WHAT IS STARCH?  Starch is a complex carbohydrate stored in plants  Cereal grains contain plant cells that are source of starch  Common starches used in cooking: wheat flour cornstarch tapioca

How is starch used?  Starch is primarily used as a thickening agent  Mixtures thickened with tapioca and cornstarch are translucent (light passes through, but not clear)  Mixtures thickened with flour are opaque (cannot see through)

FOOD SCIENCE AND STARCH  Sauces usually must be thickened  Most thickening agents are forms of starch  Starch granules will absorb moisture when placed in a liquid  That process is called gelatinization

Characteristics of Sauces  No lumps  Flavor that is not starchy or pasty  Sticks to the back of a spoon  Will not break apart when cooked

MOIST HEAT  Mixing starch with water and heating them causes the starch to become soluble  Starch granules absorb water and swell or get bigger  The swelling causes the mixture to thicken  As starch mixture becomes thicker it reaches maximum thickness known as gelatinization

COOLING PROCESS  During cooling, bonds form between the starch molecules  The starch mixture forms gels which hold water  If your product stands too long, the gel breaks and water may leak out.  This is called syneresis

What food products are thickened with starch?  Gravy  Cooked Pudding  Pie Filling  Sauces – sweet and savory

Thick Chocolate Sauce 1 T. cornstarch1 C. boiling water ¼ cup cocoa ½ tsp. vanilla ½ cup sugar1/8 tsp. salt Mix dry ingredients Add water to dry mix slowly Boil slowly about 5 minutes, stirring constantly. Do Not Scorch (burn) Add vanilla and serve.