Ngh Thc Phm, nh xut bn Khoa Hc V K Thut.

Quch nh, Nguyn Vn Tip, 1996, Cng Ngh Sau Thu Hoch V Ch Bin Rau Qu, Nh xut bn khoa hc v k thut H Ni.

Sng, H. 1982. vi sinh vt trong bo qun v ch bin thc phm

Thng, Nguyn nh. 1986. Nc gii kht. NXB khoa hc v k thut.

Tip, Nguyn Vn; Quch nh v Ng M Vn. 2000. k thut sn xut hp rau qu. Nh xut bn khoa hc k thut.

Ting Anh

Ashurst PrP.R. Ashurst and Associates, Kingstone, Hereford, Production and Packaging Of Non-Carbonated Fruit Juices and Fruit Beverages, Blackie Academic and Professional.

CNTP: V920 In-Pack Thermai Processing Of Foods.

Jean Paul Curtay Josette Lyon, 1996

Cc website

http://class.fst.ohio-state.edu/fst605/lectures/lect17.html

http://chemistry-software.com



PHU LC 1 NHNG PHNG PHP PHN TCH NH LNG

1.1 Cm quan

Bng 8: Cch nh gi cm quan

Ch tiu

im H s quan trng

Yu cu

Mu sc

5

4

3

2

1.0 Mu sc t nhin, rt c trng ca sn phm

Mu sc t nhin c trng ca sn phm

Mu sc t nhin, tng i c trng ca sn phm

Hi bin mu, khng c trng

Mi v

5

4

3

2

2.0 Mi v rt c trng

Mi v c trng

Mi v tng i c trng

Mi Vit Nam khng c trng

Hnh thi

5

4

3

2

1.0 C ln bt qu, khi khuy nh phn tn u

C ln bt qu, vn nh, khi khuy nh phn tn u

Vn nh, lc t tan

Vn cc, lc khng tan

Xc nh mu, mi. Mu c t nhin khng, c mi c trng. Khng c tp cht, khng c v l.

1.2 Cc ch tiu ho l

1.2.1 Kim tra Brix

Mc ch: kim tra hm lng cht kh ha tan trong dch.

Phng php: ta tin hnh ly mu cn kim tra Brix cc im sau p, sau lc v sau thanh trng cho vo 3 cc ring bit. Ta kim tra bng thit b my o Brix. Ly mt git mu cho vo con mt cm ng ca thit b ri y np li, sau nhn nt Start, sau thit b s hin th s liu m ta cn kim tra.

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang ix


Hnh 24: Thit b o Brix

1.2.2 Xc nh pH

Mc ch: xc nh pH ca sn phm.

Yu cu: n nh.

Cch tin hnh: ta trch mt phn mu em cho vo cc thy tinh 100ml, trn u, sau ta dng my o pH xc nh pH c trong dch. My hin th thng s PH. Ta so snh pH va o vi yu cu ca khch hng hoc ca cng ty.

Hnh 25: Thit b o pH

1.2.3 Xc nh % acid

Mc ch: xc nh chua hm lng acid citric c trong dch.

Yu cu: Nm trong khong yu cu ca n t hng v nguyn liu.

Cch tin hnh: cn Gm (g) mu (Nu l mu lng ly 25ml mu) dch qu sau khi p, em cho vo bnh nh mc. Pha long mu trong bnh nh mc 200ml bng nc ct c pH = 7 c th d dng nhn bit c s i mu ca dch. Sau ly 25ml (mu sau khi pha long) cho vo erlen cng vi 5 git phenoltalein 0,1% lm cht ch th mu,

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang x


lc u. Tin hnh chun bng dung dch NaOH 0,1N cho n khi xut hin mu hng nht bn khong 30s th dng. Ghi th tch NaOH dng, ri tnh kt qu:

%Acid =Gm

nRVK nb 100****

Trong :

K: H s chuyn pha acid tng ng (acid citric k = 0,07)

Vb: Th tch dung dch NaOH 0,1N dng chun

n: Nng NaOH

R: H s pha long

Gm (g): Khi lng mu dng kim nghim (Nu l mu lng: V(ml)

1.2.4 Xc nh pulp

dch sau khi p ta bt u xc nh cm quan bn thnh phm

Mc ch: xc nh hm lng tht qu c trong dch qu c t yu cu ca cng ty.

