Name two signs that food may have been contaminated.

Changes in color and texture are strong indicators that food may have been contaminated. When food is contaminated, its appearance can often change; for example, fruits and vegetables may show signs of spoilage such as browning or mushiness, while meats may have discoloration or an unusual sheen. Texture can also be affected; for instance, if a product feels slimy or sticky when it shouldn't, this could be a sign of bacterial growth or spoilage.

Though strange packaging may also suggest tampering or contamination, it is mostly indicative of improper storage or handling rather than direct evidence of food contamination. Expiration dates are critical for safety but relate more to the age of the food rather than immediate signs of contamination. Lastly, the signature on the label does not provide any relevant information about food safety or contamination. Thus, observing changes in color and texture is a direct and unmistakable sign that food safety may be compromised.