Searching for Starch in the Food Pyramid.

The objective of this presentation is to teach young students about plants, foods and nutrition through hands-on experiments and demonstrations.  Elementary students learn what an indicator is, and then use iodine, an indicator for the nutrient starch, to visualize it in cereals, breads, crackers, and noodles.  The plants used to make these foods and from what part of the plant these foods originate are discussed.  The students then examine various imbibed corn seeds to see if they contain starch, and where in the seed the starch is located.  Students discover that the seed from sweet corn has very little starch, while field and popcorn seed contain lots of starch.  In fact it is the starchy endosperm in pop corn that expands when the kernels are heated.  The food pyramid is introduced, and blocks in the food pyramid are identified.  Students give examples of vegetables and fruits and name the parts of plants they eat when these foods are consumed.  Examples of fruits and vegetables are checked for the presence of starch, and students learn that some vegetables contain lots of starch (potatoes) while others contain very small quantities of starch (celery).  They learn that certain fruits contain starch.  Using the iodine to ‘see’ starch they can better understand why very yellow bananas are sweeter than those that are still a bit green (as bananas ripen the starch is converted into sugar).  Students discuss the plants found in the ‘meat block’ and use iodine to see if the seeds from peanut, bean and pea plants contain starch also.  Students learn that they can use a simple color indicator to find starch, the nutrient starch is found in many different types as well as parts of plants, and that starch is found in many processed foods we eat.