What is a common indicator of food spoilage?

A change in color is a common indicator of food spoilage because it often signals the breakdown of pigments and the growth of microorganisms, which can lead to food becoming unsafe to consume. For example, many fruits and vegetables will change color when they begin to rot or ferment, showing a shift from fresh to spoiled. This visual cue can alert individuals to the potential deterioration of the food product.

In contrast, increased size may occur due to factors such as swelling from moisture but doesn't necessarily indicate spoilage. Improved texture is typically associated with freshness—examples include crisp vegetables or tender meats, and therefore it doesn't indicate spoilage in a negative way. Better aroma, similarly, generally signifies that food is fresh and appetizing; spoiled food often has off-putting odors instead. Thus, change in color remains a clear and reliable indicator of food spoilage that can be easily observed.