N04_HuongMauChatBaoQuan

7/28/2019 N04_HuongMauChatBaoQuan

1/31

GVHD: VNH LONGTHI GIAN: TH 4; TIT 11-12NHM 04: L Quc Nht 3005100541

Dng Th Bch Trm 3005100801Trn NhThi 3005100709Nguyn Hi Triu 3005100837Nguyn Th Duy 3005100149

BCNG THNGTRNG I HC CNG NGHIP THC PHM

THNH PH H CHNH MINH

KHOA CNG NGH TH C PHM

TM HIU C IM, TNH CHT CA NGUYN LIU

HNG THM, CHT TO MU, CHT BO QUN

TRONG NC GII KHT

TP.HCM thn 12, nm 2012


2/31

2

MC LC

Ni Dung Trang1. TNG QUAN V PH GIA THC PHM...................................................................................4

1.1. Cc Khi Nim ..............................................................................................................................4

1.2. Phn Loi: .....................................................................................................................................41.3. Qun L Cc Ph Gia: ..................................................................................................................7

2. HNG THM TRONG NC GII KHT ...........................................................................10

2.1. Khi Nim VMi Hng..........................................................................................................10

2.2. Phn Loi Cht Thm: ................................................................................................................10

2.2.1. Cht Thm T Nhin: ..........................................................................................................10

2.2.1.1. Cc Thnh Phn Ha Hc C Trong Tinh Du Ca Cc Qu Thuc H Cam Chanh: 11

2.2.1.2. Cu To Ha Hc Ca Mt S Thnh Phn Chnh To Mi Trong Tinh Du Ca QuH Cam Chanh. ..........................................................................................................................12

2.2.1.3. c im chung ca cht thm .....................................................................................13

2.2.1.4. Tnh cht ca cht thm ................................................................................................13

2.2.2. Cht Thm Tng Hp: .........................................................................................................14

2.2.2.1. Khi nim: .....................................................................................................................14

2.2.2.2. Sn xut cht thm tng hp: ........................................................................................14

3. CHT MU......................................................................................................................................16

3.1. Khi Nim ...................................................................................................................................16

3.2. Vai Tr Ca Cht Mu ................................................................................................................16

3.3. S Dng Cc Cht Mu ..............................................................................................................163.4. ng Dng ....................................................................................................................................16

3.5. Phn Loi ....................................................................................................................................17

3.5.1. Cht mu t nhin ................................................................................................................17

3.5.2. Cht Mu Nhn To ............................................................................................................17

3.6. Cc Loi Cht Mu Ph Bin Trong Nc Gii Kht ................................................................18

4. CHT BO QUN..........................................................................................................................24

4.1. Tng Quan ...................................................................................................................................24

4.2. Cht Chng Vi Sinh Vt..............................................................................................................25

4.1.1. Acid benzoic (E210).............................................................................................................25

4.1.2. Sodium benzoate (E211) ......................................................................................................26

4.2. Cht Chng Oxi Ha ...................................................................................................................27

4.2.1. Khi Nim ............................................................................................................................27

4.2.2. C Ch Hot ng ...............................................................................................................27

4.2.3. Yu Cu ................................................................................................................................28

4.2.4. Li ch ..................................................................................................................................28

4.2.5. Acid ascorbic (Vitamin C) ...................................................................................................29

TI LIU THAM KHO ...................................................................................................................31


3/31

3

LI NI U

Trong cng nghip nc gii kht, nu khng tnh cc loi thc ung c cn hay

nc tinh khit th chc chn rng tt c cc loi nc gii kht t nhiu u phi s

dng cc loi ph gia. Trong , hng v mu gn nh khng th thiu trong mt s

sn phm nc gii kht thng dng hin nay, bn cnh to cho sn phm c gi tr

cm quan cao ngi ta cn cn phi bo qun sn phm trong thi gian cng lu cng

tt. Do cc cht bo qun cng khng km phn quan trng trong sn xut nc

gii kht.

Trong bi tiu lun ny nhm xin php gii thiu v mt s loi ph gia

(hng, mu, cht bo qun) thng dng trong sn xut nc gii kht hin nay.


4/31

4

TM HIU C IM, TNH CHT CA NGUYN

LIU HNG THM, CHT TO MU,

CHT BO QUN TRONG NC GII KHT

1. TNG QUAN V PH GIA THC PHM

1.1. Cc Khi Nim

Theo FAO: Ph gia l cht khng dinh dng c thm vo cc sn phm vi

cc nh khc nhau. Thng thng, cc cht ny c hm lng thp dng ci

thin tnh cht cm quan, cu trc, mi v, cng nh bo qun sn phm.

Theo WHO: Ph gia l mt cht khc hn l thc phm hin din trong thc

phm l kt qu ca mt s mt: sn xut ch bin, bao gi, tn tr Cc cht nykhng bao gm cc cht bn b nhim vo thc phm.

Theo y ban Tiu chun ha Thc phm Quc t (Codex Alimentarius

Commission-CAC) th ph gia thc phm (food additives) l "mt cht c hay khng

c gi tr dinh dng, m bn thn n khng c tiu th thng thng nh mt thc

phm v cng khng c s dng nh mt thnh phn ca thc phm. Vic ch b

sung chng vo thc phm gii quyt mc ch cng ngh trong sn xut, ch bin,

bao gi, bo qun, vn chuyn thc phm, nhm ci thin kt cu hoc c tnh k

thut ca thc phm . Ph gia thc phm khng bao gm cc cht nhim hoc cc

cht c b sung vo thc phm nhm duy tr hay ci thin thnh phn dinh dng ca

thc phm".

1.2. Phn Loi:

- C nhiu cch phn loi cht ph gia. Theo Quyt nh s3742/2001/Q-BYT

ngy 31/8/2001 ca B Y t v vic ban hnh "Quy nh danh mc cc cht ph giac php s dng trong thc phm" phn loi ph gia thc phm theo chc nng

gm 23 nhm cht sau: (Phn loi ph gia theo nhm chc nng)

1/ Cht iu chnh acid: Cc cht iu chnh acid c s dng thay i hay

kim sot chua v kim hoc c tc dng bo qun, chng oxy ha cho thc

phm nh Acid Citric, Acid Ascorbic, Acid Tartaric, Acid Malic, Acid Fumaric, Acid

Lactic...

