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Analysis of Food additives

Analysis of Food additives. Abdul Rohman Bagian Kimia Farmasi, Fakultas Farmasi Universitas Gadjah Mada. Food additives are substances added to products to perform specific technological functions.

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Analysis of Food additives

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  1. Analysis of Food additives Abdul Rohman Bagian Kimia Farmasi, Fakultas Farmasi Universitas Gadjah Mada

  2. Food additives are substances added to products to perform specific technological functions. • These functions include preserving, i.e. increasing shelf-life or inhibiting the growth of pathogens, or adding colouring and flavouring to food for interest and variety. • There are over 300 permitted additives that can be used. What are food additives?

  3. Additives may be: • Natural– found naturally, such as curcumin, used as a colouring agent; • Manmade versions – synthetic such as benzoic acid (E210), used as a preservative; Types of additives

  4. Food additives • Preservatives • Sweetener • Colouring agents • Antioxidants • Flavor enhancer

  5. Preservatives aim to: • Prevent the growth of micro-organisms which could cause food spoilage and lead to food poisoning; • Extend the shelf-life of products, so that they can be distributed and sold to the consumer with a longer shelf-life. • For example beef and other meats are often treated with nitrite and nitrate (E249 to E252) during the curing process. Preservatives

  6. Pengawet • Asamsorbat • Asambenzoat • Asampropionat • Nitrit • Sulfit

  7. Asamsorbat • tergolongasamlemakmonokarboksilat yang berantailurusdanmempunyaiikatantidakjenuh (α-diena). • Bentukyang digunakanumumnyagaram Na- atau K-sorbat. • Asamsorbatdigunakansebagaipengawetdalamberbagaijenismakanan. • Asamsorbatmenghambatpertumbuhanjamurdanpadaumumnyaditambahkankebahanmakanandalambentukgaramnya. • Asupanharian yang diterima (acceptable daily intake atau ADI) asamsorbatadalah 25 mg/kg beratbadan.

  8. MetodeAnalisisasamsorbat • SpektrofotometriUv • Kromatografi Gas • KromatografiCairKinerjaTinggi

  9. Spektroskopi UV • Asamsorbatmempunyaiguguskromofor (ikatanrangkapterkonjugasi ) padaalfa-diena • Panjanggelombangmaksimalnyakuranglebih 250 nm

  10. Kromatografi Gas

  11. High Performance Liquid Chromatography

  12. Chromatographic conditions • Column: a Supelco 516 C18 column (15 cm×4.6mm, 5µm) at room temperature. • The detector used was UV-1570UV–vis spectrophotometer set at 254 nm • The mobile phase: methanol–acetate buffer (pH 4.4) (35:65, v/v) for 9min, after which it was changed to methanol–acetate buffer (pH 4.4) (50:50, v/v).

  13. HPLC for analysis of sorbic acid

  14. Asambenzoat • Asambenzoatdigunakansebagaipengawetpadaberbagaimacammakanan. • Asam benzoat menghambat pertumbuhan yeast danjamur. • Asupanharian yang diterima (acceptable daily intake atau ADI) asambenzoatadalah 5 mg/kg beratbadan

  15. Alkalimetri

  16. Spektrofotometri • Benzoatdapatditetapkankadarnyasecaraspektrofotometrikarenabenzoatmempunyaikromofor yang dapatmenyerapsinar ultraviolet. • Dalamair, natriumbenzoatakanmempunyaipanjanggelombangmaksimal 225 nm. dalam air sebesar 665.

  17. Kromatografi Gas • Dalampublikasiilmiahbiasanyadilakukansecarabersama-samadenganpengawet lain (sepertiasamsorbat) • Dilakukanekstraksidenganeter • Derivatisasi • kolom1,8 m x 2 mm i.d yang dilapisidenganOV-1 (100 – 120 mesh). • Suhuoperasional, oven: 80 – 2100C dengankenaikan 80C/menit; • Injektor2000C; detekorionisasinyala (FID) 2800C. • Gas pembawa: nitrogen dengankecepatanalir 20 mL menit. Wakturetensiasamkaproat, asamsorbat, asambenzoat, danasamfenilasetatmasing-masingkuranglebih 2,5; 4; 5; dan 6 menit.

