1 giao trinh so che rau qua 0833

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B NNG NGHIP VA PHAT TRIN NNG THN

GIAO TRINH M UN

S CH RAU QU

M S: M 01

NGH: CH BIN RAU QU

Trinh : S cp ngh

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TUYN B BN QUYN

Ti liu ny thuc loi sch gio trnh nn cc ngun thng tin c th c php dng nguyn bn hoc trch dng cho cc mc ch v o to v tham kho.

Mi mc ch khc mang tnh lch lc hoc s dng vi mc ch kinh doanh thiu lnh mnh s b nghim cm.

M ti liu: M01

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LI GII THIU

Vit Nam l mt nc thuc vng nhit i, thch hp cho nhiu loi cy trng. Mt khc, nc ta l mt nc nng nghip, hn 70% dn s sng ch yu nng thn. Sn phm t cy trng, c bit l rau qu chim phn ln trong cc sn phm nng nghip. Rau qu khng nhng l thc phm tiu dng hng ngy m cn l nguyn liu dng ch bin cho cc sn phm thc phm khc. c im ca nguyn liu rau qu l d b h hng v r theo ma v. Chnh v vy, vic ch bin rau qu s gip bo ton gi tr dinh dng, gim tn tht v cn to ra c nhng sn phm rt phong ph, a dng, p ng nhu cu ca ngi tiu dng v xut khu. Ngh ch bin rau qu rt ph hp vi iu kin ca ngi nng dn vi ngun nguyn liu ti ch, khng i hi thit b phc tp, quy trnh cng ngh kh n gin v cn t vn u t, mt khc cn gii quyt c vn tha nguyn liu khi v r v vic lm cng nh thu nhp cho ngi nng dn. V vy, ngh ch bin rau qu rt ph hp vi o to ngh cho lao ng nng thn.

bin son b gio trnh ngh Ch bin rau qu, ban ch nhim tin hnh kho st vic ch bin rau qu ti cc vng min, cc c s ch bin vi cc quy m khc nhau trong c nc. ng thi vi vic kho st, ban ch nhim mi cc chuyn gia c nhiu kinh nghim v ch bin rau qu tham gia phn tch ngh xy dng nhim v v cng vic ca ngh, t hnh thnh chng trnh ngh Ch bin rau qu. Sau khi tip thu kin ca chuyn gia v hi ng nghim thu, ban ch nhim chnh sa chng trnh. Da vo chng trnh hon thin, ban ch nhim trin khai bin son b gio trnh ngh Ch bin rau qu.

Chng trnh o to v b gio trnh ngh Ch bin rau qu c bin son theo hng tch hp nhng kin thc, k nng cn c ca ngh. B gio trnh ny trnh by cch ch bin rau qu ph hp thc t sn xut ti cc vng sn xut rau qu tiu biu trong c nc, bo m nng sut, an ton thc phm. V vy, b gio trnh ny l ti liu hc tp chnh dng trong o to ngh Ch bin rau qu trnh s cp ngh cho lao ng nng thn. Ngoi ra, gio trnh ny cn l ti liu tham kho cho nhng ngi , ang v mun lm ngh ch bin rau qu.

S ch rau qu ti l m un th nht trong chng trnh ngh Ch bin rau qu. Ni dung ca gio trnh p ng mc tiu, ni dung v kt cu ca chng trnh m un S ch rau qu ti trong chng trnh ngh. Gio trnh c th c ging dy c lp hoc kt hp vi gio trnh ca cc m un khc trong chng trnh dy ngh Ch bin rau qu.

Gio trnh S ch rau qu ti cung cp cho ngi hc nhng kin thc v k nng v chun b nh s ch, chun b thit b, dng c dng x l rau qu, tip nhn nguyn liu v thc hin cc hot ng x l trong nh s ch, vn chuyn sn phm rau qu sau khi x l n ni tiu th. Thi lng m un 68 gi, trong c 12 gi l thuyt, 48 gi thc hnh v 8 gi kim tra.

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Kt cu gio trnh gm 08 bi nh sau:

Bi 1. Cc qu trnh bin i trong rau qu sau thu hoch

Bi 2. Chun b nh s ch rau qu sau thu hoch

Bi 3. Chun b dng c, thit b x l rau qu sau thu hoch

Bi 4. Tip nhn rau qu sau thu hoch

Bi 5. X l rau qu sau thu hoch

Bi 6. ng gi v ghi nhn rau qu sau s ch

Bi 7. Vn chuyn rau qu sau s ch

Bi 8. An ton thc phm trong s ch rau qu

Trong qu trnh bin son gio trnh, chng ti nhn c s ch o, hng dn ca V T chc Cn b B Nng nghip v PTNT; Tng cc dy ngh B Lao ng - Thng binh v X hi; s ng gp kin v gip ca cc C s ch bin rau qu, Hi ng nghim thu, Ban Gim Hiu v cc thy c gio trng Cao ng Lng thc Thc phm. Xin trn trng cm n cc n v v c nhn gip , to iu kin thun li chng ti hon thin b gio trnh ny.

Trong qu trnh bin son chc chn khng trnh khi nhng sai st, chng ti mong nhn c nhiu kin ng gp ca cc ng nghip v bn c gio trnh hon thin hn.

Xin chn thnh cm n!

Tham gia bin son

1. Trn Thc (ch bin)

2. Nguyn Th Thy Linh

3. Trng Hng Linh

4. Nguyn Th Hng Ngn

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MC LC

TUYN B BN QUYN .................................................................................. 2 LI GII THIU .................................................................................................. 3 MC LC ............................................................................................................. 5 M UN: S CH RAU QU ........................................................................... 8

1. Cc loi rau qu ti ...................................................................................... 9 1.1. Cc loi r v c .................................................................................... 10 1.2. Cc loi hoa n c ............................................................................. 12 1.3. Cc loi rau (l, thn, chi) ................................................................... 12 1.4. Qu ........................................................................................................ 14

2. Cc qu trnh din ra trong rau qu ti sau thu hoch ............................... 16 2.1. Qu trnh h hp .................................................................................... 17 2.2. S thot hi nc .................................................................................. 18 2.3. S chn ca qu ..................................................................................... 19

3. S tn tht sau thu hoch i vi rau qu ti ............................................ 20 3.1. Tn tht do thng tn c hc .............................................................. 20 3.2. Tn tht do nhit.................................................................................... 22 3.3. Tn tht do bnh v vi sinh vt ............................................................. 24

BI 2. CHUN B NH S CH RAU QU SAU THU HOCH ................ 27 1. Chn a im t nh s ch rau qu ......................................................... 27 2. Kt cu, lp t nh s ch .......................................................................... 28 3. B tr v tr cc khu vc trong nh s ch .................................................... 29 4. Kim tra h thng chiu sng nh s ch .................................................... 32 5. Kim tra h thng cp, thot nc ca nh s ch ...................................... 32 6. Kim tra h thng thng gi ........................................................................ 33 7. Bo dng, v sinh v kh trng nh s ch ............................................... 33

BI 3. CHUN B THIT B, DNG C X L RAU QU SAU THU HOCH ............................................................................................................... 39

1. Yu cu chung v thit b, dng c x l rau qu ....................................... 39 2. La chn, s dng thit b, dng c dng x l rau qu ........................ 39

2.1. Dng c cha ng ............................................................................... 39 2.2. Thit b bc d, di chuyn sn phm .................................................... 41 2.3. Thit b lm sch ................................................................................... 42 2.4. Thit b phn loi ................................................................................... 43

3. Bo dng thit b, dng c x l rau qu .................................................. 46 4. V sinh, kh trng i vi cc thit b, dng c .......................................... 46

BI 4. TIP NHN RAU QU SAU THU HOCH ....................................... 49 1. V sinh v k lt ni tip nhn rau qu ....................................................... 49 2. Tip nhn nguyn liu ................................................................................. 50

2.1. Chun b phng tin chuyn nguyn liu vo nh s ch .............. 50 2.2. Vn chuyn nguyn liu vo ni tip nhn ........................................... 52

BI 5. X L RAU QU SAU THU HOCH ................................................ 56 1. Phn loi s b ............................................................................................. 56

1.1. Li ch ca phn loi s b ................................................................... 56

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1.2. Yu cu ca phn loi s b .................................................................. 56 1.3. Tin hnh phn loi .............................................................................. 57

2. Lm lnh s b ............................................................................................. 58 3. Lm sch ...................................................................................................... 58

3.1. Ra ......................................................................................................... 59 3.2. Lau bng vi mm ................................................................................. 60

4. Phn loi theo kch thc ............................................................................. 60 5. Phng tr nm bnh ..................................................................................... 62

BI 6. NG GI V GHI NHN RAU QU SAU S CH ...................... 66 1. Cc loi bao b.............................................................................................. 66

1.1. Bao b bng tre ....................................................................................... 66 1.2. Bao b bng g ....................................................................................... 67 1.3. Bao b bng cctng .............................................................................. 68 1.4. Bao b bng nha ................................................................................... 69 1.5. Bao b bng si thin nhin hay si tng hp ....................................... 69 1.6. Bao b bng mng cht do ................................................................... 70 1.7. Bao b bng xp ..................................................................................... 71

2. La chn bao b bao gi ............................................................................... 71 3. ng gi sn phm ...................................................................................... 72

3.1. Yu cu v ng gi sn phm .............................................................. 72 3.2. Lt vt m vo trong bao b ................................................................. 73 3.3. Xp sn phm vo bao b....................................................................... 75 3.4. V d v ng gi chui ........................................................................ 76

4. Ghi nhn ....................................................................................................... 78

BI 7. VN CHUYN V X L RAU QU SAU S CH ....................... 81 1. Cht xp sn phm ln phng tin vn chuyn ......................................... 81 2. Ging cht v che y hng ha khi vn chuyn ......................................... 83

2.1. Ging cht hng ha khi vn chuyn ..................................................... 83 2.2. Che y hng ha khi vn chuyn ......................................................... 84

3. Vn chuyn rau qu hng ha n ni tiu th v bc d hng ha ........... 85 3.1. Vn chuyn ............................................................................................ 85 3.2. Bc d .................................................................................................... 85

4. Cht xp v tn tr sn phm ni tiu th ................................................... 86 5. X l ti ni tiu th .................................................................................... 87

5.1. Ra, phn loi, ng gi li ................................................................... 87 5.2. Lm chn ................................................................................................ 88

5.3. Trng by sn phm .............................................................................. 89 BI 8. AN TON THC PHM TRONG S CH RAU QU ..................... 95

1. Mi nguy an ton thc phm trong rau qu ti ......................................... 95 1.1. Mi nguy ha hc .................................................................................. 95 1.2. Mi nguy sinh hc ................................................................................. 98 1.3. Mi nguy vt l ..................................................................................... 99

2. Ngn chn s nhim cc mi nguy cho rau qu ti ................................. 100 2.1. V sinh ng rung ............................................................................. 100

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2.2. Hn ch s ly nhim trong qu trnh thu hi ..................................... 102 2.3. Hn ch s ly nhim trong qu trnh x l sau thu hoch ................. 102

HNG DN GING DY M UN .......................................................... 105 V. TI LIU THAM KHO ............................................................................ 113

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M UN: S CH RAU QU

M m un: M01

Gii thiu m un

M un 01: S ch rau qu c thi gian hc tp l 68 gi, trong c 12 gi l thuyt, 48 gi thc hnh v 8 gi kim tra. M un S ch rau qu trang b cho ngi hc cc kin thc v k nng ngh thc hin cc cng vic v s ch rau qu: cch chun b nh xng, dng c v thit b x l rau qu sau thu hoch; quy trnh v cc bc tin hnh thc hin cc bin php x l rau qu sau thu hoch nh: lm sch, lm lnh s b, phn loi, loi tr nm bnh, ng gi, ghi nhn v vn chuyn rau qu sau khi s ch n ni tiu th; cc bin php m bo an ton thc phm trong qu trnh s ch rau qu. ng thi m un cng trnh by h thng cc bi tp, bi thc hnh cho tng bi dy v bi thc hnh khi kt thc m un.

