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Pertemuan 4 Karbohidrat (lanjutan). KARBOHIDRAT 1. PENDAHULUAN 2. KARBOHIDRAT DALAM BAHAN PANGAN 3. KLASIFIKASI DAN STRUKTUR KIMIA 4. REAKSI KIMIA KARBOHIDRAT.

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Presentasi berjudul: "Pertemuan 4 Karbohidrat (lanjutan). KARBOHIDRAT 1. PENDAHULUAN 2. KARBOHIDRAT DALAM BAHAN PANGAN 3. KLASIFIKASI DAN STRUKTUR KIMIA 4. REAKSI KIMIA KARBOHIDRAT."— Transcript presentasi:

1 Pertemuan 4 Karbohidrat (lanjutan)

2 KARBOHIDRAT 1. PENDAHULUAN 2. KARBOHIDRAT DALAM BAHAN PANGAN 3. KLASIFIKASI DAN STRUKTUR KIMIA 4. REAKSI KIMIA KARBOHIDRAT 5. SIFAT FUNGSIONAL KARBOHIDRAT

3 FOOD REACTIONS Table 1. Major Food Deterioration Reactions (Gould, 1995). Basis of reaction Example and consequence Physical Moisture movement, causing drying and toughening of texture, hydration and softening of texture, aggregation Chemical Oxidation, causing oxidative rancidity, loss of colour Maillard reactions, causing discolouration, change in texture Enzymatic Polyphenoloxidase, causing enzymic browning Lipoxygenase, causing oxidative rancidity Lipase, causing lipolytic rancidity Protease, causing gelation and flavour and texture changes Microbial Growth of spoilage organisms, causing quality deterioration Growth of toxigenic organisms, causing food poisoning Presence of infectious organisms, causing food poisoning

4 4. REAKSI-REAKSI KARBOHIDRAT 1. HYDROLYSIS 2. NON-ENZYMATIC BROWNING As shown in Table 4.29, the C1 and Cx factors, which were found to be endo- and exo- 1,4-β-glucanases respectively, hydrolyze cellulose to cellobiose. Since the C1 factor is increasingly inhibited by its product, a cellobiase is needed so that cellulose breakdown is not rapidly brought to a standstill. However, cellobiase is also subject to product inhibition. Therefore, complete cellulose degradation is possible only if cellobiase is present in large excess or the glucose formed is quickly eliminated.

5 4. REAKSI-REAKSI KARBOHIDRAT HYDROLYSIS : Pembuatan HFCS HYDROLYSIS : Pembuatan HFCS POLYSACCHARIDES Starch) Acid Treatment Heat Treatment Enzyme Treatment PRODUCT-2 HFCS (Fructose) PRODUCT-1 (Glucose)

6 4. REAKSI-REAKSI KARBOHIDRAT HYDROLYSIS : Fermentasi Tape BAHAN BAKU Fermentation Jenis Mikrobia Suhu Waktu PRODUCTS Ketela Pohoh Ketan Tape singkong Tape Ketan Starch Glucose Alcohol Acid

7 BROWNING ENZIMATIS NON-ENZIMATIS Reaksi Enzimatis Dipengaruhi oleh : Substrat Enzim Suhu Waktu Oksigen Reaksi Maillard Karamelisasi Reaksi Gula & Protein Dipengaruhi oleh : Jenis Gula Suhu Waktu Pemanasan Gula Dipengaruhi oleh : Suhu Waktu pH Ascorbic acid oxidation

8 BROWNING Reaksi Maillard Ilmuwan Perancis : Louis Maillard (1912)  glucose + glycine Carbonyl – Amine Reaction  action of amino acids/protein on reducing sugars Related to aroma, taste and color Roasting of coffee and cacao beans, baking of bread and cakes, toasting of cereals, cooking of meats

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10 NON-ENZYMATIC BROWNING (Maillard) REDUCING SUGAR AMINO ACID CARBONYL AMINE Melanoidins (Brown Pigments) Dipengaruhi oleh : Jenis Gula Asam Amino pH Suhu Katalis (metal)) Kadar Air Phosphate, SO 2, etc) 5-Hydroxymethyl- 2-Furfuraldehyde (HMF) R OC = H R OC = R R H N H

11 REAKSI MAILLARD Reaksi antara gula pereduksi dan Protein (asam amino) Dipengaruhi oleh suhu, waktu dan jenis gula Menghasilkan warna coklat Prosesnya berlangsung pada suasana basa Proses yang terjadi pada reaksi maillard: 1.Gugus karbonil pada gula menghasilkan N-glukosamin dan air 2.Gugus glukosamin yang tidak stabil mengalami pengaturan kembali membentuk ketosamin 3.Ketosamin mengalami proses lanjut: Memproduksi air dan redukton Menghasilkan diasetil, aspirin, pyruvaldehid, dan ikatan hidrolitik lain Membentuk melanoidin.

12 MAILLARD REACTION (i) Initial stage (colourless) a. sugar-amine condensation b. Amadori rearrangement (ii) Intermediate stage (colourless to yellow) c. sugar dehydration d. sugar fragmentation e. amino acid degradation (iii) Final stage (highly coloured) f. aldol condensation g. aldehyde-amine polymerisation, formation of heterocyclic nitrogen compounds.

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14 Maillard Reaction Effect of Temperature on the reaction rate of D-Glucose with DL-Leucine

15 Maillard Reaction Effect pH on the reaction rate of D-Glucose with DL-Leucine

16 BROWNING REACTIONS SUCROSE SUCROSE + FRUCTOSE SUCROSE + LACTOSE Maillard Reaction : (Lysine + Sugars)

17 BROWNING NON ENZIMATIS : MAILLARD Produk : Bakpia

18 CARAMELIZATION Caramelization is defined as the thermal degradation of sugars leading to the formation of volatiles (caramel aroma) and brown-colored products (caramel colors). The process is acid or base catalyzed and generally requires temperatures > 120 o C at 9 9) Caramelization occurs in food, when food surfaces are heated strongly, e.g. the baking and roasting processes, the processing of foods with high sugar content such as jams and certain fruit juices, or in wine production.

19 TEKNOLOGI KARBOHIDRAT SUMBER KARBOHIDRAT TEKNOLOGI PROSES CARBOHYDRATE-BASED PRODUCT 1.Ketela Pohon 2.Beras Ketan 3.Jagung 4.Gandum 1.Tape Ketela Pohon 2.Tape Ketan 3.HFCS 4.Karamel 5.Candy 6.Modified (CMC) 1.Asam 2.Basa 3.Panas 4.Enzimatis 5.Mikrobiologis 6.Modifikasi Struktur

20 SIFAT FUNGSIONAL 1.SWEETNESS & SWEETENERS 2.HYGROSCOPICITY 1.Reduced Aw  Preservative 2.Adsorbent  Baby care products 3.Moisture  Beauty care products 3.TEKSTURAL CONTRIBUTION 1.Rigidity : Roti 2.Viscosity: Saus

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24 V. FUNCTIONAL PROPERTIES K+K+ GelAgregated GelSolution Heat Cool Heat

25 V. FUNCTIONAL PROPERTIES Carrageenan synergy with milk proteins Casein micelle Casein micelle Casein micelle K+K+ Karaginan Milk protein

26 V. FUNCTIONAL PROPERTIES Carrageenan synergy with milk proteins


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