2/ Cht iu v: Cccht iu vlm tng hng v sn c ca thc phm.
http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%C4%91i%E1%BB%81u_v%E1%BB%8B&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%C4%91i%E1%BB%81u_v%E1%BB%8B&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%C4%91i%E1%BB%81u_v%E1%BB%8B&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%C4%91i%E1%BB%81u_v%E1%BB%8B&action=edit&redlink=1


5/31

5

3/ Cht n nh: Cc cht n nh c tc dng duy tr sng nht, n nh cu trc

ca thc phm, v d: Cccht n nh, to c v to gel, chng hnaga hay pectin

(s dng trong mt s loi mthoa qu) lm cho thc phm c kt cu c v chc.

4/ Cht bo qun:

Cc cht bo qun ngn hoc kim ch sh hng ca thc phm b gy ra bi cc

hot ng ca nm mc, vi khun hay cc vi sinh khc. Thc phm thng b mt s

vi khun, nm c, mc, men lm h hng.

Vic s dng loi ph gia ny ch ph bin trong thi gian gn y; mt trong nhng

nguyn nhn ca vic gia tng s dng loi ph gia ny l do s thay i trong sn

xut v tiu th cc sn phm thc phm. Ngy nay, ngi tiu dng mong mun rng

tt c cc loi thc phm u c quanh nm, khng b nhim c v c thi hn s

dng hp l. Do , ph gia chng vi sinh vt c vai tr quan trng trong vic bo

qun thc phm mc d c s ci tin trong h thng ng gi v ch bin bo

v thc phm m khng cn dng n ha cht.

5/ Cht chng ng vn:

Cc cht chng ng vn nh canxi silicate, silicon dioxyd gi cho cc cht bt, chng

hn nh sa bt, cacao bt, ng, mui ht nc, gip chng khng b ng vn,

kh cng, ng cc, dnh li vi nhau.6/ Cht chng oxy ha: Cc cht chng oxy ha nh Vitamin C (Acid Ascorbic) c tc

dng bo qun, chng oxy ha thc phm bng cch kim ch cc tc ng ca oxy

i vi thc phm, c li cho sc khe.

7/ Cht chng to bt: Cccht chng to bt lm gim hoc ngn chn s to bt

trong thc phm.

8/ Cht n: Cc cht n c tc dng lm tng khi ca thc phm b sung cho

mu t nhin ca sn phm b mt trong qu trnh ch bin hay lm cho thc phm

trng bt mt hn.

9/ Cht ngt tng hp: cc ph gia lm cho thc phm thm hng v, c th c to

ra t cc cht t nhin hay nhn to, c th cung cp thm mt vi thnh phn p ng

nhu cu dinh dng cho mt si tng c bit, nh ng ha hc to v ngt cho

thc phm nhng chng khng sinh hoc t sinh nng lng nn c s dng thay

thng cho bnh nhn i tho ng v bnh nhn bo ph.
http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%E1%BB%95n_%C4%91%E1%BB%8Bnh&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%E1%BB%95n_%C4%91%E1%BB%8Bnh&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Aga&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Aga&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Pectin&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=M%E1%BB%A9t&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=M%E1%BB%A9t&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_ch%E1%BB%91ng_t%E1%BA%A1o_b%E1%BB%8Dt&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_ch%E1%BB%91ng_t%E1%BA%A1o_b%E1%BB%8Dt&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_ch%E1%BB%91ng_t%E1%BA%A1o_b%E1%BB%8Dt&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_ch%E1%BB%91ng_t%E1%BA%A1o_b%E1%BB%8Dt&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=M%E1%BB%A9t&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Pectin&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Aga&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%E1%BB%95n_%C4%91%E1%BB%8Bnh&action=edit&redlink=1


6/31

6

10/ Ch phm tinh bt: b sung cht dinh dng tr li phn dinh dng mt i

do vic ch bin thc phm, hoc cho thm nhng cht vn khng c trong loi thc

phm . V d: bnh m, bt, go c cho thm vitamin B l thnh phn b mt i

khi xay xt

11/ Enzym: C tc dng bo qun thc phm, chuyn ha cc sn phm t nhin, ci

thin cu trc v bn thc phm.

12/ Cht y kh: Cccht yl cc loi kh nn c s dng y thc phm ra

khi cha ng n.

13/ Cht lm bng.

14/ Cht lm dy: Cc cht lm dy khi thm vo thc phm s lm cho cu trc ca

thc phm dy hn, chc hn, do dai hn m khng lm thay i cc thuc tnh khc

ca thc phm nh : Pectin, Agar...

15/ Cht lm m: Cc cht lm m c tc dng n nh, tng m thc phm nh

Glycerol, Canxi Dihydrogen Diphosphate.

16/ Cht lm rn chc: Cc cht lm dy khi thm vo thc phm s lm cho cu trc

ca thc phm dy hn, chc hn, do dai hn m khng lm thay i cc thuc tnh

khc ca thc phm nh : Pectin, Agar...

17/ Cht nh ha: Cc cht nh ha l cc cht lm cho hn hp nc v du tr nnng nht trong th nh tng. V d nh : Lecithine, Mono Diglyceride ca cc acid

bo...

18/ Phm mu: Mt s cht mu c cng dng lm cho thc phm c v ngoi hp dn

hn hoc phc hi mu sc nguyn thy ca thc phm; Cht mu c th l ha cht

tng hp hoc cht mu thin nhin ly t thc vt. Cht mu thng c s dng l

beta caroten (tin tvitamin A), nc c ci ng, c rt, ngh...

19/ Cht to bt.

20/ Cht to phc kim loi.

21/ Cht to xp: Cht lm bt n, nh mui bicarbonate, bt n, natri phosphat hoc

mt vi loi men, c dng khi lm bnh nng, bnh m... gip cho bnh mm xp,

nh hn.

22/ Cht xl bt: Cc cht x l bt m c thm vobt m ci thin mu sc

ca n hay s dng khi nng bnh.
http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%C4%91%E1%BA%A9y&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%C4%91%E1%BA%A9y&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%C4%91%E1%BA%A9y&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Ch%E1%BA%A5t_%C4%91%E1%BA%A9y&action=edit&redlink=1


7/31

7

23/ Hng liu: Ph gia hng liu ch mi xut hin trong vi nm tr li y do th

hiu v nhu cu ca ngi tiu dng ngy cng tng, p ng c nhng iu

cc nh sn xut lun tm cch pht trin v a dng ha sn phm ca mnh phc

v ngi tiu dng. V d: b sung hng liu nhm duy tr hng v vitamin d b

phn hy v nh sng. (vd: hng cam ca nc cam p, c vitamin C ) Cng nh

mu sc, hng thm l mt tnh chtcm quan quan trng ca thc phm v chng c

nhng tc dng sinh l rt r rt.

