PubMed · 14788697
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M M SKOPKOVA. 1950. Revitan.. https://pubmed.ncbi.nlm.nih.gov/14788697/
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To monitor chemical reactions between ferulate and proteins during breadmaking, 8-(14)C-(E)-ferulic acid-(d-galactopyranose-6'-yl)ester was synthesized as a radiotracer and added to wheat and rye flour prior to breadmaking. Breads were lyophilized, extracted by means of a modified Osborne fractionation, and the radioactivity of the fractions was determined by scintillation analysis. The major portion of the radioactivity remained in the water-soluble fraction. However, a significant enrichment of the tracer was also detected in the prolamin and glutelin fractions in comparison to the control experiment. Separation of the prolamin fraction by RP-HPLC and scintillation measurement of the fractions gave evidence for a chemical modification of the tracer. To determine the structure of the reaction product, the prolamin fractions were completely hydrolyzed to free amino acids by means of an enzyme cocktail, and the digests were studied by LC-MS. In one fraction, a newly formed compound was detected. Comparison of its chromatographic and mass spectrometric behavior with a synthetic reference compound gave evidence that the newly identified compound was a dehydroferulic acid-tyrosine cross-link. It is likely that this cross-link represented a covalent linkage between arabinoxylans and cereal proteins. The newly identified cross-link was also identified in wheat and rye flour doughs, which had been prepared without addition of the ferulate tracer. The relative concentration of the dehydroferulic acid-tyrosine cross-link increased during wheat dough preparation.
Opportunities exist for replacing reduced height (Rht) genes Rht-B1b and Rht-D1b with alternative dwarfing genes for bread wheat improvement. In this study, the chromosomal locations of several height-reducing genes were determined by screening populations of recombinant inbred lines or doubled haploid lines varying for plant height with microsatellite markers. Linked markers were found for Rht5 (on chromosome 3BS), Rht12 (5AL) and Rht13 (7BS), which accounted for most of the phenotypic variance in height in the respective populations. Large height differences between genotypes (up to 43 cm) indicated linkage to major height-reducing genes. Rht4 was associated with molecular markers on chromosome 2BL, accounting for up to 30% of the variance in height. Confirming previous studies, Rht8 was linked to markers on chromosome 2DS, whereas a population varying for Rht9 revealed a region with a small but significant height effect on chromosome 5AL. The height-reducing effect of these dwarfing genes was repeatable across a range of environments. The molecular markers developed in this study will be useful for marker-assisted selection of alternative height-reducing genes, and to better understand the effects of different Rht genes on wheat growth and agronomic performance.
Food melanoidins were isolated from bread crust, coffee, and tomato sauce and their composition was investigated by thermal degradation. Among the generated volatiles, important food flavor compounds were detected: in particular furans, carbonyl compounds, 1,3-dioxolanes, pyrroles, pyrazines, pyridines, thiophenes, and phenols. The results indicated that the isolated melanoidin fractions mainly consisted of compounds formed from carbohydrates and their degradation products. Besides proteins, other food constituents were incorporated in the melanoidin structure as well, such as lipid oxidation products in tomato melanoidins and phenolic compounds in coffee melanoidins. A comparison of the thermal generation of volatiles between these food-derived melanoidins and model melanoidins prepared from a single carbonyl compound and an amino acid showed that the degradation pattern of food melanoidins is quite different from that obtained from a glucose-glycine model system.