Hc xong m un ny, hc vin c c nhng kin thc c bn v quy trnh v cc bc cng vic s ch rau qu; yu cu ca nh xng sn xut; vai tr tng thit b, dng c, nguyn liu, bao b s dng trong qu trnh ch bin rau qu tiu th ti. ng thi c k nng v sinh nh xng, thit b, dng c s ch; la chn nguyn liu rau qu t yu cu sn xut; s dng cc thit b, dng c; thao tc thc hin cc bc cng vic; pht hin v x l kp thi nhng bt thng xy ra khi thc hin qu trnh ch bin rau qu tiu th ti.

hon thnh ni dung hc tp ca gio trnh, hc vin cn tham gia y cc bui hc l thuyt v thc hnh theo thi lng thit k trong chng trnh.

Vic nh gi kt qu hc tp l s kt hp gia l thuyt v thc hnh, nhng trng tm l thc hnh, thng qua h thng cc bi thc hnh k nng trong tng bi dy v bi thc hnh khi kt thc m un. Hc vin phi hon thnh tt c cc bi kim tra nh k trong qu trnh hc tp v bi kim tra kt thc m un.

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BI 1. CAC QUA TRINH DIN RA TRONG RAU QU TI

SAU KHI THU HOCH

M bi: M01-01

A. Ni dung

1. Cc loi rau qu ti

Rau qu ti c tiu th trn th trng bao gm nhiu b phn ca cy trng. C th phn chia cc sn phm rau qu ti thnh tng nhm da theo cc phn ca cy trng v c im chung khi x l sau thu hoch, bo qun chng. Mt s loi rau c qu c trnh by trong bng sau:

Bng 1.1. Mt s loi rau qu ti

C Rau thm Qu Rau

C c rt Hnh l u H Lan ht Bp ci

C ci H Ng bao t Ci ngt

C u Kinh gii Ng ngt Ci tho

C hnh ty L lt Qu bu Ci xanh

C hnh ty tm Ngi cu Qu b ao Cn

C khoai lang Rau bc h Qu b Dc mng

C khoai mn Rau dp c Qu b ngi Gi

C khoai s Rau hng Qu c pho Sp l

C khoai ty Rau hng thm Qu c tm Mng

C dn Rau mi Qu chui xanh Mng ti

C sen Rau mi tu Qu u bp Mp

C su ho Rau ng Qu u xanh Rau b

C gng Rau rm Qu da Rau ay

Mc tiu:

- Trnh by c nh hng ca cc qu trnh din ra trong rau qu sau thu hoch n cht lng sn phm;

- Nu c s tn tht sau thu hoch i vi rau qu ti.

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C Rau thm Qu Rau

C ring Rau th l Qu da chut Rau dn

C ti Rau x lch Qu mp Rau lang

C s Ta t Qu mp ng Rau mung

Nm Qu t ngt

1.1. Cc loi r v c

R v c l phn ca cy nm di t, thch nghi vi vic d tr nguyn liu thc n ca cy, gip cy trng sng c trong cc iu kin kh hu khng thun li v d phng thc n d tr cy trng c th pht trin nhanh khi gp iu kin thun li.

Nhm ny bao gm: khoai ty, khoai s, khoai lang, c rt, c ci, hnh Phn ln cc loi c nhm ny c thnh phn chnh l tinh bt, tuy nhin cng c trng hp trong nhiu loi c pht trin t r ci, cha nhiu ng nh c rt, c ci...

Mt s loi cy trng cho sn phm l r, c nh sau:

- Khoai s: thn c pht trin t thn di t nn cht (hnh 1.1.1).

Hnh 1.1.1. C khoai s

- Khoai ty: c khoai ty c to thnh t phn thn di t phnh ra (hnh 1.1.2).

Hnh 1.1.2. C khoai ty

- Khoai lang: r s phnh ra thnh c (hnh 1.1.3).

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Hnh 1.1.3. C khoai lang

- C rt, c ci: r ci phnh ra thnh c (hnh 1.1.4).

Hnh 1.1.4. C c rt

Hnh 1.1.5. C ci Hnh 1.1.6. Hnh ty

Hnh 1.1.7. C su ho Hnh 1.1.8. C u

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1.2. Cc loi hoa n c

Mt s cc loi rau c cm u hoa tp trung dy c, c th n c nh ci hoa, sp l...

- Sp l: sn phm sp l l do cc u hoa cha trng thnh tp trung thnh khi u cy (hnh 1.1.9).

Hnh 1.1.9. Sp l

- Qu da: l loi qu ph bin nc ta, c to thnh bi s kt hp mt khi cc bng hoa khng th phn, khng pht trin kt hp vi nhau thnh khi xung quanh thn cy chnh to thnh cm xung quanh thn chnh ca cy, cn thn chnh ny s tr thnh li ca qu da (hnh 1.1.10).

Hnh 1.1.10. Qu da

1.3. Cc loi rau (l, thn, chi)

Cc loi rau thng gp ny l nhng ngun quan trng cung cp cht khong, vitamin v cht x trong khu phn n. C nhiu loi rau nh: bp ci, x lch, rau cn

- Bp ci: l ton b phn thn cy trn mt t (hnh 1.1.11).

Hnh 1.1.11. Bp ci

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Hnh 1.1.12. X lch Hnh 1.1.13. Ci tho

- C hnh l do cc gc cy phnh to ra to thnh (hnh 1.1.14).

Hnh 1.1.14. C hnh

Hnh 1.1.15. C gng Hnh 1.1.16. C ngh

Hnh 1.1.17. C ti Hnh 1.1.18. C s

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1.4. Qu

Qu gm c ht v tht qu m phn n c l tht qu. Cc loi qu c s dng ti thng c hm lng ng cao khi chn v thng c n vo giai on ny. Mt s loi qu nh c chua, t c dng nh rau. Mt s loi qu c s dng nh rau khi cc ht cn xanh non trc khi cc ht tr nn cng nh cc loi u a, u xanh.

- Qu nc c mt ht: xoi, b(hnh 1.1.19).

Hnh 1.1.19. Qu xoi

- Qu nc c nhiu ht: gm nhiu loi nh c chua, da chut, c tm v cc loi qu c mi (cam, qut, chanh). Qu c mi l loi qu c nhiu ht, vi cc ht nm cc mi ring l (hnh 1.1.20, 1.1.21, 1.1.22, 1.1.23, 1.1.24).

Hnh 1.1.20. Qu chanh (ct ngang)

Hnh 1.1.21. C chua Hnh 1.1.22. C tm

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Hnh 1.1.23. Da chut Hnh 1.1.24. Cam

- Cc loi u nh u H Lan (hnh 1.1.25), u ng (hnh 1.1.26), u xanh, u en (hnh 1.1.27), khi gi th ch n cc ht.

Hnh 1.1.25. Qu u H Lan

Hnh 1.1.26. u ng Hnh 1.1.27. Mt s loi u khc

- Cc loi u nh: u a, u bp (hnh 1.1.28) v u c ve khi cn non, c ht pht trin mt phn u n c ton b qu (k c v v ht).

Hnh 1.1.28. Qu u bp (ct dc)

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Hnh 1.1.29. u a Hnh 1.1.30. u c ve

2. Cc qu trinh din ra trong rau qu ti sau thu hoch

Sau thu hoch, tt c cc loi hoa qu v rau u cn ti, qu trnh sinh hc ca chng vn tip tc din ra, c th theo hng c li hoc c hi n cht lng ca rau qu ti. Do , cn phi cn kim sot cc qu trnh ny hn ch nhng bt li, gi cho cht lng cua rau qu lun n nh.

Cc qu trnh din ra trong rau qu ti sau thu hoch thng l h hp, mt hi nc v ha gi.

Cc qu trnh quang hp, h hp trong rau qu c minh ha bng hnh v sau (hnh 1.1.31).

Hnh 1.1.31. Qu trnh quang hp v h hp ca cy trng

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Qu trnh quang hp l qu trnh cy xanh ang pht trin s dng nh sng mt tri chiu ln l cho phn ng kt hp gia kh cacbonic (CO2) trong khng kh vi nc (H2O) c ht ln t t thng qua h r ca cy xanh to thnh ng (C6H12O6).

Cy trng tch ly cht ng hoc kt hp cc n v cht ng ring l to thnh mch di gi l tinh bt. Cc cht ng v tinh bt c gi chung l hydrat cacbon, c tch ly trong cc b phn khc nhau ca cy trng.

Hydrat cacbon l ngun cung cp nng lng cho s pht trin v sinh sn tip theo ca cy trng. Nh qu trnh h hp, hydrat cacbon b phn hy to ra nng lng, gii phng nc v kh cacbonic.

Rau qu ti sau khi thu hoch vn duy tr s sng nn cn phi dng nng lng. V vy, qu trnh h hp ca rau qu sau thu hoch vn tip din c nng lng cho s sng. Cho nn, ngun hydrat cacbon d tr trong bn thn rau qu ti b tiu hao, dn n rau qu sau thu hoch cng b suy gim cht lng v c th b h hng, khng s dng c.

2.1. Qu trnh h hp

2.1.1. H hp

H hp l qu trnh m qua cy trng hp th kh oxy, phn hy ng trong cy trng sinh nng lng cung cp cho s sinh trng v sinh sn ca cy trng. Sn phm ca qu trnh h hp thi ra mi trng gm kh cacbonic, hi nc v nng lng di dng nhit nng.

Nh vy, qu trnh h hp cng nhiu th cng c nhiu ng b tiu tn, nhit nng v kh cacbonic ta ra mi trng cng nhiu. nh hng ca h hp n s h hng ca sn phm ti sau thu hoch c minh ha hnh 1.1.32.

Hnh 1.1.32. nh hng ca h hp n rau qu sau thu hoch

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Qu trnh h hp din ra tt c cc thc vt, c khi trc thu hoch ln sau khi thu hoch. Khi thu hoch v sau thu hoch, cc qu trnh h hp vn tip tc sn phm rau qu ti. V sn phm sau khi thu hoch khng cn c quang hp tch ly ng v tinh bt nn ngun ng hoc tinh bt tch ly trong bn thn rau qu ti b tiu hao dn do qu trnh h hp. Sau khi ngun d tr ny b cn kit th sn phm s tri qua qu trnh ha gi sau b h hng v phn hy.

2.1.2. S lin h gia h hp vi mi trng xung quanh

- Trong iu kin c cung cp khng kh y (thng thong kh) th rau qu h hp bnh thng, khi ng v tinh bt c chuyn ha thnh kh cacbonic v hi nc.

- Khi h hp trong iu kin khng cung cp khng kh v lng kh oxy trong khng kh cn 2% hoc thp hn th s xy ra qu trnh ln men thay cho qu trnh h hp. Khi ln men th ng b phn hy thnh kh cacbonic v ru. Ru gy ra mi v kh chu trong sn phm v thc y s ha gi sm ca rau qu.

- S thng gi cho sn phm khng tt do cung cp khng kh b hn ch cng dn n s tch t kh cacbonic xung quanh sn phm. Khi nng cacbonic tng ln n 1 5% trong khng kh th s lm hng sn phm v gy ra mi v kh chu, qu khng chn c v cc h hi khc.

Nh vy, vic thng gi cho sn phm rau qu sau khi thu hoch l rt cn thit bo qun rau qu trnh b h hng.

2.2. S thot hi nc

Phn ln khi thu hoch rau qu ti cha t 65 95% khi lng l nc. Rau qu ti tip tc b mt nc sau thu hoch nhng khng c b p li, lng nc mt i ging nh lng nc ly t t cung cp cho cy trc khi thu hoch nn phi dng lng nc cn li c d tr trong sn phm khi thu hoch. Chnh s mt nc ca rau qu ti sau thu hoch l nguyn nhn gy nn hin tng ho v gim khi lng sn phm rau qu ti. Cc triu chng mt nc gm sn phm b teo, nhn, nhn v mt ti gin v kh b mt.

