COMPLEX CARBOHYDRATES:

1. COMPLEX CARBOHYDRATES: STARCHES, CELLULOSE, GUMS AND PECTINS

2. FOODS RICH IN CARBOHYDRATES • SOME CARBOHYDRATES ARE SIMPLE CARBOHYDRATES • MANY ARE COMPLEX CARBOHYDRATES • CALLED POLYSACCHARIDES BECAUSE THEY ARE MADE UP OF MANY SUGAR UNITS (SACCAHARIDES) • POYSACCHARIDES ARE ALSO CALLED MACROMOLECULES BECAUSE THEY CONTAINS HUNDREDS OR THOUSANDS OF ATOMS EACH

3. TYPES OF COMPLEX CARBOHYDRATES • STARCHES • CELLULOSE • GUMS • PECTINS

4. STARCHES • MOST ABUBDANT IN THE U.S. DIET • ARE MADE UP OF MANY SUGAR UNITS LINKED IN CHAINS CALLED POLYMERS • COMPOSED OF THE SUGAR GLUCOSE. • HAS TWO BASIC STRUCTURES • AMYLOSE – UNITS ARE LINKED IN A LINE (LINEAR) • AMYLOPECTIN – UNITS ARE BRANCHED

5. STARCHES CONTINUED • MOST ARE A MIXTURE OF AMYLOSE AND AMYLOPECTIN • STARCHES COMPOSED MAINLY OF AMYLOPECTIN ARE CALLED WAXY STARCHES • PLANTS PRODUCE STARCH IN PACKETS CALLED GRANULES THAT ARE NOT SOLUBLE IN COLD WATER • GRANULES ARE A MIXTURES OF AMYLOSE AND AMYLOPECTIN • THE RATIO DETERMINES HOW STARCHES PERFORM IN FOOD MIXTURES

6. SOURCES OF STARCH • WHEAT FLOUR • BAKED GOODS • PASTA • RICE • CORN • POTATOES • OATS • GRAIN OR SEED

7. CELLULOSE • A POLYSACCHARIDE MADE FROM LARGE AMOUNTS OF BETA – D GLUCOSE • SOME ANIMALS AND INSECTS CAN DIGEST BUT HUMANS CANNOT • KNOW AS FIBER IN DIET • FORMS THE RIGID STRUCTURE IN PLANTS (STRINGS IN CELERY ND MEMBRANES SURROUNDING CORN KERNELS

8. CARBOHYDRATE GUMS • NOT GENERALLY AVAILABLE AT THE GROCERY STORE • GUMS ARE POLYSACCHARIDES THAT ARE SOLUBLE IN WATER AND EXTRACTED FROM PLANTS • USED TO THICKEN AND STABILIZE MIXTURES AND TRAP COLOR AND FLAVOR • MOST COMMON IS GUM ARABIC • SURROUNDS FLAVOR PARTICLES, PROTECTING THEM FROM MOISTURE, ABSORPORBTION, EVAPORATION, OR CHEMICAL OXIDATION • COMMONLY USED IN SALAD DRESSINGS AND GUMMY CANDIES

9. PECTIN • FOUND IN PLANT CELLS • MADE OF CHEMICAL DERIVATIVES OF SUGAR CALLED SUGAR ACIDS • NATURALLY OCCURS IN FRUITS • PRODUCES A STRONG GEL • REMAINS STABLE TO 1000 C (2120 F) • CREATES A THICKENING STRUCTURE • USED IN JAMS AND JELLIES

10. FUNCTION OF STARCH IN FOOD PREPARATION • PROVIDES STRUCTURE • RETAINS SHAPES • RESPONSIBLE FOR TEXTURE • BINDS • HOLDS PRODUCTS TOGETHER • STABILIZES TO PREVENT SETTLING • THICKENS (GELATINIZATION) • MOLECULES TAKE UP WATER • HYDROGEN BONDS FORM BETWEEN STARCHES AND WATER

11. STRUCTURE • MANY BONDS BETWEEN STARCH AND WATER MOLECULES CAN FORM • STARCH MOLECULES ARE LARGE • SPACES BETWEEN THEIR SUGAR UNITS • TRAPS OR HOLDS WATER MOLECULES • THE MORE WATER THEY HOLD. THE THICKER THE MIXTURE • HEAT STRETCHES THE MOLECULES AND ALLOWS THEM TO HOLD MORE WATER

