Idea 1 was Biomimicry:
Idea 2 is Moldy Matters: Remember that the one exception to doing a project with mold is that you are allowed to measure the time (quantitative, dependent variable) it takes for a food to show evidence of mold – but that you have to destroy the food and mold as soon as it is observed.
So how about a project that asks the question:
How much longer do store-bought foods stay preserved relative to home-made versions?
It would be interesting and relevant because it would give people insight into just how much preservatives must be in store-bought food and how much healthier it would be to eat more of the home-made alternatives.
To get started, think about foods that might be highly preserved, like fast food choices: French fries, hamburgers, chicken nuggets, tacos, etc. or grab-and-go sweet snacks: packaged cupcakes, cookies, Twinkies, snack cakes, etc. Also consider common foods that would be easy to make at home, like bread, popcorn, jelly, or yogurt. Choose a few (these are your independent variables) so you have some variety – and once you set it up, it is really easy to monitor. The hypothesis would be that the store-bought versions would take more time to mold because they contain presevatives.
The experimental design needs to include replication (at least 3 sets each) and controls. The way I laid out the project, the control would be the home-made version – made at home on the same day as the store-bought item was bought and opened.
For example, you could place matching pairs of food items (example: French fries from fast-food chain and French fries made at home) in the same container, side-by-side but not touching, and covered with a breathable top (cheese cloth, or screening or some sort, or even just left open). Mark your calendar. Check the pair every day until you see mold on either item (then discard that item, leaving the other one in the container). Count the number of days it takes to see mold start to develop.
Do some research on the environmental conditions that molds thrive under to determine where you store the project (warning – depending on food items selected, this could take close to a year or longer… so pick your storage spot with that in mind).