Yu cu: lng qu c trong dch qu phi t tiu chun % ca cng ty a ra, khng ln tp cht.

Cch tin hnh

Dch qu sau khi p ta trch mt lng nh dch lm mu.

Dng 2 ng nghim c khi lng m1, cn mu vo ng nghim c khi lng m2. Sau khi cho khi lng mu vo ng nghim. em 2 ng nghim cho vo thit b lng ly tm vi cng sut 5000 vng/pht. Ta ly tm trong vng 5 pht. Sau khi ly tm xong ta ly ng nghim ra, loi b phn lng bn trn v thu lng kt ta pha di dy ng nghim em cn. Ta c khi lng l m.

Ta tnh Pulp theo cng thc:

Pulp = %100*2

1

mmm

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang xi


Hnh 26: Cn in t v thit b ly tm

1.2.5 Xc dnh vitamin C

Mc ch: xc nh hm lng vitamin C t nhin c trong dch qu ph hp vi mc cho php ca cng ty. y l hm lng quan trng v n nh hng n cht lng ca sn phm.

Yu cu: vitamin C c trong dch qu phi t theo yu cu ca cng ty.

Cch tin hnh: Ta em cn 1 lng m (g) vo bnh tam gic, thm acid oxalic v lc u, em chun bng cht Diclorophenol indolphenol. Chun cho n khi xut hin mu bm nht ri c th tch VDI.

Cng thc tnh:

Vitamin = 1000*)(

* DI)(gm

CV DIMDI

VDI: l th tch tiu tn khi chun ca dch Diclorophenol indolphenol.

CM(DI): l nng ca Diclorophenol indolphenol.

M: l khi lng mu em chun

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang xii


Hnh 27: Khu vc chun

1.3 Kim tra vi sinh

Mc ch: xc nh hiu qu ca ch tit trng.

Yu cu: Xc nh hm lng vi sinh vt c trong thnh phm c ph hp vi tiu chun quy nh.

Ly mu v chun b mu theo TCVN 4886-89

Lng mu cn ti thiu pha long khng t hn 1ml i vi cc sn phm lng.

Thit b v dng c

a petri thy tinh ng knh 90100mm Pipet c chia loi 1, 5, 10ml tit khun.

Ni cch thy iu chnh c nhit 45 1oC.

T m iu chnh c nhit 30 1oC.

T sy kh.

Ni hp p lc.

Bnh thy tinh dung tch 250-500ml.

ng nghim loi 16-160mm hoc ln hn.

Mi trng dng nui cy cho tng loi vi sinh vt.

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang xiii


1.4 Kim tra bao bi

1.4.1 ng gp mp

Bung tai c phn u v y hp.

Cc np gp phi thng hng hoc i xng nhau.

1.4.2 ng chng m mi hn dc

o chiu rng ca phn hai m ghp chng ln nhau.

1.4.3 Mt trong bao b

Cc lp nha bn trong bao b trn phng.

Khng c lp try xc nhn, phng.

1.4.4 Kim tra putch

Tnh trng nguyn vn ca putch, khng c vt xc hoc nhn trn mng putch.

Ti mt trong bao b, kim tra putch (mng bc mt di) c dng hon ton vo mt trong ca giy bao b ph qua l ca pulltab.

Kim tra dnh ca putch dn trn giy bao b, bi mc ln phn patch v xung quanh. ch 5 pht khi mc thm. lt b tab. Quan st xung quanh mp l mc khng c thm qua mp ca l pulltab.

Khong nha cn li ti mp ca l pulltab phi nh hn 2 mm.

1.4.5 Kim tra mi hn ngang TS

Cc im quan trng cn ch cc gc cc im giao ca mi hn TS v LS.

Ct ti a 1mm ti mi bn ca hp theo hng vung gc vi mi hn TS.

Ct mt ng ngang thn hp phn khng c mi hn LS

Ra sch hp gp ngc bao dc theo mi hn TS dng ngn tay ci r theo pha trong.

T mt u ca mi hn cn thn x mi hn TS khong 1/3 chiu di cu mi hn.

Ko tng t nh trn cho mi hn bn kia ca mi hn ti im gia ca mi hn LS v TS.

