Carbohydrates (Part 1 & 2) PDF

Food Technology Study Program, IPB University http://fst.ipb.ac.id  TPN1211 Food Chemistry, 3(3-0) 3 Carbohydrates (Part 1 & 2) Food Chemistry Division...

Food Technology Study Program, IPB University http://fst.ipb.ac.id  TPN1211 Food Chemistry, 3(3-0) 3 Carbohydrates (Part 1 & 2) Food Chemistry Division Department of Food Science & Technology Food FoodTechnology TechnologyStudy StudyProgram, Program,IPB IPBUniversity University http://fst.ipb.ac.id  Course Learning Outcomes After completing this topics, you will : ▪ be able to explain the chemistry underlying the physicochemical properties and reactions of various carbohydrate components. ▪ have sufficient knowledge of role of carbohydrates to control reactions in foods. ▪ be able to explain the major chemical reactions of carbohydrates that affect of food characteristics. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Sub-topic 3.1 Definition, Source, Classification, and Role of Carbohydrates in Food System Week 3 3.2 Functional Properties and Chemical Reaction of Carbohydrates 3.3 Starch Chemistry and its Role in Food System Week 4 3.4 Starch Gelatinization Process and its Characteristics Food Technology Study Program, IPB University http://fst.ipb.ac.id  Mention SOMETHING about carbohydrates ? Food Technology Study Program, IPB University http://fst.ipb.ac.id  Carbohydrates ▪ One of the most classes of organic compounds ▪ The macromolecules in which energy from the sun is stored by photosynthesis. 6nCO2 + 6nH2O (C6H12O6)n + O2 + 675 kcal/mol ▪ An essential structural component of living cells: ▪ Simple sugars: monosaccharides ▪ Complex carbohydrate: polysaccharides ▪ Play a major role in human diets, comprising 40-75% of energy intake. Energy value : 4 kcal/g Food Technology Study Program, IPB University http://fst.ipb.ac.id  Carbohydrates ▪ Play important role in food characteristics (taste, color, texture, etc) ▪ Main sources: Plant produce ▪ Application: ▪ Food: sugar, syrup, starch, edible film, etc. ▪ Non-food: pharmacy, wood, paper, chemical, etc ▪ Application in food industry ▪ Sweetener, coloring agent, energy sources ▪ Texture (thickening agent, gelling agent, stabilizer, etc) Food Technology Study Program, IPB University http://fst.ipb.ac.id  Foods Containing Carbohydrates ▪ Cereals : wheat, maize, rice, barley, sorghum ▪ Sugar crops : sugar cane, sugar beet, corn ▪ Root crops : sweet potato, potato, cassava ▪ Pulses : mungbean, kidney bean, soybean ▪ Fruits : banana, grape ▪ Vegetables ▪ Milk products Food Technology Study Program, IPB University http://fst.ipb.ac.id  Definition ▪ Organic compounds that consist of carbon (C), hydrogen (H) and oxygen (O) ▪ The polyhydroxy aldehydes, ketones, alcohols, acids, their derivatives, and the polymers derived from these compounds. O O O C C H C O-H Aldehyde group Ketone group Carboxyl group ▪ They vary from simple sugars containing from three to seven carbon atoms to very complex polymers. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Classes of Carbohydrates Based on Functional Groups Name Functional group Example Any monosaccharide (triose, Glycose Aldehyde/ketone ribose, pentose, hexose) Aldose Aldehyde D-glucose Ketose Ketone D-fructose Glycitol or alditol Alcohol D-glucitol Glyconic or aldonic acid Carboxylic acid D-gluconic acid Glycaric or aldaric acid Dicarboxylic acid D-glycaric acid Carboxylic acid, Uronic acid D-glucuronic acid aldehyde Food Technology Study Program, IPB University http://fst.ipb.ac.id  Degree of Polymerization (DP) ▪ DP - The average number of monomer Class (DP) Sub-Group DP