how do you tell apart mature and immature fava beans/broad beans?.

I have a bag of frozen broad beans. it does not say mature or immature and they are not in pods.

I also have a bag of dried broad beans. They have a dull greenish colour.

I would like to know if they are mature or immature. since the nutritional difference b/w the two arehuge, the immature has like 1/5 of the calories of the mature beans( based on weight).

thanks for the help people!