1.4.6 Kim tra mi hn dc LS v SA

V tr strip dan trn bao b.

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang xiv


Tim mt vo phn trng bn di strip ch cc v tr ti ni giao nhau ca mi hn LS v TS np gp u v nh hp.

Ct dc theo mi hn LS ti im gia ca strip.

X b lp giy chng bn ngoi.

Dng ko ct mt gc 45o ti u mi hn, ko nh nhng khong 20mm strip ra khi hp theo gc 90o.

Gi li phn strip tha ri ko tip on khc.

Kim tra sut c chiu di ca strip.

Nu strip t trong khi ko ct mt gc bao ngay ti v lm li nh t u.

Kim tra c hai bn strip

1.4.7 Th mc

Ct ngang hp ra lm hai phn, ra sch bn trong hp, lau kh hp

mc vo hp sao cho mc ph khp y hp ch cc mi hn TS v phn gp ca LS cc gc hp.

khong 2-5 pht. phn mc tha ra sch hp lau kh

Tch phn giy bao bc xung quanh hp.

Quan st cc vt mc trn lp giy.

Vt mc thm ra trn giy chng t c vt thng lp nha v lp nhm.

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang xv


PHU LC 2 Gi tr pH ANOVA Table for pH by Thoi gian Analysis Summary Dependent variable: pH Factor: tuan Number of observations: 15 Number of levels: 5 ANOVA Table for pH by tuan Analysis of Variance ----------------------------------------------------------------------------- Source Sum of Squares Df Mean Square F-Ratio P-Value ----------------------------------------------------------------------------- Between groups 0.000306667 4 0.0000766667 2.88 0.0800 Within groups 0.000266667 10 0.0000266667 ----------------------------------------------------------------------------- Total (Corr.) 0.000573333 14 Table of Means for pH by tuan with 95.0 percent LSD intervals -------------------------------------------------------------------------------- Stnd. error tuan Count Mean (pooled s) Lower limit Upper limit -------------------------------------------------------------------------------- 0 3 3.75667 0.00298142 3.73864 3.74803 2 3 3.74667 0.00298142 3.74197 3.75136 6 3 3.75 0.00298142 3.7453 3.7547 4 3 3.74667 0.00298142 3.74197 3.75136 8 3 3.74333 0.00298142 3.75197 3.76136 -------------------------------------------------------------------------------- Total 15 3.74867 Multiple Range Tests for pH by tuan -------------------------------------------------------------------------------- Method: 95.0 percent LSD tuan Count Mean Homogeneous Groups -------------------------------------------------------------------------------- 8 3 3.74333 x 2 3 3.74667 x 4 3 3.74667 x 6 3 3.75 x 0 3 3.75667 x Gi tr brix ANOVA Table for brix by Thoi gian Analysis Summary Dependent variable: Brix Factor: tuan Number of observations: 15 Number of levels: 5 ANOVA Table for Brix by tuan

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang xvi


Analysis of Variance ----------------------------------------------------------------------------- Source Sum of Squares Df Mean Square F-Ratio P-Value ----------------------------------------------------------------------------- Between groups 0.00666667 4 0.00166667 0.77 0.5691 Within groups 0.0216667 10 0.00216667 ----------------------------------------------------------------------------- Total (Corr.) 0.0283333 14 Table of Means for Brix by tuan with 95.0 percent LSD intervals -------------------------------------------------------------------------------- Stnd. error tuan Count Mean (pooled s) Lower limit Upper limit -------------------------------------------------------------------------------- 0 3 12.2 0.0268742 12.1577 12.2423 2 3 12.1667 0.0268742 12.1243 12.209 4 3 12.1333 0.0268742 12.091 12.1757 6 3 12.1667 0.0268742 12.1243 12.209 8 3 12.1667 0.0268742 12.1243 12.209 -------------------------------------------------------------------------------- Total 15 12.1667 Multiple Range Tests for Brix by tuan -------------------------------------------------------------------------------- Method: 95.0 percent LSD tuan Count Mean Homogeneous Groups -------------------------------------------------------------------------------- 4 3 12.1333 a 2 3 12.1667 a 6 3 12.1667 a 8 3 12.1667 a 0 3 12.2 a -------------------------------------------------------------------------------- Gi tr acid ANOVA Table for Acid by Thoi gian Analysis Summary Dependent variable: Acid Factor: tuan Number of observations: 15 Number of levels: 5 Analysis of Variance ----------------------------------------------------------------------------- Source Sum of Squares Df Mean Square F-Ratio P-Value ----------------------------------------------------------------------------- Between groups 0,00916427 4 0,00229107 85,91 0,0000 Within groups 0,000266667 10 0,0000266667 ----------------------------------------------------------------------------- Total (Corr.) 0,00943093 14 Table of Means for Acid by Thoi gian with 95,0 percent LSD intervals -------------------------------------------------------------------------------- Stnd. error Thoi gian Count Mean (pooled s) Lower limit Upper limit -------------------------------------------------------------------------------- 0 3 0,426 0,00298142 0,421303 0,430697 2 3 0,422667 0,00298142 0,417969 0,427364 4 3 0,426 0,00298142 0,421303 0,430697 6 3 0,432 0,00298142 0,427303 0,436697

