Carbohydrates

“polyhydroxy aldehydes or polyhydroxy ketones, or substances that yield such compounds on hydrolysis”

(C6H10O5)n

C6H12O6 => (C6H10O5)n + nH20

Colonic fermentation of fibre produces butyrate which is beneficial for gut health

Monosaccharides and disaccharides

Glucose, fructose, galactose

Lactose, maltose, sucrose

polysaccharides (starch) non-starch polysaccharides (dietary fibre)

(2-6 carbon units) – Biose, triose, tetrose, pentose, hexose (# of C) – Glucose, fructose, galactose

(2 monosaccharides) – Sucrose (glucose + fructose) – Maltose (glucose + glucose) – Lactose (glucose + galactose)

(3-10 monosaccharides) – Not as common in food; pulses – Inulin (fructan - chain of fructose; extracted from chicory)

(10+ monosaccharides) – Complex carbohydrates – Dextrin, starch, cellulose, pectin, gums

Glucose, Fructose Beet & cane (table) sugars, molasses/treacle, maple syrup

Glucose, Galactose Milk & milk products

Glucose Branched/linear, contributes to viscosity & gel formation

Glucose Hydrolysis product of starch

Glucose Meat products and seafood

glucose skeletal structure of plant cell (indigestible)

Sweetness * Other taste/aroma * Colour * Volume (e.g. fermentation in bread) * Texture (e.g. crystallisation vs gelling in jams) * ↓ freezing point * Binds water (shelf-life)

• Complex carbohydrate (polysaccharide) • Long chains of glucose (C6H10O5)n n=400-4000 – Amylose (linear) (gel) 25% of starch – Amylopectin (branched) (waxy) 75% of starch • Found in granules (small packets) Derived from various plants: – Roots (e.g. potato, tapioca) – Cereal (e.g. corn, wheat, rice)

• Browning of sugar (>100°C) • Dry & moist heat • e.g. crème caramel

Browning of starchy food * Dry heat * Breaks down starch > dextrins * e.g. toasting bread

Thickening * Starch heated with water * Forms a suspension * 60°C = swell * 80°C = burst

sugar + protein