1.3. Qun L Cc Ph Gia:

- S E (Enumber) l cc m s cho cc ph gia thc phm, thng c tm

thy trn cc nhn mc bao b thc phm trong khu vc Lin minh chu u. S

nh s tun theo cc quy tc ca H thng nh s quc t (INS The International

Numbering System) c y ban Codex Alimentarius xc nh, ch mt tp con ca

cc ph gia INS l c chp nhn cho s dng ti Lin minh chu u. E l k hiu

ch Europe/Europa ngha l chu u. Trong ngn ng thng thng ti Vng quc

Anh v Ireland, thut ng E number c s dng nh l mt thut ng ch cc

ph gia thc phm nhn to.

- Cc s E cng c thy trn tem mc thc phm ti cc quc gia khc, bao

gm Australia, New Zealand, Israel... Chng c tm thy ngy cng nhiu trn ccbao b thc phmti Bc M, c bit ti Canada..

Phn loi theo khong s (INS)

100199

To mu

100109 Vng

110119 Vng cam

120129

130139 Lam & Tm

140149 Lc

150159 Nu & en

160199 Khc

200299

Cht bo qun

200209 Cc sorbat

210219 Cc benzoat


8/31

8

220229 Cc sulfit

230239 Cc phenol & format (metanoat)

240259 Cc nitrat

260269 Cc axetat (etanoat)

270279 Cc lactat

280289 Cc propionat (propanoat)

290299 Khc

300399

Cht chng xi ha& cht iu chnh

chua

300305 Cc ascorbat (vitamin C)

306309 Tocopherol (vitamin E)

310319 Cc gallat & erythorbat

320329 Cc lactat

330339 Cc citrat & tartrat

340349 Cc photphat

350359 Cc malat & adipat

360369 Cc succinat & fumarat

370399 Khc

400499

Cht to c,cht n nh& cht to

th sa

400409 Cc alginat

410419 Cc gm t nhin

420429 Cc tc nhn t nhin khc

430439 Cc hp cht polyoxyethen

440449 Cc cht to th sa t nhin

450459 Cc photphat

460469 Cc hp cht xenluloza

470489 Cc axt bo & hp cht

490499 Khc

500599

Cht iu chnh pH& cht chng vn

500509 Cc axt khong & baz

510519 Cc clorua & sulfat

520529 Cc sulfat & hirxt

530549 Cc hp cht kim loi kim


9/31

9

550559 Cc silicat

570579 Cc stearat & gluconat

580599 Khc

600699

Cht iu v

620629 Cc glutamat

630639 Cc inosinat

640649 Khc

700799

Cht khng sinh710713

900999

Linh tinh

900909 Cc loi sp

910919 Men bng tng hp

920929 Cht hon thin

930949 Cc kh ng gi

950969 Cc cht to ngt

990999 Cc cht to bt

11001599

Cc ha cht b sung

Cc ha cht mi khng thuc s phn loi tiu

chun

Ghi ch: Khng phi cc cht trong mt khong u nm trong khong s cho, v d cc

cht trong khong E400499 c cc mc ch khc nhau. Ngoi ra hng thm khng c

khong m s quy nh l do cht hng rt phong ph v a dng.


10/31

10

2. HNG THM TRONG NC GII KHT

2.1. Khi Nim V Mi Hng

- Mi hng l mt cm gic tm sinh l c cm nhn bi khu gic con

ngi, m tc nhn to nn chnh l cc cht thm.

- Cht thm:

+Dbay hi, lan truyn trong khng kh.

+n cht hay hn hp cc hp cht.

+Cc c quan cm nhn mi s cm nhn c mi ca cht thm.

-Mi ph thuc vo: Thnh phn ha hc ca cht thm v cu to ha hc ca

cht thm.

-Nh vy, c tn hiu mi, yu t tin quyt l cht thm.2.2. Phn Loi Cht Thm:

- Cht thm t nguyn liu t nhin (thc vt ch yu): tinh du t v, hoa, l, r,

thn cy

- Cht thm t nguyn liu tng hp: cc ph phm ca cc ngnh cng ngh sn

xut, ch bin

2.2.1. Cht Thm T Nhin:- Cc loi cht thm tnhin dng trong nc gii kht thng l cc loi tinh

du ly t v ca cc loi qu hcam chanh, chng c thin nhin tng hp, khng

qua bn tay con ngi. Chng trnn ph bin v l nhng hng thm t nhin rt

c a dng trong vic phi chhng liu.

- Cc loi qu thuc h cam chanh in hnh: Qut, cam, chanh, bi.

- khai thc chng trong cng nghip, ngi ta thng s dng b phn no

cy c cha nhiu tinh du th nht nhm sn xut ra tinh du c cht lng cao. Hm

lng tinh du th: Tp trung ch yu l, v qu, ht, cnh, cung l, cung qu,

r. B phn cha nhiu nht l v qu cha 5,55. Sau v qu l l cha 2,71.

Ht cha 1,47 v c tm thy nhiu trong cc v qu c mi thuc h cam chanh.

Nhng nguyn liu cha t tinh du thng qu v t tin (nh tinh du hoa hng...).


11/31

11

Hm lng tinh du trong mt vi loi qu nc ta.

Tn qu T l gia v v tht

qu%

Hm lng tinh du %

V Tht V Tht

Chanh 30 70 2,0 0,3

Cam 28 72 2,4 0,24

Qut 57,5 42,5 1,2 0,23

- Sau khi c c tinh du th ngi ta tin hnh x l cho ra tinh du bng

cch: Chng ct hoc c c cc cht thm t nhin t cc ngun giu cht thm, sau

a chng vo cc sn phm thc phm khc nhau. V cht thm vn d bay hi v

thng khng bn nn ngi ta dng cc bin php k thut v thit b phc tp thu hi cc cht thm b tch ra khi sn phm trong qu trnh gia nhit.

2.2.1.1. Cc Thnh Phn Ha Hc C Trong Tinh Du Ca Cc QuThuc H Cam Chanh:

+Tinh du chanh: (Citras limon Burun)

Chanh c nhiu loi.

Tinh du chanh c mi c trng, ngt sc c phn ging citral v gy n tng, kch

thch dch v. N tham gia nhiu thnh phn cht thm.

Sn xut tinh du chanh theo phng php chng ct hi nc, b phn s dng l v

xanh ca qu chanh gi.

Thnh phn chnh cng thay i theo loi, vng kh hu, t trng v phng php sn

xut.

