Carbon isotope measurements of foods containing sugar: A survey.

Over 200 sugars, high sugar content foods, and sugar-free alternative products found in Canadian supermarkets were analyzed for carbon isotope (δC) values, adding to the record of food items with reported δC values, which can aid in food authentication and human diet studies. The δC values of the products were mostly consistent with the photosynthetic pathway of the plant from which the main ingredients were derived. With the exception of those sugars and syrups derived from known C3 sources, all of the sugars and syrups and most of the sugar added to food products were from C4 plants such as sugar cane or corn syrup. Many sweeteners are chemically manufactured, and most reflect an intermediate δC value. A mixing model estimated the contribution of C3- and C4-based ingredients in foods with high sugar content, which may be used to evaluate the percentage of added sugar from C3- or C4-sources.