Product freshness is the top priority of all restaurant brands and so for Subway. Some of their menu items do include add-on preservatives to prevent them from being destroyed. On the other hand, there are many items that do not contain any type of food color, flavors, or preservatives and are 100% natural. Also, the restaurant focuses primarily on using natural sources of preservatives that do not harm the customers. So you can have your preferred dishes anytime you want.