In analyzing our options, we decided that the most feasible ways to package this bar would be to use natural leaves, such as banana leaves or corn husks, plastic wrap (such as saran wrap), or to develop a biodegradable plastic that would work like Saran wrap but that would biodegrade on its own.
Using an ordinary plastic wrap would create an inordinate amount of waste that would not biodegrade, and that would not be picked up either. In addition, actually making traditional plastic wrap would be a difficult task, and the use of it would force people in developing nations to buy the plastic from other nations. This kind of cyclical purchasing actually results in wealth flowing from developing nations to developed ones which is the opposite of what we’re aiming for.
Using natural leaves or corn husks also creates serious problems. Sanitizing something like a banana leaf or corn husk would be challenging in a developing nation where sanitation and food safety is already a problem. In addition, finding a way to seal these kind of wrappers would be difficult and would likely not keep the product as fresh, nor be as visually pleasing as a plastic wrapper.
Bioplastics have been used by many companies in hopes to reduce the usage of environment-costly plastic. According to Elizabeth Royte of the Smithsonian magazine, the production of plastic uses 200,000 barrels of oil per day in the US alone. With rising oil prices, the creation of alternative forms of plastic has not only become appealing environmentally but economically as well. Cornstarch-based plastics have been produced by companies, such as Plantic and Newman’s Own Organics, for the purpose of packaging foods and other products such as utensils and pens (1). These starch-comprised plastics are biodegradable, meaning organisms such as bacteria or fungi break down the plastic into natural components (water, carbon dioxide and biomass). This is an important advantage supplementing our goal of creating a recipe for a packaging plastic that can be made in a Guatemalan home. The distribution of the product and homemade plastic would generate income. Another advantage of starch-based plastic includes its ability to be biologically broken down in a compost pile or in soil when other bioplastics require strict conditions for industrial composting (2). This would be beneficial for the people of Guatemala who could use the degraded components of the plastic for personal farming. Also, this packaging could be thrown in the backyard and would help with the problem of trash flooding the streets of Guatemala.
To test this, we conducted a decision matrix, which confirmed that biodegradable plastic was the best option.
|biodegradable||cost||ease to make||materials readily available||capability to wrap||ability to keep product fresh||generate income|
The other problem we would have to solve is to find a recipe for this plastic that could be made in a place such as Guatemala. Luckily enough, you can make biodegradable plastic in a microwave with as little as three ingredients (4). With a little oil, water, and cornstarch, developing nations could package these nutrition bars and make it their own business. In addition, the recipes form a moldable plastic that would be ideal for making packaging. The plastic can also be colored with food dye, and again would make the product more sellable (5). We will have to try several recipes, but based on our decision matrix, it appears that cornstarch plastic would be the best packaging solution.
1. “World Centric: For a Better World.” 2004. <http://www.worldcentric.org/biocompostables/bioplastics>
2. “Bioplastic.” Wikipedia, The Free Encyclopedia. Wikimedia Foundation, Inc. 28 December 2011. Web. 20 January 2012. <http://en.wikipedia.org/wiki/Bioplastic>
3. Royte, Elizabeth. “Corn Plastic to the Rescue.” Smithsonian. August 2006. <http://www.smithsonianmag.com/science-nature/plastic.html?c=y&page=1>
4. “Easy Biodegadable Plastic” Instructables.com http://www.instructables.com/id/Easy-Biodegradable-Plastic/#step1
5. “Corny Recipes for the Classroom” http://texascorn.org/cornwebsite/files/Corny_Recipes_IL.pdf
Here are a few prototypes that we tried using cornstarch, water, and vegetable oil:
2 ounces cornstarch, 3 ounces water, splash of vegetable oil. Microwaved for 5 minutes.
Notes: Too much vegetable oil was used and we microwaved for too long. Prototype was solid and impossible to roll thin with out breaking off into pieces.
Below: We scaled down the recipe to use the same proportion but in tablespoons. We were able to get the prototype thinner this time, but it remained clumpy and brittle. It was microwaved for two twenty second intervals.
We switched from using the microwave to using a hot plate. The solution was stirred until the liquid became gel-like. The gel was much easier to spread but remained clumpy and non-pliable when dried.
Now that we found a heating mechanism that worked better, we decided to change the ingredients to see if that make a difference in the texture of the plastic: we used potato starch instead of cornstarch, and glycerine and vinegar instead of vegetable oil.
The results improved drastically. Our new plastic is much more pliable when dried, it isn’t nearly as brittle, and is transparent. The proportions are as follows: 1 tablespoon potato starch, 4 tablespoons water, 1 teaspoon glycerine, 1 teaspoon vinegar.
-Finding the correct ingredients/proportions
-Finding the best heating method and and optimal heating duration
-Determining the best medium to spread the plastic on
Solution to thinning the plastic:
-Plastic tasted sweet; vinegar flavor absent
-2×3 inch piece began to break down after about 2 minutes during taste test
-Placed one 2×3 inch piece in jar of water and another was buried
-Revisited after a week; plastic in water was slimy but still intact, piece that was buried still intact will little breakage.
We wrapped a piece of bread in the plastic and bound the ends with rubber bands (see below), but after two days, the piece of bread resembled a crouton.
Current Issues to Solve:
-How to seal the plastic to retain freshness.
-Eliminate use of wax paper (not biodegradable)
-We had difficulty pealing the plastic off of the aluminum without tearing, so we need a better way to remove the plastic
Where we are leaving off….
-We have developed a plastic wrap prototype that future groups may perfect:
-the plastics ability to keep the food fresh
-prolong the time it takes to degrade
-other uses for this biodegradable plastic?? Flower pot that can be planted directly into soil??