Transcript ANTIMICROBIAL AGENT (PENGAWET)

PENDAHULUAN
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PERLU
PENCEGAHAN
PENDAHULUAN
 Bahan pengawet
senyawa yg mampu menghambat dan
menghentikan proses fermentasi,
pengasaman atau bentuk kerusakan lainnya
dan dapat memberikan perlindungan bahan
pangan dari pembusukan.
TUJUAN PENGGUNAAN PENGAWET
SIFAT ANTIMIKROBIA
 Menghambat pertumbuhan mikrobia dg cara:
1. Gangguan sistem genetik
2. Menghambat / mengganggu dinding sel ataupun membran sel
3. Pennghambatan enzim
4. Pengikatan nutrient esensial
PERSYARATAN BHN PENGAWET YG
BAIK
1. Memiliki arti ekonomis dr pengawetan
2. Hanya digunakan jika cara pengawetan tdk
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mencukupi
Memperpanjang umur simpan
Tidak menurunkan kualitas
Mudah dilarutkan
Aman dlm jmlh yg diperlukan
Mudah dianalisis
Tidak menghambat enzim pencernaan
Tidak bersifat toksik
Spektra antimikrobia yg luas.
JENIS BAHAN PENGAWET
 PENGAWET ORGANIK
terdiri dari asam-asam organik dan garamnya, seperti
asetat, benzoat, propionat, sorbat, epoksida, dll.
 PENGAWET ANORGANIK
- digunakan dlm bentuk garam seperti nitrit,
metabisulfit
- dalam bentuk gas seperti sulfit (SO2)
- dalam bentuk liquid seperti hidrogen peroksida
 Pengawetan
 Mencegah/menghambat fermentasi, pengasaman atau
penguraian lain thd makanan yg disebabkan oleh
mikroorganisme
 Ditambahkan pd makanan yg mudah rusak (daging,
buah2an)
 Contoh :
 As benzoat utk menghambat pertumbuhan bakteri,
ragi, jamur pd buah2an, minuman, ringan, sirup,
kecap (500 mg – 1 g/kg)
 As sorbat menghambat pertumbuhan jamur dan ragi
(roti, buah kering 250 mg-1 g/kg)
 As propionat menghambat pertumbuhan jamur
(adonan roti : 2 g/kg adonan roti)
ORGANIC ACID
 Commonly used as antimicrobial preservative or
acidulan
 The activity related to pH and generally limited to pH
< 5,5
 Mechanism:
- organic acid influence cell walls synthesis in
prokaryotes.
- organic acid likely act at the cytoplasmic membrane
level. Organic acid penetrates the cell membrane
bilayer, and once inside the cell it dissociates because
the cell interior has a higher pH than exterior.
a. Acetic acid & acetate salt
 More effective against yeast & bacteria
 The activity depend on product, environment, and
microorganism.
 Application:
- addition of acetic acid at 0,1% to scald tank water used in
poultry processing ddecrease the salmonella &
campylobacter (okrend et al., 1986)
- used as a spray sanitizer on meet carcases effective for
beef, lamb, & catfish fillets. Use of 2 % acetic acid resulted
reduction in viable E. coli.
- added at 0,1% to bread dough inhibited growth bacillus
subtilis in wheat bread (pH 5,14) > 6 days.
 Sodium acetate is an inhibitor of rope-forming bacillus
in baked goods and of the mold.
 It is useful in the baking industry because t has little
effect on the yeast used in baking.
b. Benzoates & other
 Primary uses as antimycotic agent (most yeast and mold)
 Benzoates are most effective at pH 2,5 – 4,0.
 Mechanism: benzoic acid destroyed the proton motive
force of the cytoplasmic membrane by continous transport
of proton into the cell causing disruption of the transport
system.
 Benzoates also inhbit enzymes in bacterial cell as those
controlling acetic acid metabolism & axydative
phosphorylation.
 Benzoates had no carcinogenic effect were given 1 – 2% and
nonmutagenic.
Other organic antimikrobial agents
 Lactic acid is primary used to many fermented diary,
vegetable, and meet product. It is usually used as a
food additive for pH control & flavoring.
 Propionic acid & propionate use to against mold, yeast,
& bacteria gram negative. Usually used in baked goods
& cheese.
 Sorbic acid & sorbates have been used in food as
effective inhibitor of fungi, including that produce
mycotoxin, and certain bacteria.
NITRITES
 Nitrite salt (KNO2 & NaNO2 ) primarily used to
inhibit the growth and toxin roduction of C.
botulinum in cured meats.
 Nitrite is most inhibitory to bacteria at acidic pH
and more inhibitory under anaerobic condition
 Mechanism: the inhbitory effect f nitrite on
bacterial sporeformers is apparently due to
inhibition of outgrowth and during cell division.
 Nitrite does not inhibit spore germination to a
significant extend. Nitrite inactivated enzymes
associated with respiration .
 Lethal dose of nitrites in human is 2 – 6 g,
prolonged ingestion nitrite cause
methemioglobinemia, that is, excessive production
of abnormal mioglobin.
NATAMYCIN
 Natamycin or pimaricin ( C33 H47 NO13 )is a polyene
macrolide antibiotic.
 Natamycin is active against nearly all molds and yeast,
but no effect on bacteria or viruses.
 Several factors affect the stability & resulting
antimycotic activity of natamycin:
-pH, 100% natamycin activity is retained at pH 5 - 7
-temperature, high temperature will decrease activity
-light,
-oxidant,
-heavy metal.
 Mechanism: polyene macrolide antibiotic is binding to
ergosterol & other sterol group of the fungal cell
membrane.
 Generally, binding of the natamycin by sterol causes
inhibition of ergosterol biosynthesis and distortion of
the cell membrane with resultant leakage.
 Application: cheese, baking industry, fruits, and meets
as a mold spoillage inhibitor.
DIMETHYL DICARBONATE (DMDC)
 The primary target microorganism for DMDC are
yeast.
 It was more effective than sorbate & benzoate. Mold
are generally more resistant to DMDC than yeast or
bacteria.
 DMDC used in product: wine, teas, carbonated &
noncarbonated juice beverages, and carbonated &
noncarbonated nonjuice beverages.
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Other antimicrobial agents
 Lysozyme (1,4-β-N-acetylmuramidase), catalyzes
hidrolysis peptidoglican of bacterial cell walls.
 Nisin, peptide produced by a strain of dairy starter
cultur L. lactis
 Phosphates
 Sulfites
Pelanggaran Penggunaan
Pengawet
 Menggunakan bahan pengawet yang dilarang
penggunaannya untuk pangan.
 Menggunakan pengawet melebihi dosis yang
diizinkan.
PENGAWET DILARANG
 Formalin (pengawet mayat)
 Asam Borat (Boric Acid) dan senyawanya
 Antibiotik (Chloramphenicol)
 Asam Salisilat dan garamnya (Salicylic Acid and its
salt)
 Dietilpirokarbonat (Diethylpirocarbonate DEPC)
 Kalium Klorat (Potassium Chlorate)
 Kalium Bromat (Potassium Bromate)
 Nitrofurazon (Nitrofurazone)