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Antimicrobial Agents in Food Preservation: Selection, Types & Mechanisms

Learn about antimicrobial agents, their selection criteria, types such as organic acids, parabens, nitrites, and their mechanisms in preserving food quality.

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Antimicrobial Agents in Food Preservation: Selection, Types & Mechanisms

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  1. ANTIMICROBIAL AGENT(PENGAWET) Kuliah Bahan Tambahan Makanan Universitas Padjadjaran 2011

  2. PENDAHULUAN time PERLU PENCEGAHAN time time

  3. PENDAHULUAN • Bahan pengawet senyawa yg mampu menghambat dan menghentikan proses fermentasi, pengasaman atau bentuk kerusakan lainnya dan dapat memberikan perlindungan bahan pangan dari pembusukan.

  4. WHY???

  5. TUJUAN PENGGUNAAN PENGAWET • Menghambat pertumbuhan mikrobia • Memperpanjang umur simpan • Mempertahankan kualitas gizi dan sensori • Memudahkan proses pengolahan

  6. 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

  7. Factor in selecting antimicrobial agent: • The antimicrobial spectrum of the compound to be used must be known. • Chemical & physical properties of both the antimicrobial and the food product must be known • The condition of storage of the product and interaction with other processes must be evaluated to ensure that the antimicrobial will remain functional over time. • A food must be of the highest microbiologically quality initially if an antimicrobial is to be expected to contribute to its shelf-life.

  8. PERSYARATAN BHN PENGAWET YG BAIK • Memiliki arti ekonomis dr pengawetan • Hanya digunakan jika cara pengawetan tdk 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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 & axydativephosphorylation. • Benzoates had no carcinogenic effect were given 1 – 2% and nonmutagenic.

  14. 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.

  15. PARABENS • Parabens: alkyl ester of p-hydroxybenzoic acid. • Effective at pH 3-8 (effective at acidic an alkaline pH), and generally more active against mold & yeast than bacteria. • Mechanism: is most likely related to their effect on cytoplasmic membrane. The parabens were capable of inhibiting both membran transport and electron transport system. • To take advantage solubility & increased activity, methyl and propylparabens are normally used in a combination 2-3 : 1

  16. The used of parabens are application in beverages, soft drink, jelly, juice, salad, etc. • The FDA consider parabens total addition limit of 0,1%

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  21. 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.

  22. 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

  23. Pelanggaran Penggunaan Pengawet • Menggunakan bahan pengawet yang dilarang penggunaannya untuk pangan. • Menggunakan pengawet melebihi dosis yang diizinkan.

  24. 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)

  25. CASE STUDY • Pemutaran video repostase investigasi dg judul/kasus: “penjualan otak-otak berbahaya pengawet”

  26. QUIZ PEWARNA • Jelaskan pengertian pewarna tambahan makanan dan sebutkan 3 jenis pewarna sintetik! • Sebutkan & jelaskan sifat fisikokimiawi dr pigmen klorofil!

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