bài mứt từ vỏ cam

n mn hc

Mc lcMc lc.................................................................................................................. 1 LI CM N...........................................................................................................2 M u...................................................................................................................3 Chng 1: TNG QUAN..........................................................................................4 1.1. Cam ............................................................................................................4 1.1.1. Ngun gc ,c im thc vt:.............................................................4 1.1.2. Thnh phn dinh dng ca cam ti c trnh by trn bng: .........5 1.1.3. Phn loi cc ging cam:.......................................................................5 1.2. Thnh phn ha hc ca v cam...............................................................10 1.2.1. Pectin.................................................................................................. 10 1.2.2. Cellulose.............................................................................................11 1.2.3. Hesperidin...........................................................................................12 1.2.4. Naringin...............................................................................................12 1.3. Sn phm mt...........................................................................................13 1.4. C s l thuyt ca cc qu trnh c bn...................................................14 1.4.1. Chn la v phn loi nguyn liu......................................................14 1.4.2. Ra......................................................................................................15 1.4.3. Chn....................................................................................................16 1.4.4. Thm thu ng ...............................................................................19 Chng 2: NGUYN LIU, PHNG PHP, NI DUNG NGHIN CU....................20 2.1. Nguyn liu.............................................................................................. 20 2.1.1.V cam.................................................................................................20 2.1.2. ng saccharose...............................................................................20 2.1.3. Mui n................................................................................................20 Phng php nghin cu..................................................................................21 Kho st cc yu t trong qu trnh nghin cu............................................21 nh gi cm quan v cht lng sn phm................................................21 2.3. Ni dung nghin cu..................................................................................26 2.3.1. Quy trnh sx d kin ...........................................................................26 Chng 3: KT QU NGHIN CU........................................................................38 3.1. Kho st nng ca dung dch ngm nh hng n v ng ca sn phm................................................................................................................ 38 3.1.1. Dung dch Ru:..................................................................................38

GVHD: Nguyn Th Thu Huyn

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3.1.2. Dung dch mui:..................................................................................39 3.2. Kho st loi dung dch ngm nh hng n v ng ca sn phm.......39 3.3. Kho st thi gian chn nh hng n v ng ca sn phm. ...............40 3.4. Kho st t l v cam : ng v thi gian thm thu nh hng n nng cht kh (%) ca sn phm. .......................................................................41 3.5. nh gi cm quan v cht lng sn phm............................................42 3.5.1. nh gi cm quan.............................................................................42 3.5.2. Phn tch nh gi cht lng cm quan sn phm mt v cam Vinh 43 3.6. Gi thnh sn phm. ...............................................................................44 Chng 4: THIT K QUI TRNH THIT B.............................................................45 4.1. My ngm: ................................................................................................45 4.2. My Phn loi: .........................................................................................45 4.3. Thit b Chn.............................................................................................45 4.4. Thit b sy...............................................................................................47 Chng 5. Kt lun v kin ngh..........................................................................48 TI LIU THAM KHO...........................................................................................50

LI CM N Trong qu trnh hc tp v nghin cu hon thnh ti ny, ngoi s phn u ca bn thn, nhm em cn nhn c rt nhiu s gip , h tr ca cc thy c, bn b Em xin chn thnh gi li cm n n: - C Nguyn Th Thu Huyn tn tnh hng dn, truyn t nhng kinh nghim qu bu, b ch trong sut thi gian thc hin ti. - Qu thy c B mn Cng ngh thc phm v Ban lnh o trng i hc K Thut Cng Ngh nhit tnh gip trong thi gian qua. - Cc bn 07DTP8 ngnh Cng ngh thc phm ng gp nhng kin b ch trong thi gian hc tp v thc hin ti.


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- Cui cng, em xin gi li cm n n ba m, nhng ngi to mi iu kin em c c thnh qu ny. V thi gian thc hin ti c hn, qu trnh thc hin ti cn gp nhiu kh khn nn khng th trnh khi thiu st. Em xin chn thnh n nhn nhng kin, ng gp ca cc thy c v cc bn. Xin chn thnh cm n! Tp. HCM, ngy 19 thng 12 nm 2010