Hnh 1.1.33. Qu cam ho Hnh 1.1.34. Rau ho

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Khi rau qu ti mt 5 10% khi lng nc th bt u ho v nhanh chng tr nn mt gi tr. ko di tui th ca sn phm, phi tm cch duy tr lng nc trong sn phm rau qu v hn ch lng nc mt i cng t cng tt.

- Rau qu ti trong khng kh kh th b mt nc nhiu. Do vy lm gim i s mt nc ca rau qu ti th cn phi bo qun n trong khng kh m.

- Khng kh chuyn ng qua rau qu ti cng nhanh th nc trong rau qu b mt cng nhiu. Tuy nhin chuyn ng ca khng kh qua rau qu l cn thit lm thot bt nhit nng c sinh ra t qu trnh h hp. V vy cn khng ch tc chuyn ng ca khng kh cng thp cng tt.

Cc loi rau l xanh mt nc nhanh hn cc loi c. V vy i vi cc loi rau xanh cn ch khng ch khng kh xung quanh gim s mt nc.

2.3. S chn ca qu

Cc loi qu nc phi tri qua mt giai on pht trin t nhin gi l giai on chn. Qu trnh ny xy ra khi qu ngng pht trin. C hai loi qu nu da vo giai on chn:

- Qu chn sinh l: l nhng qu ch chn trn cy nh: da chut, nho, chanh, da Cht lng ca chng gim nu nh thu hoch trc khi chn hon ton trn cy.

- Qu chn p: l nhng qu c th thu hoch trc khi giai on chn bt u nh: chui, u , c chua... Nhng loi qu ny c th chn t nhin hoc chn dm. Chn dm l phng php c dng khng ch tc chn ca qu trong khi sn xut, tiu th sn phm.

Nu sn phm c thu hoch khi cha chn, chng s khng c mi hng v mn ca v, hoc khng th chuyn sang giai on chn to ra hng v v cho ngi tiu dng. Nu sn phm c thu hoch khi qu chn, hin tng qu gi c th xy ra trc khi sn phm ti c ngi tiu dng.

Cha chn (xanh) Chn (vng)

Hnh 1.1.35. Cc chn ca chui

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Kh etylen l yu t quan trng i vi s chn ca qu. Kh etylen dng dm chn cc loi qu chn p, lm mt mu xanh ca qu c mi trng cc nc nhit i.

Etylen sinh ra nhiu khi qu chn, qu b thng tn hoc b nm mc gy h thi. V vy, khi vn chuyn cc loi qu cn tch ring qu chn, qu h hng, thng tn nhm hn ch qu b chn trong khi vn chuyn.

3. S tn tht sau thu hoch i vi rau qu ti

3.1. Tn tht do thng tn c hc

Cc biu hin thng tn trn rau qu ti do b va p c hc c th xut hin bn trong hoc bn ngoi. C th nhn bit c nhng biu hin ny ngay sau khi b va p hoc ch c th nhn bit c sau mt khong thi gian.

Thng tn c hc khng ch lm bin dng sn phm m c th cn lm tng t l thot hi nc, t l h hp hoc to ra cht etylen v to iu kin cho cc sinh vt gy bnh xm nhp vo bn trong rau qu v dn n cc gim st v cht lng.

Thng tn c hc c th xy ra trong bt c cng on no t sn xut n khu tiu th t thu hoch, x l, ng gi, vn chuyn v tiu th, nguyn nhn ch yu l do:

- Cc phng tin thu hoch, vn chuyn khng m bo yu cu k thut.

Hnh 1.1.36. Phng tin vn chuyn khng m bo yu cu k thut

- Cc thng cha ng sn phm khi thu hoch hoc khi vn chuyn sn phm i tiu th khng thch hp (c cnh sc, c inh nhn, c mnh g vn).

- S lng rau qu ng gi khng m bo yu cu k thut: ng qu nhiu hoc qu t sn phm vo thng cha.

- Lm ri vi, nm hoc gim p ln sn phm hoc ln cc thng cha sn phm ng gi.

Cc hnh thc biu hin ca thng tn c hc gm c:

- B dp, thm tm: y l hin tng ph bin thng hay xy ra i vi cc loi sn phm rau qua c v mm. Lm dp hay thm c th khng din ra nhanh chng ngay sau khi c cc va p c hc, i khi ch c th xut hin trn

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vng d b dp khi mang sn phm ra tiu th trn th trng.

Thng khng nhn thy nhng vt dp trn sn phm rau qu c b mt v bn ngoi cng hoc chc. B mt cng c th b bin dng sau li quay tr li trng thi bnh thng ban u sau khi b va p, li hu qu h hi bn trong m ch c th nhn bit khi sn phm n tay ngi tiu th.

Cc vng b h hi thng m c, mt mu hoc c mu sc khng bnh thng.

Rau qu b dp v thm c th do va p hoc do p sut. Nhng h hi do va p c th xy ra do nh ri, do ng gi hoc do va p vo cc thit b trong qu trnh vn chuyn.

Hnh 1.1.37. Qu b dp c hc

- B try xc: hin tng try xt cc b mt ca rau qu dn n v cc cu trc bn trong v d n mt nc, li trn b mt cc vng kh en hoc nu.

Hnh 1.1.38. Qu b try xc

Mt s du hiu h hng c th nhn thy ngay lp tc, tuy nhin thng mt vi ngy mi c th nhn bit. Triu chng c th nghim trng i vi cc loi hoa qu nh chui tri qua qu trnh chn.

Nguyn nhn ph bin dn n cc vt try xc l do c ra cc cht bn trn bn mt cc sn phm rau qu do c xt vo b mt th rp ca thng cha sn phm, vi cc thit b vn chuyn hoc cc sn phm ng gi lng lo trong qu trnh vn chuyn.

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- B bin dng hnh dng.

Hnh 1.1.39. Qu b bin dng

- B nt: va p mnh vo cc loi rau qu c bn mt cng c th gy ra cc vt nt. Hin tng ny c th xy ra trong trng hp sn phm b ri vo mt b mt cng hoc khi thng cha sn phm b ri hoc cc sn phm chuyn ng c xt vo nhau trong qu trnh vn chuyn.

Hnh 1.1.40. Qu b nt b mt

Khi b thng tn c hc th cc bin php x l nh ct b phn b thng tn hoc gt b v ngoi sn phm s gy ra cc bt li nh:

- Vi khun hoc nm mc d dng thm nhp vo sn phm qua cc ch b ct mt v hoc t cc vt ct.

- Tng lng nc mt i t cc ch b ct b.

- Tc h hp tng ln.

3.2. Tn tht do nhit

3.2.1. H hng do lnh

Cc loi rau qu ti cc vng kh hu nhit i nh nc ta d b h hng nhit thp. Nhng thng tn do hi lnh c th xy ra trong qu trnh lm lnh, bo qun lnh v vn chuyn hoc c th b phi di nhit khng kh thp cc vng c thi tit lnh.

Tc ng ca nhit thp i vi rau qu ti bao gm cc dng nh:

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- Bn trong hoc bn ngoi hoc c hai thng chuyn sang mu nu hoc en.

- R v: c vt lm trn v.

- Chn khng u hoc khng chn c, mt mi v c trng.

- Ci c mu ti sm

- B chy nc.

Hnh 1.1.41. Qu b en do nhit lnh

Do vy, i vi cc loi rau qu nu cn bo qun trong mt thi gian di th cn phi bo qun rau qu nhit cao hn nhit an ton thp nht. Nhit an ton thp nht ca mt s loi rau qu c trnh by bng 2 nh sau:

Bng 1.2. Nhit an ton thp nht bo qun rau qu

Sn phm Nhit an ton thp nht (0C)

Triu chng h hng do lnh

C tm 7 Vt bng trn b mt

Chui 12 14 Mu v xn li, nu xm

Da chut 7 R, vt ngm nc, h hng do ngm nc

Chanh 13 15 R, vt en

Xoi 10 13 Vt bng trn v mu xm, chn khng u

Da hu 5 R, v ng

u 7 R, khng chn, mt mi v, thi ra

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3.2.2. H hng do nhit cao

Hi nng c nhit cao c th xut pht t cc ngun sau y:

- Sn phm sau khi thu hoch khng che chn cn thn, nhit cao s nhanh chng b h hng do b mt nhiu nc.

- Cc sn phm c ng gi, hay trn thnh xe ca cc phng tin vn chuyn.

- Sinh ra trong cc chng sn phm c t l h hp cao.

- Bn thn cc sn phm c th nng ln bi chnh qu trnh h hp ca chng, c bit nu sn phm cha c lm lnh y ng cch.

Khi b phi trc tip di nh nng mt tri, nhit c th ln n 500C, nn kh nng h hng rt d xy ra.

V vy, rau qu cn phi che y, chng nng, nng cho rau qu ti ko di thi gian bo qun rau qu ti.

Cc biu hin h hng do nhit cao:

- B nhn, mm

- Mt mi thm

- L, qu chuyn sang mu vng

- Ho, kh.

Hnh 1.1.42. Qu b ho do nhit cao

3.3. Tn tht do bnh v vi sinh vt

Nhim sinh vt gy bnh, hu ht l vi khun v nm, l nguyn nhn chnh dn n cht lng cc loi rau qu gim st. Nhim bnh c th xy ra trn cnh ng trong qu trnh tng trng hoc trong qu trnh x l sau thu hoch.

Rau qu ti b cc loi bnh do vi sinh vt gy ra phn ln do b nhim vi sinh vt trong khng kh, t, nc, cc phng tin vn chuyn, dng c b dnh bi t v trong cc cy trng b h hng.

Mt nhn t quan trng l b va p c hc, b thm tm, b try xc v b nt, khin cc sinh vt gy bnh xm nhp vo trong sn phm.

Cc loi bnh trn rau qu sau thu hoch c th c lan truyn bng:

- Cc thng ng khi thu hoch b nhim bn t hoc sn phm h hng.

- Nc bn dng ra sn phm trc khi ng gi.

- Sn phm h thi thi ra nm xung quanh nh s ch, khu vc ng gi.

- Sn phm sch b nhim bn trong lc bao gi.

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Hnh 1.1.43. Qu v c b h thi

B. Cu hi v bi tp thc hnh

1. Cu hi:

1.1. Cu hi s 1.1.1: K tn cc nhm sn phm rau qu ti ca Vit Nam?

1.2. Cu hi s 1.1.2: Hy cho bit trong rau qu ti sau thu hoch din ra cc qu trnh bin i no?

1.3. Cu hi s 1.1.3: Hy trnh by cc dng tn tht sau thu hoch ch yu ca rau qu ti v nguyn nhn chnh gy ra cc dng tn tht ?

1.4. Cu hi s 1.1.4: Hy cho bit nguyn nhn gy ra cc dng tn tht sau thu hoch ca rau qu ti trong cc hnh sau (hnh 1, hnh 2, hnh 3, hnh 4)?

Hnh 1. Hnh 2.

Hnh 3. Hnh 4.

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C. Ghi nh

- Rau qu ti sau thu hoch vn cn h hp nn cht dinh dng d tr b tiu hao, dn n rau qu b ha gi, b h hng v tin n khng cn s dng c. Hn ch h hp ca rau qu bng cch gi rau qu ni mt hoc c iu kin th bo qun nhit thp nhng trn gii hn cho php.

- Rau qu ti sau thu hoch cn trnh mt nc gy kh ho. Do ct gi ni mt v m.

- Cn trnh cho rau qu sau thu hoch b tn thng c hc, tn thng do qu lnh hoc qu nng v tn thng do vi sinh vt v khi b tn thng th gi tr ca rau qu b suy gim.

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BI 2. CHUN B NH S CH RAU QU SAU THU HOCH

M bi: M01-02

A. Ni dung

Sn phm rau qu ti c bn cho cc ch hoc trc tip bn cho ngi tiu dng hay cc i l cn phi tri qua mt s cng on x l nht nh nh lm sch, phn loi, ng gi Phn ln cc cng on x l nguyn liu rau qu ny c tin hnh trong nh s ch. Nh s ch c th thuc loi n gin lp mi tranh nng thn hay dng quy m ln x l mt lng ln nguyn liu cho c mt vng sn xut. D n gin hay phc tp, nh s ch u phi to c mt mi trng bo v rau qu ti vi mc ch tp trung, phn loi, chn lc v ng gi sn phm theo cch c trt t, gim tn tht v t tr ngi trong qu trnh x l.