Thnh phn chnh ca tinh du chanh: limonene 50-71; -terpinen 7-10,5; -pinen

8-12,7; -pinen 1-2%; myrxen 1-2,5%; geranial 0,8-2,2; -tecpineol 1-1,4%;

terpinen-4-ol 0,2-1,2%.


12/31

12

+Tinh du qut: (Citrus reticulate Blanco)

Tinh du qut c mi c trng, m v nh, c n tng v ngt.

Sn xut theo phng php ct hi nc. B phn s dng l v qu.

Thnh phn chnh ca tinh du qut: limonene 6-9,4%; -terpinen 1-20; -pinen 0,7-

2,37%; myrxen 1,5-2,3; -pinen 1,0-2,03%; tecpinolen 0,4-1,0%; decanal 0,09-

0,9; -terpineol 0,1-0,44%.

+Tinh du cam (Citrus sinensis L.)

Tinh du cam c mi c trng, nhng khng mnh bng chanh.

Sn xut t v qutheo phng php ct vi nc.

Thnh phn: limonene 92,3-95,5%; myrxen 1,79-1,89%; linalyl axetat 0,81-0,89%.

+Tinh du bi (Citrus paradisis Macfa)

Tinh du bi c mi c trng ca hoa qu, c mi g nh.

Thnh phn chnh: limonene 83-93%; myrxen 1,4-1,6; -xiaryophyllen 0,2-2,7%;

nootkaton 0,1-1%; octanon 0,1-0,3; octanol 0,1-0,2%.

2.2.1.2. Cu To Ha Hc Ca Mt SThnh Phn Chnh To Mi Trong

Tinh Du Ca Qu H Cam Chanh.

*Limonene: Cht thm c mi in hnh trong cc loi qu h cam chanh.


13/31

13

Tn IUPAC: 1-methyl-4-(1-methylethenyl)-cyclohexene

* -terpinen: c mi m v nhhn mi ca limonene.

Tn IUPAC: 4-methyl-1-(1-methylethyl)-1,4-cyclohexadiene

2.2.1.3.c im chung ca cht thm

-L nhng hp cht dbay hi c mang cc nhm chc mang mi (cacbonyl,

hydroxyl, andehyt, amin, este, ete, lacton), c cm nhn bi c quan khu gic

ca con ngi.

-Phn tlng cht thm b hn 400vC. Nu phn tlng cht thm ln hn

400vC, con ngi khng th cm nhn c mi ca cc cht thm ny.

-Mi ca ph thuc: Thnh phn cht thm, cu trc ha hc ca mi thnh

phn, slng thnh phn trong hn hp, nng ca mi thnh phn trong hn hp,

nng hn hp, quan h gia cc thnh phn ca hn hp c v mt tnh cht ln mt

cu trc.

2.2.1.4. Tnh cht ca cht thm

-Mi ca hn hp nhiu cht thm khng ch l tng cc mi ca mi thnh

phn m cn l mt t hp tng tc cc mi .


14/31

14

V d: Pha ch hn hp hng du t nhin t cc ngun nguyn liu t nhin:

500g alcohol 95 0,5g t.du tho mc lovage

2g tinh du hoa hng 2,5g tinh du n lang

2,8g tinh du hoa nhi 0,02g tinh du cn ty

1g tinh du cassle 0,1g tinh du rau mi

1g tinh du lc 520g nc ct

-Mi thm cng ph thuc vo hm lng ca cc cht thm.

V d: Pha ch hn hp hng t nhin t cc cht thm tnhin sau y:

Etyl buryrat 7%

Isoamyl axetat 0,8%-Nonalacton 1,8%

Vanillin 0,4%

Cn 96 90%

- Hn hp ny c mi da chn (Etyl butyrat) . Nhng nu ta nng hm lng

ca Isoamyl axetat ln 7% v gim hm lng Etyl burytat xung cn 0,8% th hn

hp ny li c mi chui chn.

- bn mi ph thuc thi gian bay hi cc cht mi.

-Cng mi ph thuc bn cht cht mi v ch th nhn mi.

-c tnh a cht bo l c tnh hng u ca cht mi.

- tan ph thuc vo phn cc v khnng to lin kt hydro vi nc.

-Nhit si ph thuc vo cc thnh phn cu to nn cht mi.

2.2.2. Cht Thm Tng Hp:

2.2.2.1. Khi nim:

-Cc cht c mi ging hoc khng ging vi tnhin m do con ngi tng hp

gi l cht thm tng hp.

2.2.2.2. Sn xut cht thm tng hp:

-Nguyn liu sn xut cht thm tng hp: T thin nhin hoc t cc ph phm

ca cc ngnh cng nghip sn xut du m, giy

-Ngi ta bt chc mi ca thin nhin bng cch: Sau khi phn tch tht chitit thnh phn ha hc, hm lng cc cht v cu to ca chng, cc nh khoa hc


15/31

15

tin hnh cho ph phm i qua cc phn ng (oxy ha, hydro ha, ng phn ha)

nhm to c cht thm mong mun.

- Ngi ta pha ch cc thnh phn v cht gn nh mi thin nhin c mt mi

gi l mi tng hp (hay mi bt chc). Sau ngi ta thay i thnh phn lm cho

mi thu c khng nhng gn ging mi thin nhin m cn c sc thi ring, hp

dn, quyn rv c nhiu ngi a thch. Loi mi ny phong ph v thnh phn,

chng loi v mang tnh hin i.

V d: Hng du tng hp t cc cht ha hc tng hp (Ashurst, 1999):

0,8g ethyl heptylate 5g methyl amyl ketone

0,8g tinh du sweet birch 6g diacetyl

2,1g aldehyt C14 21,2g ethyl valerate2,4g cinamyl isobutyrate 23,15g aldehyde C16

2,6g ethyl vanillin 43,2g ethyl lactate

3g ch phm corps praline 100g alcohol 95%

3,2g cinnamyl isovalerate 783,15g propylene glycol

3,4g dipropyl ketone

- S dng cht thm tng hp nhm ci thin c cc khuyt im ca hng

thm t nhin. Loi hng tng hp khng nhng a dng v thnh phn ha hc m

cn v chng loi.

-Li ch khi s dng cht thm tng hp: V d: 1kg Vanillin chit tch t thin

nhin gi 4.000USD nhng cht thm tng hp ha hc ch c 12USD.


