Step 1: Understanding the Concept:
The question asks about the general change in the texture (firmness) of fruits as they are stored.
Step 2: Detailed Explanation:
During storage, fruits undergo ripening and senescence (aging). A key process during ripening is softening. This is caused by the enzymatic breakdown of structural components in the cell walls. The primary "glue" that holds plant cells together is pectin. Enzymes like polygalacturonase (PG) and pectin methylesterase (PME) break down this pectin into soluble forms, weakening the cell walls and the bonds between cells. This results in the fruit becoming softer. Therefore, as storage progresses, the firmness of most fruits generally reduces.
Step 3: Final Answer:
The firmness of fruit reduces during storage.