Kch thc v v quy m ca nh s ch ph thuc vo khi lng nguyn liu cn x l, yu cu th trng, c s h tng ca a phng v kh nng ti chnh. Vic chun b nh s ch cn xem xt cc yu t sau: a im t nh s ch, thit k, kt cu, b tr trong nh s ch, trang b chiu sng, h thng cp thot nc.

1. Chn a im t nh s ch rau qu

a im t nh s ch cn bo m yu cu sau:

- Cao ro, bng phng, khng b ngp ng.

- C din tch ln cha cc phng tin vn chuyn.

- Thun tin v giao thng: c ng giao thng ni t a im sn xut n trc giao thng chnh.

- Tch bit vi khu dn c, bnh vin, khu chn nui tp trung, c s git m gia sc, gia cm tp trung khng b nh hng bi cc tc nhn ly nhim t mi trng xung quanh nh: khi bi, cht thi bn

Mc tiu:

- Nu c cc yu cu v a im, kt cu, thit k v b tr nh s ch rau qu;

- Trnh by c yu cu i vi h thng chiu sng v h thng cp nc, thot nc cho nh s ch rau qu;

- Thc hin c vic kim tra, pht hin cc im khng t yu cu quy nh i vi nh s ch;

- Thc hin c vic v sinh, kh trng nh s ch;

- Thi lm vic cn thn, tun th cc yu cu quy nh i vi nh s ch.

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- Gn ngun in, c ngun nc sch ra sn phm.

Hnh 1.2.1. Trnh gn ngun cha cht thi

Hnh 1.2.2. Trnh nhng ni trng, ngp

nc

Hnh 1.2.3. B tr ni thun tin v in

Hnh 1.2.4. Trnh s dng nh s ch c din tch cht hp

Hnh 1.2.5. Trnh sn nh trng, ng nc

2. Kt cu, lp t nh s ch

Nh s ch phi p ng cc yu cu v an ton v sinh thc phm theo quy nh hin hnh ca Vit Nam trong s ch v phn phi rau qu ti.

Kt cu bn trong nh xng cn c xy lp bng cc vt liu c bn cao, thun li cho vic bo dng, v sinh v kh trng khi cn thit.

c bit, kt cu nh xng cn p ng mt s iu kin c th nh sau bo m v sinh an ton thc phm cho rau qu ti:

Hnh 1.2.6. Nh s ch phi bo m an ton v sinh thc phm

- Nh s ch c mi che chc chn, trnh c ma nng, mi nh ra khi tng bao xung quanh t nht 1m rt c ch trong vic che bng mt cho tng nh, trnh cc tia mt tri (hnh 1.2.7), ng thi bo v cho tng nh khi b ht nc khi tri ma (hnh 1.2.8).

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Hnh 1.2.7. Mi nh ra chng nng cho tng

Hnh 1.2.8. Mi nh ra chng ma cho tng

- B mt tng, vch ngn v sn cn c lm bng vt liu khng thm nc, khng gy c ln sn phm.

Vt liu lm tng ph hp vi quy m, d lm v sinh.

- Ca ra vo nn thit k b mt nhn khng thm nc v d dng v sinh, kh trng khi cn thit. Hnh 1.2.9. Vch ngn v ca

- Tng bao xung quanh bo m thng thong, nhng trnh c bi, ma, gi, nng chiu trc tip.

Hnh 1.2.10. Tng bao quanh nh

- Nn nh phng, cng chc, khng ng nc v phi c rnh thot nc

- B mt bn lm vic tip xc trc tip vi rau qu ti cn nhn, c lm bng vt liu khng thm nc, khng nh hng ti thc phm, d v sinh, kh trng trong iu kin vn hnh thng thng.

Hnh 1.2.11. Bn lm vic

3. B tr v tr cc khu vc trong nh s ch

Vic b tr cc khu vc x l trong nh s ch c nh hng trc tip n

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cc qu trnh lm vic nh thi gian, nng sut lm vic, cht lng sn phm.

B tr cc khu vc trong nh s ch c t chc, trt t theo tng bc th c th tit kim c thi gian x l, bo m c cht lng sn phm v tit kim chi ph.

Cch b tr thun tin nht l nh mt tng vi khu tip nhn mt u v khu giao hng u kia, tch ring bit. Theo cch b tr ny tch ring din tch tip nhn hng l ni b bn vi khu vc ng gi v giao hng, nh gim c s nhim bn cho cc sn phm c phn loi v ng gi. Vic b tr cng cn trnh n tc v hn n gia xe i v n (hnh 1.2.12).

Hnh 1.2.12. B tr hp l cc khu vc ch bin trong nh s ch

Kho

bo qun

Vn phng

(nu c)

Khu vc hot ng chnh Chn lc, lm sch Phn loi, lm kh ng gi v cc x l khc

Khu vc tp trung cha sn phm ng gi

Nguyn liu vo

Sn phm ra

Khu vc tip nhn lm sch v la chn s b

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- Nguyn tc b tr trong khu vc nh s ch:

+ Cc thit b, dng c sp xp theo trnh t ch bin mt chiu (nguyn liu t khi vo n khi sn phm i ra theo mt chiu) dy chuyn s ch m bo lin tc v ngn, trnh sn phm nhim bn t nguyn liu cha x l.

+ Khu vc tip nhn v x l nguyn liu nn c t u dy chuyn.

+ Khu vc tip nhn nguyn liu v khu vc thnh phm cch xa nhau trnh nhim cho.

+ Khu vc sn xut phi rng lm vic c hiu qu.

+ Tch ring khu vc t v kh cng xa nhau cng tt.

Mi khu vc cn c din tch vic di chuyn sn phm qua cc giai on c d dng.

- Khu vc tip nhn: cn c gi l khu vc nhp hng, khu vc ny kim sot vic thu nhn, la chn s b v lm sch sn phm, gm c vic ra khi cn thit (hnh 1.2.13).

Hnh 1.2.13. Khu tip nhn nguyn liu

Ni ny c th b bn v t, bi v cc mu rau qu thi, hng. Tt nht l tch ring khu vc ny c th bng vch ngn, c ca hn ch s nhim bn sn phm c lm sch, la chn, ng gi cc khu vc khc.

- Khu vc chun b v ng gi: khu vc ny thc hin cc hot ng chnh ca vic x l sau thu hoch nh: lm kh sn phm sau khi ra hoc c x l bao gm c ra v lm kh, chn la v phn cp sn phm, ng gi sn phm (hnh 1.2.14).

Hnh 1.2.14. Khu chun b v ng gi

khu vc ny cng cn c khng gian bo qun v tp trung vt liu ng gi trong iu kin kh ro. Ton b din tch khu vc ny cn c bo v ma nng nhng thng thong tt v c nh sng. Nhng din tch chn la, phn cp v ng gi cn c gi sch s v kh ro.

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- Khu giao hng i: cn gi l khu vc xut hng, khu ny cn t ngay sau khu ng gi nhng cn b tr ni hon ton khng c thit b thng xuyn c vn hnh (hnh 1.2.15).

Hnh 1.2.15. Khu giao hng i

Khu vc giao hng i phi rng ri bo qun tm thi sn phm ng gi ng thi vn cho php cng nhn vn ng khng b hn ch v sn phm c lun chuyn. Din tch giao hng phi sch v thng gi tt. C th t ch giao hng mt vn phng hoc mt ch kim tra cht lng.

4. Kim tra h thng chiu sng nh s ch

H thng chiu sng ca nh s ch bo m yu cu nu bo m:

- S dng nh sng t nhin hoc nhn to bo m sng thc hin cc hot ng x l.

- Nu dng nh sng nhn to th bng n ti khu vc s ch, ng gi c lp t chp bo v.

5. Kim tra h thng cp, thot nc ca nh s ch

Ngun nc dng ra sn phm l mt yu t quan trng xc nh a im t nh s ch. H thng cp, thot nc nh s ch bo m yu cu nu khi kim tra t cc tiu chun:

- Nc s dng trong nh s ch rau qu ti cn m bo tiu chun nc sinh hot v p ng tiu chun theo cc quy nh hin hnh ca Vit Nam.

- C h thng cung cp, d tr, phn phi nc m bo an ton thc phm v lng s dng cho sn xut.

Hnh 1.2.16. B nc ra

- Nc s dng x l rau qu cn c lm t nc sinh hot. Nc

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c sn xut, vn chuyn v bo qun phi m bo khng b nhim.

- Cc rnh, cng thot nc thi c dc thch hp, khng gy ng nc, khng gy nhim cho sn phm v h thng nc cp.

6. Kim tra h thng thng gi

Nh s ch cn bo m thng thong tt. S thng gi s c tng cng nu li vo ca khng kh c t pha di sn nh, v li ra c t pha trn nc nh. Nu c iu kin th dng qut ht kh t trn nc kho ko khng kh nng ra khi nh.

Hnh 1.2.17. B tr ca thng gi cho nh s ch

7. Bo dng, v sinh v kh trng nh s ch

- Nh s ch phi c qut dn bn trong (hnh 1.2.18) v khu vc xung quanh (hnh 1.2.19) m bo sch s, loi b cc b phn ca rau qu cn st li sau khi x l v bi bn l ngun nhim ln sn phm.

Hnh 1.2.18. Qut dn nn v tng nh

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- V sinh v kh trng cn c thc hin mt cch thn trng v tun th theo hng dn ca nh sn xut. Vt liu v sinh v kh trng cn c ct gi ni ph hp cch bit vi rau qu ti v nh du ch dn r rng trnh nhng ri ro gy nhim.

Hnh 1.2.19. Qut dn xung quanh nh s ch

- Phng nga v tiu dit cn trng, ng vt gy hi.

- Cc rnh, h ga thot nc thi phi c qut dn thng xuyn, m bo khng c bn rc, khng ng nc, gim thiu mi hi.

- Nh v sinh c b tr cch ly vi khu vc s ch v phi c v sinh thng xuyn.

- Nh v sinh c y thit b/phng tin v sinh, ra, kh trng tay cho cng nhn.

* Nh s ch n gin, quy m nh

Nh s ch n gin c kt cu n gin gm c mi che hoc nh mt tng c th c ci thin thnh mt khu cho cc cng on x l trong nh khc nhau, c minh ha trong hnh. Yu cu ti thiu l sn v mi che thch hp, s thng gi y , v c khu phn loi, bao gi, x l theo yu cu ca tng mt hng (v d: ra sch/lm kh, x l chn), v lu gi rau qu ng gi. Sn nh ti thiu cho mt tn qu c lu tr l 20m2.

Kt cu ca nh s ch n gin minh ha cc hnh 1.2.20 nh sau:

Hnh 1.2.20. M hnh nh s ch n gin

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Mt dng nh s ch n gin trn cnh ng c th c dng nn t cc ct g v mt tm polyethylene. Lp mi l ly bng rm, v gi mt cho trm bao gi. Cu trc ny nn quay v hng ng phn nh ra ca mi nh c th che c nh mt tri.

Hnh 1.2.21. Kt cu ca nh s ch n gin


1. Cu hi:

1.1. Cu hi s 1.2.1: Hy cho bit iu kin cn c khi chn a im v xy dng kt cu, lp t nh s ch rau qu ti.

1.2. Cu hi s 1.2.2: Ti sao khi b tr mt bng cc khu vc trong nh s ch phi sp xp theo trnh t mt chiu?

1.3. Cu hi s 1.2.3: Ti sao phi b tr v tr khu vc tip nhn nguyn liu v khu vc thnh phm phi cch xa nhau?

1.4. Cu hi s 1.2.4: Hy cho bit iu kin khng m bo trong cch b tr cc khu vc sn xut ca nh s ch rau qu trong cc hnh sau (hnh 1, hnh 2):

Hnh 1 Hnh 2

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2. Bi thc hnh:

2.1. Bi thc hnh s 1.2.1: V sinh, kh trng chun b mt bng cc khu vc trong nh s ch rau qu ti.

- Mc tiu: Cng c kin thc v rn luyn k nng ngh thc hin cc bc cng vic v sinh, kh trng chun b mt bng cc khu vc lm vic trong nh s ch rau qu ti.