16/31

16

3. CHT MU

3.1. Khi Nim

- Cht mu thc phm l mt nhm nhng cht c mu c dng lm ph gia

thc phm, to ra hoc ci thin mu sc ca thc phm, nhm lm tng tnh hp

dn ca sn phm. Nhng cht mu ch l cht lm tng cm quan v hon ton khng

c gi trdinh dng khi n vo.

3.2. Vai Tr Ca Cht Mu

C 3 nguyn nhn chnh gii thch ti sao phi cn n cc cht to mu:

-Th nht, cc cht to mu c n nh khc nhau.

-Th hai, cc loi mu c bit cn thit cho cc loi thc phm khc nhau.

-

Th ba, mt lot cc cht mu cn thit tho mn nhu cu ca ngi tiudng.

3.3. S Dng Cc Cht Mu

Nhng iu cn ch khi s dng cht mu.

ng lut.

ng cht lng.

ng c tnhthc phm.

Cc yu t nh hngn cht mu.

iu kin ch bin.

iu kin ngoi cnh.

H qukhi s dng qu liu cc cht mu .

3.4. ng Dng

-Thng c s dngsn xut bnh ko v sn xut nc ung khng ru,

sn xut hp ch yu l hp rau qu.

-Liu lng cht mu c s dng trong nc gii kht l 5-200ppm, liu

lng trung bnh l khong 75ppm.

-Nhiu trng hp c quan bo v sc khe nh Cc VSATTP, Vin dinh

dng cm s dng vo trong thc phm cc cht mu hu c nhn to v cha bit

ht c tc dng phc tp ca n i vi con ngi.


17/31

17

3.5. Phn Loi

Cc cht to mu thc phm c chia lm hai loi chnh:

3.5.1. Cht mu tnhin

- L cc cht mu c chit xut ra hoc c ch bin t cc nguyn liu hu

c (thc vt, ng vt) sn c trong t nhin.

- Nhm cht mu t nhin c bn km, li kh ha tan trong nc, d phai

mu, nn nu s dng sn xut nc gii kht phi s dng vi lng ln nn gi

thnh sn phm cao.

3.5.2. Cht Mu Nhn To

L cc cht mu c to ra bng cc phn ng tng hp ho hc.

u im:

-Mu sc p

-a dng v mu sc

-Bn mu, kh phai mu.

-D ho tan trong nc.

-

Gi thnh r-Ch mt lng nh c th t c yu cu t ra.

Nhc im

-Nu s dng qu liu th a s u gy c

-Hin nay, trong s 35 cht mu c s dng cho thc phm Vit Nam mi

ch c 10 cht mu c chit xut t thc vt, cc cht mu cn li l nhn to v u

phi nhp t nc ngoi. Do yu cu v ATVSTP, b Y t nc ta ch cho php nhp

v s dngcc cht mu thc phm vi s lng hn ch.

Liu lng sdng hng ngy ca cht mu tng hp:

Cht to muLiu lng tiu th trung

bnh hng ngy(mg/kg)

Lng cho php tiu th

trung bnh hng ngy(mg/kg)

FD&C Blue No.1 16 12.5

FD&C Blue No.2 7.8 5.0

FD&C Green No.3 4.3 12.5c

FD&C Red No.3 24 0.05


18/31

18

FD&C Red No.40 100 Cha c d liu

FD&C Yellow No.5 43 7.5

FD&C Yellow No.6 37 5.0

3.6. Cc Loi Cht Mu Ph Bin Trong Nc Gii Kht

a. Sunset yel low FCF (E110):

1. Tn khc, ch s CI Food Yellow 3, FD&C Yellow No. 6, Sunset yellow EG,

Para Orange, FD&C Yellow No 6, Jaune Orange S, Jaune

Sunset, FCF CI Food Yellow 3, Lebesmittel Orange No 2

INS: 110

ADI = 0-2,5 mg/kg th trng/ngy2. nh ngha L mui Na ca axit Naphtol- sulphonic

Sn xut t cc hydrocacbon thm t du kh, nha than ,

Tn ha hc dinatri 6-hydroxy-5-(4-sulfonphenylazo)-2-naphthalen-6-

sulfonat.

Cng thc ha hc C16H10N2Na2O7S2

Cng thc cu to

Khi lng phn t 452,38

3. Cm quan Dng bt hoc ht mu cam.Sunset yellow rt bn nhit, bn vi nh sng.

4. Tnh cht

Nhit nng chy 300C

tan Tan trong nc, t tan trong ethanol, phenol, Khng tan trong

cc dung mi cht bo.

tan trong nc 24C: 510g/100mL H2O

5.ng dng Sunset yellow c dng trong thc phm ln men c x l


19/31

19

nhit.

Sunset yellow thng c s dng kt hp vi Amaranth

Red, to ra mt mu nu scla v caramel.

Mt s sn phm s dng sunset yellow:

Thng c s dng trong thc phm ln nc gii kht,

ru mi, thch mu cam, nc st, mt s loi mt, bnh

ko,mt s thc phm khc Ngoi ra cn c tm thy

hu ht cc sn phm c mu , mu vng hoc vng cam.

Gii hn ti a cho php trong thc phm theo B Y T Vit

Nam quy nh i vi Sunset yellow l 70mg/L.

6. c Tnh Sunset Yellow c hp thu qua ng tiu ha chmc

nh v do hu ht liu dng trong thc ung c bi tit ra

ngoi

Sunset yellow l mt phin bn sunfonat ha ca Sudan I.

Sunset yellow gy d ng nhng ngi khng dung np

aspirin. Gy ra nhiu triu chng khc nhau: dng, kh chu

d dy, tiu chy, nn, pht ban, sng da v chng au na

u. Sunset yellow gy ra chng hiu ng tr nh . V thnnph gia ny khng c khuyn co cho ngi tiu dng

c bit l tr em.

- nu dng loi khng nguyn cht hoc lm dng qu mc s

rt c hi cho sc kho, c th gy ngc cp tnh, do hu

qu s dng lu di tch lu cao c thgy ung th v t bin

gen.

b. Tatrazine: (E102)

1. Tn khc, ch s CI Food Yellow 4, FD&C Yellow No. 5;

INS: 102

ADI = 0 - 7,5 mg/kg th trng.

2. nh ngha L dn xut axit pyrazol cacboxylic, c mu vng chanh.

L mt cht mu c ngun gc t nha than .


20/31

20

Tn ha hc Trinatri 5-hydroxy-1-(4-sulfonphenyl)-4-(4-

sulfonphenylazo)-H-pyrazol-3-carboxylat


Cng thc cu to


3. Cm quan Dng bt hoc ht mu cam nht.

Bn vi nhit (130oC) v nh sng.

