1. SUGARS, STARCHES, PECTINS, AND OTHER CARBOHYDRATES

2. CHARACTERISTICS Organic compounds Carbon, Hydrogen, Oxygen
Simple or complex
Source of energy or fiber
Important food CHOs - Sugars, dextrins, starches, celluloses, hemicellulose, pectins, gums

3. FUNCTIONS SWEETENERS THICKENERS STABILIZERS GELLING AGENTS
FAT REPLACERS

4. MONOSACCHARIDES
SIMPLE SUGARS
MOST COMMON - 5 OR 6 CARBON

5. GLUCOSE Dextrose Naturally present in fruit Basic unit for starches
Less sweet than fructose
Used in food industry because of water holding properties and ability to control crystals
Food for yeast

6. FRUCTOSE Levulose Part of sucrose Sweetest of all sugars
In many fruits
Very soluble
Not easily crystallized
Glucose isomerase to change glucose to fructose

7. GALACTOSE Part of lactose – milk sugar Basic unit of pectic substances
Building block of many vegetable gums

8. COMMON MONOSACCHARIDES

9. DISACCHARIDES Two monosaccharides
Glycosidic bonds-readily hydrolyzed by heat, acid, enzymes

10. SUCROSE Table sugar From sugar cane or sugar beet Glucose + fructose
Invert sugar important in controlling crystallization
Most common disaccharide

11. MALTOSE Glucose + glucose Product of starch breakdown Corn syrup
Flavoring and coloring agent in beer, candies, shakes

12. LACTOSE Glucose + galactose Milk sugar
Extracted from solutions of whey
Not broken down or fermented by yeast
Does not react in batter leavened with baking soda or baking powder
Available for Maillard reaction so added to bakery products for browning

13. DISACCHARIDES

14. PROPERTIES OF SUGAR

15. SOLUBILITY Solution in foods
Varying degrees of solubility for monosaccharides and disaccahrides
As temperature increases  greater the amount of sugar that dissolves
Slow heating increases the solubility
As concentration increases  boiling point increases
Each gram molecular weight of sucrose increases boiling point 0.940F (0.520C)
Can use temperature to determine sucrose concentration

16. SATURATION
Unsaturated – small amount of sugar in water, can hold more sugar
Saturated – no more sugar can be dissolved
Supersaturated – holds more than what is usually soluble at a certain temperature
Supersaturation – heat to high temperature and cool slowly

17. CRYSTALLIZATION Cool supersaturated solution
Formation of closely packed molecules from the solidification of dispersed elements in a precise orderly structure
Arranged around a nuclei
Size of crystal depends on rate of formation of nuclei and rate of growth
Crystals form too soon  only a few  crystals too large, continue to grow, candy grainy

18. MELTING POINT/HEAT DECOMPOSITION
Apply dry heat  sugars melt to liquid state
Sucrose melts and forms liquid that turns brown
Carmelization – nonenzymatic browning, flavors food
Noncrystalline

19. HYGROSCOPICITY Ability to absorb moisture
Responsible for lumpiness (sugar)
Decreases staling in bread
Gives stickiness for high moisture characteristics to foods
Fructose most hygroscopic

20. INVERT SUGAR Acid hydrolysis of disaccharide sucrose
Heat increases hydrolysis
Glucose and fructose in equal amounts (equimolar)
Resists cyrstallization and retains moisture
Add cream of tartar, vinegar, molasses (acids)
Enzyme hydrolysis with invertase

21. CRYSTALLINE AND NON-CRYSTALLINE
TYPES OF SUGARS
CRYSTALLINE AND NON-CRYSTALLINE

22. GRANULATED SUGAR Crystalline – table sugar Sugar cane or sugar beet
Affects texture of baked goods
Improves body and texture of ice cream
Fermented by yeast
Retards growth of microorganisms
Raw sugar banned by FDA
Turbinado –raw sugar separated in centrifuge, washed with steam
Retailed as fine or extra fine