12. THICKENING POWER OF COMPEX CARBOHYDRATES • TOO MUCH HEAT WILL CAUSE STARCH MOLECULES TO BREAK DOWN AND LOSE THICKENING ABILITY AND STABILITY • THE PRESENCE OF SALT OR SUGAR ALSO AFFECTS STARCH’S THICKENING ABILITY BECAUSE THEY ARE ALSO POLAR MOLECULES THAT WILL BOND WITH THE WATER • GUMS AND PECTINS ARE ALSO USED FOR THICKENING FOOD PRODUCTS

13. WHICH STARCH SOURCE IS BEST? IT DEPENDS ON WHAT TYPE OF FOOD PRODUCT OR STARCH-LIQUID MIXTURE IT WILL BE USED IN. REMEMBER THAT THE MOST IMPORTANT FACTOR IS USUALLY FLAVOR.

14. TYPES OF STARCH AND LIQUID MIXTURES • SLURRIES – UNCOOKED MIXTURES OF WATER AND STARCH USED IN PROCESSING AND CHEMICAL ALTERATIONS. • SOLS– THICKENING LIQUIDS THEY ARE POURABLE LIKE BATTER ARE COOKED SOLS LIKE GRAVY • PASTES – THICKENING MIXTURES THAT HAVE VERY LITTLE FLOW AND CAN BE STIRRED INTO HOT LIQUIDS WITHOUT LUMPING • GELS – MIXTURES THAT ARE RIGID AND ARE BOUND TOGETHER IN A 3-DIMENSIONAL NETWORK

15. PROPERTIES • There are five properties that food scientists evaluate before selecting a starch for a starch-liquid mixture • Retrogradation- the firming of a gel during cooling and standing • Viscosity- the resistance of a mixture to flow • Stability- the ability of a thickening mixture to remain constant over time and temperature changes • Opacity- refers to how much an object blocks light • Texture- the way a product feels to the fingers, tongue, teeth and palate

16. HOW DO YOU LIKE YOUR GRAVY? • OPAQUE VS. TRANSLUCENT • OPAQUE – USE FLOUR FOR THICKENING • TRANSLUCENT – USE CORNSTARCH • LUMPS OR NO LUMPS • If you prefer no lumps • GRAVY MIXES - may contain modified starches • COLD WATER PASTE – stir starch and an equal amount of water until smooth before adding to hot mixture • STARCH AND FAT – stir starch and an equal amount of heated fat until smooth and then slowly added liquid • STARCH AND SUGAR – combine starch and sugar thoroughly then add to liquid

17. NUTRITIONAL IMPACT • DIGESTABLE STARCHES • PROVIDE 4 CALORIES OF ENERGY PER GRAM • MOST ABUNDANT AND ECONOMICAL SOURCE OF CALORIES • PROVIDE OVER HALF OF DAILY CALORIES • CARBS IN THE FORM OF GLUCOSE IS THE ONLY ENERGY SOURCE THE BRAIN CAN USE • STARCHES AND SUGARS CAN BE EFFICIENTLY CHANGED TO ENERGY • EXCESS CARBS ARE STORED AS GLYCOGEN • GLYCOGEN IS STORED IN THE LIVER AND MUSCLES • WHEN STORES ARE FULL THE EXCESS TURNS INTO FAT

18. NUTRITIONAL FACTS • INDIGESTABLE FIBER • CELLULOSE • TERMS USED ON LABELS • FIBER • BRAN • BULK • HELPS YOU FILL FULL • AIDS IN DIGESTION AND ELIMINATION • SOURCES ARE COMPONENTS OF VEGTABLES, FRUITS, GRAINS AND ADDITIVES TO OTHER FOOD PRODUCTS TO SLOW DOWN STALING RATE

19. FUNCTION OF CARBS • PROVIDES ENERGY FOR BODY FUNCTIONS • PROVIDES BULK FOR DIGESTION PROCESSES • DECREASES BILE ACIDS REABSORPTION • LOWERS CHOLESTEROL LEVELS • PROMOTES UTILIZATION OF FAT

20. CARBS ARE NOT THE ENEMY • IN FACT, THEY ARE SO IMPORTANT THAT THEY REPRESENT THE LARGEST PORTION OF THE USDA’S MyPyramid SYMBOL