M u Vit Nam l nc nm trong vng nhit i m nn cy n tri nhit i a dng v phong ph, trong cam la loai cy n tri rt ph bin, trng c khp ca cac vung min nc ta, co quanh nm, la loai trai cy ngon, gia tri dinh dng cao nhng gia thanh re, c bit co nhiu tac dung cho sc khe nh: thanh nhit, gii c, tr ho... nn rt c a chung. Cam c tn dng tt c cc b phn: l, hoa, v, qu u cha tinh du, dng iu ch hng liu; trong ht cam c rt nhiu pectin, c th thay th pectin ha hc trong ch bin thc phm, trong sn xut thuc cha bnh; nc cam cha nhiu cht b dng nh cc loi ng tri cy, bta caroten, vitamin C v cc cht khong Phospho, St. Hin nay, ngoi vic mi cam c s dng ch yu dng n ti, p ly nc ung ti th hu nh nhng b phn cn li c coi l d tha v b ph. Gn y, trong dn gian cng c ngi tn dng v cam ti hay phi kh nu nc ung c tc dng tiu m, d tiu nhng khng nhiu v cn mt lng rt ln v cam cha c tn dng. Vi


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mong mun tn dng ngun ph liu v cam di do, c th thu mua c d dng, rt r; to ra sn phm mt c hng v mi l lm a dng ha cc sn phm thc phm. ti c thc hin quy m sn xut th da trn cc qu trnh c bn trong ch bin thc phm nhm mc tiu xy dng quy trnh sn xut sn phm Mt v cam; t chc anh gia cam quan san phm bc u thu nhn phan hi v san phm, lam c s hoan thin quy trinh san xut v ng dung vao thc t san xut.

Chng 1: TNG QUAN 1.1. Cam 1.1.1. Ngun gc ,c im thc vt: Cy cam c bit n t rt lu khong 2200 nm trc cng nguyn Trung quc nhng mt s ngi li cho rng cy cam c ngun gc t n . Cam c trng rt ph bin t n . Sau c lan rng v pha ng n c vng ng Nam ,vo khong th k th 3 trc cng nguyn, cy cam c a n Chu u,v n lan ra ti c vng a Trung Hi. Sau cy cam c a n Chu M. Nhng nm sau , nhng ngi lm vn Chu M v Chu u em cy cam n Chu c v Chu Phi. Ngy nay cy cam c trng rt ph bin rt nhiu ni trn th gii. Cam l loi cy n tri cng h vi bi thuc gii Plantae, ngnh Magnoliophyta, lp Magnoliopsida, b Sapidales. Loi cam l mt cy lai c trng t xa, c th lai ging gia loi bi (Citrus maxima) v qut (Citrus reticulata).


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Cam sinh trng v pht trin nhit 23-29 0C. Nhng vng c nhit bnh qun l 150C cng c th trng c cam qut. Cam c th chu c rt, nhit qu thp v ko di cy s ngng sinh trng v cht. Nhng nhit cao qu t 400C tr ln, cy cng ngng sinh trng, cnh l cy b kh ho. Cng c mt s ging cam chu c nhit cao. S pht trin ca cam cng cn nh sng. Nu thiu nh sng th cy cam cng sinh trng v pht dc km, kh phn ha mm hoa, nh hng ln n nng sut v sn lng. Cam l loi cy tri a m. Lng ma thch hp hng nm l 1000-1500mm. Trng cam nhng ni c m khng kh 70-80% cy d cho tri to, u, v bng, nc nhiu, phm cht tri tt, t b rng. Loi t thch hp cho cam l t ph sa ven sng, xp nh, ph nhiu, mu m. pH ca t khong 5,5-5,6. 1.1.2. Thnh phn dinh dng ca cam ti c trnh by trn bng: Nc Protid Glucid Acid hu c Cellulose Calcium St Caroten Vitamin C 87,5%, 0,9% 8,4% 1,3% 1,6% 34mg% 23mg% 0,4mg% 40mg%

Cam l ngun viatmin C, c th t ti 150mg trong 100ml dung dch, hoc 200-300mg trong 100g v kh. L v v cam cn xanh cha I-stachydrin, hesperdin, surantin, acid aurantinic, tinh du cam rng (petitgrain). Hoa cha tinh du cam (nerili) c limonen, linalol, geranoiol. Tinh du v cam c thnh phn chnh al2 D-limonen (90%) decyelicaldehyd to nn mi thm, cc alcol nh linalool, D, L- terpineol, alcol nonylic, cn c acid butyric, authrannilat methyl v ester caprylic. 1.1.3. Phn loi cc ging cam: Tri cam


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C nhiu loi cam khc nhau ty tng quc gia v a phng. Trong thng mi, cam c chia lm hai loi, cam ngt v cam chua. Cam chua thng c dng trong sn xut mt cam. Cam ngt gm: Cam trn: Ging cam trn ph bin l valencia c ngun gc t o Azores v B o Nha. Cy cam trn c kh nng thch ng vi nhng vng ni a, ni c s chnh lch su sc v kh hu gia ngy v m, c tc dng lm hot ha h sc t ca v to cho n mu sc hp dn. Tri cam trn c kch c nh ti trung bnh thch hp cho sn xut cng nghip. V mng, da nhn, ht mu cam cam sng. Mi v dch p cam rt thm ngt ngay khi cn ti hay sau khi ch bin thnh nc p. Loi cam ny c hin tng regreen trong thi tit m. Khi tri chn trn cy, v cam chuyn sang mu cam sng nhng khi nhit nng ln v hp th li chlorophyll t l nn cam chn c mu xanh nht. Thu hoch chnh v t thng 2 n thng 10. Sn phm s dng ch yu lm nc p tri cy, t l dch tri thu c cao. Dch p c mu sm v bn.Tri c t ht nn khng to v ng.Valencia cng c th dng bn dng ti.

