Aroma chemistry of African Oryza glaberrima and Oryza sativa rice and their interspecific hybrids.

Background: To increase rice production in Africa, considerable research has focused on creating interspecific hybrids between African (Oryza glaberrima Steud.) and Asian (O. sativa L.

Characterization and discrimination of premium-quality, waxy, and black-pigmented rice based on odor-active compounds.

Background: Odor-active compounds have been studied in cooked aromatic rice, but not in specialty rice types that have distinctly different flavors. We analyzed the odor-active compounds emanating from three different types of specialty rice (premium-quality, waxy and black-pigmented) and identified the differences in odor-active compounds among them.

Results: Twenty-one, 21 and 23 odorants were detected using GC-O for cooked samples of premium-quality, waxy and black-pigmented rice cultivars, respectively.

Comparison of odor-active compounds from six distinctly different rice flavor types.

Using a dynamic headspace system with Tenax trap, GC-MS, GC-olfactometry (GC-O), and multivariate analysis, the aroma chemistry of six distinctly different rice flavor types (basmati, jasmine, two Korean japonica cultivars, black rice, and a nonaromatic rice) was analyzed. A total of 36 odorants from cooked samples were characterized by trained assessors. Twenty-five odorants had an intermediate or greater intensity (odor intensity >or= 3) and were considered to be major odor-active compounds.

Dielectric properties of honeydew melons and correlation with quality.

Dielectric properties of three honeydew melon cultivars, grown and harvested to provide a range of maturities, were measured with an open-ended coaxial-line probe and impedance analyzer over the frequency range from 10 MHz to 1.8 GHz. Probe measurements were made on the external surface of the melons and also on tissue samples from the edible internal tissue.

Characterization of volatile aroma compounds in cooked black rice.

Black rice ( Oryza sativa L.), an aromatic specialty rice popular in Asia, has a unique flavor, the volatile chemistry of which has not been reported. The objectives of this research were to study volatile profiles of cooked black rice and to characterize the odor-active compounds.

Mutation of a chitinase-like gene causes ectopic deposition of lignin, aberrant cell shapes, and overproduction of ethylene.

Chitinase-like proteins have long been proposed to play roles in normal plant growth and development, but no mutations in chitinase-like genes have been obtained previously to support this hypothesis. In this study, we have shown that the gene responsible for the elp1 mutation in Arabidopsis encodes a chitinase-like protein (AtCTL1). Mutation of this chitinase-like gene caused ectopic deposition of lignin and aberrant shapes of cells with incomplete cell walls in the pith of inflorescence stems.