Which of the following is a common sign of thawing and refreezing?

A common sign of thawing and refreezing is the presence of ice crystals. When food thaws and then refreezes, moisture within the food can form ice crystals. This occurs because the water content within the food freezes and expands, leading to the formation of larger ice crystals over time. The development of these ice crystals can affect the texture and quality of the food, making it less palatable once it is thawed again.

While loss of flavor and discoloration are also concerns related to improper freezing and thawing, they are not as directly indicative of the thawing and refreezing process itself as ice crystals are. Ice crystals are a clear and observable sign that the food has undergone this cycle, as they form due to the changes in the state of water within the food during repeated temperature fluctuations. Therefore, recognizing ice crystals is critical for assessing the condition of food that has been improperly stored.