Cam trn Cam Navel Cc ging cam Navel in hnh nh cam caracara, cam Washington. Cc ging cam ny c trng Florida trc nm 1835 Brazil 1870, Trung Quc. Thu hoch chnh t thng 11 n thng 1.


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Tri cam vng Navel to hn cam valencia v cc loi cam ngt khc. V tar1i c mu vng m sng cho ti cam dy v d lt. Loi cam ny khng c ht, t l thu dch p cao. Thi tit lnh lm mu tri cam vng sng v th tri c th chn v vn cn mu xanh nht trn da. Nhc im ca loi cam ny l to ra v ng nn dng sn xut nc cam p.

Cy cam Navel Cam Blood: Ging cam ny c xem l ngon v hp dn nht trong cc tri c mi c tm thy u tin a Trung Hi. Kch thc tri c trung bnh vi v mng c t hoc khng ht. Mi v tp cam c mu sm sng p. Dch p nhiu, ngt, c mu sm v t chua hn cc loi cam khc. Nhc im ln nht ca cam Blood l hm lng anthocyanins to m c khuynh hng b nht trong qu trnh ch bin v bo qun. Cam Blood c th dng dng ti hay dng p.

Tri cam blood Cam ngt Loi cam ny trng a Trung Hi, cho nc p c hm lng acid thp khng kh nng c ch vi sinh vt, ngt qu cao, v vy khng thch hp cho vic sn xut nc cam p.


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Cam Vit Nam c chia lm ba nhm: cam chanh, cam snh v cam ng. Cam chanh c ba nhm cam l cam thng, cam rn v cam . Cam snh c v dy, sn si, rut vng , hng v thm ngon. Cam ng cha nhiu cht c v ng cht lng khng cao.

Cy cam ngt 1.1.4. Mt s ging cam ph bin Vit Nam Cam X oi (Ngh An): cy tng i cao, t cnh, trng X oi, tnh Ngh An.

Tri cam ngon, thm c v mng v bng, v ngt m t x. ng dng ch yu trong sn xut nc cam, v mt cam. Cam ng nh: cy to, l xanh nht, tai l to. Tri to, mu ta, nhiu nc, hi

chua, d trng, c sc chng chu, l ging lai gia cam v bi. Hin loi cam ny c trng Hi Hng. Cam ng: hng v gn ging qut hn cam. Cy cao 2-3m tn rng nhiu cnh

l, l khng c tai. Khi lng trung bnh 100g/tri, v mng, mu vng hay sm, d bc, mi d chia. C ba loi cam ng l cam Giy vi c ging cam Canh ,cam ng D, cam Ngc cc, cam Hnh Thin, cam B, cam Chua, d trng sai tri, v hi chua, ph bin Hng Sn,Tuyn Ha, cam Voi tri to 300-350g lai gia cam B v bi, trng Tuyn Ha. Cam snh: c tn khoa hc Citrus nobilis var, nobilis, tn Anh l mandarin, king

organge. Cy cao 2-3m, phn cnh thp, l c tai nh. Dng tri hi dt, khi lng 200400g/tri c v sn si v mn, v dy, khi chn c mu vng hay sm, tuy dy nhng d bc, rut , ht c mu nu lc, v ngt, hi chua, hng v thm ngon, thch hp lm ngt tri nc ng.


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Vng chuyn canh BSCL l Tam Bnh, Tr n,. Din tch trng khong 2413 ha, sn lng 48000 tn /nm, ma v chnh t thng 7 n thng 12. Ging cam snh ph bin l cam B H trng bi ph sa H Bc trn t thot nc ,tri dt, nng trung bnh 200-250g, mu vng dp chn vo thng 11-12 qua n thng 1 nm sau v dp tt Nguyn n. Cam snh cn c tn l Citrus nobilis lour. Qut trc y cng c xem l mt th cam snh. Cam son: citrus sinensis thuc h Rutaceae, tn ting anh l sweet orange, c