4. ng dng Dng trong sn xut bnh ko, thc phm trng ming, mt,

ru, trng c mui, tm, v ngoi phomat, v ngoi tht

chn...

Tartrazine cn c s dng trong x phng , m phm ,

du gi v cc sn phm chm sc tc, kem dng m , bt

mu, sn mng tay, mc v thuc nhum con du...

5. Tnh cht

tan Tan trong nc 20oC, t tan trong ethanol.

150g tartrazine c thha tan trong 1 lt nc.6. c tnh Dng trong sn xut bnh ko, thc phm trng ming, mt,

ru, trng c mui, tm, v ngoi phomat, v ngoi tht

chn...

Tartrazine cn c s dng trong x phng , m phm ,

du gi v cc sn phm chm sc tc, kem dng m , bt

mu, sn mng tay, mc v thuc nhum con du...


21/31

21

c. All ura red1. Tn khc, ch s CI Food Red 17, FD&C Red No. 40;

INS: 129

ADI = 0 - 7 mg/kg th trng.

2. nh ngha Ban u Allura Red AC c sn xut t nha than , hinnay ch yu c sn xut t du kh.

Tn ha hc Dinatri 6-hydroxy-5-(2-methoxy-5-methyl-4-sulfon-

phenylazo)-2-naphthalen-sulfonat


Cng thc cu to


3. Cm quan Dng bt hoc ht mu sm.

4. ng dng c s dng trong thuc, m phm, thc phm. S dng

trong mt s loi mc xm v dng trong mt s sn phm

nh nc gii kht, thuc, ko bng cho tr em

5. Tnh cht

Nhit nng ch

y >300C

tan Tan trong nc, t tan trong ethanol.

Phi c phn ng c trng ca cht mu.

6. c tnh y l loi ph gia sgy anh hng nghim trng i vi

tr b hen suyn.

Allura Red AC l mt trong mt s cht mu nhn to lm

tng mc hiu ng thi qu tr em, th hin vic mt

tp trung v ch s thng minh thp.


22/31

22

Allura Red AC c th c cht dng i vi nhng ngi k

aspirin v cc bnh nhn hen hoc nhng ngi c da nhay

cm.

d. Caramel1. Tn khc, ch s Cht mu caramel c chia thnh bn loi da vo s khc

nhau gia cc cht phn ng c s dng trong sn xut.

Tn khc v ch s ca mi loi nh sau:

Lp INS S E Tn M t

c s

dng

trong

I 150a E150aCaramel I-

Plain

Khng c s

dng hp cht

amoni hoc

sulfite.

Whiskey

II 150b E150b

Caramel II

Sulfite

Process

Trong s hin

din ca sulfite

hp cht nhng

khng c hp

cht amoni c

th c s

dng

Ru

Cognac

III 150C E150c

Caramel III

- Ammonia

Process

Trong s hin

din ca cc hpcht ammonium

nhng khng c

sulfite hp cht

c th c s

dng

Bia, nc

st v

bnh ko

IV 150d E150dCaramel IV

- Ammonia

Trong s hin

din ca c hai

Mi

trng nh


23/31

23

Sulphite

Process

sulfite v cc

hp cht amoni

vy c tnh

axit nh

nc ngt

ADI i vi nhm I Khng xc nh;

ADI i vi nhm III = 0-160 mg/kg th trng

ADI i vi loi IV 0-200 mg/kg th trng (0-150 mg/kg th

trng i vi dng rn)

2. nh ngha Nhn chung y l cc hn hp phc tp, trong mt s

dng t hp keo, sn xut bng cch un nng ring

carbohydrat hoc cng vi s c mt ca acid, kim hoc

mui loi thc phm.3. Cm quan Cht dng rn hoc lng, mu nu sm ti en c mi

ng chy.

4. Chc nng S dng to mu cho thc phm

5. Tnh cht

tan C th trn ln vi nc

tinh khit Arsen: Khng c qu 1 mg/kg

Ch: Khng c qu 2 mg/kg

Hm lng cht rn Loi I: 62-77%

Loi III: 53-83%

Loi IV: 40-75%

Cng mu Loi I: 0,01-0,12

Loi III: 0,08-0,36Loi IV: 0,10-0,60

Nit ton phn Loi I: Khng c qu 0,1%

Loi III: 1,3 -6,8%

Loi IV: 0,5-7,5%

Lu hunh ton phn Loi I: Khng c qu 0,3%

Loi III: Khng c qu 0,3%

Loi IV: 1,4-10,0%


24/31

24

Lu hunh dioxyd Loi I: -

Loi III: -

Loi IV: Khng c qu 0,5%

Nitamoniac Loi I: -

Loi III: Khng c qu 0,4%

Loi IV: Khng c qu 2,8%

4-Methylimidazol

(MEI)

Loi I: -

Loi III: Khng c qu 300 mg/kg & khng c qu 200

mg/kg tnh theo cht mu tng ng

Loi IV: Khng c qu 1000 mg/kg & khng c qu 250

mg/kg tnh theo cht mu tng ng

2-Acetyl-4-

tetrahydroxy-

butylimidazol (THI)

Loi I: -

Loi III: Khng c qu 40 mg/kg & khng c qu 25

mg/kg tnh theo cht mu tng ng.

Loi IV: -

6. c tnh C khnng gy ung thcho ngi

4. CHT BO QUN

4.1. Tng Quan

- Cht bo qun l cc ha cht t nhin hay tng hp c thm vo sn phm

nh thc phm ngn nga hoc lm chm li s thi ra, h hng gy ra bi s

pht trin ca cc vi sinh vt hay do cc thay i khng mong mun v mt ha hc.

Chng c th s dng nh l mt ha cht duy nht m cng c th trong t hp vinhiu loi ha cht c cc tc dng khc.

- Thnh cn phn bit r rng nhm cht bo qun ngn nga vi sinh vt, nm

nem nm mc pht trin, thng c gi l cht bo qun trong ting Anh gi l

preservative v nhm cht ngn chn qu trnh oxi ha cc thnh phn dinh dng

ca sn phm, thng c gi l cht chng oxi ha, trong ting Anh gi

l antioxidant.
http://vi.wikipedia.org/w/index.php?title=H%C3%B3a_ch%E1%BA%A5t&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=H%C3%B3a_ch%E1%BA%A5t&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=H%C3%B3a_ch%E1%BA%A5t&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=H%C3%B3a_ch%E1%BA%A5t&action=edit&redlink=1


25/31

25

- Do dng vi mc ch bo qun cho nn ngi ta thng gi chung l cht bo

qun.