23. POWDERED SUGAR Pulverized granulated sugar
Add cornstarch to prevent caking
X designates fineness

24. BROWN SUGARS From cane sugar – late stages of refining
Crystals of sugar coated with molasses
Contains invert sugar
Sold in grades
More refined  lighter color, less flavor, lower grade – for baking – less flavor
Higher, darker grades more flavorful and suitable for cooking strong flavored foods

25. CORN SYRUP Acid and high temperatures to hydrolyze corn starch
Varying degrees of sugars
High fructose corn syrup (HFCS) from high glucose corn syrup – use enzyme glucose isomerase
Significant use in food industry

26. MOLASSES AND SORGHUM By-product of sugar production from sugar cane
Mineral content varies
Bitterness increases as refinement continues – blackstrap molasses
Treacle – dark fluid left after sugar cane is processed
Sorghum – from cane sorghum, similar to molasses

27. MAPLE SYRUP AND HONEY Maple syrup from sap of mature maple trees
Water evaporated, organic acids cause flavor
Honey flavors according to flower nectars
USDA has standards for grades of honey

28. ALTERNATIVE SWEETENERS
Non-nutritive – high intensity sweeteners
Approved saccharin, aspartame, acesulfame-K, sucralose, neotame
Except for sucralose not enough bulk to substitute in recipes
Cyclamates – banned
Sugar alcohols - polyols– improve bulk, mouthfeel, and texture

29. SUGAR COOKERY
CANDIES

30. CRYSTALLINE CANDIES Generally soft
Smooth, creamy with tiny crystals that cannot be detected with the tongue
Fondant and fudge
Use interfering agent to prevent early crystallization
Must concentrate solution-test temperature to determine concentration
Complete solution of crystalline sugar

31. INTERFERING AGENT Interfere with size or rate of crystal growth
Contribute to viscosity of syrup and elevate the boiling point
Examples – milk, butter, cream, eggs, chocolate, cocoa, proteins, fats, dextrins, invert sugar, corn syrup

32. NON-CRYSTALLINE CANDIES
Amorphous
No definite crystalline pattern
Cook to very high temperature
Adding large amounts of interfering agent
Combination of methods
Hard – brittles, high temperature, low moisture
Chewy – caramels, high interfering agent
Aerated – marshmallows, air trapped in protein foams and interfering agent

33. POLYSACCHARIDES Complex carbohydrate polymers
Properties depend on sugar units, glycosidic linkage and degree of branching
Starches, Pectins, Gums most important
Hydrocolloids – water loving colloidal substances

34. STARCH Plant polysaccharide - linked glucose monomers
GRANULES - formed in cells, grow by adding on layers
Long-chain glucose polymers
Insoluble in water
Form temporary suspension

35. SOURCES Characteristic of finished food depends on starch source
Seeds, roots and tubers
Cereal grains - wheat, corn, rice, oats
Roots and tubers - potatoes, arrowroot, cassava

36. AMYLOSE AND AMYLOPECTIN
STRUCTURE
AMYLOSE AND AMYLOPECTIN

37. AMYLOSE Straight chain or linear fraction 1/4 of all starch
Thousands of glucose units
Forms thick gels-hold shape when molded, rigid

38. AMYLOPECTIN Highly branched 3/4 of starches Thickens but does not gel
Proportion of amylose:amylopectin influences cooking qualities and keeping characteristics of finished food product

39. AMYLOPECTIN

40. STARCH CHARACTERISTICS
Ability to absorb water limited
In uncooked stage is insoluble in cold water - forms temporary suspension because polymer is too large
Doesn’t change boiling point or freezing point of liquid
Reversible

41. EFFECTS OF HEAT

42. DRY HEAT Heating - increases uptake of water Dextrinization
Color and flavor changes
Reduced thickening power
Nonenzymatic browning
Dry flour browned

43. MOIST HEAT
Complete absorption as heat increases - permanent swelling, irreversible
Sol - as starch continues to come out of granules
Viscosity-thickness, thinness of liquid
Translucency increases during heating

44. GELATINIZATION
Sum of changes in first stages of moist heating of starch granules
Gelatinized granules = opaque, fragile, ordered structure disrupted
Temperature of gelatinization differs for each starch
Short chains of amylose come out of the granules
Irreversible changes