trng l t BSCL. Cam snh c l xanh sm v to hn cam mt. Tri to xanh ng vng khi chn dng tri hnh cu phn di tri c nm ng tin lm vo bng u ngn tay. Cc tp cam ro nc, v ngt thanh, hp vi khu v ngi Vit v Chu hn khu v dn u M. Cn nhng loi cam gn vi chanh c v mng hn nhng kh bc ,khi chn mu vng. nc ta cam hu nh c quanh nm nn c th dng tri ti. Ngi ta cng thng thu hi tri non rng gc cy lm loi thuc dng ng Y. 1.1.5. Thu hoch v bo qun cam nc ta cam c trng rng ri trn khp c nc ly tri n. Cy ra hoa quanh nm,thng c hoa vo thng 1-2 ,c tri vo thng 11-12. Thi gian thu hi thch hp l vo khong 212-221 ngy sau khi u tri. Biu hin bn ngoi ca tri cam chn l v tri c mu vng nht v d dng tch ra khi tht tri, phn v xp c mu hi vng, chnh gia y tri xut hin m trn (c ng knh 1,5-2mm) v chua ngt hi ha. Nu thu hi khi tri cn qu xanh, v tri s c mu xanh m, v chua gt ,c v hu ng. Ty theo ging sm hay mun m thi gian thu hoch khc nhau. Thu hi ng chn khi 1/3 v tri chuyn mu vng. Khng nn tri chn hon ton trn cy ,tri s b xp, kh nc. Chn ngy tri nng ro thu hoch cam. Dng ko ct st cung tri ,thao tc cn nh nhng khng l dp ti tinh du ngoi v tri s d b hng khi bo qun. Bo qun cam bng ct Ct xp c tc dng hp th m ,nhit, CO2, thot ra t nguyn liu ,bo qun v ngn chn mt phn s xm nhp ca kh. Nh vy cc tc dng iu chnh t nhin cc thng s k thut bo qun. Ri mt lp cam ln trn lp ct ,sau li ri mt lp ct dy 5cm ln trn mt lp cam. C nh vy lp ct ri lp cam cho n khi chiu cao ca ng cam t


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yu cu th ph mt lp ct trn cng dy 30cm. Trong thi gian bo qun ,c mi thng kim tra mt ln pht hin h hng .Bng cch bo qun ny c th gi cam c trong 3 thng. Phng php bo qun cam ny ch thch hp cho bo qung quy m gia nh. Bo qun bng ha cht: Sau khi thu hi ,cam c lau chi sch s ri mi x l bng ha cht. Ha cht thng dng l Topxin-M. Trc tin nhng cam vo nc vi bo ha, vt ra ro nc trong khng kh. Khi c C trong khng kh s tc dng vi Ca(OH)2 to thnh mng CaCO3. Bao quanh tra cam, hn ch s h hp ngn nga vi sinh vt xm nhp. Sau nhng cam vo dung dch Topxin-M 0,1% ri li vt ra, ro. Khi ro nc cam c gi thnh tng tri bng giy bn mm hoc ti polyethylen dy, 4mm. Xp cam vo st v a i bo qun ni thong mt nhit thng hoc lnh. 1.2. Thnh phn ha hc ca v cam 1.2.1. Pectin Pectin l cht nhy bao quanh v ht cam v trong ci qu bi chn. Bn cht ca n l mt loi cht x, tan trong nc, lm tng nht. Trong ci cam ti cha t 1-2% pectin (kh), nhng khi phi ci cam kh th ch cn 0.5 1% pectin (kh). Quanh v ht cam ti c t 3-16% pectin (kh), khi phi kh v ht cam (nhn trong cn m) th c 4-20% pectin (kh). Pectin tinh ch c dng cht bt trng mu xm nht, l mt cht keo ht nc v rt d tan trong nc. Trong qu cam ti, ci ti chim 10-40%. Ht ti chim 3-6%, v ngoi 10% (c qu ht lp ht ch cn vi ht my). Tc dng dc l ca pectin Pectin l mt loi cht x ha tan trong nc. N khng cung cp nng lng nhng c nhiu gi tr phng, cha bnh nh: Ko di thi gian tiu ha thc n trong rut, c tc dng tng hp thu dng cht trong thc n.


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Gim bo (do to cm gic no bng ko di, gim nng lng n vo, do gip gim cn ngi bo ph). Gim hp thu lipid. Gim cholesterol ton phn trong mu (c bit l gim cholesterol xu LDL) ngi ri lon lipid mu. Khng ch tng ng huyt trc v sau ba n ngi c bnh tiu ng. Cc ng dng ca pectin Tc nhn to gel thc phm: Pectin l tc nhn to gel thng dng c dng cho cc sn phm thc phm nh cc loi jam truyn thng, jam t ng, jelly, ko jelly v nhiu sn phm khc. ng dng trong nc gii kht: HM pectin c DE cao hn 70% c s dng n nh sn phm sa thanh trng, tit trng hoc sa chua, sa u nnh v cc sn phm khc. Pectin c ng dng nhiu trong ngnh nc gii kht nh nc tri cy hoc cc loi nc ngt khng cn. N c th s dng n nh bt tht qu hoc tinh du, n nh trang thi l lng ca nc cam v ngn chn s lng cn cu m bo tri cy trong nc cam c c c tng cc cht ha tan ln hn 45% bng cch to mt gel pectin yu.