  18. HPLC method for benzoic acid applicable for foodstuffs containing benzoic acid in the range 50–2000 mg/kg. The following conditions have been shown to be satisfactory. HPLC Elution order: benzoic acid sorbicacid methyl 4-hydroxybenzoate ethyl 4-hydroxybenzoate propyl 4-hydroxybenzoate

  19. Nitrit • Garamnitritumumnyadigunakanuntuk proses curingdaginguntukmemperolehwarna yang baikdanmencegahpertumbuhanmikroba. • Penggunaannatriumnitritdalamikandandagingternyatamenimbulkanefek yang membahayakankesehatan. • Nitritdapatberikatandengan amino atauamidadenganmembentukturunannitrosamin yang bersifattoksik (karsinogenik).

  20. MetodeGriess I • PrinsippenetapankadarnitritdenganmetodeGriess I iniadalahreaksidiazotasiantaraasamnitrit (darinitritdalamsuasanaasam) denganaminaromatis primer (asamsulfanilat). • Garamdiazonium yang dihasilkandarireaksidiazotasiiniselanjutnyadireaksikan (dikopling) denganalfa-naftilaminmembentuksenyawaberwarna yang dapatdiukurpadapanjanggelombang 520 nm.

  21. ReaksipadapenentuanGriess I

  22. Metode Griess II • Metode Griess II prinsipnya hampir sama dengan metode Griess I. • Sebagai amin aromatis primer, metode Griess II ini menggunakan sulfanilamid sementara agen pengkoplingnya adalah naftiletilendiamin (NED).

  23. ReaksipadaanalisisnitritdenganGriess II

  24. Method development

  25. Summary for nitrite determination

  26. Sebanyak 25,0 gram sampeldagingditimbangsecarasaksama, digerus, laluditambahdenganair bebasnitritsuhu 800C sampaivolumenya ± 300 mL, dimasukkandalamlabutakar 500 mLlalumemanaskannyadiataspenangas air 800C selama 2 jam sambilsesekalidigoyang, danditambah air sampaibatastanda. Sebanyak 20,0 larutanhasilpenyaringandipipetlaludimasukkankedalamlabutakar 50 mL, ditambah 2 mLpereaksiGriess, dandiencerkandengan air bebasnitritsampaibatastanda. Larutandibiarkanselama 1 jam supayaterbentukwarna. Larutandibacaabsorbansinyapadapanjanggelombang 520 nm terhadapblanko, danmempunyainilaiabsorbansisebesar 0,215 nm. Sebanyak 100,0 mg standar NaNO2dilarutkandengan air bebasnitritsampai 100,0 ml. Sebanyak 1,0 mLlarutaninidiambil, ditambah 2mL pereaksiGriessdanditambahdengan air sampai 50,0 mL.Larutaninidibacaabsorbansinyadi 520 nm danmempunyaiabsorbansisebesar 0,250. Berapakahkandungannitritdalamsampeldagingdiatas. Contoh

  27. Sulfit • Sulfit digunakan sebagai pengawet dalam bentuk SO2, garam Na- atau K-sulfit, danbisulfit. • Bentuk efektifnya sebagai pengawet adalah dalam bentuk tidak terdisosiasi pada pH di bawah 3. • The acceptable daily intake (ADI) for sulphites (expressed as sulphur dioxide) is 0.7 mg/kg body weight

  28. AnalisisSulfit • Titrimetric (Monier–Williams method) • enzymatic

  29. Monier–Williams method • The test portion is heated with a refluxing solution of hydrochloric acid to convert sulphite to sulphur dioxide. • Sulphurdioxide is oxidized with hydrogen peroxide to sulphuric acid. • The generated sulphuric acid is titrated with standardized sodium hydroxide solution. • The sulphite content is directly related to the generated sulphuricacid

  30. Enzimatis • Sulphite was oxidized to sulphate in the presence of sulphite oxidase with the liberation of hydrogen peroxide at the same time.

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