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang xvii


8 3 0,488 0,00298142 0,483303 0,492697 -------------------------------------------------------------------------------- Total 15 0,438933 Multiple Range Tests for Acid by Thoi gian -------------------------------------------------------------------------------- Method: 95,0 percent LSD Thoi gian Count Mean Homogeneous Groups -------------------------------------------------------------------------------- 2 3 0,422667 a 4 3 0,426 a 0 3 0,426 a 6 3 0,432 a 8 3 0,488 b Gi tr vitamin C ANOVA Table for vit C by Thoi gian Analysis Summary Dependent variable: Vitamin C Factor: tuan Number of observations: 15 Number of levels: 5 Analysis of Variance ----------------------------------------------------------------------------- Source Sum of Squares Df Mean Square F-Ratio P-Value ----------------------------------------------------------------------------- Between groups 908,526 4 227,131 33107,93 0,0000 Within groups 0,0686033 10 0,00686033 ----------------------------------------------------------------------------- Total (Corr.) 908,594 14 Table of Means for vit C by Thoi gian with 95,0 percent LSD intervals -------------------------------------------------------------------------------- Stnd. error Thoi gian Count Mean (pooled s) Lower limit Upper limit -------------------------------------------------------------------------------- 0 3 21,35 0,0478203 21,2747 21,4253 2 3 6,668 0,0478203 6,59266 6,74334 4 3 2,14833 0,0478203 2,07299 2,22368 6 3 1,23167 0,0478203 1,15632 1,30701 8 3 0,528 0,0478203 0,452657 0,603343 -------------------------------------------------------------------------------- Total 15 6,3852 Multiple Range Tests for vit C by Thoi gian -------------------------------------------------------------------------------- Method: 95,0 percent LSD Thoi gian Count Mean Homogeneous Groups -------------------------------------------------------------------------------- 8 3 0,528 a 6 3 1,23167 b 4 3 2,14833 c 2 3 6,668 d 0 3 21,35 e

Ngnh Cng ngh thc phm-Khoa Nng nghip v Sinh hc ng dng Trang xviii


Gi tr L ANOVA Table for L by Thoi gian Analysis Summary Dependent variable: L Factor: tuan Number of observations: 15 Number of levels: 5 Analysis of Variance ----------------------------------------------------------------------------- Source Sum of Squares Df Mean Square F-Ratio P-Value ----------------------------------------------------------------------------- Between groups 36,232 4 9,05799 743,68 0,0000 Within groups 0,1218 10 0,01218 ----------------------------------------------------------------------------- Total (Corr.) 36,3538 14 Table of Means for L by Thoi gian with 95,0 percent LSD intervals -------------------------------------------------------------------------------- Stnd. error Thoi gian Count Mean (pooled s) Lower limit Upper limit -------------------------------------------------------------------------------- 0 3 33,42 0,0637181 33,3196 33,5204 2 3 32,23 0,0637181 32,1296 32,3304 4 3 30,83 0,0637181

Documents

87 Khảo Sát Quá Trình Chế Biến Nước Khóm Đóng Hộp Và Sự Biến Đổi Chất Lượng Sản Phẩm Trong Thời Gian Bảo Quản Của Công Ty TNHH Nước Giải