PENDAHULUAN

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PERLU PENCEGAHA

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PENDAHULUANBahan 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

1.Menghambat pertumbuhan mikrobia

2.Memperpanjang umur simpan

3.Mempertahankan kualitas gizi dan

sensori

4.Memudahkan proses pengolahan

SIFAT ANTIMIKROBIAMenghambat 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 BAIK1. Memiliki arti ekonomis dr pengawetan2. Hanya digunakan jika cara pengawetan tdk

mencukupi3. Memperpanjang umur simpan4. Tidak menurunkan kualitas5. Mudah dilarutkan6. Aman dlm jmlh yg diperlukan7. Mudah dianalisis8. Tidak menghambat enzim pencernaan9. Tidak bersifat toksik10.Spektra antimikrobia yg luas.

JENIS BAHAN PENGAWETPENGAWET 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

PengawetanMencegah/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 ACIDCommonly used as antimicrobial preservative

or acidulanThe activity related to pH and generally limited

to pH < 5,5Mechanism:

- 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 saltMore effective against yeast & bacteriaThe 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 & otherPrimary 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 agentsLactic 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.

NATAMYCINNatamycin 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.

Other antimicrobial agentsLysozyme (1,4-β-N-acetylmuramidase),

catalyzes hidrolysis peptidoglican of bacterial cell walls.

Nisin, peptide produced by a strain of dairy starter cultur L. lactis

PhosphatesSulfites

Pelanggaran Penggunaan PengawetMenggunakan bahan pengawet yang dilarang

penggunaannya untuk pangan. Menggunakan pengawet melebihi dosis yang

diizinkan.

PENGAWET DILARANGFormalin (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)