CAROTENOID CONTENT OF THERMALLY PROCESSED TOMATO-BASED FOOD-PRODUCTS

Tomato-based food products such as tomato paste, tomato sauce, and tomato-based soups are rich in carotenoid compounds and are frequently consumed in the United States. Foods such as these, which. are high in carotenoid content, are of interest because of the demonstrated association between consumption of fruits and vegetables and reduced risk of lung and other epithelial cancers in humans. Limited analytical data on the carotenoid content of tomato-based products are available in food tables and data bases; however, they are usually reported only in terms of vitamin A activity. In this study name-brand and store-brand tomato-based food products purchased in three major U.S. cities were extracted and carotenoids were individually identified and quantified by reversed-phase HPLC according to methodology developed in our laboratory. The carotenoids that were detected and quantified included lycopene, lycopene-5,6-diol, lutein, alpha-, beta-, gamma-, and zeta-carotenes, neurosporene, phytoene, and phytofluene. As expected, lycopene was the most abundant carotenoid, ranging in concentration from 0.3 mg/100 g in vegetable beef soup to 55 mg/100 g in tomato paste. The concentration of beta-carotene ranged from 0.23 mg/100 g in tomato soup to 1.51 mg/100 g in vegetable beef soup. Lutein was found at very low concentrations (less than 0.2 mg/100 g) in all products analyzed except tomato paste, which contained 0.34 g/100 g.