Is HFCS Natural? Yes, Under FDA Policy.
High fructose corn syrup meets the Food and Drug Administration’s (FDA) test for use of the term “natural.”1 As noted in the letter, the FDA’s longstanding policy on use of the term “natural” means that “nothing artificial (including artificial flavors) or synthetic (including all color additives regardless of source) has been included in or has been added to a food that would not normally be expected to be in the food.”
HFCS is made from corn, a natural grain product, and enzymes used in production of HFCS are found in nature.
HFCS and Sugar: They're Both Processed Foods
It is a popular misconception that high fructose corn syrup is more “processed" than sugar, fruit juice concentrate or agave nectar production. HFCS is refined with similar production methods to other sugars, making it no more "processed" than any other sweetener.
How HFCS is made
Source
White JS. 1992. Fructose syrup: production, properties and applications, in FW Schenck & RE Hebeda, eds, Starch Hydrolysis Products – Worldwide Technology, Production, and Applications. VCH Publishers, Inc. pp. 177-200 and Center for Science in the Public Interest, Food Additives, http://www.cspinet.org/reports/chemcuisine.htm
1. Letter from Geraldine June, FDA Center for Food Safety and Applied Nutrition, to Audrae Erickson, President of the Corn Refiners Association, July 3, 2008.