- Ngun lc:

+ a im: khu vc mt bng lm vic trong nh s ch rau qu ti.

+ Dng c, trang thit b: chi, cy lau nh, bnh phun xt dung dch kh trng

+ Ha cht dng v sinh, kh trng: x phng, dung dch kh trng.

+ Trang phc bo h: gng tay cao su, ng cao su,.....

- Cch thc tin hnh: chia cc nhm nh (3 5 hc vin/nhm).

- Nhim v: mi nhm nhn nhim v v sinh, kh trng mt khu vc mt bng nh s ch.

Cc hot ng cn thc hin:

+ Mang mc bo h lao ng.

+ Chn ra nhng dng c, trang thit b c giao v sinh, kh trng.

+ Thc hin cc bc v sinh, kh trng khu vc mt bng nh s ch theo ni dung hng dn:

B1. Pha ch dung dch x phng v sinh v dung dch kh trng

B2. Qut dn khu vc mt bng nh s ch v khu vc xung quanh

B3. V sinh khu vc mt bng nh s ch bng nc, x phng

B4. Kh trng khu vc mt bng nh s ch bng dung dch kh trng

B5. Ra li bng nc sch

B6. Lm kh

B7. Kim tra khu vc mt bng nh s ch v khu vc xung quanh sau khi v sinh, kh trng.

- Thi gian hon thnh: 30 40 pht/1 nhm.

- Kt qu v tiu chun sn phm cn t c sau bi thc hnh:

+ Thc hin cc hot ng theo ng trnh t;

+ Thao tc v sinh, kh trng theo ng yu cu;

+ Cc khu vc mt bng nh s ch m bo sch sau khi v sinh, kh trng.

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2.2. Bi thc hnh s 1.2.2: Kim tra cc iu kin lm vic ti cc khu vc trong nh s ch rau qu ti.

- Mc tiu: Cng c kin thc v rn luyn k nng ngh thc hin cc bc cng vic kim tra cc iu kin lm vic ti cc khu vc trong nh s ch rau qu ti.

- Ngun lc:

+ a im: khu vc mt bng lm vic trong nh s ch rau qu ti.

- Cch thc tin hnh: chia cc nhm nh (3 5 hc vin/nhm)

- Nhim v: mi nhm nhn kim tra cc iu kin lm vic ti mt khu vc trong nh s ch rau qu ti.


+ Lit k cc yu cu cn c v iu kin lm vic trong nh s ch rau qu ti.

+ Tin hnh kim tra cc yu cu cn c v iu kin lm vic trong nh s ch rau qu ti

B1. Kim tra iu kin a im xy dng nh s ch

B2. Kim tra kt cu xy dng nh s ch

B3. Kim tra vic b tr mt bng cc khu vc lm vic trong nh s ch

B4. Kim tra h thng chiu sng

B5. Kim tra h thng cp, thot nc

B6. Kim tra h thng thng gi

+ Pht hin cc im khng t yu cu quy nh v iu kin lm vic trong nh s ch rau qu ti.

+ a ra cc bin php ngh sa cha, khc phc cc im khng t yu cu quy nh.



+ Thc hin cc hot ng kim tra theo ng trnh t;

+ y cc mc kim tra theo ng yu cu;

+ Cc iu kin lm vic trong khu vc mt bng nh s ch u c kim tra;

+ Cc im khng t yu cu quy nh c pht hin v c bin php sa cha, khc phc.

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C. Ghi nh

Cn ch cc ni dung trng tm ca bi:

- Nh s ch rau qu ti l ni tp trung nguyn liu rau qu ti, x l, ng gi v to thnh sn phm cung cp cho i l hoc ngi tiu dng. Nh s ch phi c b tr

ni bo m cc iu kin cho php bo m sn xut an ton, hiu qu.

- Vic b tr cc khu vc ch bin trong nh s ch rau qu ti c nh hng trc tip n cc qu trnh lm vic nh thi gian, nng sut lm vic v cht lng sn phm. V vy, phi tun theo cc quy nh v b tr trong nh s ch.

- V sinh, kh trng bn trong v xung quanh nh s ch rau qu ti phi bo m thc hin theo ng qui nh, trnh gy nhim sn phm.

39

BI 3. CHUN B THIT B, DNG C X L RAU QU SAU THU HOCH

M bi: M01-03

A. Ni dung

1. Yu cu chung v thit b, dng c x l rau qu

Cc loi thit b v dng c c s dng trong x l rau qu phi m bo cc yu cu sau:

- Lm bng vt liu bn, khng c, khng g st, khng lm nh hng ti cht lng sn phm. Cc loi vt liu ph bin hay c s dng nh: tre, g, inox, nha

- c lp t ng quy cch, d bo dng, v sinh v kh trng.

- D dng dch chuyn thun tin trong vic b tr hoc lp t. Do vy nn hn ch dng cc b ra bng xi mng.

- Thun tin cho c nhn vn chuyn sn phm ti khu vc ng gi nh cc thng hoc cc khay bng nha, g hoc inox...

2. La chn, s dng thit b, dng c dng x l rau qu

2.1. Dng c cha ng

2.1.1. Dng c cha ng bng nha

Dng c cha ng bng nha c dng ph bin trong ch bin rau qu, c bit l trong khu x l rau qu ti v loi thit b ny c nhiu u im nh bn, d v sinh, chi ra, c nhiu hnh dng ph hp vi cc mc ch s dng khc nhau (hnh 1.3.1).

Hnh 1.3.1. Mt s loi dng c bng nha

Mc tiu:

- Nu c yu cu i vi thit b, dng c dng trong s ch rau qu; - Thc hin c vic bo dng v v sinh cc thit b, dng c s ch rau qu; - Nhn thc c nh hng ca thit b, dng c i vi qu trnh x l rau qu; c thi lm vic kin tr, cn thn.

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Thng nha c l thng gi lm thot nhit rau qu khi vn chuyn v tn tr (hnh 1.3.2).

Hnh 1.3.2. Thng nha c l to s thng thong

Mt vi loi thng nha c th xp lng vo nhau khi rng nn s tit kim khong khng gian, to s thun tin cho vic ct gi hoc khi di chuyn (hnh 1.3.3). Khi cha y, chng c xp thnh tng gn gng v chc chn (hnh 1.3.4).

Hnh 1.3.3. Cc thng nha xp lng vo nhau

Hnh 1.3.4. Cc thng nha xp thnh tng khi cha vt liu

Thng cha nn c ra sch s nh k bng nc clo v thuc ty hn ch c hi ly lan s thi hng t mt sn phm sang phn cn li.

2.1.2. Dng c cha ng bng g

Loi thng lm bng g rt c a chung s dng s dng ng rau qu ti do c cng cp v c th gi c bn ca n qua thi gian di m tng i cao.

Loi dng c bng g ny bao gm mt s dng nh sau:

- Thng c np (hnh 1.3.5)

- Thng khng np (hnh 1.3.6)

- Khay (hnh 1.3.7).

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Hnh 1.3.5. Thng g c np Hnh 1.3.6. Thng g khng np

Cc thng g l loi dng c c trng ng nho.

Khay g n gin vi 4 chn c ng ni ln, d chng xp, v cho php thng hi tt cho cc loi nng sn d hng nh c chua chn (hnh 1.3.7).

Hnh 1.3.7. Khay g

2.2. Thit b bc d, di chuyn sn phm

- Cc loi xe nng c ng c (hnh 1.3.8) c dng trong nh s ch quy m ln nng cc palt (hnh 1.3.9) cha sn phm ln cc xe chuyn ch hoc di chuyn sn phm trong nh s ch.

Hnh 1.3.8. Xe nng c chc nng, di chuyn sn phm

Hnh 1.3.9. Palet g

- Trong cc nh s ch quy m nh hn c th dng cc xe nng y hng bng tay (hnh 1.3.10) l phng tin hu hiu di chuyn sn phm. Tuy nhin loi xe ny khng dng nng hng ha ln cc xe ch hng c.

42

Hnh 1.3.10. Xe nng y bng tay

2.3. Thit b lm sch

Lm sch nhm loi b t , bi, nha cy trn sn phm rau qu. C th dng thit b ra hoc lau sch bng vi mm.

Vic dng vi mm lau c th loi b c nhng ht bi, t khi sn phm, c bit l qu. i vi cc loi rau qu cn lm sch nha cy v cc loi rau qu khng th lau bng tay c th phi dng thit b ra.

Mt s thit b ra n gin nh sau:

2.3.1. Thit b ra

a/ Thit b ra n gin lm bng thng thp hnh tr:

Hnh 1.3.11. Thng ra lm bng thng thp

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Nhng chic thng ny c ca i gia theo chiu dc ca thng, ni vi ng dn nc, v tt c nhng cnh, g kim loi c lt bng vng m lm bng cao su hoc nha. Thng thp ny sau c t vo trong mt chic bn g nghing. Bn c lm t nhng thanh g mng, v c s dng nh mng lm kh trc khi ng gi.

b/ Thng ra lm bng cc tm kim loi m km:

Mt vch ngn c lm bng tm kim loi m km c l c t v tr gn ng dn nc, gip cho vic lu thng nc qua sn phm. Nc sch c a vo di p lc, qua cc ng dn c l nh, s gip di chuyn cc sn phm ni trn mt nc n ci mng cui cng ca thng ly ra sau khi ra sch (hnh 1.3.12).

Hnh 1.3.12. Thng ra lm t tm thp

2.4. Thit b phn loi

Thit b phn loi c s dng nhm mc ch:

- Chn la nguyn liu: nhm loi tr cc nguyn liu a vo ch bin khng quy cch k thut v cht lng nh: su bnh, mc, thi, hng ...

- Phn loi nguyn liu: nguyn liu ng u v kch thc, hnh dng, mu sc hoc chn.

C hai bin php phn loi:

- Phn loi th cng (bng tay)

- Phn loi c gii (thit b phn loi).

2.4.1. Bn phn loi khng c l

Loi bn phn loi ny l s kt hp hai bc: phn loi v bao gi. Sn phm tip nhn vo c t trong ngn phn loi, c cng nhn phn loi ri chuyn sang ngn bao gi v c ng gi (hnh 1.3.13, 1.3.14).

44

Hnh 1.3.13. Thit b phn loi

Hnh 1.3.14. Kt cu bn phn loi

Chiu cao ca bn phn loi nn mc ph hp nht cho ngi phn loi. V tr ca bn v ngn phn loi nn c chn sao cho vic phi chuyn ng tay l t nht. Cn c gh ngi, hoc mt tm m cao su (nu ng) c th gip gim s mt mi.

2.4.2. Vng phn loi

Cc sn phm c hnh trn c th c phn loi bng l trn xc nh kch thc. Cc l trn ny c th c khoan trn tm g, hoc mua sn vi nhiu kch c khc nhau (hnh 1.3.15, 1.3.16) ph hp vi kch thc ca tng loi sn phm rau qu.

Hnh 1.3.15. Vng phn loi n Hnh 1.3.16. Vng phn loi kp

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2.4.3. Bn phn loi c c l

Bn phn loi c c l (hnh 1.3.17) l mt trong cc loi bn phn loi c s dng ph bin phn loi cc loi rau qu dng c nh hnh ty.

Mi bn c lm bng g dn v c c l vi kch thc ring. Bn v tr cao nht s c l ln nht v bn thp nht s c l nh nht.

