115 Bread crumb grain study: Wheat and flour characteristics.

S. H. PARK (1), O. K. Chung (2), P. A. Seib (1), and M. S. Caley (2). (1) Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506; (2) USDA, ARS, Grain Marketing and Production Research Center, Manhattan, KS 66502.

To investigate the relationships between crumb grain and wheat and flour characteristics, we used 61 hard winter wheats and flours varying with crumb grain scores from 1 (poorest) to 5 (best), loaf volumes from 795 to 1055 cc, and flour protein (FP) contents from 9.8 to 13.5%. Among baking parameters, loaf volume and water absorption were not significantly correlated with crumb grain scores whereas mixing time (r = –0.336, P < 0.01) showed a significant correlation. Crumb grain scores were significantly correlated with flour particle size (PS) distribution: they were correlated positively with the small particle-size fraction (<38 µm, 9.6–19.3 wt%) (r = 0.611, P < 0.001) and negatively with a large particle-size fraction (>75 µm, 37.5–64.0 wt%) (r = –0.450, P < 0.001). In addition, crumb grain scores showed significant correlations with rheological properties determined by a computerized mixograph: they were positive with ascending slope (r = 0.403, P < 0.01) and negative with peak area (r = –0.413, P < 0.001). Prediction equation developed without using baking data selected 4 parameters including flour protein (FP), wheat protein (WP), and flour particle size (PS) including <38 µm and 38–53 µm. The equation is as follows: crumb grain score = –11.9 + 0.28FP + 0.07WP + 0.16PS (<38 µm) – 0.20PS (38–53 µm) (R(^2) = 0.557).