How to set up an url alias pattern for nodes using ascribed taxonomy term as part of the url?

I am using both path auto and taxonomy modules. For my content type "blog entry" I am using a category field which references to taxonomy terms (e. g. food blog, outdoor blog, writing blog ... also only one term can and must be selected upon creating the node type "blog entry") of a certain taxonomy vocabulary (e. g. blog categories).

Now I want the url to look like this: root/blogs/food-blog/node-title

I thought that it can be accomplished by using this pattern in the url alias settings:

for "blog entry" use pattern:
blogs/[node:field-kategorie:parents-all]/[node:field_kategorie]

Unfortunately this does not work. Any ideas why?