Karbohidrat (lanjutan) Pertemuan 4 Karbohidrat (lanjutan)

KARBOHIDRAT PENDAHULUAN KARBOHIDRAT DALAM BAHAN PANGAN KLASIFIKASI DAN STRUKTUR KIMIA REAKSI KIMIA KARBOHIDRAT SIFAT FUNGSIONAL KARBOHIDRAT

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. REAKSI-REAKSI KARBOHIDRAT HYDROLYSIS 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.

4. REAKSI-REAKSI KARBOHIDRAT HYDROLYSIS : Pembuatan HFCS POLYSACCHARIDES Starch) 1 Acid Treatment PRODUCT-1 (Glucose) 2 Heat Treatment 3 PRODUCT-2 Enzyme Treatment HFCS (Fructose)

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

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

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

NON-ENZYMATIC BROWNING (Maillard) REDUCING SUGAR CARBONYL Melanoidins (Brown Pigments) R R Dipengaruhi oleh : Jenis Gula Asam Amino pH Suhu Katalis (metal)) Kadar Air Phosphate, SO2, etc) C = O C = O 5-Hydroxymethyl- 2-Furfuraldehyde (HMF) H R AMINO ACID AMINE H R N H

REAKSI MAILLARD Reaksi antara gula pereduksi dan Protein (asam amino) 4/28/2017 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: Gugus karbonil pada gula menghasilkan N-glukosamin dan air Gugus glukosamin yang tidak stabil mengalami pengaturan kembali membentuk ketosamin Ketosamin mengalami proses lanjut: Memproduksi air dan redukton Menghasilkan diasetil, aspirin, pyruvaldehid, dan ikatan hidrolitik lain Membentuk melanoidin. yunia

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.

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

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

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

BROWNING NON ENZIMATIS : MAILLARD 4/28/2017 BROWNING NON ENZIMATIS : MAILLARD Produk : Bakpia yunia

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 oC at 9<pH<3  (pH < 3 or pH > 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.

TEKNOLOGI KARBOHIDRAT PROSES SUMBER KARBOHIDRAT CARBOHYDRATE-BASED PRODUCT Ketela Pohon Beras Ketan Jagung Gandum Asam Basa Panas Enzimatis Mikrobiologis Modifikasi Struktur Tape Ketela Pohon Tape Ketan HFCS Karamel Candy Modified (CMC)

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

V. FUNCTIONAL PROPERTIES Cool Cool K+ Heat Heat Solution Gel Agregated Gel

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

V. FUNCTIONAL PROPERTIES Carrageenan synergy with milk proteins