Cht bo qun gm c hai loi chnh:

-Cht bo qun chng vi sinh vt (Hin tng nht b mt, i thiu, mi

chuathng l do vi sinh vt, nm men hoc nm mc pht trin gy ra)

-Cht bo qun chng oxy ha (Hin tng i du, gt du, ti mu, mt hng

v thng l do qu trnh oxy ha gy ra)

- Theo nh phn loi trn, ta cn phi xc nh rng sn phm ang cn bo

qun theo hng no. T quyt nh ch s dng loi cht bo qun cn thit v

trnh vic s dng nhiu loi theo cch bao vy va khng c li ch kinh t va nh

hng n ngi tiu dng.

4.2. Cht Chng Vi Sinh Vt

4.1.1. Acid benzoic (E210)

- Acid benzoic c cng thc ha hc: C7H6O2 hay C6H5COOH.

- Acid benzoic l mt cht rn tinh th khng mu, khng mi. Mui ca n

c s dng nh l mt cht bo qun thc phm v acid benzoic l mt tin thn

quan trng i vi s tng hp ca nhiu cht hu c khc.- Trong tnhin, acid benzoic c tm thy cc loi cy nh: mn, qu v hu

ht l qu mng. Acid benzoic v mui Natri ca n tlu c s dng c

ch s pht trin ca VSV.


26/31

26

Mn, qu, qu mng

- Acid hp thu vo trong t bo VSV nhm:

+ c ch h hp t bo VSV.

+ Hn ch kh nng nhn c cht ca VSV.

- Acid benzoic vi tc dng bo qun ch xy ra trong mi trng axit pH =

2,53,5.- Acid benzoic (E210) dng trong bo qun thc phm: ML = 0,1%.

4.1.2. Sodium benzoate (E211)

- Sodium benzoate ccng thc ha hcNaC6H5CO2, ngoi ra cn c cc mui

khc nh Potassium benzoate (E212), Calcium benzoate (E213) cng c tnh cht

tng t nh Sodium benzoate.

- Sodium benzoate l cht c s dng rng ribo qun thc phm, visE l E211.N l mui natri caacid benzoic,ha tan c trongnc.

-Mc d cht bo qun benzoic acid bo qun thc phm hiu qu hn, song

Sodium benzoate thng c s dng nh mt ph gia thc phm v axit benzoic

khng ha tan c trong nc. Mc s dng ca acid benzoic bo qun thc

phm thng t 0,05-0,1%. Axit benzoic c mt trong thc phm phi c kim sot

theo quy nh ca php lut.

-Hot tnh chng khun ca benzoate ph thuc rt nhiu vo pH ca thc phm,

hot tnh ny cao nht khi pH thp nht (thng c dng bo qun cc loi thc

ung vi nng 0.03-0.05%). Cc mui benzoate dng kt hp vi acid

ascorbic (vitamin C - E300) s hnh thnh hp cht benzen, mt hp cht gy ung th.

Tuy nhin hp cht ny khng hn mc nguy him cao n sc khe ngi tiu

dng. Nhit , nh sng v thi hn s dng c thnh hng n t l benzen hnh

thnh.- Mui benzoate c sn xut bng cch trung ha acid benzoic vi NaOH.
http://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Food_preservationhttp://en.wikipedia.org/wiki/Food_preservationhttp://en.wikipedia.org/wiki/Food_preservationhttp://en.wikipedia.org/wiki/Food_preservationhttp://en.wikipedia.org/wiki/E_numberhttp://en.wikipedia.org/wiki/E_numberhttp://en.wikipedia.org/wiki/E_numberhttp://en.wikipedia.org/wiki/E_numberhttp://en.wikipedia.org/wiki/Benzoic_acidhttp://en.wikipedia.org/wiki/Benzoic_acidhttp://en.wikipedia.org/wiki/Benzoic_acidhttp://en.wikipedia.org/wiki/Waterhttp://en.wikipedia.org/wiki/Waterhttp://en.wikipedia.org/wiki/Waterhttp://vi.wikipedia.org/wiki/Acid_ascorbichttp://vi.wikipedia.org/wiki/Acid_ascorbichttp://vi.wikipedia.org/wiki/Benzenhttp://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_g%C3%A2y_ung_th%C6%B0http://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_g%C3%A2y_ung_th%C6%B0http://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_g%C3%A2y_ung_th%C6%B0http://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_g%C3%A2y_ung_th%C6%B0http://vi.wikipedia.org/wiki/Benzenhttp://vi.wikipedia.org/wiki/Acid_ascorbichttp://vi.wikipedia.org/wiki/Acid_ascorbichttp://en.wikipedia.org/wiki/Waterhttp://en.wikipedia.org/wiki/Benzoic_acidhttp://en.wikipedia.org/wiki/E_numberhttp://en.wikipedia.org/wiki/E_numberhttp://en.wikipedia.org/wiki/Food_preservationhttp://en.wikipedia.org/wiki/Chemical_formula


27/31

27

4.2. Cht Chng Oxi Ha

4.2.1. Khi Nim

- Cht chng oxi hal mt loi ha cht gip ngn chn hoc lm chm qu

trnh oxi ha cht khc. S oxi ha l loiphn ng ha hctrong electron c

chuyn sang cht oxi ha, c kh nng to cc gc t do sinh ra phn ng dy chuyn

ph hyt bosinh vt

4.2.2. C Ch Hot ng

- Bnh thng cc phn t ca c th chng ta trng thi cn bng, trong qu

trnh trao i cht, mt s nguyn t b mt electron s tr thnh k kht mu v i

chim ot cc electron t nhng nguyn t khc. Nhng k kht mu chnh l gc

t do. Khi chim ot electron, cc gc t do s gy ra mt lot gc t do mi, lm

cho cc t bo bh hi hoc bin cht, dn dn s dn ti thnh phn ca thc phm

b thay i..

