Polyphenols: Total amounts in foods and beverages and US per capita consumption


Joe A. Vinson, vinson@scranton.edu, Department of Chemistry, University of Scranton, Scranton, PA 18510
It is well known that increased consumption of fruits and beverages leads to a decreased risk of chronic diseases such as heart disease, stroke, cancer and diabetes. These epidemiology studies led scientists to believe that the antioxidant vitamins C, E, and beta carotene were responsible for the health effects. More recently epidemiology has shown that polyphenol consumption from the foods may be the major agents responsible. However measuring individual compounds is a difficult, if not impossible task due to the very large number (8000 and growing) of these compounds. Another obstacle is that in many foods some of antioxidant phenolic groups are tied up with sugars and are not measured when simple food extracts are analyzed. Acidic or basic hydrolysis is often needed to liberate the phenolic groups that are the functionality that provides the health effects. Using market samples of fruits, vegetables, beverages, oils, spices, nuts and grains, we have determined the amount of phenols in foods and beverages by hydrolysis and subsequent measurement of the total amount of polyphenols using a Folin colorimetric assay. With this data and the USDA database, the contribution of each type of food to the average estimated US per capita consumption was calculated.