Do Microwaves Kill Vitamin C? Jasmyne Kassam York House School Floor Location: J94H

Using microwave ovens, we are able to cook our food faster than ever before. In just a minute or two, we can reheat yesterday’s leftovers, make a bowl of porridge or even pop popcorn. They are a staple in the kitchens of over 90% of households today. However, are microwave ovens really as innocuous as they look? Is something that can heat food as quickly as it does actually safe? First we must look at the method that microwave ovens use to heat food.

Inside every microwave oven, micro wavelength radiation is produced. When this radiation bombards the food inside the microwave, it makes the water particles change polarity. These changes cause the molecules affected to rotate billions of times per second. All the agitation caused by the polarity changes creates molecular friction, which heats up the food. It is due to the rapidity of the polarity changes that food heats up much more quickly in a microwave than in any other type of cooking appliance.

This unorthodox method of heating is vastly different from the traditional process of heating by conduction, and it could have an effect on the nutritional value of our food. The intense molecular friction involved when foods are microwaved could potentially destroy the fragile molecules inside them.

My work investigates the effects of microwave cooking on vitamin C (ascorbic acid) levels in broccoli, peppers and vitamin C tablets. For each, vitamin C levels after cooking in a microwave were compared to vitamin C levels after conventional cooking (such as boiling, steaming). Vitamin C levels were determined using an iodine-starch complex as a reagent. Results will be presented and compared.