Components units in the molecule. When applied to Triose (3C), tetrose (4C), Monosacharides 1 starch, maltodextrin or glucose syrup pentose (5C), hexose (6C) molecules it refers to the average Sugars Disacharides 2 Sucrose, lactose number of anhydroglucose units in the Polyols 1 Sorbitol, mannitol molecule. Other oligo- Raffinose, stachyose, fructo- Oligosacharides 3-10 ▪ Carbohydrates can be classified saccharides oligosaccharides (FOS) according to their DP and may be Malto-oligosa- 11-200 Maltodextrins divided initially into three principal charides groups, namely sugars, Amylose, amylopectin, Polysaccharides Starch >200 oligosacharides and polysaccharides. modified starch Non-starch Cellulose, hemicellulose, >200 polysaccharides pectins, hydrocolloids, inulin Food Technology Study Program, IPB University http://fst.ipb.ac.id  Classes of Carbohydrates Based on Digestibility Group Sub-group Type Monosaccharides (glucose, galactose, Simple sugar fructose), disaccharides (sucrose, lactose, Digestible maltose) carbohydrate Malto-oligosakarida Maltodextrin Polysaccharides Starch (native, modified) Raffinose, stachyose, fructo- Oligosakarida oligosaccharide (FOS) Non-digestible Polysaccharide non- Cellulose, hemicellulose, pectin, carbohydrate starch hydrocolloid (gum), inulin Resistant starch, modified starch (exp: Starch cross-linked starch) Food Technology Study Program, IPB University http://fst.ipb.ac.id  Monosaccharides ▪ Parent monosaccharides are polyhydroxy aldehydes H- [CHOH]n-CHO or polyhydroxy ketones H-[CHOH]n-CO- [CHOH]m-H with three or more carbon atoms ▪ The CHO, C=O and –OH are reactive, important in carbohydrate structure and reactions ▪ The generic term ‘monosaccharide’ denoted to a single unit, without glycosidic connection to other such units ▪ Cannot be converted hydrolytically into smaller molecules ▪ Plays as sweeteners and instant energy source Food Technology Study Program, IPB University http://fst.ipb.ac.id  Monosaccharides ▪ Triose (3C) : Glyceraldehide ▪ Tetrose (4C) : Erythrose ▪ Pentose (5C) : Arabinose, ribose, xylose ▪ Hexose (6C) : Galactose, glucose, fructose Food Technology Study Program, IPB University http://fst.ipb.ac.id  Aldoses and Ketoses Carbonyl group Ketone group ▪ Aldoses: monosaccharides with an 1 CHO 1 CH2OH aldehydic carbonyl (-CHO) at C1. 2 HCOH 2 C=O Example: Glyceraldehyde, erythose, 3 HOCH 3 HOCH ribose, glucose 4 4 HCOH HCOH ▪ Ketoses: monosaccharides with 5 HCOH 5 HCOH ketonic carbonyl (-C=O) at C2. 6 CH2OH 6 CH2OH Example: fructose, sorbose Aldose Ketose (Glucose) (Fructose) Food Technology Study Program, IPB University http://fst.ipb.ac.id  Nomenclature ▪ Based on: ▪ Functional group: ketose, aldose ▪ Number of carbon atoms attached: triose, tetrose, pentose, hexose ▪ Position of OH group in Cn-1: D-glucose, L- glucose, D-fructose, L-fructose Food Technology Study Program, IPB University http://fst.ipb.ac.id  Structural Representation ▪ Fischer projection formula (acyclic/linear systems) ▪ Haworth projection formula (cyclic systems): ▪ Pyranoid ▪ Furanoid Food Technology Study Program, IPB University http://fst.ipb.ac.id  Linier Structure of Monosaccharide (Frischer Projection) Hydroxyl groups are able to form hydrogen bonds among the molecules Food Technology Study Program, IPB University http://fst.ipb.ac.id  Aldoses CHO CHO CHO CHO CHO CHO HCOH HOCH HCOH HOCH HCOH HOCH HCOH HCOH HOCH HOCH HCOH HOCH HCOH HOCH HCOH HCOH HOCH HOCH HCOH HOCH HCOH HCOH HCOH HCOH CH2OH CH2OH CH2OH CH2OH CH2OH CH2OH D-Allose L-Glucose D-Glucose D-Mannose D-Gulose D-Talose Cn-1: OH position determine the D (dextro) and L (levo) isomers