Glucose used in blood storage is beneficial due to the following reason:

Additive solution using for red cell preservation contain saline, adenine, and glucose, with or without mannitol to decrease hemolysis. The duration of red cell storage in additive solutions is extended to 42 days. The increased glucose allows an adequate supply of energy for the RBCs beyond 35 days. Red cells in additive solution are now the most common preparations available for transfusions. Red cells collected in any of the anticoagulants and preservatives must be stored at 10-60C to maintain optimum function.