Which of the following is a sign of food spoilage?

Mold growth is a clear indicator of food spoilage. When food develops mold, it signifies that microorganisms are breaking down the food, leading to a change in its safety and quality. Mold can produce toxins, which can be harmful if ingested. Recognizing mold as a sign of spoilage is essential for food safety, as consuming spoiled food can result in foodborne illnesses.

In contrast, bright colors can indicate freshness and attractiveness in food, while a fresh smell typically suggests that the food is still safe to consume. A firm texture is often associated with quality and freshness in fruits and vegetables. Therefore, mold growth stands out as a definitive sign that food has spoiled and should not be consumed.