35-5

J. YANG, L. Halim, and R. H. Liu. Dept. of Food Science, Cornell Univ., Stocking Hall, Ithaca, NY 14853-7201

Epidemiological studies have shown that consumption of nuts has been associated with reduced risk of cardiovascular disease. Phytochemicals, mainly phenolics and flavonoids, are suggested to be the major bioactive compounds responsible for the health benefits of nuts. However, little is known about antiproliferative activity of nuts. The objective of this study was to investigate the profiles of total phenolics, including both soluble free and bound forms, total antioxidant activities, and antiproliferative activities of selected nuts commonly consumed in the United States. Ten nuts - almonds, Brazil nuts, cashews, hazelnuts, macadamia nuts, peanuts, pecans, pine nuts, pistachios, and walnuts - were analyzed. The profiles of total phenolics and flavonoids of nuts, including both soluble free and bound forms were determined. Total antioxidant activities of these nut extracts were determined using the Total Oxyradical-Scavenging Capacity (TOSC) assay. Antiproliferative activities on HepG₂ human liver cancer cells and Caco-2 human colon cancer cells were measured by the MTS assay. Walnuts had the highest total phenolic and flavonoid contents (1581 ± 58, and 745 ± 93 mg/100 g, respectively; p<0.05). Walnuts also exhibited the highest total antioxidant activity (458 ± 14 micromole vitamin C equiv/g of nut; p<0.05), followed by pecans, peanuts, pistachios, cashews, almonds, Brazil nuts, pine nuts, macadamia nuts, and hazelnuts. The proliferation of HepG₂ and Caco-2 cancer cells was significantly inhibited in a dose-dependent manner after exposure to the extracts of walnuts, pecans, peanuts, pine nuts, almonds, macadamia nuts, and cashews, with walnuts and pecans exhibiting the highest antiproliferative activity against both HepG2 and Caco-2 cells. Both soluble free phenolic and flavonoid contents were strongly correlated with total antioxidant activity (R²=0.9901, p< 0.05; and R²=0.9749, p< 0.05, respectively). This study clearly showed that phytochemicals in nuts have potent antioxidant and antiproliferative activities.

Session 35, Nutraceutical & Functional Foods: General I
9:00 AM - 12:00 PM, Monday AM Room 398

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana