TRNG I HC K THUT CNG NGH TP.HCM KHOA CNG NGH THC PHM

BI TP MN CNG NGH CH BIN RAU TRI

B AO V SN PHM T B AO

NHM SVTH : NGUYN TH NGC HNG NGUYN TH NGC HN NGHUYN TH KIM HNG NGUYN TH M HIN QUCH BO LINH GVHD: ThS. TN MINH NGUYT 0851100073 0851100078 0851100080 0851100097 0851100147

TP H CH MINH 11/20101

MC LC 1. TNG QUAN V NGUYN LIU ............................................................................4 1.1. Ngun gc, tn gi v phn loi ...............................................................................4 1.1.1. Ngun gc ..............................................................................................................4 1.1.2. Tn gi ...................................................................................................................4 1.1.3. Phn loi ............................................................................................................. 4

1.2. c tnh thc vt hc ................................................................................................51.3. Ngun gc sinh vt hc ca b ao ........................................................................... 5

1.4. K thut gieo trng b ao ........................................................................................5 1.4.1. Thi v gieo trng ..................................................................................................5 1.4.2. Lm t .................................................................................................................. 6 1.4.3. Phn bn................................................................................................................. 6 1.4.4. Cc bin php chm sc..........................................................................................6 1.4.5. Phng tr su bnh .................................................................................................6 1.5. Thu hoch b ao .......................................................................................................7 1.6. Bo qun b ao ........................................................................................................7 1.7. Thnh phn ha hc ..................................................................................................7 1.8. Gi tr ca b ao .......................................................................................................81.8.1. Gi tr kinh t ....................................................................................................................8

1.8.2. Gi tr dinh dng......................................................................................................... 81.8.3. Gi tr s dng ........................................................................................................8

1.8.4. Gi tr dc phm ..................................................................................................8 2. CC SN PHM T B AO .................................................................................10 3. QUY TRNH SN XUT CC SN PHM T B AO.......................................... 11

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3.1. Sn xut mt b ao.................................................................................................11 3.1.1. Tng quan v mt........................................................................................................11 3.1.2. Nguyn liu sn xut mt ....................................................................................12 3.1.2.1. Nguyn liu chnh .............................................................................................12 3.1.2.2. Nguyn liu ph.................................................................................................12 3.1.3. Quy trnh sn xut....................................................................................................... 15 3.1.4. Thuyt minh quy trnh .........................................................................................16 3.2. Sn xut nc p b ao...........................................................................................19 3.2.1. Nguyn liu sn xut nc p b ao ...................................................................19 3.2.2.1. Nguyn liu chnh .............................................................................................19 3.2.2.2. Nguyn liu ph v ph gia khc ......................................................................19 3.2.3. Quy trnh sn xut nc p b ao .......................................................................20 3.2.4. Thuyt minh quy trnh......................................................................................... 21 3.3. Sn xut tr b ao ...................................................................................................26 3.3.1. Thnh phn c trong tr b ao ............................................................................26 3.3.2. Quy trnh cng ngh sn xut tr b ao ..............................................................27 3.3.3. Thuyt minh quy trnh .........................................................................................28 4. CC TIU CHUN CHT LNG .......................................................................30 4.1. Tri ti................................................................................................................30 4.2. Mt b ......................................................................................................................31 4.3. Nc p b ao v tr b ao ...................................................................................31

3

DANH MC BNG

Bng 1.1 Thnh phn ha hc trung bnh ca tri b ao ............................................................7 Bng 3.1 Cc ch tiu cht lng ng ghi trn bao b ...........................................................13 Bng 3.2 Cc ch tiu ha hc ca acid citric ........................................................................... 14 Bng 4.1 Hm lng ti a cho php ca mt s kim loi nng v c t trong sn phm rau ti theo ( FAO/WHO nm 1993 ) ..................................................................................................30

Bng 4.2 Hm lng mt s vi sinh vt ti a cho php trong rau qu ti ................30 Bng 4.3 Hm lng cc cht trong sn phm ..............................................................32

DANH SCH HNH V

Hnh 1.1 B ao phn .................................................................................................................4 Hnh 1.2 B ao ....................................................................................................................4

Hnh 1.3 L b ao........................................................................................................... 5 Hnh 1.4 Hoa b ao .........................................................................................................5 Hnh 1.5 Tri b ao .........................................................................................................5Hnh 2.1 Nc p b ao ...........................................................................................................10 Hnh 2.2 Mt b ao...................................................................................................................... 10 Hnh 2.3 Tr b ao ...................................................................................................................10 Hnh 2.4 Tr b ao ...................................................................................................................10

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ti: B AO V CC SN PHM T B AO1. TNG QUAN V NGUYN LIU 1.1. Ngun gc, tn gi v phn loi 1.1.1. Ngun gc: Bn a ca b ao l vng ng Nam nhng nay ph bin trng khp t Nam sang ng . Cy b ao cn sc nng mi mc nhng tri ca n th chu c nhit thp, c th qua ma ng m khng h mc d dy b ao ch mc nm mt, n ng th tn. B ao gc n , c trng rng ri khp cc vng nhit i v nhit i ca chu v min ng ca chu i Dng. nc ta, B ao cng c trng khp ni ly qu. 1.1.2. Tn gi: Tn thng gi: B ao. Tn khc: B xanh, B phn, B trng Tn ting Anh: waky pumkin. Tn khoa hc: Benincasa hispida (Thumb. Ex Murr.) Cogn. In DC. Tn ng ngha: Cucurbita hispida Thumb. ex Murr., Benincasa cerifera Sav. Thuc h Bu b Cucurbitaceae 1.1.3. Phn loi: B ao c hai loi l b ao phn v b ao : B ao phn: v qu c phn sp trng, qu to nhng nhiu rut. B ao : v qu dy cng v nhn thn, qu nh di nhng t rut.

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Hinh 1.1 B ao phn

1.2. c tnh thc vt hc Hnh 1.2 B ao

Cy dy leo, l mc cch. Phin l x 5 thng. Hoa mu vng. Hnh th qu ty thuc vo dng chng ging. Qu cc loi b nh, thun di. Khi gi v ngoi lc sm v cng, khng c phn trng. Cc loi b gi c qu to, dy ci, nhiu rut, qu gi c ph phn trng.

Hnh 1.3 L b ao

Hnh 1.4 Hoa b ao

Hnh 1.5 Tri b ao

1.3. Ngun gc sinh vt hc ca b ao: B xanh l cy a m thuc h bu b. Nhit thch hp t 24 28 0C. Mc d vy ht c th ny mm nhit 10 150C nhng tt nht l 250C giai on cy con (vn m), yu cu nhit thp hn khong 20 22 0C. Song cho qu pht trin bnh thng th li cn cng nh sng gim (va phi).B xanh c kh nng chu hn, chu kht nh h r kh pht trin. Thi k cy con n ra hoa cn yu cu m t 65 70%, thi k ra hoa kt qu cn m t 70 80 %. B xanh chu ng km, thi k pht dc ra hoa kt qu gp m ln do ma hoc ti khng hp l s gy vng l, rng hoa, rng qu, nh hng nghim trng n nng sut. B xanh c th lm vic vng t tht va, hi nng song tt nht trn t tht nh v ph sa, PH thch hp 6,5 8,0. 1.4. K thut gieo trng b ao: 1.4.1. Thi v gieo trng: C hai thi v gieo trng chnh: v thu (20/8-5/10) v v ng xun (1/12-15/2). Gieo ht: Lng ht cn gieo cho 1 ha khong 0,9 1,1 kg. Ht nn ngm t 4 6 gi ri em gieo. Gieo ht trn lung, ph ht bng lp t bt mng khng nn ph qu dy, ht khng i ln c. Khi cy mc c 7 8 ngy ( 2 l mm r) c th sang

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bu, kch thc bu 7 x 10 cm, n khi cy 2 3 l tht th em trng l tt nht ( Bu to 10 x 15cm c th cy n 4 5 l tht mi a ra trng).Trng bu tranh th thi gian v d chm sc cy con, t lm bu l t hn hp t bt + phn mc theo t l 1:1. 1.4.2. Lm t: Nu lm dn nn trng lung rng: 1,5 2,0m, khong cch trng 40 50 x 80 cm, cy cch cy 40 50 cm v hng cch hng 80cm. Nu khng lm dn (cy b trn mt lung) nn lung rng trn 3,5m, trng 2 hng gia lung, khong cch trng cy x cy = 40 50 cm, hng trng cch mp lung 15 20cm v vy hng x hng 2,5 3m. Ch nu trng b b cn c rm, r ph mt lung cho b b v qu. 1.4.3. Phn bn: Phn chung cn: 800 1000kg/so. m Ur: 10 12 kg/so. Ln Super: 15 18 kg/so. Kali: 10 12 kg/so. Bn lt: Ton b phn chung + Ln + 1/4 Kali +1/4 m. Thc ln 1: Khi cy bt u leo hoc ng ngn b ( Sau khi cy mc 30 40 ngy). Bn 1/4 Kali +1/4 m. Thc ln 2: Sau khi cy ra qu r, bn 1/3 Kali + 1/3 m. S phn cn li ha vi nc phn chung long dng ti khi thy cy sinh trng, pht trin km. 1.4.4. Cc bin php chm sc: Vun ln 1 kt hp vi bn thc khi cy 30 40 ngy, vun ln 2 kt hp vi bn thc khi cy ra hoa r (55 65 ngy sau trng). B xanh ra nhiu nhnh, mi cy cn 1 2 nhnh, mi nhnh cho u 1 2 qu, sau khi qu u 5 10 ngy c th nh qu sao cho mi gc cy ch 1 2 qu. Nu b b, khi cy di 60 70 cm, dng dy nilon gm dy khi gi lt v to iu kin ra d ph ( bt nh) tng kh nng ht cht dinh dng cho cy. 1.4.5. Phng tr su bnh: B xanh t phi phun thuc, khi cy c 2 10 l lc ny cy non, mm thng b su xanh, rp ph hoi. Dng Ofatox 0,1 % hoc dng Oncol 20EC phun cho cy. Cy b

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bnh sng mai dng Kasuzan, Zineb 80 WP, bnh phn trng dng Bavistyl nng 0,25 % phun cho cy. 1.5. Thu hoch b ao: B xanh rt d tiu th. Khi qu 50 60 ngy tui tr i c th thu lm b rau rt tt. Nu tiu th b gi hoc bo qun th khi qu xut hin phn trng, ct vo bui sng, c cung, xp cn thn ni thong mt c th bo qun qu 1 2 thng. 1.6. Bo qun b ao: B ao thuc loi rau n tri, thuc h dy leo. B ao c tc h hp trung bnh cng h hp vo khong 10-20 mgCO2/kg. V vy c ch v lm gim qu trnh h hng: Khng c cht ng v qu trnh h hp xy ra mnh. Trnh b dp c hc trong qu trnh thu hoch. Bo qun nhit 10-12oC, m khng kh 85-90%, c th bo qun 1-2 thng. 1.7. Thnh phn ha hc Trong thnh phn ca b ao tuyt i b phn l nc, hm lng dinh dng tng i thp v khng cha lipid. Ngoi ra b ao cn cha nhiu Vitamin v cht khong vi hm lng ng k. Sau y l bng thnh phn dinh dng ca b ao tnh trn 100g n c : Bng 1.1:Thnh phn ha hc trung bnh ca tri b ao Thnh phn ha hc Nng lng Nc Protein Carbonhydrates Cht x Canxi Phospho St Natri Kali Beta-caroten n v Kcal g g g g mg mg mg mg mg mcg Trong 100g tht tri 12 95,5 0,6 2,4 1,0 26 23 0,3 13 150 5,0

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Vitamin B1 Vitamin C 1.8. Gi tr ca b ao 1.8.1. Gi tr kinh t:

mcg mcg

0,01 16,0

B ao l cy trng khng i hi yu cu chm sc cao, u t thp nhng a li hiu qu kinh t cao, bnh qun cho nng sut t 3-4 tn qu/so Trung b. Thi gian sinh trng v khai thc t thng 4 n thng 8 hng nm. 1.8.2. Gi tr dinh dng: B ao l mt qu c cha nhiu dinh dng. B ao c hm lng nc rt cao 92-97%, cht ng bt kh cao 5-7%, vitamin C kh 5-22mg, protein thp 1%. Ngoi ra cn cha cc nguyn t khong nh: Ca, P, Fe, K, Na 1.8.3. Gi tr s dng: B ao thuc loi rau n tri, dng lm thc phm ti l chnh. B ao l loi rau xanh thng dng trong cc ba n ca nhn dn ta, cng nh da chut. C th dng b ao n luc hoc nu canh tm, canh cua, lm nm, xo tht g, tht ln. Chng u c tc dng ci thin sc khe ngy h cho mi la tui. Cc b phn ca cy b ao u c dng lm mn n v thuc: qu (gm cung, v, tht, ht), thn, l, hoa...Mt phn nh sn lng dng ch bin: tr b ao, mt b ao http://www.botanyvn.com/cnt.asp?param=news&newsid=383 1.8.4. Gi tr dc phm: B ao ngoi dng lm thc phm, cn c dng lm thuc. V qu dng cha i dt do bng quang nhit hoc i c ra cht nhy. Ht B ao cng dng rang n v dng cha ho, gii c v tr rn cn. L B ao gi nt trn vi gim rt p cha cc u ngn tay sng au. Nhng nghin cu mi nht cho thy, b ao c tc dng gim bo. Thnh phn ca b ao c ti 95% l nc, y l loi thc phm ngho nng lng (100g b ao ch cho 15 Kcal). V vy n nhiu, n thng xuyn b ao cng khng s tng cn. B ao c tc dng c ch qu trnh chuyn ha cht ng bt thnh m (cht bo). V nhng l do trn, nhng ngi bo ph, tha cn, ngi b x va ng mch, cao huyt p, bnh mch vnh, vim thn... thng xuyn n b ao rt tt. V tnh nng, cng dng tp hp t nhiu sch c cho thy: b ao v ngt, tnh hn, vo cc kinh ph, v, bng quang, tiu trng, khng c c tnh. C tc dng r rt kin t, ch kh, tiu thy. n b xanh lu di c th tiu tr nc tha trong c th, gim cn chng mp ph. B ao thch hp cho ngi b kh h, t yu, bo bu, ph thng cc b hoc ton thn. B xanh c ghi trong nhng phng thuc b truyn lm p ca9

m nhn, cung phi. Trong Trung dc hc bn tho ni r thm tnh kh thp, tr nhit (h st cao), Hi Thng Ln ng vit trong Y tng tm lnh: B ao gii kht, thanh tm h nhit phin, tiu ng thng trng v li thy

2. CC SN PHM T B AO

10

Hnh 2.1 Nc p b ao

Hnh 2.2 Mt b ao

11

Hnh 2.3 Tr b ao

Hnh 2.4 Tr b ao

3. QUY TRNH SN XUT CC SN PHM T B AO 3.1. Sn xut mt b ao 3.1.1. Tng quan v mt-

-

-

Mt l cc sn phm ch bin t qu ti hoc t qu bn ch phm (purre qu, nc qu, qu sunfit ha) nu vi ng n kh 65 75%. 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 ng kh ln. 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 sinh. Nh vy, trong mt qu hm lng ng trong mi trng bn ngoi cao s lm cho vi sinh vt c trng thi co nguyn sinh v ngng hot ng. V vy c nhiu loi mt nu xong khng cn phi 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).12

-

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. (K thut sn xut hp rau qu, Nguyn Vn Tip v cng s)

Phn loi mt (theo trng thi cu trc sn phm) Mt ng : - Ch bin t nc p hay purre tri cy. - To gel ng bng pectin hay aga. - C 3 dng : Jelly, Jam, Marmalade. Mt rim : - Ngoi 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%. 3.1.2. Nguyn liu sn xut mt : 3.1.2.1. Nguyn liu chnh: Nguyn liu chnh sn xut mt b ao l loi b gi, dy cm, khng b h hng, dp nt. 3.1.2.2. Nguyn liu ph: Nguyn liu ph gm c: ng saccharose v acid citric ng Saccharose ng ct trng c thnh phn ch yu l saccharose, c sn xut ch yu t ma v c ci ng. Saccharose l mt saccharide c cng thc C12H22O11 (M=342). Khi lng ring d =1,5879g/cm3. Saccharose c cu to t hai ng n l -glucose v -fructose. Cng thc cu to nh sau:

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Tnh cht ca ng : Saccharose rt ph bin trong gii thc vt c bit chim t l cao trong cy ma (14 20%), trong c ci ng (16 -20%). Saccharose d tan trong nc, khi kt tinh t dung dch nc s cho nhng tinh th ln, dng A c nhit nng chy 1850C, khi kt tinh t dung dch methanol thu c dng tinh th B c nhit nng chy l 170C. Saccharose kh tan trong ru methylic. Trong dung dch nc saccharose lm quay cc sang phi. Nng saccharose trong dung dch nc c th xc nh bng phn cc k hay ng k. Saccharose khng c tnh kh do cu to ca n khng c nhm OH hemiceltal t do. Do n khng cho phn ng trng gng, khng kh dung dch Fehling, cng khng cho phn ng vi phenythydrazin. Saccharose rt d thy phn trong mi trng acid hay ngay c vi acid yu nht nh H2O + CO2 to thnh D-glucose v D-fructose. Do D-fructose cho quay tri mnh, cn saccharose v D-glucose cho gc quay phi yu, nn sau khi thy phn dung dch tr nn quay tri ([a]= -200). Hin tng c gi l s nghch o ng. Saccharose cng c th b thy phn di tc dng ca men nh men saccharrase. Saccharose c th to thnh cc Saccharide kim loi kim th vi canxi. Saccharat canxi C12H22O11.CaO.2H2O tan trong nc. Nh c tnh ny ngi ta tinh th saccharose bng nc vi (Ca(OH)2). Sau khi lc b tp cht, ngi ta cho lun kh CO2 li qua dung dch Saccharose tan trong nc s lm CaCO3 kt ta lc, c c v kt ta thu c Saccharose tinh khit. Gi tr dinh dng, ng dng ca ng trong sn xut ch bin thc phm: o ng saccharose c gi tr cao i vi con ngi, n cung cp nng lng cn thit cho c th hot ng, mi gam ng cung cp khong 4,1cal. o ng c v ngt tan trong H2O, khi ha tan trong nc to ra p sut thm thu cng ln. C kh nng bo qun sn phm do c ch vi sinh vt. Kh nng c ch vi sinh vt ca ng cn do n to ra nng cht kh cao, gim lng nc v lng oxy ha tan trong dung dch. o ng saccharose cn c gi tr cao i vi con ngi n cung cp nng lng cn thit cho c th hot ng, mi gam ng cung cp khong 4,1cal. Bn cnh n cn c dng nhiu trong cng ngh thc phm, lm tng khu v cho cc sn phm thc phm nh hp, bnh ko, mt, cc loi nc gii kht o Khi x l ng nhit trn 1200C s xy ra phn ng caramel ng b nhit phn thnh cc sn phm khc nhau, chng c phn t ln, mu sm c gi l caramel. Phn ng ny c xc tc bng acid (pH = 2-4) hay bazo (pH = 9-10) v cng c th xc tc bng mui amonium. Ngi ta pht hin mt s cht c kh nng sinh ung th

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hay cc c t kch thch thn kinh trong thnh phn ca sn phm caramel (ch yu l 4 methylimidazole v cc hp cht c lin quan ). o ng cn c kh nng tng tc vi cc hp cht amino to nn phn ng melanoidin (cn gi l phn ng maillard). Sn phm ca phn ng ny l mt hn hp cc cht c kch thc phn t khc nhau, chng to ra mu t vng n nu, c kh nng chng oxy ha bo v c cht bo. Phn ng ny xy ra mnh mi trng kim (mnh nht pH = 9-10), khi hot ng ca nc bng 0,7 th phn ng xy ra mnh nht ( tng ng vi thc phm c 40-70% m). o Ngoi ra ng cn l mt cht d ha tan, khi ch bin cc sn phm qu sy bng phng php DIS (Dewatering and impregnation soaking procees: tch nc bng phng php thm thu ) ngi ta ngm nguyn liu trong dung dch nc ng, nc trong sn phm s i ra dung dch v ng s chuyn theo ng ngc li t dung dch vo sn phm v th aw ca sn phm gim xung v sn phm c hng v c trng. Tm li trong cng ngh thc phm, ngi ta thng c s dng ng to mu, to mi, to v, to ng v bo qun sn phm. Bng 3.1: Cc ch tiu cht lng ng ghi trn bao b STT 1 2 3 4 5 Tn ch tiu Saccharose ng kh (Rs) m (MOISI) Hm lng tro (ASH) mu (CV) Gi tr 99,8% cht th 0,03% 0,05% 0,03% 300 ICUMSA

