Undergrad going to apply for graduate school. I recently came back from a trip where I got some goodies - I thought it would be nice to give some of my favorite professors gifts. However, I am now concerned there might be some ethical issues at hand here. I will definitely ask them for LORs and it is unlikely they will refuse. However, will giving them the gift before requesting a LOR prevent them from being able to say yes to writing a letter? Also, is it just wrong to do such a thing - it might be considered close to bribery (but then again I am not deliberately stating that I want a better LOR nor am I giving them the gifts because I want such a thing). 

Giving them the gift after having requested the letter is not an option as this goodie does have an expiration date. I am not sure how to proceed. (The goodie is less than $13)