45. CONTINUED HEATING Gelatinization requires addition of heat
Cooking develops flavor
Pasting occurs
Granules swell
Granules of starch swell independently

46. PASTE CHARACTERISTICS
Concentration of starch affects consistency
Clear thickened gel made from root starches or waxy versions of starches
Cloudy gels from cereal starches

47. FACTORS AFFECTING GELATINIZATION

48. ACID
Fragments (hydrolyzes) starch molecule = thinner hot paste and less firm product
Hydrolysis = less hydration of starch
Add acid after gelatinization and after starch has cooked
Applicable - lemon juice, vinegar, tomatoes

49. AGITATION
Over-stirring causes granules to burst, empty bound water = gel will thin
Creates more uniform mixture

50. OTHER FACTORS
FAT AND PROTEIN- coats (adsorbs) to surface of granule = delays hydration
Fat in pie crust to prevent clumping
SUGAR - competes for liquid = delays absorption by granule = thinner mixture
Elevates temperature for gelatinization
ENZYMES - hydrolyze starch molecules

51. TIME AND TEMPERATURE
Lengthen heating time = causes granules to rupture - thins product
More rapid heating = smoother paste
Bring to boil over direct heat

52. GELATION Formation of a gel when gelatinized starch is cooled
Strong amylose bonds
Elastic solid
Retrogradation-reverting to crystalline state
Syneresis - water loss during retrogradation, “weeping”-as water evaporates dried out rubbery matrix of starch
Non-pourable, highly viscous

53. SEPARATING AGENTS
DEFINED - ingredients or additives which physically separate starch granules during hydration, allowing maximum hydration
Prevents lump formation
FAT -ROUX- forms film around granule = each granule swells independently of others
COLD WATER- SLURRY-physically separates granules (hot water causes partial gelatinization)
SUGAR-LIAISON - physically separates

54. MODIFIED STARCHES
Defined-starches which have been chemically altered to produce physical changes
Will improve stability, convenience, performance during food processing
Use acids or oxidizing agents
FDA-regulations governing modification

55. EXAMPLES
PREGELATINIZED STARCH - gelatinized, dried, can reconstitute without heat (instant potatoes, hot cereal)
Acid-modified starch - treated with acid slurry, forms strong gel upon cooling
Cross-linked starches - acid resistant, resists rupture
Cold water-swelling - instant starch that remains intact

56. FUNCTIONS OF MODIFIED STARCHES
Increase acceptability of product flavor and consistency
Prevent retrogradation
Stabilizers in conjunction with emulsifiers
Improve freeze-thaw stability
Prolong shelf life of frozen food by preventing oxidation

57. WAXY STARCHES Commonly used in pie fillings Made from natural starches
Practically no amlyose
Thicken at lower temperature but no gelling
Less retrogradation
Barley, corn, rice, sorghum

58. HIGH AMLYOSE STARCHES Genetic manipulation
Form films and bind other ingredients

59. PECTINS AND GUMS Polysaccharides Plant tissue
Used as gelling agents, thickeners, stabilizers

60. PECTIC SUBSTANCES Part of primary cell wall
Hold cells together, hold skin on fruit
Protopectin - immature fruits
Pectinic acid- mature fruit, includes pectins
Pectic acid - over ripe fruit

61. PECTIN Dispersible in water Forms a sol
Can be converted to a gel in the presence of water with addition of sugar or acid
Attraction to water is decreased
Pectin under skin of fruits melts with heat application (peel tomatoes, etc)

62. PECTINS
Commercially extracted from apple cores and skins; form white inner skin of citrus fruits
Boiling too long - depolymerization occurs, gel may not set
Boiling too short - insufficient invert sugar formed, sucrose may crystallize

63. GUMS All are colloidal polymers (too large to dissolve)
All are very hydrophilic
All are thickeners in water dispersions
Galactose most common sugar
All are polysaccharides – EXCEPT for gelatin
Examples: Guar gum, gum arabic, carob bean gum, carageenan, agar, xanthan gum

64. USES Thickening agents replacing starch Stabilizers of emulsions
Maintain smooth texture of products like ice cream
All do not form gels