cong nghe bao quan va che bien rau qua 2

7/30/2019 Cong Nghe Bao Quan Va Che Bien Rau Qua 2

1/28

Cng ngh bo qun vch bin rau qu

Trng i hc Cng ngh ng Nai

Ging vin: Nguyn QuangEmail: [email protected]

[email protected]

Phone number: 01689.034.127
mailto:[email protected]:[email protected]:[email protected]:[email protected]


2/28

Cng ngh bo qun rau qu Mc tiu: sau khi hc xong phn ny,

sinh vin c kh nng: Bit c cc thnh phn dinh dng ctrong rau qu. Xc nh c nguyn nhn gy h hng

v s h hng ca rau qu. Nm vng c nhng nguyn tc v

phng php bo qun c bn. ng thitm hiu mt s thit b thng s dng bo qun rau qu.


3/28

Chng II. Nguyn nhn gy h

hng v s h hng ca rau qu

1. Nhng nguyn nhn gy h hng

rau qu ti2. Nhng nguyn nhn gy h hng

sn phm rau qu ch bin

3. S h hng ca cc sn phm rauqu ch bin


4/28


rau qu ti Tc nhn sinh hc

Tc nhn vt l Tc nhn ha hc Tc nhn khc

Theo em c nhng nguyn nhn no gy h hng rauqu ti?


5/28


rau qu ti T h hng

Hot ng ca enzym ni ti Cc phn ng ha hc m khng cn xc tc ca

enzym B h hng

S pht trin v hot ng ca vi sinh vt Tc nhn vt l nh: dp, chy, sy kh, lnh

ng Cn trng, cc loi gm nhm hoc cc ng vt

khc

Thc phm h hng c th do mt hocnhiu nguyn nhn


6/28


rau qu ti Phn loi thc phm da vo tnh n

nh v mc thi hng: Thc phm kh hng: khng d dng hngnu bo qun ng cch (cc loi u) Thc phm tng i d hng: khng b

hng nu bo qun ng cch (khoai ty,

to, qu c v cng) Thc phm d hng: thc phm d hng

nu khng c bo qun c bit (huht cc loi rau qu)


7/28


sn phm rau qu ch bin Theo em c nhng nguyn nhn no gy h hng sn

phm rau qu ch bin? S lng vi sinh vt sng st sau khi x

l nhit Hm lng dinh dng c trong sn

phm rau qu pH sn phm Hm lng O2

Nhit bo qun


8/28

3. S h hng ca cc sn phm

rau qu ch bin3.1. H hng v sinh3.2. H hng hu sinh

3.3. Biu hin h hng3.4. S h hng ca cc sn phm rau qu nghp

3.5. S h hng ca cc sn phm nc tch chitt rau qu

3.6. S h hng ca cc sn phm mt qu3.7. S h hng ca cc sn phm qu ng lnh3.8. S h hng ca cc sn phm rau qu sy kh

3.9. S h hng ca cc sn phm rau ln men


9/28

H hng v sinh Theo em, em hiu th no v h hng v sinh v h hng

hu sinh? Do nhng thay i v mt ha hc v vt l

trong sn phm. S hot ng ca enzym Oxy ha cht bo Kt ta protein

Phn ng to mu gia ng v acid amin(Melanoidin) Ho, ng cn hoc ha rn (vt l)

Nguyn nhn chnh gy h hng dng ny lnhit v m.


10/28

H hng hu sinh S h hng dng ny thng lin quan n

vi sinh vt.

Yu t nh hng ti s h hng rau qu dovi sinh vt: Hm lng nc pH ca rau qu Ngoi ra cn mt s yu t tc ng bn ngoi

nh: loi rau qu, iu kin bo qun: nhit , m, thnh phn cc kh trong mi trng boqun


11/28

H hng hu sinhVi khun

Coliforms, cc vi khun to bo t, vi

khun lactic v acetic. C th ko di thi gian bo qun bng

cch ko di pha tim pht:

Hn ch s nhim tp vi sinh vt Kim sot iu kin mi trng (nhit , pH,

m)


12/28

H hng hu sinh Nm mc

Nm mc thng sinh c t (alflatoxyn,

patulin) v thay i thnh phn ca qu(h thi)

Nm men C mt nhiu trn b mt qu c khnng phn cch tinh bt, pectin nn gy ra

nhng bin i v thnh phn ca qu.


