Final answer:
A sign of spoilage in canned foods is when liquid spurts from the jar or can upon opening. This often indicates bacterial activity inside. Improved canning procedures have decreased foodborne illnesses like botulism.
Step-by-step explanation:
A sign of spoilage in canned foods is b. Liquid spurts from the jar or can when it is opened. This could indicate that gas has been produced by bacteria, which can create pressure inside the can or jar, leading to liquid spurting out when opened.
Foods known for not requiring refrigeration, such as jams and dried meats, have certain preservation characteristics such as high sugar content or low moisture that inhibit bacterial growth. The characteristics of foodborne illnesses and cases of botulism have decreased over time due to improved sterilization and canning procedures.
Factors like sourness are associated with spoilage, indicating that the food has undergone chemical reactions that may have been accelerated by factors like temperature. Better sterilization practices have played a significant role in reducing foodborne illnesses such as botulism, particularly through enhanced safety protocols in preparing and storing canned goods.