1.2.2. Cellulose Cellulose thuc loi polysaccharide cao phn t khng c tnh cht ng, l thnh phn chnh ca t bo thc vt. Tnh cht v nhng vai tr ca cellulose Cellulose khng tan trong nc. Nc lm phng ln tng phn cellulose. N hp thu nc vi lng 7 - 8% khi lng. Lng nc hp thu tng ln 22 - 24% trong trng hp khng kh bo ha hi nc. S phng ln lm tng ng knh si cellulose nhng chiu di khng i. Tnh bn c hc l c tnh ch yu ca cc si cellulose. Tnh bn c hc ca cellulose l do di ln ca i phn t v hng song song ca chng. Cc i phn t lin kt vi nhau bng lin kt hydro gia cc nhm - OH.


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Con ngi khng th tiu ha c cellulose trong khu phn v khng c cc enzyme

cn thit phn hy chng. Tuy nhin, mt s loi vi khun c kh nng phn hy cellulose thnh CO2 v H2O. Cc tc nhn oxi ha nh ozeic, peroxide, hydro, natri hipocloride, C th oxi ha cellulose to thnh hn hp phc tp gi l oxycellulose. Cellulose c th tc dng vi kim c to thnh sn phm tng t cc ancolat gi l cellulose - kim. Cellulose - kim d b thy phn tr li cellulose di dng hydrat cellulose, dng ny ging cellulose v thnh phn ha hc nhng ho nc hn v t bn hn. Cellulose - kim tc dng vi sulfurcarbon to thnh xentogenat cellulose. Xentogenat tan trong kim thnh mt dung dch rt nht gi l vis.Cellulose c th b este ha khi tc dng vi anhydride acetic (c mt H2SO4 lm xc

tc) to thnh mono, di, triacetat cellulose v c th nitrat ha thnh hn hp mono, di, trinitrat cellulose. Chc nng ca cellulose v cc cht x thc n nh sau: Phng nga ung th rut kt

Phng nga x va ng mch Phng nga hnh thnh si mt, gim c hm lng m trong mu

Gy nh hng n mc ng huyt, gim bt tc dng da vo insulin ca

bnh nhn tiu ng Ngn nga s tha nng lng v bo ph 1.2.3. Hesperidin Hesperidin C28H34O5 ,c nhiu trong v qu h Citrus v cc m khung, khng c v ng, c hot tnh vitamin P, gi vai tr iu chnh thm thu v tnh n hi ca cc thnh mch mu. Khi thu phn, hesperidin s thu phn n ramnoza v aglucon hesperidin. 1.2.4. Naringin Naringin C27H32O14 , c trong v trng v c trong dch qu h Citrus. Khi qu cn xanh, naringin gy ra v ng. Khi qu chn, do tc dng ca enzyme peroxidaza, naringin b thu phn thnh glucoza, ramnoza v aglucon naringin khng c v ng. Trong chanh non cn c neohesperidin c v rt ng. Bng tm tt thnh phn, t l phn trm, gi tr dinh dng v tc dng dc l ca cc thnh phn trong qu cam:


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Thnh phn V qu ngoi

T l (%) 19 21

Gi tr dinh dng v tc dng dc l Cha ho c nhiu m, hen, y bng kh tiu, au thot v, au d dy, ph thng. - Chng lot d dy, lm bn thnh mch, h huyt p, chng ng mu.

V qu V qu gia 18 19

- Cha cc chng ri lon tun hon mao mch tnh mch, phng nga nhi mu c tim v bnh au d dy.

Dch qu

59 61

Cha chng thiu vitamin C -B v ngoi, nng chn, nghin thnh bt dng bi cha chc u.

