Food that makes people sick will often
a. look bumpy with odd color
b. taste the same as normal
c. taste sharp or bitter
d. smell slightly woody

Almost any of these could be true depending on the food item. Condiments such as mayonnaise may look, smell, and taste perfect, but if they are out in the heat, will go bad and make anyone that ingests it ill. Food products such as meat may take on an odd grayish color and have a rotting type smell. Other foods will have a bitter taste, maybe described as "tangy". Be sure to read food labels and check all foods before consuming. And if ever in doubt, don't eat it!