Submitted to: Polyphenols Actualites
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2000
Publication Date: N/A
Interpretive Summary: Cereals provide dietary fiber, an important nutritional commodity in human and animal foods. So-called "ferulates" in plant fibers cross-link polysaccharides making "diferulates." Cross-linking provides structural strength but limits the digestibility of the polysaccharides. As ferulates and diferulates are important components of our food, possessing antioxidant and other favorable properties, we analyzed a number of cereals (maize, wheat, rice, wild rice, barley, rye, oats and millet) for these compounds. The whole spectrum of diferulates that had previously been found in plant stems were found at surprisingly high levels (0.2 to 1.3%) in the insoluble fiber fractions; cross-linking is quite effective at a low level. Such high levels made it possible to identify two new diferulate compounds that had not previously been reported. Wild rice also contained two unique new compounds from cross-linking of related compounds, "sinapates". Since cereals are an important source of dietary fiber, a knowledge of the contributions of ferulates and diferulates will help to elucidate their roles. Such studies are aimed at understanding the limitations to fiber digestibility, and providing a basis for improving plant utilization and agricultural sustainability.
Technical Abstract: Diferulates have varied roles as significant components of many plant fibers. The 4-O-5-coupled dimer has been found in cereal grain insoluble fiber fractions where total diferulate levels range from 2.3 to 12.6 mg/g (in maize). A new form of the 8-8-dimer has also been found. Disinapates are found in wild rice.