Ht cam

12 -Cm mu, c th dng trong y hc(nh rng)

1.3. Sn phm mt Mt qu l cc sn phm ch bin t qu ti hoc t qu bn ch phm (pur qu, nc qu, qu sunfit ha) nu vi ng n kh 65 70 %. Sn phm mt ni bt l v ngt, thm t nhin tinh khit ca qu. Ngoi hm lng ng c sn trong qu, ngi ta cn b sung thm mt lng kh ln ng. ng cho vo mt qu khng ch tng ngt m cn bo qun sn phm.Ta bit rng, hu ht mng t bo ca qu v vi sinh vt c tnh thm thu chn lc, ngha l c th cho mt s dung mi hay cht tan nht nh i qua, ty thuc nng cht tan cao hay thp trong mi trng bn ngoi t bo m c hin tng co hay trng nguyn sinh. Nh vy, trong mt qu, hm lng ng trong mi trng bn ngoi cao s lm vi sinh vt c trng thi co nguyn sinh v ngng hot ng. V vy, c nhiu loi mt nu xong khng cn thanh trng. Mt s loi mt c hm lng ng tng i thp cn phi thanh trng vi thi gian ngn, ch yu l dit nm men, nm mc trn b mt mt. Mt qu c hm lng acid cao cng lm c ch hot ng ca vi sinh vt. Phn ln cc loi mt qu cn c ng nht nh. Cht to ng c sn trong qu l pectin. Trng hp cn tng ng ca mt qu, ngi ta pha thm pectin bt, pectin c c, aga aga (thch) hoc cc loi qu giu pectin (nh to).


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Trong qu trnh tn tr, mt dn dn b va, thot u trn mt ri lan dn ra. Nu bo qun nhit thp, sn phm c pH di 2.8 v c nhiu tp cht, hoc b tc ng c hc, mt cng chng b va hn. Phn loi mt: (theo trng thi cu trc sn phm). Mt ng:

- Ch bin t nc p hay pur tri cy. - To gel ng bng pectin hay agar. - C 3 dng : Jelly, Jam, Marmalade - Hm lng cht kh khong 60 65 %. Mt rim: - Ngi phn ci (bt ch, ming, tri) c thm sir ng, khng to gel ng. - Hm lng cht kh khong 65 75 %. Mt do: - Dng ming hoc nguyn tri - Mm, hi t, khng cn sir ng bao quanh ming mt (mt tc, mt me). - Hm lng cht kh khong 70 75%. Mt kh: - Dng ming hay nguyn tri. - Bn ngoi c mt lp v o ng. - Hm lng cht kh 75 80%. Sn phm Mt v cam l mt sn phm mi, c sn xut da trn quy trnh ca cc loi mt kh c cha hm lng cht kh cao. 1.4. C s l thuyt ca cc qu trnh c bn 1.4.1. Chn la v phn loi nguyn liu 1.4.1.1. Khi qut Chn la: l loi b cc thnh phn nguyn liu khng qui cch ch bin nh

b su, bnh thi hng, khng kch thc v hnh dng, mu sc khng thch hp. Phn loi: nhm phn chia nguyn liu thnh cc phn c tnh cht ging nhau, c

cng kch thc, hnh dng, mu sc, trng lng... c ch x l thch hp cho tng


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loi v gip thnh phm c phm cht c ng u. La chn c tin hnh ngay sau khi thu nhn, khi a vo ni ch bin: Ra, vn chuyn, ct gt, cho sn phm vo bao b... Vic phn loi, la chn thng tin hnh bng phng php th cng. Nhng vi phng php th cng s tn nhiu cng sc, v do gi gic lm vic lin tc, hot ng cng thng, nn cng nhn chng mt mi, thng nh hng khng tt n cht lng phn loi. Do ngi ta c th c kh ha vic la chn phn loi, da trn s khc nhau v mu sc, kch thc v khi lng ring ca nguyn liu. 1.4.1.2. Cc nguyn tc phn loi, la chn i vi cc nguyn liu cn phn loi theo mu sc: Nh ng dng tnh cht ca t bo quang in hot ng theo s thay i ca tia sng. Ty theo trng thi b mt ca nguyn liu (mu sc, nhn) m nh sng phn chiu c di sng khc nhau, t c cng kch thch khc nhau ln t bo quang in . i vi nguyn liu cn phn loi theo kch thc - S dng my phn c kiu ry lc: My c nhiu tng ry, c kch c mt li khc nhau, tng trn cng mt li rng nht, tng cui cng mt li nh nht. H thng ry thc nh: u phng, mn... - My phn c kiu dy cp: B phn phn loi l h thng dy cp cng gia hai trc quay, chuyn ng theo chiu dc ca dy. Khe h gia 2 dy cp to dn. Qu i gia 2 dy cp, s ri dn theo th t t nh n ln. My ny dng phn loi qu to nh cam, bi, da leo, c tm ...

i vi nguyn liu cn phn loi theo trng lng ring (phn loi ht kh) S dng my phn loi thy lc: My phn loi da theo ni khc nhau trong cht lng do khi lng ring ca nguyn liu chnh lch nhau. My phn loi thy lc dng phn loi nguyn ht: u, lc ( u phng) v.v...

1.4.2. Ra 1.4.2.1. Khi qut: Sau khi la chn phn loi, nguyn liu c a qua khu ra. giai on r ny


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n mn hc

nhm mc ch l loi tr cc tp cht, bi, t ct bm xung quanh nguyn liu, ng thi lm gim 1 lng ln vi sinh vt nguyn liu. Yu cu nguyn liu sau khi ra: Phi sch, khng b dp nt, t b tn tht cht dinh

dng (khi r trnh nguyn liu tip xc vi nc lu). 1.4.2.2. Tiu chun nc dng trong cng nghip thc phm: Nc ra cng nh nc dng trong khi ch bin (nh chn, pha ch) phi l nc s dng cho thc phm, m bo cc ch tiu theo qui nh. Nc phi trong, khng mu, khng mi v . 1.4.3. Chn 1.4.3.1. Khi qut: Trong qu trnh ch bin, nhiu loi nguyn liu trong ch bin s b bng c hc,

cng nh trc khi cho vo bao b c x l bng nhit. Ngi ta nhng nguyn liu vo nc hay dung dch, hay x l nguyn liu bng hi nc, ty theo tnh cht nguyn 0 liu v yu cu ch bin, nhit 75 - 100 C, trong thi gian 3-15 pht. Cc yu t nh hng n thi gian chn: trong qu trnh chn, ngoi mc ch v hot enzyme, cn phi m bo cht lng sn phm, nn thc phm phi c gia nhit nhanh. Do , vic la chn nhit v thi gian ph hp cho mi loi nguyn liu c ngha rt quan trng v thi gian gia nhit ph thuc vo cc yu t: Loi nguyn liu Kch thc nguyn liu Nhit gia nhit Phng thc gia nhit Sau khi chn, hp xong cn lm ngui nhanh. Hp th tn tht cht dinh dng t hn chn, nhng trong thc t sn xut, ngi ta thng chn v thao tc thun tin, thit b n gin, truyn nhit tt hn khi hp. 1.4.3.2. Mc ch: Chn hp nguyn liu nhm cc mc ch: nh ch cc qu trnh sinh ha xy ra trong nguyn liu, gi mu sc ca nguyn liu khng hoc t b bin i.


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n mn hc

i vi nguyn liu thc vt, di tc

dng

ca enzyme peroxidase,

polyphenoloxidase trong cc nguyn liu thng xy ra qu trnh oxy ha cc cht cht, to thnh flobafen c mu en. Chn, hp, un nng lm cho h thng enzyme b ph hy nn nguyn liu khng b thm en. i vi nguyn liu ng vt, qu trnh chn, hp lm cho qu trnh phn gii b nh ch. Nc chn nguyn liu c th c s dng lm nc rt hp. Lm thay i trng lng v th tch ca nguyn liu cc qu trnh ch bin tip theo c thun li. Khi gia nhit, cc nguyn liu cha nhiu tinh bt ht nc s trng n, nh u kh sau khi chn s tng th tch gn 2 ln v khi lng tng 1,85 ln, nn khi thanh trng s chng chn, dung dch rt vo khng b ht nhiu. Vi nguyn liu giu protid, do b ng t di tc dng ca nhit, s lm gim th tch v trng lng. S thay i trng lng v th tch ca nguyn liu sau khi gia nhit lm cho sn phm n nh, p ng cc yu cu v t l ci - nc v thnh phn cc cu t trong hp. Gim t l tn tht nguyn liu v nng cao hiu sut ch bin i vi nguyn liu thc vt, qu trnh chn, hp lm cho tinh bt b h ha, gip nguyn liu n hi, kh gy v khi xp hp. Mt khc, khi chn protopectin thy phn thnh pectin ha tan, lm cho vic bc v b ht nhanh v ph liu t. Lm tng thm thu ca cht nguyn sinh, lm cho dch bo thot ra d dng (khi p nc qu) hoc dung dch nc rt d ngm vo nguyn liu (trong sn xut qu nc ng, mt ming, rau ngm gim) i vi nguyn liu ng vt, khi x l nhit th colagen chuyn thnh gelatin gip cho qu trnh tch tht ra khi xng, da d dng, do nng cao hiu sut ch bin. ui kh c trong gian bo ca nguyn liu Nhm hn ch tc dng ca Oxy xy ra trong hp, trnh phng hp, n mn v hp st, oxy ha vitamin...Chn cn lm gim cc cht c mi v khng thch hp nh v ng (mng, c tm) cc hp cht lu hunh (rau ci, ci bp, gia cm). Lm cho rau qu c mu sng hn do ph hy mt s cht mu Khi chn trong dung dch acid citric hoc NaHSO3...nhng cht ny s ph hy mt s hp cht mu, lm cho nguyn liu c mu sng hn. Lm gim lng vi sinh vt bm trn b mt ca nguyn liu.


