American Association of Cereal Chem- ists/AOAC collaborative study was conducted to evaluate the accuracy and reliability of an enzyme assay kit procedure for measurement of total starch in a range of cereal grains and products. The flour sample is incubated at 95°C with thermostable α-amylase to catalyze the hydrolysis of starch to maltodextrins, the pH of the slurry is adjusted, and the slurry is treated with a highly purified amyloglucosidase to quantitatively hydrolyze the dextrins to glucose. Glucose is measured with glucose oxidase-peroxidase reagent. Thirty-two collaborators were sent 16 homogeneous test samples as 8 blind duplicates. These samples included chicken feed pellets, white bread, green peas, high- amylose maize starch, white wheat flour, wheat starch, oat bran, and spaghetti. All samples were analyzed by the standard procedure as detailed above; 4 samples (high-amylose maize starch and wheat starch) were also analyzed by a method that requires the samples to be cooked first in dimethyl sulfoxide (DMSO). Relative standard deviations for repeatability (RSDr) ranged from 2.1 to 3.9%, and relative standard deviations for reproducibility (RSDr) ranged from 2.9 to 5.7%. The RSDr value for high amylose maize starch analyzed by the standard (non-DMSO) procedure was 5.7%; the value

a b s t r a c tIn cereal seeds, mutations in one or more starch synthases lead to decreased amylopectin and increased amylose content. Here, the impact of starch synthase IIa (SSIIa or SGP-1) mutations upon durum starch was investigated. A screen of durum accessions identified two lines lacking SGP-A1, the A genome copy of SGP-1. The two lines were determined to carry a 29 bp deletion in the first exon of SSIIa. The SGP-A1 nulls were crossed with the durum variety 'Mountrail' and F 5 derived SGP-A1 null progeny lines were treated with EMS. From each EMS population, one SGP-B1 null mutation was recovered with each being a missense mutation. Each of the SGP-1 nulls was found to have large increases in amylose content and reduced binding of SGP-2 and SGP-3 to the interior of starch granules. RNA-Seq was used to examine the impact the loss of SGP-1 has upon other starch biosynthetic genes. Significant increases in transcript levels of several starch biosynthetic genes were observed in SGP-1 nulls relative to Mountrail. The resultant high amylose durums may prove useful in the creation of value added pasta with increased firmness and reduced glycemic index.

Ninety-six 14-d-old male broiler chicks were divided into three dietary groups and fed a corn-soybean meal diet, a barley diet with beta-glucanase and that diet without beta-glucanase. All diets contained 4 g cholesterol/kg. Average daily body weight gain, plasma total cholesterol concentration, LDL cholesterol concentration and digestibility of lipids and protein were lowest (P < 0.05) in the chicks fed the barley diet without beta-glucanase and highest (P < 0.05) in the chicks fed corn-soybean meal diet. Supplementation of the barley diet with beta-glucanase resulted in greater (P < 0.05) average daily weight gain, plasma total and LDL cholesterol concentrations and digestibility of lipids. Viscosity of small intestinal digesta was greatest in chicks fed barley, lowest in those fed the corn-soybean diet and intermediate in chicks fed enzyme-treated barley. Significant (P < 0.01) negative correlations occurred between viscosity of the small intestinal contents and average daily weight gain, plasma total and LDL cholesterol concentrations, and digestibility of lipids and protein. A lower concentration of insoluble beta-glucans in small intestinal digesta of the chicks fed barley supplemented with beta-glucanase compared with the chicks fed the unsupplemented barley diet reflects hydrolytic activity of the supplemental beta-glucanase in the diet.

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Cereal Chem. 90(3):249-255Molecular markers for the red grain color (R) loci controlling seed color and the polyphenol oxidase (Ppo-A1) locus controlling polyphenol oxidase (PPO) activity in seed have recently been developed. These markers provided the opportunity to convert the hard red spring wheat cultivars Choteau and Hank to white-seeded versions with high and low PPO levels, respectively. These sets of near-isogenic lines provided material to test the effects of seed color and PPO activity on a range of end-use quality traits. We tested recurrent parents Choteau and Hank, along with nearisogenic derivatives with white seed, in two replicated trials in Bozeman, Montana, for end-use quality parameters. The white-seeded lines consisted of both high-and low-PPO near-isogenic lines. The primary impact of white seed was the production of whole wheat bread with a perceived sweeter taste relative to the red-seeded lines. Noodle color was not consistently impacted by the level of PPO variation despite relatively large reductions in PPO level. The alleles for white seed color did not appear to impact agronomic traits. These results suggested that hard white low-PPO hard spring wheat would be advantageous in terms of conferring brighter color to Asian noodles and a sweeter taste to whole wheat bread.