Which of the following food products has a total shelf life of 4 hours?

The option identifying hot syrup held in a heated state has a total shelf life of 4 hours due to food safety standards governing temperature control and holding times. When food items are kept hot, they are typically stored at temperatures above 135°F, which helps to prevent the growth of bacteria. However, there is still a critical limit on how long these items can remain in holding to ensure they are safe for consumption. After 4 hours, the safety of the food product cannot be guaranteed, and it should be discarded.

In contrast, other food products listed have different shelf lives based on their nature and storage requirements. Mashed potatoes may remain hot and safe for longer than 4 hours if they are properly maintained, and depending on the ingredients and preparation method, they can often last longer when reheated. Belgian waffle batter, being a raw mix, does not have the same considerations as prepared hot foods, and its shelf life is influenced by how it is stored. Sliced or diced onions, while perishable, also do not face the same immediate time constraints when kept refrigerated. Each of these has varying shelf lives but does not align with the specific 4-hour limit set for hot syrup in a holding situation.