No abstract

The fatty acid concentrations and the flavor compound release levels of two different strains Agaricus bisporus were studied at different stages of development. Two strains (hybrid white and brown) and three developmental stages (button, medium, and flat) were considered. Results showed that linoleic acid and 1-octen-3-ol are the major fatty acid and flavor compound, respectively, whatever the strain or the developmental stage. Moreover, higher linoleic acid concentrations were found at the button stage in the hybrid white strain and at the medium stage in the brown strain. In contrast, greater amounts of 1-octen-3-ol were encountered at the medium stage in the two strains. The flavor quality ratio, r, defined as the ratio of the amount of 1-octen-3-ol released and detected to the linoleic acid content, was greater at the medium stage, whatever the strain, and in all developmental stages for the Br one. Keywords: Agaricus bisporus; fatty acids; flavor; strain; development

The effects of combined high pressure (300 and 400MPa) and low temperature (50°C) treatments on the microbial contamination of duck foie gras samples were compared with those of classical thermal pasteurization (85°C at the coldest point). A multilayer packaging film (PE/PA/PE) was selected from two films commonly used for these types of food, by preliminary tests showing its ability to limit microbiological development in such samples. In each experiment, microbiological contamination was analysed on treated and untreated samples, and results were systematically compared with those obtained from a classically pasteurized sample of the same liver. A pasteurization type effect (drastic reduction of vegetative mesophilic and psychrophilic contaminations, destruction of coliforms and of Stuphylococcus aureus) was obtained at this temperature with samples pressurized at 400 MPa for at least 10 min.

Identification, quantification, and location of fatty acids in the newly cultivated fresh mushroom, Lepista nuda, as well as three aromatic effluents (1-octen-3-ol, 1-octen-3-one, and 3-octanone) from mushroom homogenate, were established. The highest amounts of fatty acids as well as the three aromatic compounds formed and released were encountered in the gills rather than in the pileus or the stipe. Among these components, 1-octen-3-ol (“mushroom alcohol”) was the major aromatic compound trapped, and linoleic acid was the major fatty acid extracted, whatever the morphological tissue considered. Observed results indicate that the gills are the major compartment for the metabolic interconversion of fatty acids into aromatic compounds. Keywords: Lepista nuda; fatty acids; flavor