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n mn hc

Mc d x l nhit khng cao lm, vi thi gian khng di, nhng c th nhng c th tiu dit mt s vi sinh vt km chu nhit bm trn b mt nguyn liu. 1.4.3.3. nh hng ca qu trnh chn, hp n cht lng sn phm V dinh dng Trong qu trnh chn, hp, cht lng sn phm gim khng nhiu. S mt mt cht dinh dng thng do ha tan hn l b bin i. Cc cht khong, vitamin cng nh mt s cc cu t ha tan b ho tan trong nc chn. Lng cc cu t ha tan ph thuc vo cc yu t sau: Mi trng cht ti nhit (nc, hi nc hay khng kh nng): qu trnh hp s Nhit , thi gian chn, hp: nhit cng cao, thi gian cng di, s tn tht

tn tht cht ho tan t hn chn, tuy nhin cu to thit b phc tp v chi ph tn km hn. dinh dng cng nhiu. V mu sc Mu chlorophyl Chlorophyl thng tn ti 2 dng: chlorophyl A v chlorophyl B. Trong chlorophyl A tng i nhy cm vi nhit hn chlorophyl B. Chlorophyl bin i khi x l trong mi trng acid hoc c oxy (chlorophyl c mu xanh bin i thnh pheophytin c mu vng xanh vng olive. Chlorophyl A Nhit, acid Pheophytin A

Nhit, acid Chlorophyl B Mu anthocyan Pheophytin B

Trong nguyn liu, anthocyan thng tn ti dng phc hp leucoanthocyan. Anthocyan l cht ha tan trong nc. Do , khng nn chn nguyn liu cha anthocyan trong mi trng c nhiu nc.


Page 18

Mu caroten

Caroten tng i bn nhit, v vy t b bin i trong qua trnh chn, hp. Mt khc, trong qu trnh tn tr, nguyn liu c chn, hp th hm lng caroten li n nh hn nguyn liu khng chn. V mi v Cc cht mi thng hin din trong nguyn liu l cc hp cht ester d bay hi. V vy, mi v gim mt t sau khi chn. V cu trc Mt trong nhng mc ch ca qu trnh chn, hp l lm mm cu trc ca rau qu, to iu kin d dng khi cho vo bao b hoc tch v, ht ra khi tht qu. Tuy nhin, i vi mt s sn phm th qu trnh chn, hp, lm mm cu trc khng mong mun. M mt trong nhng nguyn nhn lm mm cu trc l do protopectin bin thnh pectin. V vy, duy tr cng ca sn phm, ta c th cho thm CaCl 2 vo nc chn, to thnh phc pectat calci 1.4.4. Thm thu ng Thm thu l hin tng mt khi c mt s khc bit nng (hay chnh xc hn s khc bit nng (hay chnh xc hn, mt khc bit ca hot tnh ha hc ca dung mi) lm cho dung mi (nc) i xuyn qua mt mng c tnh cht thm dung mi tt hn cht tan. Mng gi l mng bn thm. Thm thu l mt trng hp c bit ca khuch tn. l s khuch tn qua mng bn thm nc c th thm qua mng,cc cht tan khc khng qua mng c. Thm thu l mt s vn chuyn ca nc ngang qua mt mng bn thm t pha c nng nc cao hn n pha c nng nc thp hn.Khi hai dung dch c nng cht tan khc nhau phn tch nhau bi mng bn thm nc nhau phn tch nhau bi mng bn thm, nc t dung dch long s qua mng bn thmvo dung dch m c hn gim gradient nng .

S di chuyn nc s ngng khi no nng ca hai dung dch bng nhau.Th tch ca phn dung dch long s gim li v th tch ca phn dung dch m c s tng ln sau khi tin trnh chm dt. Hnh: S thm thu nc qua mng t bo

Chng 2: NGUYN LIU, PHNG PHP, NI DUNG NGHIN CU 2.1. Nguyn liu 2.1.1.V cam C 2 ngun cung cp v cam ch yu: T ph liu ca cc nh my sn xut nc p tri cy vn rt sn c ti Vit Nam Thu gom t cc h gia nh trong khu vc Thnh Ph H Ch Minh, nguyn liu sn c ti nh. 2.1.2. ng saccharose S dng ng tinh luyn Bin Ha

Saccharose m ( Moisture) mu ( colour value ) ng kh ( reducing sugar) Tro (Ash) Ngun gc: Cng Ty C Phn ng Bin Ha Khu cng nghip Bin Ha 1 ng Nai Vit Nam 2.1.3. Mui n Mui tinh sy I-T

>= 99.8%

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