2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center

Barley is strongly favored for increased incorporation into the human diet since it is naturally healthy, readily available and inexpensive. Dark discoloration of barley-based food products, however, has hampered increased utilization of barley in food formulations and decreased consumer acceptability. The objectives of this research were to determine discoloration potentials of barley from different classes and varieties when used in food products. Barley grains of various classes, including hulled and hull-less, waxy and non-waxy, proanthocyanidin-containing and proanthocyanidin-free, were abraded, milled into flour, and analyzed for composition and polyphenol oxidase (PPO) activity. Lightness (L* value) of abraded grains, flour, cooked grains, 10% flour gels, and dough sheets with 64% water were determined. Large variations in L* values of abraded grains, cooked grains, gels, and dough sheets were observed among different classes and among varieties within classes. Cooked grains were darker than uncooked grains. L* values of gels and dough sheets were generally higher in hulled than in hull-less barley, and higher in proanthocyanidin-free than in proanthocyanidin-containing barley. PPO activity of grain correlated positively with protein content (P<0.01) and negatively with L* values of abraded grains (P<0.05) and dough sheets (P<0.01).