Food Technology Study Program, IPB University http://fst.ipb.ac.id  Aldoses CHO CHO CHO CHO CHO CHO HOCH HCOH HCOH HOCH HCOH HOCH HCOH HOCH HCOH HCOH HOCH HOCH HOCH HOCH HCOH HCOH HCOH HCOH HCOH HCOH CH2OH CH2OH CH2OH CH2OH CH2OH CH2OH D-Idose D-Galactose D-Ribose D-Arabinose D-Xylose D-Lyxose Cn-1: OH position determine the D (dextro) and L (levo) isomers Food Technology Study Program, IPB University http://fst.ipb.ac.id  Ketoses CH2OH CH2OH CH2OH CH2OH O=C C=O C=O C=O HCOH HOCH HCOH HCOH HOCH HCOH HOCH HCOH HOCH HCOH HCOH CH2OH CH2OH CH2OH CH2OH L-Fructose D-Fructose D-Sorbose D-Pentulose Cn-1: OH position determine the D (dextro) and L (levo) isomers Food Technology Study Program, IPB University http://fst.ipb.ac.id  Change to Haworth Projection ▪ The monosaccharide structure is not linear → Oxygen bridge occurs between C1 and C5 (because of H-bond) ▪ In the six-carbon monosaccharide (glucose), a covalent bond can form through a reaction between the aldehyde at C1 and the -OH at C5 → produces glucopyranose ring structures. ▪ The ketone at C2 (in fructose) can also react with the OH at C5 → produce a glucofuranose ring Food Technology Study Program, IPB University http://fst.ipb.ac.id  Change from Frischer to Haworth Projection -D-glucose -D-glucose Food Technology Study Program, IPB University http://fst.ipb.ac.id  Haworth Projection -D-glucopyranose The “pyranose” portion of the name refers to the pyranoid ring in the molecule. -D-glucofuranoid The “pyranose” portion of the name refers to the furanoid ring in the molecule. Food Technology Study Program, IPB University http://fst.ipb.ac.id  D and L Configuration ▪ The D & L designator specifies the configuration at C5 (the chiral center farthest from the reference group) =D =L Food Technology Study Program, IPB University http://fst.ipb.ac.id   And  Configuration ▪ OH group points downward, in the alpha () form of the sugar, = as in -glucose. ▪ -OH group points upward from the ring in a beta () position of the sugar as in -glucose. Aldose Sugar ▪ Stereochemistry at C1 is given by  ▪ Prefix: “gluco” ▪ If the configuration at C1 is inverted, -D-glucopyranose is = formed Ketose Sugar ▪ Stereochemistry at C2 is given by  = ▪ Prefix: “fructo” ▪ If the configuration at C1 is inverted, -D-glucofuranose is formed Food Technology Study Program, IPB University http://fst.ipb.ac.id  Reducing sugar ▪ Sugar with aldehydic carbonyl group has reducing power ▪ Reducing property is determined by the presence of free OH in C1 ▪ Example: Glucose, lactose Food Technology Study Program, IPB University http://fst.ipb.ac.id  Amylose vs Cellulose ▪ Cellulose, synthesized from -glucose units, is insoluble and cannot be digested as a food source by most animals. ▪ Amylose, which are assembled from -glucose units, are soluble and easily digested. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Glycosidic bonds ▪ These are the covalent chemical bonds which link anhydroglucose units in starch chains. ▪ The glycosidic linkages can be alpha () or beta () 1-2, 1-3, 1-4, and1-6. ▪ In starch structure, the bonds may be linked in the -1,4 configuration to form a linear chain or in the -1,6 configuration which gives a branch point. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Disaccharides C1 C4 ▪ Monosaccharides in the ring form can link together to form disaccharides or in greater numbers to form polysaccharides. ▪ Disaccharides are formed when two monosaccharides are coupled together. Glycosidic (1,4) ▪ The coupling is of a specific type: an oxygen atom C1 C4 forms a bridge between the units coupled together ▪ This oxygen atom must be part of an acetal or ketal group. Glycosidic (1,4) Food Technology Study Program, IPB University http://fst.ipb.ac.id  Disaccharides ▪ Linkage of two monosaccharide molecules to form the disaccharides such as maltose, lactose and sucrose. ▪ The linkages are designated as alpha () or beta () depending on the orientation of the -OH group at the number C1 forming the bond. ▪  glycosidic: C1 is alfa configuration ▪  glycosidic: C1 is beta configuration ▪ The glucosidic bonds may be ruptured by enzymes at specific sites in the amylose and amylopectin polymers. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Disaccharides ▪ Linkage of two monosaccharide molecules to form the disaccharides such as maltose, lactose and sucrose. ▪ The linkages are designated as alpha () or beta () depending on the orientation of the -OH group at the number C1 forming the bond. ▪  glycosidic: C1 is alfa configuration ▪  glycosidic: C1 is beta configuration ▪ The glucosidic bonds may be ruptured by enzymes at specific sites in the amylose and amylopectin polymers. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Sub-topic 3.1 Definition, Source, Classification, and Role of Carbohydrates in Food System Week 3 3.2 Functional Properties and Chemical Reaction of Carbohydrates 3.3 Starch Chemistry and its Role in Food System Week 4 3.4 Starch Gelatinization Process and its Characteristics Food Technology Study Program, IPB University http://fst.ipb.ac.id  Relative Physical Properties of Sugars Sweetener sweetness Saccharin 20.000 – 70.000 ▪ Sweetness Cyclamates 3000 – 8000 ▪ When dissolved, all sugars are sweet Aspartame 200 to the tongue Acesulfamate-K 200 Fructose 1.3 ▪ Sugars contribute 4 kcal/g Xylitol 1.01 ▪ Sugars have different sweetness Sucrose 1.0 ▪ Very sweet sugar → smaller Invert sugar 0.85 – 1.0 quantities → less calories Xylose 0.59 Glucose 0.56 ▪ Relative sweetness: sucrose → used Galactose 0.4 – 0.6 as a standard → 1.0 Maltose 0.3 – 0.5 Lactose 0.2 – 0.3 Food Technology Study Program, IPB University http://fst.ipb.ac.id  Physical properties of sugar ▪ Hygroscopicity Percentage of water absorbed 20oC 25oC ▪ Ability to attract and hold water, which is Sugar RH = 60%, RH = 100%, RH =90%, characteristic of sugars to varying degrees 1hr 25 days equilibrium ▪ Maintaining the freshness of some baked -Maltose 5.05 -Lactose 5.05 products D-Fructose 0.28 73.4 42 – 43 ▪ A source of potential problems in texture D-Glucose 0.07 14.5 17 – 18 when RH is high Invert 0.16 74.0 sugar ▪ An elevation in temperature increases the Sucrose 0.04 18.4 50 – 56 absorption of moisture from the RH = relative humidity atmosphere Food Technology Study Program, IPB University http://fst.ipb.ac.id  Physical properties of sugars Glucose (Soluble in Water) ▪ Solubility ▪ Sugar is soluble in water because of numerous OH groups. ▪ Sugars have different solubility in water ▪ As the temperature of water rises, the Grams of sugar dissolved amount of sugar capable of being Sugar in 100 ml water dissolved in water increases Fructose 86.9 Sucrose 72.2 Glucose 65.0 Maltose 58.3 Lactose 29.8 Food Technology Study Program, IPB University http://fst.ipb.ac.id  Chemical Reactions ▪ Hydrolysis Hydrolysis of sucrose to invert sugar ▪ Disaccharides undergo hydrolysis when heated ▪ An acidic medium favors this degradative reaction as does the presence of water ▪ Invert sugar: sugar formed by hydrolysis of sucrose, a mixture of equal amounts of fructose and glucose Food Technology Study Program, IPB University http://fst.ipb.ac.id  Chemical Reactions ▪ Caramelization ▪ When sugars are heated to such intense