Cereal Chem. 76(4):573-576Near-infrared spectroscopy (NIRS) was used to detect scab damage and estimate deoxynivalenol (DON) and ergosterol levels in single wheat kernels. Results showed that all scab-damaged kernels identified by official inspectors were correctly identified by NIRS. In addition, this system identified more kernels with DON than did a visual inspection. DON and Publication no. C-1999-0526-06R. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. American Association of Cereal Chemists, Inc., 1999.

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Various whole‐kernel, milling, flour, dough, and breadmaking quality parameters were compared between hard red winter (HRW) and hard red spring (HRS) wheat. From the 50 quality parameters evaluated, values of only nine quality characteristics were found to be similar for both classes. These were test weight, grain moisture content, kernel size, polyphenol oxidase content, average gluten index, insoluble polymeric protein (%), free nonpolar lipids, loaf volume potential, and mixograph tolerance. Some of the quality characteristics that had significantly higher levels in HRS than in HRW wheat samples included grain protein content, grain hardness, most milling and flour quality measurements, most dough physicochemical properties, and most baking characteristics. When HRW and HRS wheat samples were grouped to be within the same wheat protein content range (11.4–15.8%), the average value of many grain and breadmaking quality characteristics were similar for both wheat classes but significant differences still existed. Values that were higher for HRW wheat flour were color b*, free polar lipids content, falling number, and farinograph tolerance. Values that were higher for HRS wheat flour were geometric mean diameter, quantity of insoluble polymeric proteins and gliadins, mixograph mix time, alveograph configuration ratio, dough weight, crumb grain score, and SDS sedimentation volume. This research showed that the grain and flour quality of HRS wheat generally exceeds that of HRW wheat whether or not samples are grouped to include a similar protein content range.

Reaction of CH 3 Co(dmgBF 2 ) 2 L (dmgBF 2 ) (difluoroboryl)dimethylglyoximato); L ) py, PEt 3 ) with 2 equiv of [Ni(tmc)]OTf (tmc ) 1, 4,8,4,8,) CF 3 SO 3 -) gave Co(dmgBF 2 ) 2 py -, [Ni(tmc)]OTf 2 , and [Ni(tmc)CH 3 ]OTf in 80% yield. The overall transformation provides the first model for the transfer of a CH 3 group from methylcobalamin to the Ni-containing enzyme carbon monoxide dehydrogenase during acetyl coenzyme A synthesis. RRSS-[Ni(tmc)CH 3 ](BAr′ 4 ) (BAr′ 4 -) B(3,5-(CF 3 ) 2 C 6 H 3 ) 4 -) has been characterized by X-ray diffraction. The products and 1CH 3 Co(dmgBF 2 ) 2 L:2[Ni(tmc)]OTf stoichiometry of the reaction are consistent with a three-step mechanism initiated by electron transfer from [Ni(tmc)]OTf to CH 3 -Co(dmgBF 2 ) 2 L. The second step is rapid CH 3 -Co -bond homolysis yielding Co(dmgBF 2 ) 2 L -and CH 3 •; then the CH 3 radical is captured by the second equivalent of [Ni(tmc)]OTf, yielding [Ni(tmc)CH 3 ]OTf. Radical clock experiments have corroborated the production of free radicals. Reaction of (5-hexenyl)Co(dmgBF 2 ) 2 L with [Ni-(tmc)]OTf, followed by hydrolysis of the organonickel products, gave methylcyclopentane, consistent with the formation and cyclization of the 1-hexenyl radical. The second-order rate constants measured by stopped-flow experiments parallel the relative radical stabilities: R ) CH 3 (2.43 × 10 3 M -1 s -1 ) < C 2 H 5 (7.88 × 10 3 M -1 s -1 ) < CH(CH 3 ) 2 (19.2 × 10 3 M -1 s -1 ), L ) py (2.43 × 10 3 M -1 s -1 ) < PEt 3 (5.01 × 10 3 M -1 s -1 ). During the course of these studies the following molecules were also characterized by X-ray diffraction, CH 3 Co(dmgBF 2 ) 2 L, L ) PEt 3 , py, H 2 O.