Which of the following factors does NOT affect the growth of bacteria?

The correct choice highlights that the color of the food does not influence the growth of bacteria. Bacterial growth is primarily affected by factors such as the presence of food, acidity, and moisture levels in the environment.

Food provides the necessary nutrients that bacteria need to develop and multiply. The acidity level can create an environment that is either conducive or hostile to bacterial growth; different bacteria thrive in different pH levels. Similarly, moisture is crucial since bacteria require a certain level of water activity to reproduce effectively.

While the color of the food may have some implications for food safety, such as indicating spoilage or freshness to the human eye, it does not inherently affect the actual bacterial growth process. Therefore, among the listed factors, color is the one that does not play a role in bacterial proliferation.