temperatures (170oC for sucrose) → melt → caramelization occurs ▪ Caramelization requires very high temperatures. When a sugar is heated to temperatures above its melting point, dehydration occur resulting in the formation of furfural derivatives, which undergo a series of reactions ending with polymerization to brown pigments. ▪ Creates pleasing color and flavor changes ▪ Caramel colour: can be used as colorant in food processing Food Technology Study Program, IPB University http://fst.ipb.ac.id  Chemical Reactions ▪ Maillard reaction ▪ A reaction of prime importance with regard to quality of foods as it affects colour, flavour and taste, and nutritional quality. ▪ Involves the reaction of an aldehyde (usually a reducing sugar) and an amine (usually a protein or amino acid) in its initial stages. ▪ As a result of the initial interaction of sugars and amines, volatile food flavors and aromas are produced and dark-colored polymeric materials arise. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Louis-Camille Maillard (1878-1936) Photographed in his laboratory in 1915 1912 – 1916: He published 8 papers on his observations of colour changes on mixing amino acids and sugars. No one else took much interest in the reaction until 1950s. Food Technology Study Program, IPB University http://fst.ipb.ac.id  John Hodge: 1914 -1996 ▪ Chemist at USDA in Illinois (1941 – 1980) ▪ His proposed mechanism for the chemistry of non- enzymic browning is largely unchanged after 60 years. Citations since 1970 Paper Citations Hodge, J. E. Chemistry of browning reactions in model systems. 890 J. Agric. Food Chem. 1953, 1: 928-943. Maillard, L. C. Maillard-Hodge Reaction? Action des acides amines sur les sucres: formation des melanoidines par voie methodique. 634 Compt. Rend. 1912, 154: 66-68. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Steps of Maillard Reaction H + HOH 2C H O ▪ Aldose (especially reducing sugar) reacts HO HO :NH2G H OH with amino a acids or other amine groups to H H form Schiff Base (N-Substituted Glycosylamine) ▪ Through Amadori re-arrangement pathway, H HOH 2C H H O HOH 2C H O N-Glysosylamine forms carbonyl HO + HO HO NHG HO H compounds. H OH H OH H H H NHG ▪ Carbonyl compounds forms melanoidin with different reaction pathway, depending on Anomers of N-phenyl-D-glucosamine reaction condition and temperature : forming brown colour and flavour Food Technology Study Program, IPB University http://fst.ipb.ac.id  Maillard reaction Food Technology Study Program, IPB University http://fst.ipb.ac.id  Maillard Reaction Pathway Maillard Reaction in Milk Food Technology Study Program, IPB University http://fst.ipb.ac.id  Reaction Rates in Food System as Affected by Water Activity Food Technology Study Program, IPB University http://fst.ipb.ac.id  Oligosaccharides ▪ These are relatively small linear or branched fragments of the original starch molecule which have been formed as the result of acid, enzyme or other degradative action on starch. ▪ They normally contain between 3 and approximately 10 anhydroglucose units. ▪ Example: raffinose, stachyose, fructo- oligosaccha-rides (FOS), maltodextrin Food Technology Study Program, IPB University http://fst.ipb.ac.id  Challenge Questions ▪ Why some oligosacharides are considered as prebiotics? ▪ What is maltodextrin and what for? ▪ Why “dodol” easily experiences to form brown color? DISCUSSION FORUM Answer and Comment One of the Questions in LMS by next week (in English) http://newlms.ipb.ac.id Food Technology Study Program, IPB University http://fst.ipb.ac.id  Review ▪ How to differentiate caramelization and Maillard