- Cht chng oxi ha ngn qu trnh ph hy ny bng cch kh i cc gc t do,

cht chng oxy ha l nhng chtlm v hiu ha tc ng ca gc t do.C th hn

cht oxy ha c electron d tha cung cp cho gc t do kht mu, nh vy lm v

hiu ha tc hi ca gc t do. Ngi ta hay dng cccht

kh(nh thiol hay polyphenol) lm cht chng oxi ha. Do , trnh s gy hica

cc gc t do th cn thit phi loi b chng bng cch s dng cc cht chng xi

ha b sung nh Vitamin A, Vitamin C, VitaminE, polyphenol,S kh gc t do

ca cht chng xi ha, trong cc electron khng ghp i ca gc t do s c

nhn electron ca cht chng xi ha to thnh cc electron ghp i bn vng.
http://vi.wikipedia.org/w/index.php?title=Oxi_h%C3%B3a&action=edit&redlink=1http://vi.wikipedia.org/wiki/Ph%E1%BA%A3n_%E1%BB%A9ng_h%C3%B3a_h%E1%BB%8Dchttp://vi.wikipedia.org/wiki/Ph%E1%BA%A3n_%E1%BB%A9ng_h%C3%B3a_h%E1%BB%8Dchttp://vi.wikipedia.org/wiki/Ph%E1%BA%A3n_%E1%BB%A9ng_h%C3%B3a_h%E1%BB%8Dchttp://vi.wikipedia.org/wiki/Electronhttp://vi.wikipedia.org/wiki/T%E1%BA%BF_b%C3%A0ohttp://vi.wikipedia.org/wiki/T%E1%BA%BF_b%C3%A0ohttp://vi.wikipedia.org/wiki/T%E1%BA%BF_b%C3%A0ohttp://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_kh%E1%BB%ADhttp://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_kh%E1%BB%ADhttp://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_kh%E1%BB%ADhttp://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_kh%E1%BB%ADhttp://vi.wikipedia.org/wiki/Thiolhttp://vi.wikipedia.org/w/index.php?title=Polyphenol&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Polyphenol&action=edit&redlink=1http://vi.wikipedia.org/w/index.php?title=Polyphenol&action=edit&redlink=1http://vi.wikipedia.org/wiki/Thiolhttp://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_kh%E1%BB%ADhttp://vi.wikipedia.org/wiki/Ch%E1%BA%A5t_kh%E1%BB%ADhttp://vi.wikipedia.org/wiki/T%E1%BA%BF_b%C3%A0ohttp://vi.wikipedia.org/wiki/Electronhttp://vi.wikipedia.org/wiki/Ph%E1%BA%A3n_%E1%BB%A9ng_h%C3%B3a_h%E1%BB%8Dchttp://vi.wikipedia.org/w/index.php?title=Oxi_h%C3%B3a&action=edit&redlink=1


28/31

28

C ch hot ng ca cht chng oxy ha

4.2.3. Yu Cu

- Cc cht chng oxi ha c dng trong thc phm phi m bo cc yu cu

sau:

+ Bo tn cc gi tr dinh dng c bn ca thc phm.

+ Cc gi tr cm quan ca thc phm phi c gi nguyn.

+ Qu trnh s dng nhng cht ny phi tin li, chi ph thp.

4.2.4. Li ch

- Cc cht chng oxy ha c sn trong thnh phn cc loi rau qu(nh cam ch

vitamin C).

- Li ch chnh ca vic s dng nhng hp cht chng oxy ha t nhin l tnh

an ton so vi vic s dng nhng hp cht chng oxy ha tng hp. Tuy nhin cc

nh khoa hc cng khuyn co nn thn trng trong vic s dng nhng hp cht ny,

v vi mt liu lng no c thc nhng tc ng ph i vi ngi s dng.

- Cc cht chng oxi ha c ngun gc t nhin thng gp: Axit L - ascorbic

(vitamin C) dng t nhin, Acid citric hoc Acid limonic, Tocopherol (vitamin E),

Acid tactric v mt s loi gia v tho mc nh cy hng tho (Rosmariquinon v

Rosmaridiphenol l hai thnh phn c kh nng chng oxy ha ca loi cy ny).

Ngun gc nhn to: Vitamin C tng hp, Vitamin E (hay Tocopherol) tng hp,BHA, BHT, BTHQ


29/31

29

- Vitamin C c nhiu trong cc loi rau qu ti nh nc cam, chanh, qut, v

c hm lng cao trong rau xanh, c bit l bng ci xanh, tiu, khoai ty, ci

brussel, rau ci, c chua, cam, qut, chanh, bi

4.2.5. Acid ascorbic (Vitamin C)

- Axit ascorbic l mt hp cht hu c t nhin vi nhng c tnh chng oxy

ha. N l mt cht rn mu trng, ha tan ctrong nc to nn tnh axit nh.

- Lng polyphenol c trong hu ht cc loi rau, c, qu..., ty theo loi nguyn

liu m hm lng polyphenol s khc nhau. Cng tn ti trong nguyn liu

l enzym polyphenoloxidase. Khi tip xc vi oxi khng kh skch hot enzym

polyphenoloxidase hot ng v xc tc cho phn ng oxi ha cc hp cht

polyphenol thnh nhng hp cht mi gy sm mu v to v ng cho rau qu. Thphm ca hin tng ny l enzyme. VD: To c hng ngn cc t bo nh v n cha

trong cc tbo ny l enzyme cng nh cc thnh phn ha hc khc. Khi mt qu

to c ct khi cnh, bnh ri (v d ri t trn cy xung hay ri t trn bn

xung) hoc b ct ra, cc t bo nhb mt s v, nu trong mt t bo nguyn

vn, enzyme v phenol c tch bit vi nhau th gichng b trn ln v phn ng

vi nhau cng vi oxy (qu trnh PPOPolyphenol oxidase). Mu nu c to ra do

qu trnh phn ng v xy ha l do sn phm ca nmelanin.


30/31

30

C ch hot ng ca Acid Ascorbic

- Khi c cht chng oxy ha acid ascorbic vo s gim s to thnh mu nu, lm

cho qu to khng b sm mu.

- Chnh v c chny m acid ascorbic c s dng ph bin bo qun cc

loi thc ung (ngoi ra cng c s dng ph bin bo qun cc loi thc phm

khc): chng li s oxy ha trong mt s loi nc gii kht, nc p rau qu


31/31

TI LIU THAM KHO

[1] Vn Ngc Hng,Hng liu v ng dng, NXB Khoa hc v k thut, H Ni.

[2] L Vn Vit Mn, Cng ngh sn xut cc sn phm tsa v thc ungTp 2

Cng ngh sn xut thc ung pha ch,NXB i hc Quc gia Tp.HCM.

[3] m Sao Mai (Ch bin),Ph gia thc phm,NXB i hc Quc gia Tp.HCM.

[4] Nguyn nh Thng, Cng ngh sn xutnc gii kht, NXB Khoa hc v K

thut, H Ni.

Documents

N04_HuongMauChatBaoQuan