Acid Citric Tnh cht: Acid citric l cht kt tinh bn trong sut , khng mu hoc dng bt kt tinh mu trng, khng hi v rt chua. V chua ca n hp vi khu v v du nht trong cc loi acid hu c nn c ng dng rng ri trong ch bin rau qu. Acid citric ch th hin hot tnh chng mt s nm mc v vi khuun, c kh nng c ch Samonella mnh hn Acid lactic v acid hydrochlocric. ng dng: trong ch phm nc p tri cy, tri cy ng hp, mt tri cy v thc ung nc p tri cy. Bng 3.2: Cc ch tiu ha hc ca acid citric STT 1 2 Tn ch tiu C6H8O7 Tro Hm lng 99% 0,1%

15

3 4

Kim loi nng Tp cht

50 ppm khng

B ao

Phn loi

Qu dp, h, khng t tiu chun

Ra

Ct, gt

V, rut

X l c nhit

3.1.3. Quy trnh sn xutCt ming

Thm thu

C c (rim)

Sy, o ng

Bao gi

Mt Kh B ao

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3.1.4. Thuyt minh quy trnh: Phn loi: Chn b ao c chn k thut. Chn nhng tri t yu cu v ch tiu cht lng nh chn, mc h hng, kch thc loi b nhng tri su thi, m bo cht lng sn phm khng b mt mu do Tamin b oxy ha. Ra: Mc ch: Loi b bi bm, t ct, vi sinh vt bm trn b mt nguyn liu, thuc tr su bm trn b mt tri do qu trnh trng trt thu hi vn chuyn gip cho qu trnh gt v, tch rut bn trong tin hnh thun li v m bo v sinh hn. Tin hnh: s dng nc sch nhit phng 250C ra. Ra bng tay. Yu cu: nc ra phi t tiu chun v nc sch. B ao sau khi ra phi sch s, khng cn t ct hay tp cht bn bm trn v, khng b cn dp do thao tc. Ct, gt: Mc ch: thu ly phn tht b ao.

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Tin hnh: dng dao gt b v, ch lm i ly phn rut bn trong ra. Yu cu: tht v thu c khng b dp, khng dnh rut, khng ln tp cht. Bin i: mt lp v bo v dch bo cha cht dinh dng thot ra trn b mt d b oxy ha vi sinh vt c iu kin pht trin. X l c nhit: Mc ch: y l cng on ngn c thc hin trc khi a b ao sang khu thm thu nhm gp phn tng gi tr cm quan cho sn phm. i vi sn phm b ao phng php ta thng x l l chn. Mc ch ca qu trnh chn l nh ch cc qu trnh sinh ha ca nguyn liu, dit enzyme, ui bt kh trong gian bo, tiu dit vi sinh vt bm trn b mt nguyn liu. Tin hnh: chn trong nc nng. Bin i: Lm gim cu trc cng ca nguyn liu, tri mm ra. Protein ca cht nguyn sinh b ng t. thm thu ca t bo tng. Nu chn lu qu sn phm s c mi nu. Nhit cao th vitamin b phn hy, hm lng cht kh b mt mt phn. Mt mu. Mt mi. Th tch v khi lng b thay i. nh ch qu trnh sinh ha, dit enzyme. Ct ming: Mc ch: ct nh nguyn liu, to hnh sn phm theo thch. Tin hnh: th cng hoc bng thit b. Yu cu: dao bn, vt ct ngt, khng dp. Thm thu: Mc ch: tng nng ng cho sn phm, ci thin thnh phn dinh dng, to mu c trng cho mt. Acid citric c tc dng km hm s bin mu khng do enzyme.

