APIs:
The ESHA Nutrition Database API provides several APIs including an API that returns a JSON representation of the specified food, one that returns all known nutrients, one that returns all known units, one that supports food search and another one for food recommendation.
The Edamam APIs including a Nutrition Analysis, Food Database, and Recipe Search API (search over 2.3 million recipes by diets, calories and nutrient ranges).
Spoonacular offers a variety of widgets that allow you to work with food data, including an ingredient visualizer widget which lets you show a recipe‘s ingredient list in a visually appealing way, price visualizer widget which lets you show the total estimated cost for a recipe, a taste visualizer widget which lets you display the taste distribution of an ingredient or an entire recipe, a nutrition visualizer widget which lets you display macro and micro nutrients of a recipe, and an equipment visualizer widget which lets you show the tools required to make recipe.
Other tools and sources:
NYT ingredient phrase tagger: https://github.com/NYTimes/ingredient-phrase-tagger