Citrobacter freundii are the bacteria which give raffinose utilization test. Along with it Klebsiella pneumonia and E. coli are also taken into account for utilizing raffinose.

C18H32O16

Benedicts reagent tests for reducing sugars, so the question is, is raffinose a reducing sugar. Raffinose is a trisaccharide made up of glucose, fructose and galactose. It is not a reducing sugar because all of its anomeric carbons are bonded, so it will not react with benedicts reagent.

You are probably referring to raffinose - a trisaccharide found in many fibrous vegetables. You can find more information online at: http://www.absoluteastronomy.com/topics/Raffinose

A carbohydrate containing three monosaccharide residues, e.g., raffinose.