Try combining your food with the term "superfood" in one of the following resources.
Example: Walnuts AND superfood.
The resources below are more scholarly/academic in nature.
Try combining your food with one of these terms: nutritional value; nutrition research. In Academic Search Complete and Proquest Central, also place a checkmark next to "scholarly/peer reviewed journals."
Example:
Dark Chocolate and (nutritional value OR nutrition research)
Articles from scholarly journals, magazines and newspapers covering every area of academic study and news.