Purdue iGEM Page through the registry : 
We are currently working on developing new projects to do. Right now we have 3 "pet projects"
- Engineering Bacteria to create colored proteins to be used as an alternate food coloring.
We are also affiliated with the Institute of Biological Engineering, IBE. You can visit their website to learn more. 
Links to Outside Sources that may be useful
IBE Student Chapter Wiki, 
A general overview of milk and how factors affect its lifespan and production, .
Go through Purdue Libraries  to get to the research databases. I prefer Web of Science.
Wiley Protocols in Molecular Biology. Link will only work on Purdue Recognized Computers. 
University of Guelph Overview of Milk: .
Literature Articles that may be of use
Investigations into the activity of enzymes produced by spoilage-causing bacteria: a possible basis for improved shelf-life estimation: Braun et al. Food Microbiology. v.16 Pgs. 531-540. 1999.
Microbial and biochemical spoilage of foods: An overview. intVeld, JHJH. International Journal of Food Microbiology. v.33 Pgs. 1-18. 1996.