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Tin hnh: khi ngm b ao trong dung dch ng c nng cao bng quy lut thm thu nc trong sn phm s i ra, dung dch v cht ha tan s chuyn dch theo chiu ngc li t dung dch vo trong sn phm. Bin i: Di tc dng ca nhit v tnh thm thu ca ng nc t do s bc hi ht sn phm s b teo bp khng cn gi nguyn hnh dng ban u, ngt ca b ao cng nh kh tng ln. Cc cu t hng, cc acid v cc cht hu c d bay hi s bc theo hi nc lm gim hng v sn phm. Hm lng vitamin trong sn phm c bit l vitamin C b tht thot nhiu do tc dng ca nhit cao trong thi gian di. C c: Mc ch: to cu trc mong mun cho sn phm. Ngoi ra qu trnh cn c tc dng v hot ha cc enzyme c bit l enzyme pectinase, ng thi thanh trng trnh s h hng v tng thi gian bo qun. Yu cu: trong sut qu trnh cn o trn u n v tht nh nhng ng thi khng ch nhit nhit hp l trnh hin tng kht y ni v trnh hin tng tc ng nhit khng u nh hng ti s ng u ca sn phm. Sy, o ng: Mc ch: lm gim s bc hi nc, hot nc ca sn phm t lm tng hng s dng ca sn phm. Yu cu: sn phm sau khi sy, o ng c kh, ngt, gin theo yu cu sn phm, c mt lp ng kh bao bc bn ngoi. Nhit phi hp l trnh hin tng kht chy sn phm, gim gi tr cm quan. Bao gi: Mc ch: to hnh sn phm thun li cho qu trnh vn chuyn v tiu th trn th trng.Mt khc vic bao gi tt cn gp phn quan trng trong vic tng gi tr cm quan cho sn phm v bo qun sn phm chng s nhim bn t mi trng. Yu cu: l, hp hoc bao b u phi thanh trng bo m v sinh, qu trnh phn phi sn phm vo l, hp, bao b phi v sinh, trnh ri vi gy tht thot sn phm. Bin php thc hin: Mt c th ng trong cc loi bao b khc nhau: h nha, l thy tinh, bao MAP vi nhiu kch c khc nhau Bao b cn phi ra sch, thanh trng nc si 1000C trong 30 pht.19

Do sn phm c hm lng ng cao v m thp khng phi l mi trng tt vi sinh vt pht trin nn c th khng thanh trng b sung.

3.2. Sn xut nc p b ao 3.2.1. Nguyn liu sn xut nc p b ao : 3.2.2.1. Nguyn liu chnh: Nguyn liu chnh sn xut nc p b ao l qu b ao (b xanh) c chn k thut t yu cu nn tri tch t v mt dinh dng, tri vn cn cng. 3.2.2.2. Nguyn liu ph v ph gia khc : ng: to v ngt l loi ng tinh luyn. Acid citric + Dng iu v, to v chua va phi theo yu cu ca sn phm. + iu chnh acid ca sn phm. Vitamin C + Lm tng gi tr dinh dng cho sn phm.

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B ao

La chn, phn loi + Chng oxy ho, n nh mu cho sn phm.

Tri h khng ht

Pectin: to gel, chng tch pha, c tc dng lm bn cu trc ng nht cho sn phm. Ra CMC + To gel, chng tch pha.V, ht + Phi hp vi pectin lm bn cu trc ng nht cho sn phm trnh hin tng nc ni ln trn b mt. Chn Ct, gt

Xay nghin p B p Nc sch Lc

B lc

ng, ph gia

Phi trn

ng ho

3.2.3. Quy trnh sn xut nc p b aoHp, np Rt hp

Bi kh, ghp m

Thanh trng

Lm ngui

Nc b ao

Bi kh, ghp m

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Thanh trng

Lm ngui

3.2.4. Thuyt minh quy trnh: La chn, phn loi: Mc ch: Loi tr tri khng ng quy cch v chin, mc h hng, kch thc, hnh dng. Bin i: -Nguyn liu ng nht v kch thc, mu sc, chn. -Loi b c tri h hng, khng t cht lng ( Tr b ao ha tan. Sau khi phi ch em c c => sy => nghin nh => bao gi (c th b sung ng dng ht vo sn phm tng hm lng cht kh).

4. CC TIU CHUN CHT LNG 4.1. Tri ti

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Qu thng, khng su bnh, khng b d tt, khng h hng, lp v bng. Hm lng nitrat cho php l: 400mg/kg.

Bng 4.1: Hm lng ti a cho php ca mt s kim loi nng v c t trong sn phm rau ti (Theo FAO/WHO Nm 1993) STT 1 2 3 4 5 6 7 8 9 10 Asen (As) Ch (Pb) Thy ngn (Hg) ng (Cu) Cadimi (Cd) Km (Zn) Bo (B) Thic (Sn) Patulin (c t) Aflatoxin (c t) Tn nguyn t Mc gii hn (mg//kg,l) 0.2 0.5-1.0 0.005 5.0 0.02 10.0 1.8 200.0 0.05 0.005

Bng 4.2 Hm lng mt s vi sinh vt ti a cho php trong rau qu ti STT 1 2 3 Salmonella E.Coli Coliform Vi sinh vt Mc cho php (khun lc) 0.25/g 100/g 1000/g

http://sonongnghiep.hochiminhcity.gov.vn *Bn cnh cc thit b vt t cng phi m bo v sinh:

Thit b, thng cha v vt liu tip xc trc tip vi sn phm phi c lm t nhng cht khng c hi. Thng ng cht thi, ho cht v cc cht nguy him khc phi c nh du r rng v khng dng chung ng sn phm.32

Bo dng thng xuyn thit b, dng c hn ch nguy c nhim. Thng cha sn phm thu hach v vt liu ng gi phi t ring bit vi kho cha ha cht, phn bn v cht ph gia ng thi thc hin cc bin php hn ch nguy c nhim t cc loi ng vt gy hi. Thng ng rau qu cn m bo chc chn, sch s trc khi s dng. Sau khi ng gi, cc thng cha khng c t trc tip xung t.

4.2. Mt b

B c chn lm nguyn liu phi l b ti, trng lng t 5kg tr ln mi c dy cm, gin. Cc loi b khc va nh, li b nn khng th lm mt c. Mt b phi c trng trong, p mt, ng c s dng l loi ng trng, th sch. Khng s dng ha cht lm trong. Bo qun trong cc l thy tinh.

*Ch tiu cm quan

Mi v: mi thm v ngt khng c mi kh kht hay mi v l khc. Mu sc: mu trng trong, ng u. Trng thi: mt c dng ng c, kh, khi mt c th ln chm trn mt phng. Mt phi c dn ngt. Khng b mc, khng cha vi sinh vt, khng c mu sc l. Lp ng bao bn ngoi phi l ng kt tinh v mn. Sn phm c kh l 65-70%, hm lng ng 60-65%.

4.3. Nc p b ao v tr b ao Sn phm phi c sn xut t ngun b ao ti, tri ln, v cng cho ra nc ngt thanh. Sau , dch chit c sao v c c theo phng php c truyn thu c ct b ao dng st mu vng nu sng, nc rt trong, v ngt thanh, mi thm. Thnh phn c bn v ch tiu cht lng:

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Cht rn ha tan: hm lng cht rn ha tan (khng tnh ng b sung ) khng c nh hn gi tr tng ng hm lng cht rn ha tan ca qu chn khi cha iu chnh acid. ng:c th b sung nhiu lo ng rn vi hm lng khng qu 100g/kg. Hm lng etanol khng qu 5g/kg. Phi gi c hm lng cht dinh dng v vitamin trong qu. Khng cha cc cht c hi, cc ph gia b cm s dng.

Tnh cht cm quan

Sn phm c mu sc hng v ca b ao. Mu sc p. Khng c cn, v hp cn mi, khng b try xc v khng b h. Bng 4.3 Hm lng cc cht trong sn phm Thnh phn Hm lng 0 3 3.5 22 0 0 n v g mg mg g mg g

Protein Vitamin C St(iron) ng(sugar) Cholesterol Cht bo bo ha

Khi ng hp sn phm cng cn tun th theo cc quy nh v ng gi bao b. Trong qu trnh ng gi, chai v np u p dng cch kh trng bng dung dch PAA 2000 ppm vi thi gian 60 giy, trng ra, sy kh theo tiu chun hin i. Dy chuyn sn xut ng dng cng ngh chit v trng trong ngnh sn xut nc gii kht, hn ch s pht trin ca cc vi sinh vt khi p tri cy ti ly nc ct, gip nc p bo qun trong chai trong mt thi gian di m khng nh hng n cht lng. Bn ngoi v hp phi ghi r tn cng ty v cc thnh phn c trong sn phm v hm lng cht dinh dng c trong sn phm.

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TI LIU THAM KHO1 L Vn Lai, 1996, Tch mt lm kh, ng gi, bo qun, vn chuyn ng. Nh xut bn Nng nghip. 2 Nguyn Ng, L Bch Tuyt, Trn Mnh Hng, 1984, Cng ngh sn xut ng ma. Nh xut bn khoa hc k thut H Ni.

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3 Tn N Minh Nguyt, L Vn Vit Mn, Trn Th Thu Tr, 2008, Cng ngh ch bin rau qu phn 1, Cng ngh sau thu hoch, NXB HQG.

4 http://trangnong.com.vn 5 http://vi.wikipedia.org/wiki/bidao 6 http://sonongnghiep.hochiminhcity.gov.vn

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