Hnh 1.3.17. Bn phn loi c c l

2.4.4. Mng phn loi

Thit b phn loi dng mng thng c dng phn loi qu c mi. Thit b gm c mng hnh ch nht lm bng g dn, c lt tm mt trnh qu b bm, dp.

bt gic u mng l ni tip nhn nguyn liu. Trn mng c 3 khe hp c kch thc khc nhau gi cc qu c kch thc khc nhau. Cng v cui mng th khe cng hp dn (hnh 1.3.18) tng ng vi kch thc ca rau qu t nh n ln, t c phn ra cc kch c khc nhau.

Hnh 1.3.18. Mng phn loi

46

3. Bo dng thit b, dng c x l rau qu

- Cc b phn chuyn ng phi c bi trn du m.

- Lng du m d tha dnh trn thit b, my mc phi c loi b, chi sch.

- Dng c, thit b phi c hiu chnh, bo m hot ng tt.

4. V sinh, kh trng i vi cc thit b, dng c

- Thit b tip xc vi thc phm nh bng ti, thng cha phi chi ra bng nc sch, ring b mt tip xc trc tip phi c v sinh k hn bng x phng.

Sau khi v sinh c th dng cht ty ra kh trng mt s thit b my mc c nh hng trc tip n cht lng sn phm.

Hnh 1.3.19. Thng cha rau qu

Cht ty ra c dng ph bin l dung dch Javen (Natri Hypoclorit).


1. Cu hi:

1.1. Cu hi s 1.3.1: Hy nu cc yu cu k thut v cc thit b, dng c dng trong x l rau qu ti.

1.2. Cu hi s 1.3.2: Hy cho bit cng dng ca cc thit b, dng c sau s dng trong x l rau qu ti.

Thit b, dng c Cng dng

1. Dng c cha ng

2. Thit b phn loi

3. Thit b lm sch

4. Thit b bc d, di chuyn sn phm

2. Bi thc hnh:

2.1. Bi thc hnh s 1.3.1: V sinh, kh trng v bo dng cc thit b, dng c dng trong x l rau qu ti.

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- Mc tiu: Cng c kin thc v rn luyn k nng ngh thc hin cc bc cng vic v sinh, kh trng v bo dng cc thit b, dng c trong x l rau qu ti.

- Ngun lc:

+ Cc thit b: thit b bc d, di chuyn sn phm; thit b lm sch; thit b phn loi.

+ Cc dng c: dng c cha ng bng nha, bng g.

+ Ha cht dng v sinh thit b: x phng, ha cht kh trng.

+ Trang phc bo h: gng tay cao su, ng cao su.....


- Nhim v: mi nhm nhn nhim v v sinh, kh trng v bo dng mt s thit b, dng c trong x l rau qu ti.


+ Mang bo h lao ng.

+ Chn ra nhng thit b, dng c c giao v sinh, kh trng v bo dng.

+ Thc hin cc bc v sinh, kh trng v bo dng thit b, dng c theo ni dung hng dn:

B1. Pha dung dch x phng v sinh v dung dch kh trng ha cht kh trng

B2. Lm sch b mt cc thit b, dng c

B3. V sinh nc sch, x phng

B4. Kh trng cc thit b, dng c tip xc trc tip vi sn phm bng dung dch kh trng

B5. Ra li bng nc sch

B6. Lm kh

B7. Bo dng cc thit b, dng c

B8. Kim tra thit b, dng c sau khi v sinh, kh trng v bo dng.



+ Thc hin cc hot ng theo ng trnh t;

+ Thao tc v sinh, kh trng v bo dng thit b, dng c theo ng yu cu;

+ Thit b, dng c m bo sch, hot ng tt sau khi v sinh, kh trng v bo dng.

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C. Ghi nh

- Cc dng c cha ng bng nha tuy t tin nhng c nhiu u im nh d lm sch, c th xp lng vo nhau khi khng s dng, bn v t lm xy xt, gy tn thng c hc cho qu.

- Chiu cao ca cc thit b phn loi ph hp vi ngi lao ng gim bt mt mi khi lm vic v tng nng sut lao ng.

- Cc thit b, dng c x l rau qu phi c v sinh sch s, cn thit phi c kh trng.

49

BI 4. TIP NHN RAU QU SAU THU HOCH

M bi: M01-04

A. Ni dung

1. V sinh v k lt ni tip nhn rau qu

Yu cu v sinh ti ni tip nhn rau qu l: bn trong v ngoi khu vc cha nguyn liu sch s, khng cn cht thi v rc, bi.

Hnh 1.4.1. Ni tip nhn rau qu

Dng cc dng c v sinh nh chi, cy lau nh lm sch khu vc tip nhn rau qu nguyn liu.

- Lm sch sn nh xng bng chi hoc bng my qut rc (hnh 1.4.2).

Hnh 1.4.2. Lm sch sn nh bng my qut rc

Hnh 1.4.3. Lau sn nh xng bng my lau sn nh

Mc tiu:

- Nu c yu cu v sinh i vi ni tip nhn nguyn liu rau qu;

- Thc hin v sinh, k lt ni tip nhn rau qu ng quy nh;

- Thc hin c vic bc d, kim tra s b cht lng rau qu, theo di v iu chnh nhit , m kho cha rau qu;

- Lm vic cn thn, chp hnh ng cc yu cu v chun b v tip nhn rau qu.

50

- Lau sn nh bng nc sch.

- Lau li sn nh bng nc lau nh (hnh 1.4.3).

- kh ro nh xng t nhin hoc dng qut.

Cc rnh, h ga thot nc thi phi c qut dn thng xuyn, m bo khng c bn rc, khng ng nc, gim thiu mi hi.

Khng nguyn liu trc tip trn nn t v d b cc mm bnh t t ly nhim (hnh 1.4.4).

Hnh 1.4.4. Nguyn liu trc tip trn nn t

Hnh 1.4.5. Nguyn liu c k lt khng tip xc trc tip vi nn t

V vy, nu nh s ch c nn l nn t th cn phi k lt bng palet (hnh 1.4.6) hoc tm nilon (hnh 1.4.7) ri mi rau qu nguyn liu ln trn.

Hnh 1.4.6. Palet bng g Hnh 1.4.7. K lt bng vi bt hoc tm nilon

i vi nn xi mng hoc nn lt gch trng men th phi qut dn, lau chi sch s trc khi tip nhn rau qu nguyn liu.

2. Tip nhn nguyn liu

2.1. Chun b phng tin chuyn nguyn liu vo nh s ch

vn chuyn nguyn liu t ni tip nhn vo bn trong nh s ch cn

Ch :

Vi cc khu vc thng xuyn b m t th phi dng chi nha qut sch nc v rc.

51

s dng mt s phng tin vn chuyn nh sau:

- Cu thang hoc bc gip cho hot ng bc v d hng c d dng hn. Cu thang gip cng nhn bc ln xe vn chuyn nguyn liu mang vc hng ha xung d dng, nhanh chng.

Cu thang gm c cc thanh st c dng lm chn cu thang v cc bc c th c lm bng vn g hoc tm st (hnh 1.4.8).

Hnh 1.4.8. Cu thang (bc)

- Bc dc (mng nghing): l phng php n gin v an ton cho vic bc d hng. B rng ca dc nn rng trnh cc tai nn v chc chu c sc nng ca c hng v ngi vn chuyn hng (hnh 1.4.9, 1.4.10).

Hnh 1.4.9. Mng nghing chuyn hng ln, xung xe

Hnh 1.4.10. Mng nghing c ng

- Xe y tay hoc xe 2 bnh nh cng thun tin cho qu trnh bc d hng (hnh 1.4.11).

Hnh 1.4.11. Xe y dng vn chuyn hng

52

- Xe y tay c chc nng nng y palet (hnh 1.4.12).

Hnh 1.4.12. Xe y tay dng vn chuyn hng

2.2. Vn chuyn nguyn liu vo ni tip nhn

Rau qu sau thu hoch c a t ng rung v nh s ch c th bng nhiu cch khc nhau. Bc d nguyn liu xung v chuyn vo khu vc tip nhn trong nh s ch l bc u tin trong cc hot ng x l y. Vic bc d v chuyn nguyn liu vo nh s ch yu cu phi nh nhng, cn thn, hn ch gy ra cc thng tn c hc cho nguyn liu .

Cc thng tn c hc do vn chuyn s nh hng n cht lng ca nguyn liu nh: rau qu b thm en, lm tng s mt nc, lm tng h hp v sinh ra nhiu nhit gy nng m, to iu kin thun li cho vi sinh vt xm nhp vo bn trong d dng qua cc ch b thng tn.

- C th vn chuyn nguyn liu t phng tin vn chuyn vo ni tip nhn trong nh s ch bng cch mang vc trn lng (hnh 1.4.13), khun bng tay hoc dng xe y, xe ko (hnh 1.4.14) hoc bng bng ti (hnh 1.4.15).

Hnh 1.4.13. Mang vc nguyn liu

Hnh 1.4.14. Khun bng tay v dng xe y nguyn liu

Hnh 1.4.15. Bng ti vn chuyn nguyn liu

53

Hn ch cc thng tn c hc: d bng cch vn chuyn no cng phi trnh cc tn thng c hc nhn thy v khng nhn thy. Cc vt tn thng c hc nhn thy c th l cc vt ct, l thng, vt bm, dp nt hoc vt try xc.

Bin php hn ch thng tn c hc:

- Khng dm p ln thng cha,

- Khng lm ri hoc ko mnh thng cha trong qu trnh vn chuyn.

- Khng mnh nguyn liu xung nn hoc vo thng cha, bng chuyn.

Vic nguyn liu xung ni tip nhn c th bng phng php kh hoc phng php t.

- Phng php kh: phng php ny yu cu nn t t v nh nhng ln b dc nghing c lt m cc cnh sc.

Trong hnh minh ha (hnh 1.4.16) di y, c mt bng ti dng sn phm c kh xung nh bao gi. gim tn thng c hc cho nguyn liu, on dc thoai thoi ni tip nhn nguyn liu cn lt lp vt m mm.

Hnh 1.4.16. Nguyn liu kh xung bng ti

- Phng php t: phng php ny thnh thong cng c s dng gim tn thng c hc, v xung nc th tt hn ln dc kh.

Nu trng lng ring ca sn phm, v d nh to, thp hn trng lng ring ca nc, th sn phm s ni. Vi mt vi loi sn phm nh qu l, th thm mui vo trong nc cho qu s ni.

Cho nc vo b (thng) ln ri mi nguyn liu vo b c th gim c cc vt bm dp, try xc. Khi s dng bng chuyn chuyn nguyn liu vo b, c th s dng mt tm bao ti qu khi ri mnh t bng chuyn xung.

54

Hnh 1.4.17. nguyn liu vo thng cha c nc ( t)


1. Cu hi:

1.1. Cu hi s 1.4.1: Hy nu cc yu cu v sinh cn phi m bo i vi ni tip nhn nguyn liu rau qu sau thu hoch.

1.2. Cu hi s 1.4.2: Hy trnh by cc bc tin hnh ca cng vic tip nguyn liu rau qu sau thu hoch.

2. Bi thc hnh:

2.1. Bi thc hnh s 1.4.1: Tin hnh thc hin cc bc cng vic tip nhn nguyn liu rau qu sau thu hoch.

- Mc tiu: Cng c kin thc v rn luyn k nng ngh thc hin cc bc cng vic tip nhn nguyn liu rau qu sau thu hoch.

- Ngun lc:

+ Nh xng ni tip nhn rau qu sau thu hoch

+ Phng tin, thit b vn chuyn rau qu sau thu hoch: xe y, xe ko, bng ti

+ Cc dng c k lt, tip nhn: palet, vi bt, tm nilon, cu thang, bc dc.

+ Trang phc bo h: gng tay cao su, ng cao su, qun o bo h lao ng.....


- Nhim v: mi nhm nhn nhim v tip nhn nguyn liu rau qu sau thu hoch.


+ Mang bo h lao ng.

+ Chn ra nhng phng tin, thit b vn chuyn v dng c k lt, tip

55

nhn rau qu.

+ Thc hin cc bc v sinh, k lt v tip nhn rau qu sau thu hoch theo ni dung hng dn:

B1. V sinh bn trong v bn ngoi khu vc tip nhn rau qu sau thu hoch.

