It is possible. I can't remember the name of the book I got my information on bioplastic (your "gunk") from, but it came out within the last two or three years and the author was a biologist with a Spanish surname. You might be able to locate it on a website dealing with Sindology.
When you compare this with the all other data on the shroud, a date of around 50 A.D. in a carbon dating test on a piece of material stripped of biplastic would make a VERY compelling case for the veracity of the Shroud.
You're thinking of Leoncio A. Garza-Valdes. Dr. Garza is a pediatrician from San Antonio, and an archaeologist noted for expertise in pre-Columbian artifacts.
Here is a helpful article about his work concerning the shroud.