I Blued My Food
Matthew Wong
David Thompson
Floor Location : J 159 H


My research is based on the premise that certain wavelengths of light affect bacteria growth. I predicted that blue LEDs could minimize bacterial growth. The purpose of this experiment was to see if off-the-shelf LEDs were effective in preserving food.
I placed fruits, chosen for their acidity, in three see-through shoeboxes. One continuously was lit by blue LED strips, another continuously by red LED strips, and one wasn’t lit at all, which served as a control.
Bacterial and fungal growth, and mold on the food, and temperature in and around the boxes were monitored and recorded for at least 10 days, and repeated once again with a different set of fruits for better results. I maintained a coldish 4-15 C temperature range by conducting the experiment in my detached garage.
According to the data I collected, the lit boxes weren’t too much different from the non-lit shoebox for the first run. The second run showed results indicating the blue and red boxes were better. I couldn’t come to anything conclusive based on the time given, although the second round looked more promising: the more acidic fruits seemed to fare better when lit. After the testing, I rejected my hypothesis. Perhaps a constant temperature would have given different results, and with better equipment (stronger LEDs that produce less heat, or shorter wavelengths in the low 400nm range), and more trials, my results may have differed. This experiment can be impactful by safely preserving food, without using chemicals.