B2. K lt nn nh khu vc tip nhn bng palet hoc tri bt hoc nilon trn nn nh.

B3. Chun b cc phng tin, thit b chuyn rau qu vo khu vc tip nhn.

B4. Vn chuyn rau qu vo khu vc tip nhn.

B5. Kim tra s b cht lng rau qu.

B6. Kim tra, theo di v iu chnh nhit , m kho cha rau qu sau khi tip nhn.



+ Thc hin cc hot ng theo ng trnh t.

+ Thao tc v sinh, k lt v tip nhn rau qu sau thu hoch theo ng yu cu.

+ Rau qu c tip nhn v bo qun ti ni tip nhn ng v tr v m bo yu cu v cht lng.

C. Ghi nh

- Ni tip nhn rau qu phi c v sinh sch s.

- Khng c nguyn liu trc tip trn nn t. Phi lt tm nilon hoc t bc k (palet) trn nn ri mi t nguyn liu rau qu ln trn.

- Khi tip nhn nguyn liu phi c kim tra, phn loi s b cht lng rau v khi vn chuyn trnh lm cho rau qu b dp, xy xt.

56

BI 5. X L RAU QU SAU THU HOCH

M bi: M01-05

A. Ni dung

1. Phn loi s b

1.1. Li ch ca phn loi s b

Phn loi s b (cn gi phn loi trc) thng c thc hin loi i cc phn rau qu b rn nt, dp nt, bin dng, thi hng, hoc nhng sn phm khuyt tt khc (b cn trng hi hoc b nm bnh) trc khi thc hin cc bc x l tip theo.

Phn loi s b mang li nhng li ch sau:

- Phn loi s b s tit kim c nng lng v khng phi x l nhng sn phm h hng.

- Loi b i cc sn phm thi hng s hn ch c s ly lan ca bnh ly nhim sang cc n v sn phm khc.

1.2. Yu cu ca phn loi s b

- Khng c thc hin phn loi, chn lc v ct ta sn phm trc tip trn nn t hoc sn nh (hnh 1.5.1).

Hnh 1.5.1. Khng phn loi nguyn liu trc tip trn nn nh

Mc tiu:

- Nu c yu cu cht lng ca rau qu;

- Nu c cch pha dung dch thuc tr nm cho rau qu;

- Thc hin thnh tho cc hot ng x l rau qu sau thu hoch nh: phn loi, lm sch, lm lnh s b, bc sp;

- Rn luyn tnh lm vic cn thn, c thc bo v ngi tiu dng

khi s dng ha cht tr nm cho rau qu.

57

- Cc thit b v dng c dng phn loi, chn lc v ct ta cn ph hp vi loi sn phm v phi c v sinh, kh trng thng xuyn.

Dng c phn loi, ct ta khng c t di t m phi c ct gi nhm ngn nga nhim bn (hnh 1.5.2).

Hnh 1.5.2. Dng c khng trn nn nh

Sn phm qua phn loi phi c ring bit cch ly vi cc phn h hng do phn loi b ra.

Hnh 1.5.3. ring sn phm phn loi

1.3. Tin hnh phn loi

Ngi phn loi da vo cm quan phn bit c nhng qu c cht lng tt vi km cht lng, hoc b khuyt tt (v d: nhng qu b rn nt, bin dng, thi hng, b cn trng hi, hoc b cc vt thng c hc). Khi phn loi phi loi b nhng qu qu nh, thi hng, hoc b tn thng.

Chiu cao ca bn phn loi nn mc ph hp nht cho ngi phn loi. V tr ca bn phn loi nn c chn sao cho cng nhn lm vic thun tin, chuyn ng tay l t nht.

Thc t cho thy b tr bn phn loi sao cho cnh tay ca ngi cng nhn nn to ra mt gc 450 khi h vi tay v pha bn phn loi, v rng ca bn nn nh hn 0,5 mt l ph hp.

Hnh 1.5.4. Bn phn loi to gc 45o vi cnh tay

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Phi bo m nh sng cho qu trnh phn loi, tt nht (500 1000 lux).

Tp cht v cc sn phm khng t yu cu cho vo thng cha ring, dng vo cc mc ch khc nhau.

2. Lm lnh s b

Lm lnh s b l qu trnh lm gim nhit khi sn phm n nhit khong 10 15oC gip gi c cht lng thng qua vic lm chm cc cc bin i sn phm rau qu sau thu hoch. Lm lnh ngay sau khi thu hi c th gi cht lng rau qu mc tt nht sau thu hoch.

Mt phng php lm lnh s b n gin v nhanh chng l s dng nc lnh. H thng ny gm mt b khung c lm t nhng ng nc v hai loi vt liu lt trc khi cho nc vo: u tin l nhng tm tre an, tm ct, tip theo l tm nilon ph ln trn. Nc c lm lnh n 100C bng cch cho vn vo. Qu c th c nhng ngp trong nc lnh n khi nhit tm qu t 10 13oC (hnh 1.5.5 v hnh 1.5.6).

Hnh 1.5.5. Ph bt nilon cha nc

Hnh 1.5.6. Lm lnh s b bng nc

Vi quy m nh, lm lnh s b c th thc hin bng nhng ci r nha hoc thng cha cng, cng vi nc v vn (hnh 1.5.7)

Hnh 1.5.7. Lm lnh s b trong thng nha

3. Lm sch

i vi mt vi loi qu nh to, l, dng bn chi kh cng lm sch sn phm. Nhng cc qu khc nh chui, c rt v rau th i hi phi ra. Vic

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la chn bn chi kh v tin hnh ra hay khng ra phi ty vo loi rau qu v loi nhim bn.

Ra trc khi lm lnh s b v bao gi: c chua, da leo, rau n l.

Ra sch nha m v gim s bin mu: xoi, chui.

Ra sau khi lu tr: khoai lang, khoai ty, c rt.

Chi kh sau khi x l hoc tn tr: hnh ty, ti.

Khng ra: u non, da, bp ci, mp ty, u H Lan, t.

3.1. Ra

- Nc ra: s dng nc ra cn ph hp vi tng giai on ca qu trnh s ch. V d: nhng cng on ra ban u c th dng nc ging cha qua x l, nc ti s dng t cng on ra cui cng cn nhng cng on ra cui cng phi dng nc sch, nc qua x l.

- Cho nc sch vo thng (hnh 1.5.8) di p lc, qua cc ng dn c l nh, ri cho nguyn liu vo, nguyn liu s ni trn mt nc. Nc chuyn ng lm di chuyn nguyn liu n ci mng cui cng ca thng ly ra sau khi ra sch.

Hnh 1.5.8. Thng ra c ng c l dn nc ra vo

phng nga thi hng rau qu, hn ch ly nhim mm bnh trong sut qu trnh ra c th dng nc ra c pha Clo. Cho 2ml thuc ty trng Clo (nc Javel thng mi, trong c khong 5,25% hypoclorit natri) vo trong 1 lt nc sch s to ra dung dch Clo nng 100 150 ppm (phn triu). Cn nhiu Clo hn nu s dng nhit cao hoc nu c qu nhiu cht hu c trong nc ra.

pH ca nc ra nn c gi 6,5 7,5 l tt nht. Sau thi gian ra khong 2 pht bng nc clo th ra li bng nc sch.

C th s dng thng, b c ng x y thng thng ra (hnh 1.5.9). Cho nc vo n mc thch hp ri cho rau, qu vo (khng nc trn ra ngoi). Cng nhn dng tay o trn nguyn liu lm sch cc cht bn dnh trn nguyn liu.

Trong qu trnh ra, nu pht hin c vt th l hoc cc qu thi hng th tip tc loi b. Sau khi ra mt thi gian nht nh th nn x nc bn ra ngoi, cho nc sch vo ra tip cho n khi nc ra trong, khng cn b vn c.

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Hnh 1.5.9. Ra nguyn liu

Sn phm ra cn ro nc trnh lm long thuc tr nm (nu c x l) hoc trnh h hi bng cch ri chng thnh lp mng ln cc gi bng li mt co hoc trong cc r t ni mt, thng gi tt (hnh 1.5.10) hoc c th cho vo thit b lm ro nc dng quay (hnh 1.5.11) lm vng nc ra nhanh hn.

Hnh 1.5.10. Lm ro nc bng r nha

Hnh 1.5.11. Lm ro nc bng cch quay

3.2. Lau bng vi mm

i vi mt s loi qu c th dng tay lau hoc dng my lau loi b nhng ht t bn nh hoc bi. Vic lau phi lm cn thn v s xy xt v qu ti s lm cho sn phm nhanh b thi hng.

4. Phn loi theo kch thc

Mc d sn phm c chn lc ng rung lc thu hoch hoc c phn loi s b nh s ch nhng cn c phn loi theo kch thc ln na trc khi c ng gi. Vic phn loi ny lm cho nguyn liu ng u v kch thc, hnh dng, mu sc hoc chn, bn c vi gi cao hn so vi cc loi khc.

Vic phn loi kch thc c th c tin hnh bng hai hnh thc:

- Phn loi th cng: bng mt v bng tay l rt ph bin.

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Hnh 1.5.12. Phn loi bng tay vi s h tr ca bng chuyn

- Phn loi bng my: vi s h tr ca cc dng c nh bn phn loi, mng phn loi hoc vng phn loi. Cc dng c ny ch yu dng phn loi qu hoc c.

Dng vng phn loi: phn loi cc loi qu, c c hnh dng trn, ngi ta dng vng phn loi. Ty theo loi sn phm m dng vng c kch thc ph hp.

Dng bn phn loi c l: thng dng phn loi c, qu. phn loi khi sn phm th dng nhiu bn c kch thc l khc nhau, t ni tip nhau. Khi c hoc qu cn phn loi c ln bn c kch thc l ln nht trc. Nhng c hoc qu khng lt qua kch thc l ny ca bn ny c a vo nhm c kch thc ln nht.

Phn lt qua l s ri xung mn hng, v c a vo thng cha .

Thng cha ny li c ln bn phn loi c kch thc ln th hai. Nhng c hoc qu khng lt qua kch thc l ny c xp vo nhm c kch thc ln th hai, v c tip tc nh th.

Dng mng phn loi:

Hnh 1.5.13. Mng phn loi

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Qu c vo hnh bt gic u mng, sau c cho ln theo mng, hng v pha cc khe hp. Nhng qu ln s c gi li khe hp th nht, qu va s c gi li khe th hai v nhng qu nh khe cui cng. Qu c kch thc b hn c khe hp b nht th s ln n ht mng v chuyn thng vo thng cha. Cng nhn s ly qu ra bng tay v chng vo thng cha ring.

Dng bng ti: Nu trong nh bao gi c h thng bng ti dy xch hoc dy ai c s dng phn loi, s c nhiu loi kch thc ca khe h khc nhau ca phn loi sn phm.

Bng ti c cc khe vung thng c s dng cho nhiu loi hng ha nh to, c chua, hnh ty; trong khi khe h hnh ch nht s dng cho o, v t. Cc khe hnh lc gic th thng s dng cho khoai ty v hnh ty.

Hnh 1.5.14. Khe hnh

vung

Hnh 1.5.15. Khe hnh

ch nht

Hnh 1.5.16. Khe hnh lc gic

5. Phng tr nm bnh

Nguyn tc gip rau qu ti phng nga c cn trng v bnh hi l cc bin php qun l tt trong sut qu trnh sn xut v:

- Chn ging cy trng c sc khng bnh hi, k thut chm sc tt.

- Cn trng trong qu trnh thu hi v x l trn ng rung.

- Loi b cc sn phm b tn thng hoc thi hng hn ch s ly nhim sang cc sn phm nguyn vn khc.

- Kim sot cn trng hi v vi sinh vt gy thi hng, ngay c khi mi qu trnh c tin hnh cn thn.

- Kim sot m ca mi trng: khi m tng i ca mi trng bo qun cao l mt yu t gi cht lng rau qu ti, th nc d ng trn b mt sn phm li gy ra hin tng ny mm, v lm tng kh nng nhim bnh.

