36E-95

G. ANGEL-MORALES¹, L. F. Reyes², L. A. Cisneros-Zevallos², and C. H. Brenes¹. (1) Dept. of Food Technology, ITESM-Campus Monterrey, Ave. Eugenio Garza Sada 2501 Sur, Monterrey, N.L., 64849, Mexico, (2) Dept. of Horticultural Sciences, Texas A&M Univ., 202 Horticulture and Forestry Science Bldg., 2133 TAMU, College Station, TX 77843-2133

Native Mexican crops such as black beans (Phaseolus vulgaris), blue corn (Zea mays), Jamaica flowers (Hibiscus sabdariffa), and chile poblano peppers (Capsicum annuum) are used by tradition in Mexico. Characterization of their antioxidant properties may potentially diversify their use reaching other markets. The objective of this study was to determine the antioxidant capacity of crude phenolic extracts and fractions obtained from these selected crops. Crude acetone extracts obtained from each crop were further fractionated in a C18 column based on their affinity for aqueous buffers at different pH values, ethyl acetate (EtOAc) and methanol (MeOH). Total phenolic content was evaluated and quantified in all samples. The oxygen radical absorbance capacity (ORAC) assay was used to estimate the antioxidant activity of different phenolic fractions. HPLC-DAD was used to separate different phenolic compounds in each extract. Results indicated that Jamaica Flowers and Black Beans contained the highest levels of phenolics compounds (1414 and 927 mg/100g, respectively), while blue corn and chile Poblano peppers had lower amounts (257 and 356 mg/100g, respectively). The ethyl acetate soluble fraction (EtOAc-SF) which was rich in flavonoids and isoflavonoids, and the methanol soluble fraction (MeOH-SF) which was rich in anthocyanins, procyanidins and cathechins, were found to be the major contributors to the antioxidant capacity in all samples. The ORAC values of Hibiscus flowers and black bean varieties are among those known crops considered high in antioxidant capacity (>100umol Trolox / g). On the other hand, despite the lower ORAC values of blue corn and chile Poblano peppers, the specific phenolics present in these crops show higher specific ORAC values (defined as the ratio ORAC value/phenolic content) than phenolics present in Jamaica, and black beans. The selected native Mexican crops studied may be considered novel sources of health promoting antioxidant compounds for the functional food industry.

Session 36E, Fruit & Vegetable Products: General
8:30 AM - 12:00 PM, Monday AM Room Hall I-2

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