The ornamental design for an adaptersystem for foodstorage container, as shown.
FIG. 1 illustrates a perspective front left side overview of an adapter system for food storage container illustrated between a lower food storage device portion and an upper food storage device portion;
FIG. 2 illustrates a perspective front left side overview of thereof without the illustrative latches;
FIG. 3 illustrates a lower perspective overview thereof;
FIG. 4 illustrates a perspective overview thereof without the upper and lower food storage device portions;
FIG. 5 illustrates an elevated top view thereof;
FIG. 6 illustrates an elevated front view thereof; and,
FIG. 7 illustrates an elevated side view thereof.
The top and bottom portions of the food storage container, as well as the interior circle and square elements shown in broken lines, illustrate portions of the adapter system for food storage container that form no part of the claimed design.