reaction? ▪ How to differentiate α and β structure, and D and L structure of glucose? ▪ How to differentiate α and β glycosidic bound? ▪ How to differentiate amylose and cellulose structure? Food Technology Study Program, IPB University http://fst.ipb.ac.id  Sub-topic 3.1 Definition, Source, Classification, and Role of Carbohydrates in Food System Week 3 3.2 Functional Properties and Chemical Reaction of Carbohydrates 3.3 Starch Chemistry and its Role in Food System Week 4 3.4 Starch Gelatinization Process and its Characteristics Food Technology Study Program, IPB University http://fst.ipb.ac.id  Course Learning Outcomes After completing this sub-topic, students will be able to explain: ▪ Source, definition and composition of starch. ▪ Characteristics of starch granules. ▪ Role of amylose and amylopectin to starch characteristics. ▪ Phenomenon of starch gelatinization ▪ Step of starch gelatinization ▪ Role of amylose and amylopectin to the starch gelatinization profile. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Starch ▪ The primary stored energy sources in plants. ▪ It occurs in nature as water-insoluble granules and is available in unlimited quantities. ▪ The most common starches used in the food industries are extracted either from cereals or roots and tubers. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Source of Starch ▪ Cereals : wheat, maize, rice, barley, sorghum ▪ Sugar crops : sugar cane, sugar beet, corn ▪ Root crops : sweet potato, potato, cassava ▪ Pulses : mungbean, kidney bean, ▪ Fruits : banana Food Technology Study Program, IPB University http://fst.ipb.ac.id  Starchy Foods Food Technology Study Program, IPB University http://fst.ipb.ac.id  Modern Production of Tapioca Traditional Production of Tapioca Food Technology Study Program, IPB University http://fst.ipb.ac.id  Starch ▪ In addition to their nutritive value, starches are used to affect the properties of many foods ▪ They are used in gelling, thickening, adhesion, moisture-retention, stabilising, film forming, texturising, etc. Food Technology Study Program, IPB University http://fst.ipb.ac.id  Starch ▪ Starch consists of two types of molecules, amylose (normally 20-30%) and amylopectin (normally 70-80%). Both consist of polymers of -D- glucose units in the conformation (D-glucopyranose molecules). ▪ In amylose these are linked -(1→4)-, with the ring oxygen atoms all on the same side, whereas in amylopectin about one residue in every twenty or so is also linked -(1→6)- forming branch-points. ▪ The relative proportions of amylose to amylopectin and -(1→6)- branch- points both depend on the source of the starch, e.g. amylomaizes contain over 50% amylose whereas 'waxy' maize has almost none (~3%) Food Technology Study Program, IPB University http://fst.ipb.ac.id  Amylose and Amylopection Amylose Starch Granules Amylopectin Food Technology Study Program, IPB University http://fst.ipb.ac.id  Composition of Starch Amylose : ▪ Linear chain of glucose molecules ▪ Form blue color with iodin (I2) Amylopectin : ▪ Branched chain of glucose molecules ▪ Form reddish brown color with Iodin Food Technology Study Program, IPB University http://fst.ipb.ac.id  Model Struktur Amilosa dan amilopektin Amilosa Amilopektin Food Technology Study Program, IPB University http://fst.ipb.ac.id  Structure of Starch Granules H H H H H H H H Food Technology Study Program, IPB University http://fst.ipb.ac.id  Properties of starch components Property Amylose Amylopectin General structure Essentially linear Branched Linkage  - 1,4  - 1,4 and  - 1,6 Average linier chain length 103 20-25 Molecular weight