13/28

H hng hu sinhVi sinh vt c mt trong rau:

Vi khun: Salmonella, Shigella, E.coli,

Listeria, Aeromonas, ClostridiumVirus: Heptitis

K sinh trng: Entamoeba histolytica,

Giadia lamblia, Ascasis lumbricoides


14/28

Biu hin h hng Nhng thay i bn ngoi:

Cu trc Mu sc Mi

S to nht


15/28

S h hng ca cc sn phm

rau qu ng hp Nguyn nhn:

Sinh hcVt l Ha hc Nguyn nhn khc

Nhit bo qun Nhim tp kim loi t v hp


16/28

S h hng ca cc sn phmrau qu ng hp

H hng sinh hc: do vi sinh vt S lng vi sinh vt sng st sau khi x l

nhit: iu kin ch bin cha m boVi sinh vt chu nhit hoc to bo t S nhim tp

Cc sn phm thng h hng dngny l qu ng hp, mt, nc qu


17/28


H hng vt l:Vn hnh k thut sai X cha kit in qu y Mp hp


18/28


H hng ha hc: Thng do phn ng gia cc thnh phn

rau qu, phn ng gia vt liu lm hp vthnh phn rau qu.

Hn ch h hng bng cch iu chnh

chn khng v pH (pH ~ 4.0 to iu kinthun li cho nhiu phn ng)


19/28

S h hng ca cc sn phmnc tch chit t rau qu

Sn phm nc rau qu ng hp Nc qu thng b h hng do nm men

v nm mc pH sn phm nc qu thng thp nn t

b h hng bi vi khun

Ngc li, nc p t rau d h hng do vikhun v c acid thp


20/28


Sn phm nc qu c c Sn phm c acid v hm lng ng

cao Ph hp cho s pht trin ca nm men v

cc chng chu acid v nng ng cao.

Hn ch h hng bng cch x l nhittrc khi ng gi v bo qun lnh ng.


21/28


Sn phm ung ng chai Nc gii kht khng cn:

S h hng ph thuc vo thnh phn ca ung

Biu hin h hng thng l sn phm b cv gim cht lng

Nc gii kht c gas: t h hng do hmlng CO2 cao


22/28

S h hng ca cc sn phmmt qu (Jam v Jelly) Sn phm dng ny t b h hng do:

Thng c hot nc thp C b sung acid pH sn phm thp i khi b sung cc cht bo qun (acid benzoic,

acid sorbic)

Sn phm c x l nhit Gim nhit bo qun gip tng thi hn s

dng sn phm. C th h hng do cc chng nm men chu

p sut thm thu v nm mc c kh nngchu nng ng cao.


23/28

S h hng ca cc sn phmqu ng lnh

Sn phm ng lnh thng c bsung ng hoc syrup trc khi lmlnh.

Hu ht vi sinh vt b tiu dit do tcng nhit (x l lnh ng)

Phng php ny phi s dng c chnlc (rau qu ti)


24/28

S h hng ca cc sn phmrau qu sy kh

c trng sn phm sy kh: Hot nc rt thp C qu trnh x l nhit (trong qu trnh

tch nc)

Bo t vi khun v nm mc thng

gy ra h hng dng ny. H hng do qu trnh oxy ha to mi

l, mt mu


25/28

S h hng ca cc sn phmrau ln men

Sn phm thng c pH thp nn hnch c h hng

Sn phm ln men trong iu kinkhng ti u thng c cht lng thp

Thc t, sn phm mui chua thng

d h hng (oxy ha hoc s xm nhpca vi sinh vt) do tip xc vi khngkh


26/28

Tng kt chng II

Tm hiu nhng nguyn nhn gy hhng rau qu tm cch bo qun

thch hp. S h hng thng c hn ch nh

pH, hot nc, x l nhit, iu kinbo qun.

Vi nhng sn phm c trng: nng ng cao, pH thp, hot ncthp c kh nng t bo qun.


27/28

TIU LUN Tn ti / Nhm (5 ngi)

Ni dungI. M u

II. Ni dung1. Tng quan nguyn liu

2. S quy trnh

3. Thuyt minh quy trnh

III.

Kt lun

Hnh thc Kiu ch: Times New Roman

C ch: 13


28/28

Tnh im

Kim tra gia k (1 tit bui 5)

im tiu lun:Tiu lun (50%): np 1 bn in + 1 bn quamail

Bo co (50%): bui 5 + 6

Thi cui k (trc nghim)

cong nghe bao quan va che bien rau qua 2

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