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Carbohydrates part B

Carbohydrates part B. Dissacharides. Dissacharides. Sugars in nature is generally not monosaccharide Glucose + glucose-  maltose grains (least sweet) Glucose + galactose lactose milk (contributes to milk color) Glucose + fructose sucrose beet/cane

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Carbohydrates part B

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  1. Carbohydratespart B Dissacharides

  2. Dissacharides • Sugars in nature is generally not monosaccharide • Glucose + glucose- maltose grains (least sweet) • Glucose + galactose lactose milk (contributes to milk color) • Glucose + fructose sucrose beet/cane • Hydrolysis can break disaccharides down (reduce)

  3. 3 conditions can trigger hydrolysis • 1. presence of an enzyme to set off reaction • Digestion of sucrose uses sucrose from saliva • Making lactose free milk • Each sugar type requires different enzymes in order to break down • Change ose end to ase end: • Sucrase (aka invertase) for sucrose • invert sugar= mixture of glucose and fructose from hydrolysis of sucrose • Lactase for lactose etc • 2. Addition of an acid • 3. Addition of heat

  4. Carbohydrates-disaccharides- lactose • Lactose 0.2 r.s*= galactose plus glucose Cow’s milk contains about 4-5 % Human milk contains about 6-8% Fermented by lactic acid bacteria ( example yogurt, and cheeses) - lactic acid ( acidulant, preservative) *R.S. = relative sweetness

  5. Carbohydrates-disaccharides- lactose • Lactose intolerance • Hydrolized by the enzyme Lactase • Lactose-hydrolyzed milk

  6. Class activity : • Sample the two types of milk • Regular • Lactose reduced • Will there be a difference in taste between them? Yes/ No? • Why, Why not?

  7. Carbohydrates- disaccharides- Maltose • Maltose (.3 r.s.)= glucose- glucose • Formed from starch by enzymatic (amalase) or acid hydrolysis

  8. Class activity– unsalted crackers • Dissolve cracker in mouth • Cracker should become sweet as AMALASE starts breaking down starch

  9. Carbohydrates- disaccharides- Maltose Starch amylose amylase or acid maltose/ malt sugar (Not sweet)  (slightly sweet)

  10. Carbohydrates- sugar alcohols • Organic compounds with –OH group= alcohols • Less cariogenic ( cavity causing) or even anti-cariogenic • Less impact on blood sugar (slow absorption) • As sweet as or slightly less sweet than sugar • BUT – some laxative effect ( threshholdof20-40 g/day) • Eg) maltitol, xylitol- especially in chewing gum,confectionary

  11. Carbohydrates- sugar alcohols • Organic compounds with –OH group= alcohols • Sugars have multiple –OH groups plus O with double bond • Alcohol beverages (ethanols) have high caloric content (7 cal/g) • Ethanol (ethyl alcohol)- made from sugar and starch source • Methanol (wood alcohol) can cause blindness, nerve damage or death • Isopropanol (rubbing alcohol)from petroleum • “sweet” alcohols: glycerol, mannitol, sorbitol, xylitol • Glycerol can be made from animal fats • See pg 218- “the sweet alcohols”

  12. Sources of sugar • 4 cal/g • Common sugars: • granulated,brown, confectionary (10x), honey, corn syrup, molasses, maple syrup • Sugar exrtracts: • Plants:Cane, beet, maple trees, corn. Sorghum, agava, • Bees: honey

  13. Sugar Cane • Crude boiled liquid from sugar cane= molasses • Cane sugar that is not completely refined= brown sugar • All flavors, minerals and coloring removed= granulated sugar • Grinding to a finer texture= confectionary sugar (4x, 6x, 10x) • 4x for cough drops, gum, marshmallows and choc • 6x for cream fillings fondants,icing, toppings • 10x fine icings and fillings

  14. Sugar beets • No difference in sugars • Beets are less expensive • Food allergies to beets might be an issue for consumers

  15. Sugar sources:Maple syrup = 40 gallons of sap to make 1 gal syrup

  16. Sugar source: corn syrup • Processed by hydrolyzing cornstarch to glucose • Benefits of corn syrup: • Cost • Availaablitiy • Flexible properties: • Increase viscosity ( thickness) • Control sweetness • Used for wider variety of food than sucrose

  17. Sugars-high fructose corn syrup (HFCS) Starch amylose amylase or acid maltose hydrolysis w/maltase glucose + glucose Glucose isomerase isomerization Synthetically developed HFCS- very sweet

  18. Carbohydrates- functional properties of simple sugars • Sweetening • Crystalize • Viscosity/mouth feel • Fermentation • Preservative (antimicrobial agent) • Humectancy

  19. Carbohydrates- functional properties of simple sugars • Sweetening power • Relative sweetness ( R.S) • Sweetness is NOT correlated to calories • Eg fructose and lactose = 4 cal /g • Yet fructose (1.8 r.s.) is 9 x sweeter than lactose ( 0.2 r.s.) • Only need 1/9th as much fructose for an equivalent sweetening power to lactose1/9th less caloric intake

  20. Properties of simple sugars • Crystallization • Sugar can exist in both soluable (as syrup) abd crystalline states • Easily dissolves in water ( due to the OH) • Crystallized from solution= e.g. table sugar( sucrose ) from sugar cane juice • Sugars melt upon heating and recrystallize when cooled (different crystal form and size) • Hard candy production

  21. Properties of simple sugars • Body and mouth feel • Swish sugar water in mouth vs plain water • Fermented by microorganisms • Yeast must have sugar to ferment • Yeast acts on sugar until strong enough to convert starches to sugar • Antimicrobial agents • Jelly, Jams and Preserves via water reduction in products

  22. Properties of simple sugars • Reactants in non-enzymatic browning • 1. caramelization • Heating sugar alone to a high temperature (200 degrees C) • Aroma compounds ( caramel, butterscotch flavors) & brown pigments • - eg caramel candy, toffees • Color used in cola beverages is created by caramelizing sucrose

  23. Properties of simple sugars • Reactants in non-enzymatic browning: • Mailard browning • Reducing sugar + amino compounds ( proteins or amino acids) • Reducing sugars contain a “ free” aldehyde or keytone group • Eg. Glucose, fructose, galactose, lactose • Sucrose is a non reducing sugar • ( but can be hydrolyzed to glucose and fructose by high temperature or acid)

  24. Properties of simple sugars • Products of Maillard browning reaction: • 1. Low molecular weight interactive compounds • Aroma/flavor both desirable and undesirable • 2. High molecular weight polymers (melanoidians) • Brown and black pigments • Eg) toast, roasted coffee, potato chips, bread • Sunless tanning lotions too.

  25. Properties of simple sugars • Humectancy • Influence state of water in food systems • Chewy candies • Sticky lollypops • Invert sugars ( fructose and glucose are very hygroscopic) • Attract water from the atmosphere

  26. Properties of simple sugars • Ripening • Invertase is added to the crystalline firm center • Storage • Enzyme slowly Inverts sucrose= • Mixture of sucrose, fructose and glucose • This mixture does not crystalize easily (vs. glucose alone)= soft centers

  27. Relative sweetness • See page 223 text

  28. Properties of simple sugars summary: • Sweetening • Crystalize • Viscosity/mouth feel • Fermentation • Preservative (antimicrobial agent) • Humectancy • Caramelization • Non enzymatic browning • Ripening

  29. Assign • Read text pg 224-233 • Sugars

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