- Kim sot bng ha cht: ra sn phm trong nc c Clo s ngn nga c thi hng gy ra bi vi khun, nm men v nm mc trn b mt sn phm. Mui Canxi hypoclorit (dng bt) v Natri hypoclorit (dng lng) khng t tin v c s dng rng ri. Hiu qu ca vic x l s gim i nu c nhiu cht hu c trong nc ra. Hiu qu ca Clo s tng ln khi pH gim t pH = 11 xung pH = 8, nhng nu pH thp hn na th hiu qu ra vi Clo s tr nn khng n nh.

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Hm lng Natri hypoclorit (NaOCl) thm vo nc ra ty trng c trnh by bng 5.1.

Bng 5.1. Hm lng Natri hypoclorit thm vo nc ra ty trng

Hm lng

Natri hypoclorit Nng cn t (ppm) Nng gam/lit

Natri hypoclorit (5,25%)

50 0,69

75 1,00

100 1,37

125 1,75

150 2,12

Natri hypoclorit

(12,7%)

50 0,15

75 0,21

100 0,29

125 0,36

150 0,44

Ngoi ra c th s dng mui bicacbonat: s dng mui bicacbonat phng nga thi hng sau thu hoch c p dng trn t ti, da, c chua, c rt v cc qu c mi.

Cc mui ny c gi thnh khng t, an ton khi s dng, sn c v c cng nhn l cht hu c m bo gi tr v "khng ha cht. Cc mui bicacbonat bao gm: Natricacbonat hay cn gi l bt Soda hay bt n (NaHCO3), Kalicacbonat (KHCO3).

Phng php s dng (c hoc khng c Clo): phun hoc nhng vi cc nng dung dch pha nh sau:

+ Dung dch 2% (cn 2g trong 100ml nc hoc 20g trong 1 lit nc).

+ Dung dch 3% (cn 3g trong 100ml nc hoc 30g trong 1 lit nc). Vi nng ny, sau khi phun hoc nhng th phi ra li trong nc.


1. Cu hi:

1.1. Cu hi s 1.5.1: Hy nu cc yu cu cht lng ca rau qu cn phi m bo khi qua cc cng on x l sau thu hoch.

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1.2. Cu hi s 1.5.2: Hy trnh by cc bc tin hnh ca cng on x l rau qu sau thu hoch.

2. Bi thc hnh:

2.1. Bi thc hnh s 1.5.1: Tin hnh thc hin cc bc cng vic ra v lm sch nm bnh trn rau qu sau thu hoch.

- Mc tiu: Cng c kin thc v rn luyn k nng ngh thc hin cc bc cng vic ra v lm sch nm bnh trn rau qu sau thu hoch.

- Ngun lc:

+ Nh s ch x l rau qu sau thu hoch.

+ Thit b, dng c: thau, chu, cn k thut, a khuy, vi mm, bn ra, thng cha.

+ Ha cht: dung dch dit nm.

+ Trang phc bo h: gng tay v ng cao su, qun o bo h lao ng.....


- Nhim v: mi nhm thc hin ra, lm sch mm bnh trn rau hoc qu c giao thc hnh.


+ Mang bo h lao ng.

+ Chn nhng thit b, dng c, ha cht ra rau qu.

+ Thc hin cc bc ra v lm sch nm bnh trn rau qu sau thu hoch theo ni dung hng dn:

B1. Pha dung dch thuc tr nm cho rau qu.

B2. Tin hnh ngm rau hoc qu bng dung dch ha cht dit nm, ra sch rau qu bng nc sch.

B3. Lau sch qu, ro nc i vi rau.

B4. nh gi cht lng rau, qu sau khi lm sch.




+ Thao tc ra, pha ha cht theo ng yu cu.

+ Rau qu c ra, lau kh m bo yu cu v cht lng.

2.2. Bi thc hnh s 1.5.2: Tin hnh thc hin cc bc cng vic phn loi rau qu sau thu hoch.

- Mc tiu: Cng c kin thc v rn luyn k nng ngh thc hin cc

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bc cng vic phn loi rau qu sau thu hoch.

- Ngun lc:

+ Nh s ch x l rau qu sau thu hoch.

+ Thit b phn loi, thng cha ng cc loi sn phm.

+ Cc dng c phn loi: bn dng phn loi, dao, ko, thng cha.

+ Trang phc bo h: gng tay cao su, ng cao su, qun o bo h lao ng


- Nhim v: mi nhm nhn mt loi rau qu nht nh v tin hnh phn loi rau, qu thnh cc nhm sn phm khc nhau theo kch thc v loi b cc sn phm h hng.


+ Mang bo h lao ng.

+ Chn ra nhng thit b, dng c cn dng phn loi.

+ Thc hin cc bc phn loi theo ni dung hng dn:

B1. Tin hnh phn loi rau qu.

B2. ring cc loi sn phm rau qu trong cc thng cha.

B3. Kim tra v theo di cht lng rau qu sau khi phn loi.




+ Thao tc phn loi rau qu sau thu hoch theo ng yu cu.

+ Rau qu sau phn loi m bo yu cu v cht lng.

C. Ghi nh

- Phn loi s b v phn loi theo kch thc nhm loi b cc phn b dp, nt, h hng, nhim bnh ra khi phn ti, tt nhm trnh s ly lan mm bnh v bo m cht lng ng nht. Khi phn loi ch ring cc loi sn phm khc nhau.

- Lm sch c tc dng loi b cc tp cht v mm bnh trn rau qu. C th lm sch bng nc sch hoc c th lau bng vi mm (i vi cc loi qu)

- Khi phn loi, lm sch khng c rau qu trc tip trn sn nh, nn t.

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BI 6. NG GI V GHI NHN RAU QU SAU S CH

M bi: M01-06

A. Ni dung

1. Cc loi bao bi

Bao b khng ch c chc nng cha sn phm m quan trng hn, n cn c s dng nh mt yu t bo v sn phm hu hiu, gip sn phm trnh nhng tc ng c hc v nhng nguyn nhn lm hao tn khc. Cc chc nng khc ca bao b l cung cp cc thng tin v sn phm bn trong nh: khi lng v nh gi bn ca sn phm, xut x, ngun gc ca sn phm

C nhiu loi bao b khc nhau c s dng bao gi v vn chuyn rau qu. D loi bao b no cng phi bo m cc yu cu sau:

- Bao b phi bo m rn chc v c th ti s dng, hoc tr li, c b mt nhn v d v sinh v c th xp thnh chng cao.

- Bao b dng ng gi rau qu ti phi c lm t cc cht liu khng c, khng nh hng n an ton thc phm v ph hp vi loi sn phm.

Bao b dng ng gi rau qu ti c lm t nhiu loi vt liu nh: tre, g, cctng, nha cng, nilng. Mi loi vt liu u c u im v nhc im. Ty theo loi sn phm cn ng gi, iu kin kinh t v cc yu t khc m la chn chng loi bao b cho ph hp vi tng loi sn phm.

1.1. Bao b bng tre

Cc loi bao b nh r, st an bng tre (hnh 1.6.1) c u im l chi ph thp, s dng li c nhiu ln nu c ch to tt.

Hnh 1.6.1. St tre ng tri cy

Mc tiu:

- Trnh by c u v nhc im cc loi bao b;

- Nu c cc h hng do vic ng gi gy ra i vi rau qu;

- Thc hin c vic chn lt v sp xp rau qu vo bao b, buc cht bao b ng yu cu;

- Ghi c cc thng tin cn thit ln nhn v dn nhn ng quy nh;

- Rn luyn tnh cn thn, kho lo.

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Tuy nhin, chng loi bao b ny c nhiu bt li:

- cng khng cao v b un, bin dng khi cht ng khi lng ln hng ha vn chuyn trn khong ng di.

- Kh lm sch khi b nhim bn v vi sinh vt.

- Gy ra cc thit hi v b nn p khi cha y cht.

- C cc g cnh sc gy ra try xt sn phm nu khng c s bc lt k.

1.2. Bao b bng g

Bao b bng g c cng kh cao, bn, c th ti s dng nhiu ln, chu ng c iu kin khng kh m.

Nu loi bao b ny lm theo kch thc tiu chun s xp c nhiu hng trn thng xe v trong kho cha.

S dng bao b bng g thng gp nhng bt li l:

- Kh ra sch hon ton c th dng nhiu ln.

- Nng v tn km trong vn chuyn.

- C g sc, u inh th ra nn cn phi c lp vt liu lt bn trong trc khi cha sn phm.

Thng g (hnh 1.6.2) c dng kh ph bin trong vic ng cc loi qu, l loi dng c c trng ng nho.

Hnh 1.6.2. Thng g

Khay g n gin vi 4 chn c ng ni ln, d chng xp, v cho php thng hi tt cho cc loi nng sn d h hng nh c chua chn (hnh 1.6.3).

Hnh 1.6.3. Khay g vi 4 chn c ng ni ln

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1.3. Bao b bng cctng

Bao b bng cctng c u im l nh, sch v d vit hoc in qung co v cc thng tin v sn phm cha bn trong, c nhiu loi kch c khc nhau, mu m v vng chc khc nhau, c th c lm kn bng nhiu cch nh dn, kp inh, ci cht (hnh 1.6.4).

Hnh 1.6.4. Hp cctng

Bao b lm bng cctng c nhiu dng khc nhau, ph bin nh sau:

- Hp cctng mt tm c ng v dn kn li (hnh 1.6.5)

Hnh 1.6.5. Hp cctng mt tm

- Hp cctng hai tm, c np y ring (hnh 1.6.6).

Hnh 1.6.6. Hp cctng hai tm c np ring

- Hp cctng hai tm, c np v y c dn hoc ng ghim khi ghp thnh hp (hnh 1.6.7).

Hnh 1.6.7. Hp cctng hai tm c np v y ghp thnh hp

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Cc bt li khi s dng bao b bng cctng l:

- Khng dng c nhiu ln (nu dng nhiu ln, cc hp c th b bp, v khi rng) nn tn chi ph.

- D b h hi nu qun l v cht xp khng cn thn.

- B mm, thm nc khi t ch m, t.

1.4. Bao b bng nha

Bao b bng nha cng, chc, nhn, d ra sch v c th lng vo nhau khi trng rng tit kim khng gian v c th xp thnh tng khi cha y sn phm, s dng li c nhiu ln nn so vi st tre cng dung tch cha th tit kim chi ph hn.

Hnh 1.6.8. Bao b bng nha

Cc bt li khi s dng bao b bng nha l:

- Gi thnh tng i t nn tn tin u t ban u ln.

- H hng nhanh khi lu di nh nng mt tri trc tip.

Tuy nhin nhiu nghin cu v qua thc t cho thy rng cc loi st bng nha mc d gi c cao hn cc st bng tre cng dung lng nhng s ln dng li nhiu hn, bo v sn phm tt hn, xp gn hn v d ra sch hn nn hiu qu kinh t cao hn.

1.5. Bao b bng si thin nhin hay si tng hp

Cc bao hay ti ng sn phm ti c th c lm t si thin nhin nh ay hay t si tng hp nh si polypropylen (PP), polyetylen (PE) hay

dy bn (hnh 1.6.9).

Hnh 1.6.9. Bao b bng si tng hp

Cc ti hay bao ny c dng cho nhng sn phm tng i t b h hng nh khoai ty, hnh Tuy nhin, sn phm ny cng cn qun l cn thn nga tn thng, h hng khng ng c.

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Cc bt li khi s dng loi bao b ny l:

- Thiu cng cp v vic x l c th lm h hi n sn phm cha bn trong.

- Cc ti khi b ri hay qung nm c th gy thit hi nghim trng cc sn phm cha bn trong.

- Khi cht ng s km thng thong nu cc ti lm bng vi mn, kn.

- Do b mt trn nhn, khng c gc cnh (v d: ti bng si) nn cc ng hng cht cao d b ng .

1.6. Bao b bng mng cht do

1 giao trinh so che rau qua 0833

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